University of Southern California Dissertations and Theses

Studies of frog retinal ganglion cell responses to temporal, spatial and chromatic stimuli

(USC Thesis Other)

Studies of frog retinal ganglion cell responses to temporal, spatial and chromatic stimuli

PDF

Download

Open document

Flip pages

Download a page range

Download transcript

Copy asset link

Request this asset

Transcript (if available)

Content STUDIES OF FROG RETINAL GANGLION CELL RESPONSES TO TEMPORAL, SPATIAL AND CHROMATIC STIMULI by Peter Francis Cummings A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (Anatomy) January 197 8 U N IV E R S IT Y O F S O U T H E R N C A L IF O R N IA T H E G R A D U A TE S C H O O L U N IV E R S IT Y P A RK LOS A N G E L E S , C ALI FO R N l A 9 0 0 0 7 This dissertationf written by P e te r Francis Cummings under the direction of / t A ? . . . . Dissertation Com mittee, and approved by all its members, has been presented to and accepted by The Graduate School, in partial fulfillment of requirements of the degree of DOCTOR OF P H ILO S O P H Y Dean Ph -O • /I no. C ^71 DISSERTATIO N C O M M IT T E E 'hair man ACKNOWLEDGEMENTS First, I would like to thank the Department of Anatomy of the University of Southern California School of Medicine, the Living Structure Fund, the Lumbleau Real Estate Schools, John and Geraldine Leiman, and the Veterans Administration i for their generous financial contributions to my doctoral studies. Additionally, I would like to warmly and gratefully I acknowledge the abundance of thoughtful and invaluable ! assistance given me during the course of this work. The : help of Dr. Gerald F. Hungerford, my mentor and good friend,| Dr. Richard L. Binggeli, my advisor and able teacher, 1 Dr. John M. Leiman, my statistical consultant and encourager, ! ; Robert J. Cummings, my brother and contact with the wonder- ; ful world of computer programming, Caroline Brown, my able ! I typist and friend, and Nancy L. Cummings, my wife and spirit,! has been exceptional. Others who have helped along the way | I include: Dr. Stanley Azan, Dr. Mary Ann Baker, | I Dr. Joseph Bamberger, Patricia Cummings, William Cummings, Dr. Mary Guthrie, Dr. Charles Haun, Vonda Hungerford, Michael Johnston, Michael Jones, Dr. David Lindsley, |Dr. Patricia Mensah, Dr. George Moore, Dr. Bertha Newman, ;Dr. Paul Patek, Sara Schoentgen and Joseph Yee. 11 TABLE OF CONTENTS Section Page INTRODUCTION................................ 1 I. REVIEW OF LITERATURE ...................... 2 II. METHODS.................................... 24 A. Animal Care and Preparation B. Surgical Procedure C. Ganglion Cell Recording D. Light Stimulation Methods ; 1 III. EXPERIMENTAL DESIGN 36 i A. Stimulus Conditions B. Data Gathering Protocol C. Data Analysis Protocol | D. Significance of the Proposed Project | I IV. RESULTS 48 ! A. Data Collected j B. Description of the Total Population of 68 cells I C. Description of the Subsets of the Total | Population, 36 and 32 Cells j D. Analysis of Variance of the Total Population E. Semiquantitative Groupings of the Total Population of 68 Cells F. Concordance of the Semiquantitative Groupings G. Quantitative Multiparametric Groupings of the Total Population H. Quantified Response of Ganglion Cells Sorted for Temporal Properties iii Section Page V. DISCUSSION.................................. 114 VI. SUMMARY.................................... 120 LITERATURE CITED .......................... 121 APPENDIX ................................. 127 I V LIST OF TEXT TABLES Table Number Page 1. Frequency of Cells in Classes and Color Response . 20 2. Abbreviations of Stimuli..........................51 ! 3. Frequency of Spikes - Total Population, 68 Cells . 52 ] I I 4. Density of Spikes - Total Population, 68 Cells . 53' I I 5. Mean Time of Spikes - Total Population, 68 Cells . 54 ! I 6. Temporal Responses - Total Population ........... 55 7. Probability Values............... 63; 8. Regression Statistics for Profile Graphs I of Figures 12 and 1 3 ................................67 9. Frequency of Spikes - 36 Cells.................... 72 I I I 10. Density of Spikes - 36 Cells....................... 73 ! i jll. Mean Time of Spikes - 36 Cells. . .................74 jl2. Frequency of Spikes - 32 Cells....................... 75, I 13. Density of Spikes - 32 Cells....................... 76; jl4. Mean Time of Spikes - 32 Cells....................... 77 115. Regression Statistics for Figures 13 and 14. . . . 80 I I 16. Summary of Semiquantitative Sorting...............93 j 17. Regression Statistics for Factor Groups.......... 97; 18. Factor Analysis Concordance 100 ] 19. Regression Statistics for Temporal Groups............Ill V LIST OF APPENDIX TABLES Table Legend - Appendix Tables A1-A2 7. . 138 j 1 Al. Frequency of Spikes - Factor Group #1........... 139! A2. Density of Spikes - Factor Group #1........... 140 A3. Mean Time of Spikes - Factor Group #1........... 1411 A4. Frequency of Spikes - Factor Group #2........... 142 ! A5. Density of Spikes - Factor Group #2........... 143 A6. Mean Time of Spikes - Factor Group #2........... 144 1 A7. Frequency of Spikes - Factor Group #3.......... 145 A8. Density of Spikes - Factor Group #3........... 146 A9. Mean Time of Spikes - Factor Group #3........... 147 AlO. Frequency of Spikes - Factor Group #4........... 148 : |aii. Density of Spikes - Factor Group # 4.......... 149 ' A12. Mean Time of Spikes - Factor Group #4........... 150 A13. Frequency of Spikes - Factor Group #5........... 151 i 'A14. Density of Spikes - Factor Group #5 ................................ 152 A15. Mean Time of Spikes - Factor Group #5........... 153 ! A16. Frequency of Spikes - Factor Group #6 ................................ 154 ! 1 ■A17. Density of Spikes - Factor Group #6 ................................ 155 ; A18. Mean Time of Spikes “ Factor Group #6 ................................ 156 A19. Frequency of Spikes - Factor Group #7........... 157 IA20. Density of Spikes - Factor Group #7........... 158 A21. Mean Time of Spikes - Factor Group #7 ................................ 159 Vl! _J LIST OF APPENDIX TABLES (Continued) Table Number Page A22. Frequency of Spikes - Factor Group #8. . . 160 A23. Density of Spikes - Factor Group #8. . . 161 A24. Mean Time of - Factor Group #8. . . 162 A25. Frequency of Spikes - Factor Group #9. . . 163 A26. Density of Spikes - Factor Group #9. . . 164 A27. Mean Time of Spikes - Factor Group #9. . . 165 Legend - Appendix Tables A28-A45 ......... 166' A28. Frequency of Spikes - A Priori Group #1, ON Type 167 A29. Density of Spikes - A Priori Group #1, ON Type 168' A3 0. Mean Time of Spikes - A Priori Group #1, ON Type 169 A31. Frequency of Spikes - A Priori Group #2, ON,OFF-1 Type 170, A32. Density of Spikes - A Priori Group #2, 1 ON,OFF-1 Type 171 A3 3. Mean Time of Spikes - A Priori Group #2, ON,OFF-1 Type 172; A34. Frequency of Spikes - A Priori Group #3, , ON,OFF-2 Type 173] A3 5. Density of Spikes - A Priori Group #3, ! ON,OFF-2 Type 174I A3 6. Mean Time of Spikes - A Priori Group #3, 1 ON,OFF-2 Type 175 A37. Frequency of Spikes - A Priori Group #4, 1 ON,OFF-1,OFF-2 Type 176 A38 . Density of Spikes - A Priori Group #4, ON,OFF-1,OFF-2 Type 177 A39. Mean Time of Spikes - A Priori Group #4, ON,OFF-1,OFF-2 Type 178 vii LIST OF APPENDIX TABLES (Continued) [ Table ! Number Page I i A40. Frequency of Spikes - A Priori Group #5, OFF-1 Type 179 A41. Density of Spikes - A Priori Group #5, | OFF-1 Type 180 A42. Mean Time of Spikes - A Priori Group #5, OFF-1 Type 181 A43. Frequency of Spikes - A Priori Group #6, OFF-1,OFF-2 Type 182 A44. Density of Spikes - A Priori Group #6, OFF-1,OFF-2 Type 183 A45. Mean Time of Spikes - A Priori Group #6, OFF-1,OFF-2 Type 184; Vlll LIST OF TEXT FIGURES Figure Number Page Legend - Figure 1...................................... 10 1. Frog Tectum............................................ 11 Legend - Figure 2. 13 2. Retinal Cells. .......................................14 3. Surgical Procedures.....................................27 4. Recording Instrumentation..............................30 5. The Optical System...................... 32 6. The Stimuli............................................. 34 7. Data Analysis Protocol.............. .............. 41 8. The Data Base........................................... 49 Legend - Figure 9...................................57 9. Responses of 68 Cells to Individual Stimuli (Spots) 58! Legend - Figure 1 0 ....................................59 10. Post-Stimulus-Time Response Graphs by Spot Size. . 60 Legend - Figure 1 1 61 j 11. Post-Stimulus-Time Response Graphs by Color. . . . 62 j Legend - Figure 1 2 ....................................65 i 12. Profile Graphs, Total Population, Spots.............. 66 Legend - Figure 1 3 ....................................69 13. Profile Graphs, Total Population, Color.............. 70 Legend - Figure 1 4 ....................................78 14. Profile Graphs, 36 and 32 Cells. .................. 79 I X LIST OF TEXT FIGURES (Continued) ; Figure | Number Page: Legend - Figure 15................................. 81 15. Responses of 68 Cells to Annuli.................. 82 Legend - Figure 16................................. 83 16. Profile Graph of Annuli............... 84; Legend - Figure 17. . .......................... 88; 17. Distribution of Semiquantitative Sorting . .... 89 ! Legend - Figure 18.................................... 105! 18. Profile Graphs for ON and ON,OFF-1 Cells............106 Legend - Figure 19.................................... 107 19. Profile Graphs for ON,OFF-2 and ON,OFF-1,OFF-2 Cells................................108 Legend - Figure 20.................................... 109 i 20. Profile Graphs for OFF-1 and OFF-1,OFF-2 Cells. . 110 ! X LIST OF APPENDIX FIGURES | I Figure Number Page; Legend - Appendix Figures A1-A9 - . . 128 Al. Number of Spikes - ON Period....................... 129 j A2. Number of Spikes - OFF-1 Period.....................130 I A3. Number of Spikes - OFF-2 Period.....................131! A4. Density of Spikes - ON Period....................... 132! A5. Density of Spikes - OFF-1 Period.....................133 A6. Density of Spikes - OFF-2 Period.....................134; A7. Latency of Spikes - ON Period.......................135' A8. Latency of Spikes - OFF-1 Period.....................136 A9. Latency of Spikes - OFF-2 Period.....................137 X I INTRODUCTION j It has been suggested that retinal ganglion cells of ‘ the frog, as well as those of other vertebrates, can be j grouped into distinct classes, based upon their physiologi-] cal responses to various light stimulations (see Review of i Literature). This notion assumes that the population of I ganglion cells in the retina, as measured by their physio- j logical responses, is heterogenous. Other studies have I pointed out complexities of ganglion cell responses to I light stimulation which could be considered inconsistent 1 I with proposed classification systems. Most reports have I been qualitative or semiquantitative studies of ganglion i I cell responses which were recorded from the optic tectum, geniculate body, optic nerve or directly from the retina. Studies of direct recordings from ganglion cells in the retina mainly utilized iji vitro eyecup preparations^ It is the main purpose of this study to determine whether or not the ganglion cell population of the frog retina is homogenous, as based upon its physiological re sponses. The null hypothesis of the experimental design assumed that the ganglion cell population was homogenous and the hypothesis assumed that the population was heter- I ogenous. An experimental approach was selected which uti- i I lized an iji vivo eyecup preparation. Complete sets of re- i I sponses to temporal, spatial and chromatic stimulus arrays j 1 I were collected from retinal ganglion cells. Furthermore, the data were collected in such a way that it could be sub-| jected to rigorous quantitative, statistical analysis. The statistical analysis, however, is intended to be descrip tive of the population characteristics, and not to eluci date specific, mechanistic processes within the retina. An additional purpose of this study of frog ganglion cell responses and their classifications is to investigate : ! the apparent discrepancy between the number of functional | and morphological classes reported in the literature. Cajal’s work (1972) illustrated the wide range of frog | (Rana temporaria) ganglion cell morphologies based on theiri shape, size, and dendritic arborizations. In a recent review, Griisser and Grüsser-Cornehls (1976) conservatively estimated the number of distinct morphological types at 11. Estimates in other animals are even higher, for example, Dowling and West (1972) describe 15 morphological types in the ground squirrel. In contrast, fewer (six) functional ! I types of frog ganglion cells are reported (see Review of ; 1 Literature) based on the cells’ responses to spatial, temporal, and mobile stimuli. In these studies, by the in-| j elusion of color as a stimulus parameter and by quantifying} I the cells’ responses to a complete and consistent set of j stimuli, it was hoped that an explanation for this apparent; I lack of a form-function correlation could be found. ’ I. REVIEW OF LITERATURE The first indication that ganglion cell responses to light stimulation were not homogenous was reported by Hartline (1938). In this and two subsequent reports, Hartline (1942a, b) introduced several important concepts. He used a micro-dissection technique to isolate and record from single ganglion cell axons in an excised eyecup of the bullfrog (Rana catesbiana). He found that 20% of the I ganglion cells responded only at the onset of the light I j I stimulus, 30% responded only at the offset of the light, ; ! and 50% responded at both the onset and the offset of light. The simplicity of this initial grouping was tem pered by Hartline’s own observation that occasional ganglion cell responses were intermediate between these three types. Additionally, in these studies it was ob served that responses in a given axon can be obtained only upon illumination of a certain restricted area of the i I retina. To describe this responsive area, Hartline intro duced Sherrington's notion of a reflex receptive field I (Sherrington, 1906) and reported that the type of a re- I I sponse in a fiber is not correlated with the location of ! its receptive field in the retina. Hartline also noted that: OFF and especially ON-OFF cells give vigorous responses to slight movements of a small (50 micron) light spot. 3 J This movement sensitivity became an important variable in ' subsequent classification studies. Verification of this simple scheme using micro electrode techniques was soon reported (Granit, 1947). Additional verification in another anuran species (Rana j temporaria) and the observation that an inhibitory area i surrounding a central area of high sensitivity occurred in , ON-OFF cells, but not in OFF cells, was also reported (Barlow, 1953a, b). This study emphasized that these com- : plexities of the different ganglion cells' receptive fields were probably indicative of a sensory integration role for the retina as a whole in that it acts "as a filter re jecting unwanted information and passing useful informa- | I tion." As an example Barlow noted that "the receptive field of an ON-OFF unit would be nicely filled by the ! image of a fly at two inches distance and it is difficult I I to avoid the conclusion that the ON-OFF units are matched j to this stimulus and act as 'fly detectors.'" i i ' j The first major challenge to the simple ON, OFF, i ON-OFF classification came as an elaboration of this con- I cept of ganglion cells functioning as specific "feature j i ! detectors" (Lettvin et al., 1959; Maturana et al.,1960; I ! ! Lettvin et al., 1961). Like Hartline and Barlow, they i I reasoned that the earlier notion that the output of the I i I retina is an exact copy of local light distributions is ! wrong. Rather, they hypothesized that each ganglion cell and more peripheral neurons connected to it are dedicated to detecting particular patterns of light and their changes. In other words, the unit would respond maximally to a par- ! ticular gestalt of stimulus properties, which they referred | I to as a retinal operation, and it is the result of these | operations which is reported to the tectum. They differed I I from Hartline and Barlow in their method for determining | just what and how many of these retinal operations there were. They used electrodes designed to record from either ganglion cell fibers in the optic nerve or ganglion cell terminations in the optic tectum. The frogs (Rana pipiens) I ! were anesthetized with curare and situated in front of a I I viewing screen upon which stationary or moving targets of {various shapes, sizes, and backgrounds were projected. i I From this wide range of stimuli they then tried by trial j and error to determine empirically the common set of stim- juli which were abstracted by an individual ganglion cell. I ' I In their own words, "Response of a nerve fiber was measured roughly by frequency and duration of firing. We took no records except those needed to illustrate our papers. Our ' question was not how great the response was to one or another manipulation, but rather which visual events pro- , duced the greatest response and which produced the least, I and what aspect of the image could be varied without changing the response. We dealt with our own listening to the pattern of nerve spikes as a measure of extremes, just ] as one does of an A-C Bridge. (Early in our work we found : that taking records hindered rather than helped this kind of research by leading to premature standardizing of method)." (Lettvin et al., 1961, p. 163). Using this "naturalistic" experimental design, they concluded that frog ganglion cells were dedicated to recog-I nizing five different.;.patte:ms of stimuli and hence formed i [ five natural classes. These classes were given names 1 descriptive of their primary function, and qualitatively | described. Briefly, the classes and their characteristics were: ! Class 1. Boundary or Sustained Edge Detectors (1°- 3° responsive receptive field). These cells respond with a vigorous, maintained , response to the presence or movement of a sharp edge of any' shape, lighter or darker than the background, over a wide range of illumination. This response could be suppressed j by completely darkening the field, however if the light was ! turned on again without removing the edge, the response re appeared after a short pause, i.e., the response was non erasable. These cells do not respond to full field changes I in illumination, and were thought to correspond to Hartline’s I on cells. Class 2. Convex Edge Detection (2°-5° responsive receptive field) t I ! These cells respond only to a very particular stimulus. In order to elicit a response a small object, i darker than the background, must be moved centripetally ; into the response receptive field. They respond poorly or ' not at all to targets lighter than the background. They reportedly do not respond either to standing (i.e., non moving) edges or moving, large, straight (i.e., not curved or pointed) edges. These cells do not have equivalents among the ganglion cells described by Hartline. Class 5. Changing Contrast Detectors (7°-12°responsive receptive field) These cells respond to the ON and OFF of light with bursts of two to four action potentials. They never responded with a maintained discharge to a standing con- ! trast. They are very movement - sensitive; the response to movement is always much greater than the response to changes of illumination. Two subclasses of these cells were observed. One exhibited a sustained, low frequency (4-7 spikes/second) to ordinary room illumination, increas-| ing or decreasing as a direct function of intensity. The j other subclass did not exhibit this kind of continuous ! response to illumination. These changing-contrast detec tors correspond to Hartline’s ON-OFF cells. Class 4. Dimming Detectors (responsive receptive field i up to 15°) These cells respond with a prolonged response to ; the OFF of light. This response like the Class 3 cells is | complex in that in most instances it is made up of small j bursts of a few high frequency spikes (2-4 spikes at 100-300/second) having an initial burst frequency of I 18-20 spikes/second. This response rate then decreases to I a maintained rate of about 5 spikes/second. It was re - I ported that the initial burst frequency is not an individ- j ual phenomenon but that all the OFF units tend to fire I ! together. These units also responded to any dimming pro duced by an object passing across the responsive receptive i field. These cells correspond to Hartline’s OFF cells. Class 5. Dark Detectors (responsive receptive field is large) These cells are continuously active, with this activity being inversely proportional to the light inten sity, increasing to a maximum in darkness. They do not | respond rapidly to sharp changes in illumination nor move- ! ment. These cells do not have equivalents among the ; ganglion cells described by Hartline. ! Before discussing the conclusions of this study, it should be noted that several anatomical observations were germinal in the development of this classification. First, it had long been known through anatomical studies that the retina projects in a point-to-point fashion to the visual centers, and this topography had recently (Gaze, 1958) been elegantly mapped in the frog tectum. This allowed the site of the tectal recordings to be correlated with known areas of the frog’s visual field. A second feature of tectal anatomy which proved important in this study is the sépara-| tion of the retinal projection into a series of registered I [ layers of the superficial tectal neuropile. The existence | of this layering had been observed morphologically and ; I physiologically in the retinal projections of other species! I I I ! (Maturana et al., 1960). This study found that physiologi-; I cally the five proposed functional classes of ganglion ' I cells projected to distinct tectal layers (Class 1 to layer 1, Class 2 to layer 2, Class 3 to layer 3, Class 4 to layer 4, and Class 5 to layer 3). Thus, recording from I successively deeper layers of the superficial tectum has ^ the advantage of an anatomical pre-sorting of the func- I i tional groups. This layering of the tectum has recently been demonstrated morphologically (Witpaard and ter Keurs, : 1975), (Figure 1). A third, important morphological observation was madej by Maturana himself (Maturana, 1959). He demonstrated that the frog optic nerve when viewed with the electron micro scope contained nearly 5x10^ axons, 97% of which were small] Figure 1. This figure, which visualizes the reported form- function relationships found in the superficial neuropil of the frog’s tectum, is taken from Witpaard and ter Keurs ; (1975). The distribution of responses from the optic nerve: terminals found by (a) Maturana et al. (1960) and (b) | Keating and Gaze (1970) are compared with spike amplitude i (c and d) and terminal degeneration (e) results obtained | I I by Witpaard and ter Keurs (1975). The numbers (1-5) in (a)j represent ganglion cell classes 1-5, while those (1-IV) in ■ (b), (c), and (d) represent four related types; contrast - units (1), slow ON-OFF units (2), fast ON-OFF units (3), and fast OFF units (4). S.T.N.: superficial tectal neuro- pil; S.A.C.: stratum album centrale; M.C.L.: main cell layers. 10 Spike amplitude 1 1 1 1 2 1 1 2 1 2 2 2 3 3 5 4 4 4 4 4 4 I I I ■M'l I I I m I E m IE iH m IT ET Dr n cz H 2 0 0 (juV) 300 100 100 TJ n E 200 O) PY.p-:b xp:.q:..v 300 m n 4 0 0 - E N 5 500 CL Q > Q (urn) (a) (b) (c) (d) le) 11 unmyelinated fibers that had not been counted in earlier light microscopic studies, and that in the frog retina there were an equal number of small (7-10 micron) ganglion cells which had been considered to be glia. Based on action potential spike heights recorded from the optic nerve, and different conduction velocities measured t during these recordings, these small, unmyelinated, slow- 1 conducting axons were correlated with their first and j second functional classes, while the larger myelinated ! I fast conducting axons were thought to be related to classesj 3 and 4 (Maturana et al., 1960). | The final anatomical observation which influenced ; this classification related to the structure of the ; ganglion cells themselves. Citing the extensive observa tions of Cajal (1972) and their own unpublished observa- ^ tions of methylene blue stained retinas, as well as the : receptive field sizes and types of functions being per formed, they concluded that there are five dendritic shapes correlated with their five functional classes (Maturana et | al., 1960). These ganglion cell types as well as the other ; correlated anatomical and physiological features are sum marized in Figure 2. These anatomical classes were proposed in order to achieve a form-function correlation among these i I cells. However, as mentioned in the Introduction, they 1 I represent a simplification of the morphology as compared 12 n Figure 2. This drawing summarizes the descriptions and cellular^ ; relationships in the frog retina as reported by Cajal j (1972); Maturana et al. (1960); Nilsson (1964); and ; I i I Liebman and Entine (1968). The left column contains the ' I I j names of the retinal layers and estimated numbers of cells j I in the granular layers and their percentage of the total. I The next column gives the average extent of the retinal i I layers. The cells drawn to the right are Golgi representa- I tions of the retinal cells. The values above the rod and cone labels represent the types of visual pigment they contain and their frequency of occurrence as determined by microspectrophotometrie measures. The matrix below the ganglion cells indicates Maturana et al.’s (1960) proposed functional correlation with the morphological type above each column. The last four rows list the soma and axon ! I size, conduction velocity, and percent of total for each | I class. ■ 13 s s < -S O O o CM bO o I w « o w â J 6 C*î'g 1= co e n «A S o 0 > u CM 00 «-I O o s« » M lO Mt < q SsO >-) B S lO o u 1 « lO CM ta 00 O B <r CM M 14 with Cajal (1972) and others (Griisser, Griisser-Cornehls, * 1976). ! Taken as a whole this work concluded that every point| on the visual field was being analyzed ... in terms of j four qualitative contexts (standing edges, curvatures, ] I changing contrast, and local lessening of light intensity) | and a measure of illumination. " and that this analysis was invariant with ambient light level (Gordon and Hood, 1976). Further, these five measures were proposed to be correlated with a specified anatomical substrate, j Since this frog ganglion cell classification scheme ' was published, several studies have reported observations which question both the exhaustiveness and exclusivity of j the five proposed classes. Muntz (1962a) observed an addi tional type of cell which gave a sustained response to the onset of both large and small light stimuli. He found this cell type by recording from ganglion cell terminals in the diencephalon of Rana temporaria. Obviously since Maturana et al. recorded from the tectum, they would not have noted this cell type. Muntz reported that this cell had a recep-j tive field size of 10° to 17°, and that it gave a maximal - response to the blue end of the color spectrum. In an ^ accompanying behavioral study (Muntz, 1962b), he related ' this blue sensitivity to Birukow's (1939) observation that ; blue light elicits a stronger positive phototaxic response 15 than other colors. Subsequently, a similar cell type has been recorded from in the optic nerve (Keating and Gaze, 1970) and, in conflict with Maturana et al. (1960) was ! thought to represent Hartline’s ON cell. It is commonly ! I referred to as the Class 6 or Class 0 cell type. Another type of reported inconsistency relates to the tdivision of the proposed ganglion cell types into subtypes. I i I Keating and Gaze (197 0) reported four subgroups of the ; i Class 4 cells (dimming detectors) using the cells’ complex i ! I receptive field organization as the classifying criteria. In another study of Class 4 cells (Chung et al., 1970) the ■ j pattern of the spontaneous background activity was selected ! as the classificatory criteria, and they reported three ; I ' i subtypes of dimming detectors. Maturana et al. (as men tioned above) subdivided Class 3 cells using the presence or absence of spontaneous activity as the criteria. The most frequently reported breakdown of the Maturana classification scheme relates to the lack of ex- I clusivity observed for Classes 1 and 2. While Maturana et j al. (1960) reported that these classes were closely related, : i they listed several criteria for distinguishing the two ; ]groups. Many of the subsequent reports, however, have veri-, Ified the similarity of these classes and found these cri- I I ; teria inadequate in that some cells exhibited responses ; which were intermediate between the two classes (Gaze and ; I . I I Jacobson, 1963; Crùsser et al., 1964 , 1968; Keating and I 16 i Gaze, 1970; Reuter and Virtanen, 1972; Brackstrom and Reuter, 1975). This observation of an intermediate type ofI cell encouraged Griisser and his co-workers to undertake an extensive series of experiments designed to analyze quanti-j I tatively the input-output relationships in the frog retina : (Griisser and Donnenberg, 1965; Finkelstein and Griisser, I 1965; Griisser et al., 1967; Griisser and Griisser-Cornehls, I I 1968, 1973, 1976) . Using Rana esculata, and tectal recording methods similar to Maturana et al., they studied the effects of moving stimuli where contrast stimulus size and stimulus : velocity were the variables. They found that, if adapta tion were controlled, they could model (i.e., predict) the ' output of a movement-sensitive ganglion cell as measured by the frequency of discharge (impulses per second) as a func tion of these three variables. In particular they state that the difference between Class 2 and Class 3 is related to a power function of the stimulus contrast and velocity and a log function of the angular size of a moving target. On the basis of these observations and additional i quantitative data, they have concluded that in the frog at ' least four classes of cells exist and that these classes of cells correspond to Maturana and co-workers’ Classes 1 to 4 (Griisser and Griisser-Cornehls, 1976). The unfortunate ‘ aspect of this data, as strongly stated by Gordon and Hood ' (1976), is that it is not sufficient to answer the ’ 17 ! j fundamental question of the existence of mutually exclu sive classes. Gordon and Hood (1976) point out that to i ! demonstrate mutual exclusivity each class must be shown to differ quantitatively in their responses on several stim- ‘ I ulus dimensions where their within-class variability is i 1 small when compared to their between-class variability. | Another set of experiments which points out the lack of exclusivity between ganglion cell classes and the lack ; of exhaustiveness have been reported (Reuter, 1969; Reuter ' and Virtanen, 1972 ; and Brackstrom and Reuter, 1975). These ; I studies were primarily intended to demonstrate the color j I properties of frog ganglion cells as they correlate with ; the reported ganglion cell classes. In these experiments j on light-adapted, excised eyecup preparations, Rana temporaria were used. Glass micropipettes recorded ganglion cell responses from the retinal surface. The ; responses were elicited using stationary and moving dark and bright spots of varying sizes and wavelengths shown , against a full field.background illumination which also j I varied in wavelength. By varying the wavelength of the I background illumination, they were able to saturate selec- j ! ted visual pigments known to exist in the frog photorecep- ; I I ! tors, and thus isolate the contribution of an unsaturated I I photoreceptor to the ganglion cell response. In the light- i adapted frog retina, this procedure allowed them to sepa- I rate the contribution of the green-rods which contain 18 visual pigment 432 (VP432) from that of cones which contain' visual pigment 572 (VP572). | In order to correlate the differing green rod and I i cone contributions with the ganglion cell classes, their j I I experiments were conducted in two steps. First, using j yellow lights, and no background illumination, the class ofI I the cell was determined with the aid of moving dark and I I bright spots and bars, and with ON-OFF stimuli with small I spots and with large fields covering the entire retina. I ! Then, with a yellow saturating background and small stim- I ulus spots, spectral sensitivities of the same cells were measured by determining the lowest intensity of a certain ; stimulus which still produced a discharge of one or several impulses (i.e., a threshold measurement). The results of these experiments are shown in Table 1 which is slightly modified from Brackstrom and Reuter (1975). From Table 1 it is apparent that over 30% of the cells displaying properties which indicated inclusion in | I Class 1 or Class 2 could not be confidently assigned, re- , I suiting in the creation of a new "1 or 2” class. Addition-| ! ally, a subgrouping of Class 4 was created to account for | seven OFF cells which displayed ON-OFF properties. Thus, the first step of these experiments resulted in eight i i classes whose frequency and percentage are shown in the ' Totals row in Table 1. However, the more remarkable ; l_9j TABLE 1 FREQUENCY OF GANGLION CELL CLASSES AND COLOR RESPONSE ; This table gives the frequency of occurrence of the I Lettvin-Maturana classes of frog ganglion cells as deter mined by Brackstrom and Reuter (1975). Additionally, the columns of the table list the frequency of occurrence of green-rod (VP 432) and cone (VP 572) input to this popula tion of ganglion cells. Green Rod Cone Lettvin-Maturana Class of Cell ON Input OFF None Input ON OFF Total Percent of Total 1 28 2 2 25 30 30 19% , 2 21 0 7 25 28 28 18% 1 or 2 16 0 10 22 26 26 16% 3 41 31 4 45 45 45 28% 4 17 0 3 0 20 20 13% , Deviant 4 6 2 1 0 7 7 4% 1 5 0 0 2 0 2 2 1% 6 (ON) 2 0 0 2 0 2 1% Total 131 35 29 119 158 160 100% % of Total 82 22 18 74 99 i 20 observation from these experiments results from the inclu sion of color as a variable in the second step. The column values in Table 1 list the numbers of cells receiving input from both the 432 nm receptors and the 572 nm receptors for both the ON and OFF responses. When these observed color j groups are combined with the classes, the number of ob- i Î j served groups conservatively reaches 12. While Reuter and ! j I the co-workers have not directly commented on this, their | results indicate that the inclusion of color as a variable j significantly increased the number of observed classes of j ganglion cells. The work of Reuter et al. is additionally noteworthy ! for its inclusion of some quantified data. The Lettvin- j Maturana class frequencies found in Table 1 are unique, and their papers contain many individual values for 1 intensity-threshold measurements. The Reuter and Virtanen | 1 (1972) paper gives averages and standard errors for 13 green rod-mediated and 24 cone-mediated ON responses as follows: I Response Response Response ! Length Latency Frequency j (ms) (ms) (spikes/sec.) : Green rod units 960 + 260 700±40 11.2±2.1 | Cone units 160±50 170±10 65.8±7.4 They point out that while these three parameters are significantly different from each other at p = 0.01 or 21 better, the number of spikes per response was nearly the same [10.6 spikes for the green-rod responses and 10.5 j spikes for the cone responses). This points out the impor-i tance of reporting the latency and frequency as well as the number of spikes in the response. This type of quantified, average data is rare in the literature. The study of color responses in the frog is facili tated by the biochemical studies of Liebman and Entine (1968), and the morphological work of Nilsson (1963, 1964). Nilsson’s low magnification electron-microscopie descrip tion of the four receptor types found in Rana pipiens pro vided a rigorous base for Liebman and Entine’s microspec- trophotometrie studies of these receptors. They were able to determine which specific receptor morphology contains which specific visual pigments and their frequency of occurrence. They found that the red rod receptors contain j I visual pigment 502 and constitute 50% of the receptors. | The green rod and cone receptors contain visual pigments I 432 and 575 respectively and make up 15% and 20% of the total. The double cone was determined to have visual pig ment 575 in its principal member and visual pigment 502 in its accessory member, and be 15% of the total. These cor- | relations are summarized above Figure 2. It was from thesel I values that the three colors (432, 502 and 572 nm) used in ! i this study were selected. 22 An additional brief report on frog ganglion cell | classification is that of Morrison (1975a). In these ex- | periments on Rana esculata, the responses of ganglion I cells were recorded using glass micropipettes on an in vivo| eyecup preparation. The stimuli were varied with respect to intensity, shape, movement, and velocity and direction of movement. The sample size reported on is extremely I large, 1550 cells. Unfortunately, the amount of data pre- : sented is small relative to the scope of the project. | I Morrison classifies the ganglion cells as follows : • 1 Group Number Percent of Total! i ON 147 9% : OFF 367 24% I I ON-OFF 954 62% I I Movement-sensitive only 61 4% i Direction-sensitive 10 0.5% Spontaneously firing 25 1.5% ! Morrison further reports that the ON response of both ON ! and ON-OFF groups is similar (latency = 70-90 milliseconds,i 4-8 spikes, and 200-250 spikes/second) as is the OFF re sponse in ON-OFF and OFF groups (latency = 70-210 milli seconds, 1-22 spikes and 1-280 spikes/second). Again, the brevity of this interesting report and its exemplary pre sentation, makes it difficult to analyze. 23 II. METHODS ; A. Animal Care and Preparation : ; Wild-caught, adult Rana pipiens were used in this j study. They were obtained from the Southwestern Scientific! Company (P.O. Box 17222, Tucson, Arizona 85710). The dealer reported that the frogs were caught in Sinaloa ! province of northern Mexico during the week prior to ship - i I ping and that they had not been fed or treated. The frogs ^ appeared to be of the "Mexican" type Rana pipiens as de- | scribed by Nace et al. (1974). Nace et al. (1974) also • discusses the problem of using Rana in laboratory experi ments because there is not yet wide agreement on its speci-, ation. Furthermore, standardized, inbred frogs are not yet available for experimental use. Upon arrival, the frogs were examined for symptoms of injury or illness and those appearing healthy were placed in large well-ventilated plastic baskets on moist sand. A water bath for optional swimming was provided. The frogs were commonly from three and one-half to four and one-half ; inches in length and weighed from about 70 to 130 grams. i The scleral diameter of the eye ranged from 0.9 mm to 1.0 mm. Since the frogs were ordered weekly, they were neither treated nor fed. 24 Two to three days before an experiment, the water bath was removed from the basket and the frogs were main tained on the moist sand only. This treatment effected a mild dehydration of the frogs, resulting in a 10% to 20% body weight loss. This dehydration promoted a relatively dry retinal surface and seemed to prevent the production of aqueous humor by the ciliary body during surgery. The dehydration also seemed to lengthen the time the ganglion cells could be stabilized and their responses recorded. B. Surgical Procedure: j An iji vivo eyecup was prepared. The frog's spinal ; cord and brain were both pithed, using a hypodermic needle. In order to effect complete paralysis of the eye and head region, the brain pith included severance of the i posterior eight pairs of cranial nerves. The frog was laid I on a warm (26° C) cork board and pinned through the skin ^ I on the back of the neck so that the eye to be operated ! upon was uppermost. A plastic insulating blanket was ; placed over the frog's body to maintain a warm, humid en- | I vironment, thus preventing skin dessication. A small pledget of moist cotton was placed in the frog's mouth to | protrude the eye. | The rest of the surgery required the use of a binoc- j ular dissecting microscope (1 Ox - 25x). The eyelid and J nictitating membrane were removed and a short corneal j f 25 incision was made with a scalpel. The initial release of ! aqueous humor was removed with a swab and the cornea was ; carefully removed with a fine spring scissors. A pointed ! wick (4x1 cm.) was made from #1 Whatman filter paper and i i j placed under the iris to drain additional aqueous humor. ! Two to four such filter paper wicks were needed to drain a I I I sufficient amount of aqueous fluid. The iris was retracted i by four pieces of filter paper (3.0 x 0.3 cm.) placed | I I around the eye (Figure 3). The dam, thus formed, retracted the iris, and absorbed residual aqueous fluid and revealed | all of the anterior lens surface.^ The eye was placed a ' few millimeters from a suction hose (1 cm. diameter) which i was attached to a water pump aspirator. Resulting air flow, I over the surface of the lens evaporated a minimal amount of remaining aqueous fluid, drying the lens enough to facil-- itate its removal. When the preparation was adequately dried, the iridial dam was trimmed. The lens was pulled gently to one side with a small forceps, exposing and putting tension on the anterior I zonular fibers. The anterior zonular fibers were then cut | with small spring scissors. The incision exposed a poste rior membrane, thought to be the posterior zonular fibers. ^J. D. Morrison graciously communicated his methods of preparing an in vivo eyecup in Rana temporaria. Although i i modified, this technique is similar to his. 26 FILTER PAPER FILTER PAPER ^ LENS Figure 3. Surgical Procedures FORCEPS ZONULAR FIBERS SCISSORS s CLEFT LENS 27 This membrane was pierced with the point of the closed ^ i scissors, producing a cleft between the vitreous humor which clung to the lens and the membrana vasculosa which clung to the retina. Using the closed scissors point, the cleft was enlarged by breaking the anterior and posterior ' zonular fibers around the rest of the lens. The lens was I ; then rolled toward the dorsal temporal region of the eye. ; An attachment of the vitreous humor to the optic disc could I i often be seen and detached with the scissors point. A strong attachment at the optic disc could often detach I I the retina. At this point, a good preparation was judged by the completeness of vitreal removal, lack of retinal detach ment, lack of hemorrhage, and a vigorous blood flow. The retina appeared clear on a stippled, reddish background. In a satisfactory preparation, the membrana vasculosa quickly dried, clearly outlining the retinal vessels. If additional drying was necessary it was accomplished with gentle air suction. All preparations were discarded when the blood flow ceased or became sluggish. At this point, an indifferent platinum electrode was placed under the skin on the back of the neck. The frog I was then placed in the recording cage and a small plastic i tube was placed near the eye so that a gentle stream of air I flowing over the membrana vasculosa would help maintain the dryness of the retinal surface. 28 c. Ganglion Cell Recording : Action potentials were recorded from ganglion cells I with glass micropipettes which were filled with 2 M sodium acetate. The glass micropipettes were made from 1 j special purpose glass tubing (Frederick Haer, Omega dot, j j micro-capillary tubing). The glass tubing was drawn with : ! an adjustable Kopf electrode pulling apparatus (Model No. i I 700A). The micropipette electrode was inserted with a platinum wire and connected to the preamplifier along with Î the indifferent platinum electrode that had been placed in ^ the back of the frog’s neck. ’ I Figure 4 is a schematic of the recording instrumen- I tation. The signal was first amplified by a high gain, j high impedance amplifier (Grass Model P511) and filtered (35-300 Hz band pass). The signal was then passed through an active 60 Hz filter and then a passive high-pass resis tance -capacitance filter with variable cutoffs (32, 64, 160, 1273 Hz). Next, the signal was further amplified with another Grass P511 amplifier. This final signal was then I recorded on a magnetic tape (Ampex SP- 300), as well as ! I visualized on an oscilloscope and made audible with an ; audio-amplifier. A signal indicating the ON and OFF of the light stimulus and a verbal description of the indi- ! vidual data gathering sessions were simultaneously re- I corded on the same magnetic tape. 29 Amplifier (Grass P511) Band Pass « 35 to 3 KHz » to 20 K I Amplification - 5 60 Hz Filter 00025 002 Amplifier (Grass P511) Band Pass - 35 to 30 KHz Amplification « 50 005 01 RC Highpass Filter TAPE RECORDER I OSCILLOSCOPE III OSCILLOSCOPE I OSCILLOSCOPE II AUDIO ON SI6NAL- VOICE— — TAPE RECORDER II TAPE RECORDER III OSCILLOSCOPE IV Figure 4. Recording Instrumentation 30 D. Light Stimulation Methods : The design of this experiment required a Maxwellian (i.e., directly on the retinal surface) presentation of a many-faceted search stimulus plus 21 specified stimuli to the exposed retina. The series of 21 stimuli varied with j respect to target size and shape, and the wavelength of ' I the light. The stimuli were invariant with respect to i I j movement, intensity, and duration. The optical system usedj to deliver these stimuli is illustrated in Figure 5, and ; the stimuli themselves in Figure 6. The source for the required 432, 502, and 572 nanometer light was a diffraction grating monochromator adapted from a spectrophotometer with a band width of 20 nm. (Coleman Junior Spectrophotometer, Model 6A). A hole drilled in its case emitted the light. This light path was then columniated (LI and L2) and shaped by one of | eight interchangeable targets (Figure 5). Immediately past! the target, the light path intercepted a coverslip suspended from the arm of a polygraph galvanometer. This j galvanometer was driven by a ramp function generator ' (Tektronix, Type 162) and a polygraph amplifier (Beckman , Dynograph Amplifier, Type 474A). Targets attached to the ' coverslip could be moved through the light path at velocities determined by the slope of the ramp function. | The light was then focused (L3 and L4) on a black. 31 I T I I U B 6 0 +-> ( / ) % C/D . r —1 LO C t i o 0 *H u +-> ^3 pH bJO O •H Pin 0 rP E-h dtâs 4qSn JT iHeag 4J l | l •M O O « 8 8 fe«3 ? S.S B S S > Ov _j_£aîjueaj[B^^^N- ÏJ cta^ o S ’ •o ë o £ % •o s Ü 32 Figure 6. The Stimuli 33 SEARCH S T M lL L LL S 4 3 2nm 5 02nm . ■ 5 _ Z . 2 nm 2.5 22 O O o O o O 5°x 2.5° 0 tn o \o m e n o p4 Al OQ O « O i r > O CM i r > o m CM CM i r > CM If * If * CM If* If * CM CM CM CM CM CM tn oo C D H bû •H C D e n c c î r O c c J +J cO C D m o C D fH 0 4 - > O fH 4 - > e n C D e- jaquniN linui|qs J0I03 snxnui|qs edBHS snxnm|qs 49 will then be compared with the findings about the total population. B. Description of the Total Population of 68 Cells The averaged responses of the total population of 68 ganglion cells for the nine stimulus conditions are pre- ! sented in Tables 3, 4 and 5. The tables show the responses j of the ganglion cells to each individual stimulus condition; I as well as the total response regardless of shape or color.' In addition, the average response to the shapes, regardless; of color and the average responses for the colors, regard - ; less of shape, are also presented. Each table presents one! of the three parameters needed to describe adequately the ! responses of the ganglion cells. Abbreviations were used ! to denote the various stimulus conditions. An explanation of these abbreviations is shown in Table 2. The average total number of spikes for all 68 ganglion cells, regardless of temporal, spatial or chro- ; I matic consideration, was 6.4 spikes per stimulus. The I average temporal responses of the total population are pre-j sented in Table 6. The table shows the average number of ; spikes, density of spikes and mean latency per response period, regardless of stimulus shape or color. The values i are characteristic for each of the response periods and | except for the ON and OFF-1 densities, were significantly different from each other by t-test at p = .05 or better. 50 1-1 1-2 1-3 TABLE 2 ABBREVIATIONS OF STIMULUS CONDITIONS USED IN SUBSEQUENT TABLES^ ' ^ light spot, blue (432 nm.). ^ light spot, green (502 nm.). ^ light spot, yellow (572 nm.). 2-1 = 5.0 light spot, 2-2 = 5.0° light spot, 2-3 = 5.0° light spot. blue. green. yellow 3-1 = 2 2° light spot, blue. 3-2 = 22° light spot, green. 3-3 = 22° light spot, yellow. 4-1 = 2.5° X 5° light annulus, blue. 4-2 = 2.5° X 5° light annulus, green. 4-3 = 2.5° X 5° light annulus, yellow. 5-1 5-2 5-3 = 2.5' = 2.5' = 2.5 X X X dark dark dark annulus, annulus, annulus, 22 ° 22° 22 ° light spot, blue, light spot, green, light spot, yellow 6-1 6-2 6-3 = 5' = 5 = 5 X X X 22 ° 22 ° 22° light annulus, blue, light annulus, green, light annulus, yellow. 7-1 7-2 7-3 2.5° 2 . 5° 2.5° X X X 22 ° 22 ° 22° light annulus, light annulus, light annulus. blue. green, yellow. 1-0 2-0 3-0 4-0 5-0 6-0 7-0 2.5 5° 22° 2.5' 2.5 X . o light spot, regardless of color, light spot, regardless of color, light spot, regardless of color. X 5° light annulus, regardless of color. X 5° dark annulus on 22° light spot, regardless of color. 22° light annulus, regardless of color. X 22° light annulus, regardless of color. 0-1 = Blue stimuli, regardless of shape. 0-2 = Green stimuli, regardless of shape. 0-3 = Yellow stimuli, regardless of shape. 0-0 = All stimuli pooled, regardless of shape or color. 51 TABEl 3 FREQUENCY OF SPIKES Response of 68 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions ÇC Total On Off-1 Off-2 1-1 68 5.5±.55 1.81.24 2.81.45 0.91.19 1-2 68 6 . 4 ± . 6 2 2.11.27 3.21.49 1.11.24 1-3 68 5.3±.41 2.21.25 2.51.29 0.61.13 2-1 68 6 . 5±.61 2.21.30 3.01.46 1.31.23 2-2 67 6 . 8±.64 2.31.29 3.21.46 1.31.24 2-3 68 6.5±.57 2.31.27 3.11.46 1.11.22 3-1 68 7.0±.87 1.91.36 3.21.53 1.81.39 3-2 68 6.5±.79 1.81.25 3.11.50 1.61.40 3-3 68 7.2±.90 1.71.23 3.41.62 2.01.39 1-0 (204) 5.7±.30 2.01.15 2.81.24 0.91.11 2-0 (203) 6.6±.35 2.31.16 3.11.26 1.21.13 3-0 (204) 6.9±.49 1.81.17 3.31.32 1.81.23 0-1 (204) 6.3±.4 0 2.01.18 3.01.28 1.31.16 0-2 (203) 6.6±.39 2.11.16 3.21.27 1.31.18 0-3 (204) 6.3±.38 2.11.15 3.01.27 1.31.16 0-0 (611) 6.4±.23 2.01.09 3.11.16 1.31.10 Mean Values±Standard Error 52 TABLE 4 DENSITY OF SPIKES Response of 68 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Conditions GC On Off-1 Off-2 1-1 68 28±6.2 2715.1 210.6 1-2 68 40+8.1 3116.4 3 + 0.6 1-3 68 32±6.2 3518.0 210.5 2-1 68 46±9.6 3617.6 3l0 . 6 2-2 67 65±12.5 4018.2 310 . 5 2-3 68 49±10.3 3818.4 310.7 3-1 68 56±11.0 52114.4 5ll .1 3-2 68 60±12.0 53111 .4 310.7 3-3 68 60111.6 57114.0 511.1 1-0 (204) 3314.0 3113.8 210.3 2-0 (203) 5416.3 3814.6 310 . 3 3-0 (204) 5916.7 5417.7 510 . 6 0-1 (204) 4415 . 3 3815. 7 310 . 5 0-2 (203) 5516.4 4115.2 310 . 4 0-3 (204) 4715.6 4316.0 310 . 5 0-0 (611) 4913.3 4113.3 310.3 Mean ValuesiStandard Error 53 TABLE 5 MEAN TIME OF OCCURRENCE OF SPIKES Response of 68 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-1 On Off-1 Off - 2 1-1 68 226116 725114 1293120 54 59 41 1-2 68 202115 712114 1305123 52 59 39 1-3 68 220116 702112 1309122 55 62 37 2-1 68 190115 719115 1310119 57 62 43 2-2 67 175114 693H5 1351123 57 58 41 2-3 68 200117 714115 1307120 54 59 43 3-1 68 155113 702117 1380123 51 59 44 3-2 68 141112 696116 1375128 52 59 41 3-3 68 138112 696115 1350120 54 58 43 1-0 (204) 21619 713113 1302112 161 180 117 2-0 (203) 18819 70919 1322112 168 179 127 3-0 (204) 14517 69819 1368114 157 176 128 0-1 (204) 191110 71519 1329112 162 180 128 0-2 (203) 17318 70019 1344114 161 176 121 0-3 (204) 18619 70418 1323112 163 179 123 0-0 (611) 18315 70715 133217 486 535 373 Mean Values!Standard Error 54 TABLE 6 AVERAGE TEMPORAL RESPONSES OF THE TOTAL POPULATION WITH STANDARD ERRORS AND RANGES N of Density Mean Response Spikes of Spikes Latency Period N N/sec. ms. ON 2.0±.09 4913.3 18315 (0-19) (0-402) (37-529) OFF-1 3.11.16 4113.3 20715 (0-23) (0-861) (36-530) OFF-2 1.31.10 310.3 83217 (0-16) (0-57) (542-1234) (0) = Range 55 Table 6 also shows the ranges for each response period. Responses of ganglion cells to each individual stim- ! ulus condition, shown in Tables 3, 4 and 5, are visualized ! in Figure 9 as connected data points. Figure 10 is a post stimulus - time response graph showing the spot sizes plotted by each color and Figure 11 is another post-stimulus-time response graph showing color plotted by each spot size. i responses of the ganglion cells to the individual stimulus j conditions were compared by t-test. No difference could be : shown to be significant at the p = .05 level. | The spatial effects of the three spot sizes, when ! 1 considered without regard to color, differ in several pa- ; rameters when compared by t-test. As shown in Table 7, 14 ; out of 27 possible comparisons among the spot size responses were different at the p = .05 level or better. The OFF -1 period had only one significant difference (a density), while the ON and OFF - 2 periods had six and seven differences respectively. The ganglion cells’ responses to spatial stimuli are visualized in the profile graph of Figure 12. As discussed in the Experimental Design section, the [ ’’profile” of the cells is made up of the three parameters | graphed in Figure 12 for the total population. The profilej i graphs are made up of regression lines which suggests j trends and relationships. The Y-intercept, slope and cor - ! relation coefficient (r) are found in Table 8 for these 56 Figure 9 The nine graphs in this figure represent the responses' of ganglion cells to the three spots in three colors. The , three parameters, number and density of spikes and mean j latency, are graphed on the ordinates and color of the light stimulus is on the abscissa for the three time periods. The individual lines on each graph represent the cells’ responses to the three spot sizes, small (S), medium (M) and large (L). 57 MEAN TIME 225^90-1 75-340- 25-''90 60- DENSITY • OF 30 SPIKES 0 4 3 2 NUMBER OF SPIKE'S OFF-2 OJ M S 4 3 2 502 — M — S — I 572 Figure 10 The three post-stimulus-time response graphs show the number of spikes on the ordinate and the time (in ms) on ; I the abscissa. The apex of each triangle represents the average number of spikes for each time period for each averaged stimulus presentation. The dotted line at the apex represents the standard error of the number of spikes.j The apex of each triangle is located at the mean time of responses for each period. The base of the triangle represents the interquartile range of the response. The ! arrows indicate the onset and offset of the light stimulus. Each graph shows the responses for each spatial stimulus, small spot (2.5°), medium spot (5°) and large spot (22°). ; I The letter associated with each triangle shows the response ; for each color, blue (B), green (G) and yellow (Y). ] 59 2 . 5 N O F S P I K E S 1000 5 0 0 T I M E N O F S P I K E S 1000 5 0 0 T I M E 22.0 N O F S P I K E S 5 0 0 1000 T I M E 60 Figure 11 ’ This figure shows three post-stimulus-time response graphs which are constructed in a form similar to those of , Figure 10. In this case each graph was drawn for the three I colors, blue (432 nm), green (502 nm) and yellow (572 nm). I In this case, the spot sizes are indicated by the numbers, i 1 for the small spot, 2 for the medium size spot and 3 for the large spot, and they are associated with the triangles. 61 4 3 2 n m . 3 - O F S P I K E S 2- I Oj 1000 500 T I M E N O F S P I K E S T I M E m s . N O F S P I K E S T I M E m s . 4 - , 502 0 J 500 1000 4-1 572 3- 2- 500 1000 62 Table 7 This is a table of probability values which compares responses of ganglion cells to three spot size stimuli regardless of color. The symbols used for the spot sizes are found in Table 2 and the data is derived from that in Tables 3, 4 and 5. The probability values were determined by Student’s t-test and those .05 or less are shown. TABLE 7 TABLE OF PROBABILITIES Response Period Parameter Spot Size Comparisons (larger value is first) Difference P-value' if <.05i ON OFF-1 OFF-2 N 2-0 vs . 1-0 0.3 - of Spikes 1-0 vs. 3-0 0 . 2 - 2-0 vs. 3-0 0.5 . 05 Density 2-0 vs . 1-0 21 . 01 of Spikes 3-0 vs . 1-0 26 . 01 3-0 vs . 2-0 5 - Latency 1-0 vs . 2-0 28 . 05 i 1-0 vs . 3-0 71 . 001 2-0 vs . 3-0 43 . 001 N 2-0 vs . 1-0 0.3 1 1 of Spikes 3-0 vs . 1-0 0.5 3-0 vs . 2-0 0 . 2 Density 2-0 vs . 1-0 7 of Spikes 3-0 vs. 1-0 23 . 01 3-0 vs . 2-0 16 - Latency 1-0 vs. 2-0 4 I 1-0 vs. 3-0 15 2-0 vs , 3-0 11 i ! N 2-0 vs. 1-0 0.3 ! of Spikes 3-0 vs . 1-0 0.9 . 001 3-0 vs . 2-0 0.6 . 05 Density 2-0 vs . 1-0 1 .02 of Spikes 3-0 vs . 1-0 3 . 001 3-0 vs . 2-0 2 . 01 Latency 2-0 vs. 1-0 20 - 3-0 vs . 1-0 66 .001 3-0 vs . 2-0 46 . 02 1 64 j Figure 12 I I j The three graphs in this figure are considered to j represent a profile of the 68 ganglion cells’ responses to spatial stimuli. The area of each spatial stimulus is indicated on the abscissa in logarithmic scale. The ordinate represents the three parameters, number and density of spikes and mean latency. The lines of each graph represent an averaged response for three spatial stimuli (regression lines). The dots around the regression lines give an approximate idea of the values from which the regressions were calculated. The regression statistics for these values are found in Table 8. 65 22 l o g . a r e a o f s t i m u l u s STIM ULUS LOG. AREA 66 n TABLE 8 REGRESSION STATISTICS FOR THE TOTAL POPULATION OF 68 CELLS FOR BOTH SHAPE AND COLOR AS ILLUSTRATED IN FIGURES 12 AND 13 Parameter G Time Period Y-intercept Slope (correlation coefficient) SHAPE ■... . N ON 2.28 - . 16 -.57 N OFF-1 2. 76 .20 .61 N OFF-2 . 56 .49 . 92 Density ON 30 12 .77 Density OFF-1 22 12 .97 Density OFF-2 2 1 .81 Mean Time ON 240 -37 -.95 Mean Time OFF-1 236 -13 -.34 Mean Time OFF-2 111 35 .89 COLOR N ON 2 . 01 . 01 .04 N OFF-1 3. 06 . 00 . 00 N OFF-2 1.40 - . 05 -.10 Density ON 45 1.8 .12 Density OFF-1 36 2.3 .20 Density OFF-2 3 0 . 0 . 00 Mean Time ON 187 -2 -.06 Mean Time OFF-1 218 -6 -.43 Mean Time OFF-2 837 -3 -.07 67 regressions. For the degrees of freedom (seven) used, an ! (r) value of .66 or better is a good fit at the five per- j cent level. Three of the nine values do fall below this I level, and they occur in areas which were not significant I by t-test (Table 7). Chromatic effects, unlike spatial and temporal, | I I ! showed no significant differences when compared by t-test. ■ i I I The profile graphs for color are shown in Figure 13. The , regression lines are horizontal and their (r) values are j I extremely low (see Table 8) which would suggest that the ' response parameters do not vary with color in the total I population. Additional observations on the total population of ^ 68 ganglion cells were made. Thirty-two percent of these cells fired spontaneously with an average firing rate of 1.4 spikes per second (0.5 - 5.0 spikes/second). Twenty- one percent of these cells were noted to exhibit some adaptation to the stimulus replications. A subjective ; test for movement sensitivity which involved dark bars and points against a yellow background was made on 3 9 of the 68 cells (57%). Of the cells tested, 82% indicated some movement sensitivity. All of the movement sensitivity cells responded to slow velocities of movement, while only 31% (12 cells) responded to the fast velocity of movement.! 68 Figure 13 The three graphs in this figure represent a profile I of the 68 ganglion cells’ responses to the chromatic stimuli, regardless of spot size. The format of these graphs is similar to those of Figure 12, except that the abscissa shows the chromatic wave length and is not on a logarithmic scale. The regression statistics for these averaged lines are also shown in Table 8. 69 SPIKES D EN SITY OF S P IK E S 70 50 30 1 0 C O LO R MEAN T IM E 3 0 0 OFF- 100 J C O LO R nm 70 C. Description of the Subsets of the Total Population, 56 and 5 2 Cells The averaged responses for the two subset populations, of the 68 ganglion cells are presented in Tables 9, 10 and j 11 for the 36 cells to 21 stimulus conditions and in Tables 12, 13 and 14 for the 32 cells to nine stimulus conditions. The comparison of responses of the total population of 68 ganglion cells with that of the subsets of 36 and 32 cells is visualized for spots only in the profile graph in Figure 14 and the Y-intercept, slope, and correlation co efficient (r) are found in Table 15. Although some of the regression lines appear to be different for the 32 and 36 cell subset populations, none of the values used to con struct these regressions were significant when tested by t-test at the p = .05 level. Since no difference could be shown between the two subsets, it was assumed that their apparent difference was due to random variability. The ganglion cells in the 36 cell subset were held long enough to obtain responses to the light and the dark annuli in addition to the spots (21 stimulus conditions). The responses of the 36 cell subset are visualized as connected data points in Figure 15. The profile graph of Figure 16 and the responses appear to be inhibited in some of the response parameters when compared with the responses to the spots; these differences were not significant when 71 TABLE 9 ' FREQUENCY OF SPIKES Response of 36 Frog Ganglion Cells to 21 Stimulus Conditions., Presented Individually or as a Total Group and Sorted fox Shape and Color Stimulus N N N N N L Condition GC Total On Off-1 Off-2 1-1 36 4.6±0.59 1.8±.27 2.21.43 0 . 81. 2 6 i 1-2 36 5.6± 0.67 2.1+.35 2.81.53 0.81.19 ! 1-3 36 4.7±0.51 2.1±.34 2.01.37 0.51.14 2-1 36 6.0± 0.69 2.3±.37 2.71.50 1.01.27 1 2-2 36 6.6± 0.79 2.4+.36 3.01.58 1.21.32 2-3 36 5 . 6±0.65 2.2±.34 2.51.51 0.91.20 ' 3-1 36 6.8±1.08 2.0±.43 3.11.71 1.61.48 1 3-2 36 6.5±1.08 1.9±.32 3.11.67 1.61.55 3-3 36 7.2±1.26 1.8±.29 3.41.89 2.01.52 1 4-1 36 5.1±0.64 1.9+.31 2.31.42 0.91.25 4-2 36 5.8±0.81 2.3±.40 2.41.55 1.11.37 I 4-3 36 5.4±0.64 2.1±.33 2.41.49 0.81.20 : 5-1 36 6.4+0.94 2.0±.44 2.71.63 1.81.41 5-2 36 6.0±0.87 1.7+.32 3.11.72 1.21.32 1 5-3 36 6.2±1.08 1.6±.29 3.11.80 1.41.38 6-1 36 6.2±0.88 1.8±.37 2.91.66 1.51.37 1 6-2 36 6.0±0.91 1.7±.34 2.91.68 1.41.34 6-3 36 5.7±0.82 1.6±.31 3.01.67 1.11.29 7-1 36 6.7±1.00 2.2±.44 2.91.68 1.61.43 7-2 36 6.6±0.98 2.1±.37 3.21.71 1.41.39 : 7-3 36 6.2±0.91 1.71.27 3.01.72 1.41.36 ! 1-0 (108) 5.1±0.34 2.01.18 2.41.26 1 0.71.12 i 2-0 (108) 6.1±0.41 2.31.20 2.71.30 1.01.15 3-0 (108 6.8±0.65 1.91.2 0 3.21.43 1.71.30 4-0 (108) 5.4±0.40 2.11.20 2.41.28 0.91.16 ' 5-0 (108) 6.2+0.56 1.81.21 3.01.41 1.51.21 6-0 (108) 6.0±0.50 1.7+.20 3.01.38 1.31.19 ! 7-0 (108) 6 . 5 ± 0 . 5 5 2.01.21 3.01.40 1.51.23 0-1 (252) 6.0+0.32 2.01.14 2.71.22 r 1.31.14 0-2 (252) 6.2±0 .33 2.01.13 2.91.24 1.21.14 0-3 (252) 5.8±0.33 1.91.12 2.81.25 1.21.12 0-0 (756) 6.0+0.19 2.01.08 2.81.14 1 1.21.01 Mean Values ± Standard Error 72 TABLE 10 DENSITY OF SPIKES Response of 36 Frog Ganglion Cells to 21 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color :imulus N Den Den Den iditions GC On Off-1 Off-2 1-1 36 27±07 .4 22±05.7 210 . 9 1-2 36 42+11.4 32±09.2 210.8 1-3 36 31+08.0 30±09.0 210.7 2-1 36 49±13.7 34±10.0 210.8 2-2 36 70±19.6 41111.6 210.8 2-3 36 64±17. 2 40112.4 310.9 3-1 36 53±12 . 2 36109.4 511.8 3-2 36 60±14 . 8 42+12.2 4il . 0 3-3 36 70±17.6 52121.0 611.8 4-1 36 44±12.4 28109.4 2il . 0 4-2 36 43±11.8 38+10.9 2i0.8 4-3 36 43±10.6 25106.9 210.4 5-1 36 47±12 . 0 27107 . 5 310.7 5-2 36 52±15.4 57114.1 310.7 5-3 36 40±11.4 48 + 14 . 0 310.7 6-1 36 41±11. 2 23+05.3 410.9 6-2 36 36±10.8 33109.6 310.7 6-3 36 36±11.2 45119.5 2i0.6 7-1 36 39±09.6 48+12.5 3i0 . 9 7-2 36 42±12.1 47+12.9 310.8 7-3 36 60±16.0 49114.8 310.7 1-0 (108) 33±05.2 28104 . 7 2iO. 5 2-0 (108) 61±09.4 38106 . 5 210.5 3-0 (108) 61±08.6 44+08.6 5i0 . 9 4-0 (108) 43±06.7 31+05.3 210.4 5-0 (108) 47±13.0 44+07.1 310.4 6-0 (108) 38±06.3 34107.4 310.4 7-0 (108) 46±07.4 48107.7 3i0 . 5 0-1 (252) 43±04.3 31103.3 310.4 0-2 (252) 49±05.1 41104.4 310.3 0-3 (252) 49±05.2 41105 . 5 310.4 0-0 (756) 47±02.8 38102 . 5 310.2 Mean Values!Standard Error 73 TABLE 11 MEAN TIME OF OCCURRENCE OF SPIKES Response of 36 Frog Ganglion Cells to 21 Stimulus Conditions, Presented Individually or as a Group and Sorted for Shape and Color Number of Observations Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-2 On Off-1 Off 1-1 36 246+21 721117 1299130 29 29 21 1-2 36 217122 703117 1364131 29 30 20 1-3 36 221122 700117 1326135 31 32 19 2-1 36 215122 694118 1318128 31 32 23 2-2 36 184120 675117 1412130 33 3 0 21 2-3 36 215124 714120 1335126 29 31 25 3-1 36 153114 685121 1401131 29 31 24 3-2 36 138115 711124 1342138 28 31 22 3-3 36 129114 717123 1330129 29 30 24 4-1 36 246126 706117 1351133 29 32 22 4-2 36 215121 690117 1360127 31 28 22 4-3 36 219121 708121 1326126 32 29 21 5-1 36 162119 711124 1393129 27 29 23 5-2 36 152116 720126 1364139 27 31 22 5-3 36 146116 702122 1300124 29 29 25 6-1 36 177121 730121 1314129 26 29 26 6-2 36 179120 746125 1313128 25 29 23 6-3 36 147114 718122 1342131 2 7 27 21 7-1 36 180119 713124 1368128 30 32 23 7-2 36 159117 703122 1358136 31 31 19 7-3 36 156118 686120 1314131 29 27 24 1-0 (108) 228112 708110 1329118 89 91 60 2-0 (108) 204112 694110 1353117 93 93 69 3-0 (108) 140108 704113 1358119 86 92 70 4-0 (108) 226+13 702+10 1346117 92 89 65 5-0 (108) 153110 711114 1351118 83 89 70 6-0 (108) 167111 732113 1322117 78 85 70 7-0 (108) 165110 702113 1346118 90 90 6 6 0-1 (252) 198108 708108 1349111 201 214 162 0-2 (252) 179107 707108 1358112 204 210 149 0-3 (252) 178108 707108 1324111 206 205 159 0-0 (756) 185104 707104 1344107 611 629 470 Mean Values!Standard Error 74 TABLE 12 FREQUENCY OF SPIKES Response of 32 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 32 6.3±1.00 1.81.42 3.41.88 1.01.28 1-2 32 7.0H.12 2.11.42 3.61.89 1.41.52 1-3 32 6.0± 0.66 2.31.37 3.01.46 0.71.24 2-1 32 7.011.07 2.11.49 3.41.83 1.51.39 2-2 31 7.011.04 2.21.47 3.41.47 1.41.36 2-3 32 7.610.99 2.41.43 3.81.82 1.41.44 3-1 32 7.211.41 1.81.60 3.41.80 2.11.64 3-2 32 6.511.16 1.71.39 3.21.75 1.61.59 3-3 32 7.111.29 1.71.37 3.41.86 2.11.59 1-0 (96) 6.410.53 2.11.25 3.31.43 l.li.20 2-0 (95) 7.210.60 2.21.26 3.31.45 1.41.22 3-0 (96) 6.9i0.75 1.71.29 3.41.48 1.91.36 0-1 (96) 6.810.66 1.91.29 3.41.46 1.51.24 0-2 (95) 6.810.63 2.01.25 3.41.44 1.51.28 0-3 (96) 6.910.57 2.11.23 3.41.42 1.41.26 0-0 (287) 6.8+0.36 2.01.15 3.41.25 1. 51.15 Mean Values!Standard Error . 7 _ 5 . TABLE 13 DENSITY OF SPIKES Response of 3 2 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Condition GC On Off-1 Off-2 1-1 32 29110.43 34109.0 210.8 1-2 32 38111 . 5 30108.9 410.9 1-3 32 33109.7 41114.0 2i0. 7 2-1 32 43113.4 38111.0 310.9 2-2 31 60115.4 39111.6 310 . 6 2-3 32 32111.5 36111.3 411.1 3-1 32 59H9.6 70130.1 512 . 2 3-2 32 60H9.6 65120.8 311 . 0 3-3 32 49115.0 62118.4 411.3 1-0 (96) 33i06.2 34106.2 3lO . 3 2-0 (95) 45108.3 38106. 5 310.3 3-0 (96) 57H0.5 66113.6 410. 8 0-1 (96) 44108.5 47110.8 410. 6 0-2 (95) 52109.5 45108.4 310.6 0-3 (96) 38106.8 47108.5 310.6 0-0 (287) 45104.8 4 610 5.3 310.3 Mean ValuesiStandard Error 76 TABLE 14 Mean time of occurrence of spikes Response of 32 Frog Ganglion Cells to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-2 On Off-1 Off 1-1 32 203123 730122 1289126 25 30 20 1-2 32 183118 721122 1242127 23 29 19 1-3 32 217126 703118 1290125 24 30 18 2-1 32 160H8 745124 1301125 26 30 20 2-2 31 162121 711124 1286131 24 28 20 2-3 32 182124 715125 1268129 25 28 18 3-1 32 159123 721126 1355134 22 28 21 3-2 32 144121 680122 1412141 24 28 19 3-3 32 150121 673120 1376125 25 28 19 1-0 (96) 202113 718112 1274115 72 89 57 2-0 (95) 168112 724114 1286116 75 86 58 3-0 (96) 151112 691113 1380120 71 84 59 0-1 (96) 174112 732114 1316117 73 88 61 0-2 (95) 163112 704113 1313121 71 85 58 0-3 (96) 182114 696112 1313116 74 86 55 0-0 (287) 17317 71117 1314110 218 259 174 Mean Values!Standard Error 77 Figure 14 ; The three graphs of this figure compare the responses of the ganglion cells of the 36 cell and 32 cell subsets with each other and the total population for spot sizes regardless of color as in Figure 12. As in Figure 12, the ; abscissa of this profile graph is the area of the spot I sizes in logarithmic scale. Regression statistics for j these graphs are found in Table 15. 78j __i 3 6 C E L L S . . . . . 3 2 C E L L S N O F L... 6 8 C E L L S 4 3 2 o 22 2 . 5 5 L O G . A R E A O F S T I M U L U S 3 6 C E L L S 3 2 C E L L S 6 8 C E L L S 7 0 . . O N . - O F F - 1 ^ON ' O N ^ O F F - I 5 0 O F F - I D E N S I T Y O F S P I K E S 10 2 . 5 22 L O G . A R E A O F S T I M U L U S 3 6 C E L L S 3 2 C E L L S 6 8 C E L L S - 1000 O F F - 2 O F F - 2 O F F - 2 7 0 0 M E A N 1 T I M E 3 0 0 O F F - 1 [ O N ' O N O N 100 2 . 5 22 L O G . A R E A S T I M U L U S O F 79 TABLE 15 REGRESSION STATISTICS FOR SPOTS AND ANNULI OF THE SUBSET POPULATION OF 36 CELLS AND SPOTS FOR THE SUBSET POPULATION OF 3 2 CELLS Parameter ^ Time Period Y-intercept Slope (correlation coefficient) Spots for 32 Cells N ON 2.33 -.21 -.66 N OFF-1 3.44 -.02 -.09 N OFF-2 0.7 6 . 46 .85 Density ON 27 12 . 76 Density OFF-1 20 17 .94 Density OFF-2 2 1 .57 Mean Time ON 211 -25 -.83 Mean Time OFF-1 235 -16 -.58 Mean Time OFF-2 722 60 .90 Spots for 36 Cells N ON 2. 21 - .09 - .37 N OFF-1 2.07 .45 .81 N OFF-2 0.3 .6 . 94 Density ON 33 12 . 6 5 Density OFF-1 25 8 .73 Density OFF-2 2 1 .57 Mean Time ON 263 -47 - .95 Mean Time OFF-1 203 - .42 - .02 Mean Time OFF-2 828 13 .28 Annuli for 36 Cells N ON 2.33 - .20 - . 51 N OFF-1 1.85 .44 .91 N OFF-2 . 5 .4 . 77 Density ON 43 .3 . 03 Density OFF -1 21 8 .46 Density OFF - 2 1 1 .73 Mean Time ON 281 -47 -.95 Mean Time OFF-1 190 9 .35 Mean Time OFF-2 850 -3 - .08 8 0 J Figure 15 The nine graphs in this figure represent responses of ganglion cells to the four light annuli in three colors. The three parameters, number and density of spikes and mean latency, are graphed on the ordinate and color of the light stimuli is on the abscissa for the three time periods. The individual lines on each graph represent the responses to each of the four annuli, 2.5° x 5° (4), 2.5° X 5° X 22° (5), 5° x 22° (6) and 2.5° x 22° (7). 81 OFF-2 m e a n TIME 9 0 - 3 4 0 - 60 DENSITY OF SPIKES 30 567 N UMBER OF SPIKES 2 - 67 432 502 572 82 Figure 16 The three (profile) graphs in this figure compare the responses of ganglion cells to the four annular light stimuli to those of the three light spots. The abscissa is again the area of light stimulus for these seven stimuli, expressed in a logarithmic scale. The regression statis tics for these lines are found in Table 15. 83 36 cells N O F A N N U L I S P O T S .“ ON i^FF-2 » i O F F - 2 0 - 22 2 . 5 S T I M U L U S A R E A O F L O G . 3 6 C E L L S A N N U L I S P O T S 7 0 - , . . . O N 5 0 - D E N S I T Y O F S P I K E S 3 0 - . O F F - 2 . O F F - 2 22 2 . 5 S T I M U L U S O F A R E A L O G 3 6 c e l l s M E A N T I M E S P O T S A N N U L I 1000- . 7 0 0 - 3 0 0 - lOOJ 2 . 5 5 22 L O G . A R E A O F S T I M U L U S 84 1 tested with t-tests at the p = .05 level. Frequency distributions of the individual values for ; the annuli as well as the spots of the total population are| presented in Appendix Figures A1 to A9 for the number of spikes, density of spikes and mean latency. From these distributions the dispersion of the measures studied can be I ' I I readily visualized. The shape of the distributions varyes ; j considerably. In general, the shape of the distributions , shows that the means and medians are both skewed to the left, indicating a greater dispersion of the higher values. D. Analysis of Variance of the Total Population Since some but not all of the ganglion cell responses to temporal and spatial stimuli were significantly dif ferent by t-tests, as stated above, analyses of variance were calculated to compare the cells’ responses to nine stimulus conditions for temporal, spatial and chromatic attributes for the total population of 68 cells. The number of spikes was used to calculate all of these analyses of variance. Three calculations were made. The F value needed for the degrees of freedom involved (2, 134) ' j was F = 3.06 at the p = .05 level. The F value obtained I for the temporal analysis, ON, OFF -1 and OFF-2, was i F = 9.58, confirming that the temporal responses are indeed; different. The F values obtained for the spatial analysis ! i (small, medium and large spots) was F = 2.68 which is just. 85 under significance at the p = .05 level. The F value ob tained for the chromatic analysis (blue, green and yellow) was F = .57, clearly not significant, in confirmation of the above findings. I i A fourth analysis of variance was calculated using i number of spikes for the responses of each individual cell j to the same nine stimulus conditions. The degrees of free - dom for this calculation were 67 and 1742 and the needed F | I value at the p = .05 level is F = 1.45. The F value ob- | tained for the analysis of the individual cells was F = ; I 9.35. This highly significant F value suggests that the j individual cells are not from the same population, i.e., the population of 68 ganglion cells is heterogenous. | E. Semiquantitative Groupings of the i I Total Population of 68 Cells i I The preceding analyses indicate that, in this hetero- | genous population of ganglion cells, the temporal responses I v/ere significantly different, the spatial differences were ' marginally significant, but the chromatic responses were nof significantly different in any parameter. If the popula- i tion of the cells is heterogenous, it should be possible to sort the individual cells on the basis of their differen tial responsiveness to temporal, spatial and chromatic attributes. These three semiquantitative sortings were attempted as described below. All of the sorting 86 procedures used were based on the number of spikes in the ON and OFF-1 periods. The temporal sorting procedure was based on the presence or absence of ON, OFF -1 and OFF-2 responses. A cell was considered to have reacted to the stimulus for a i given response period if its response was 0.6 spikes or I greater. If the cell reacted to the stimuli in five or I more of the nine stimulus conditions, it was considered i to have that temporal response characteristic. This type of grouping for the presence or absence of response for three periods of time, results in seven possible groups. These seven groups and their frequencies of occurrence were : Group N ON 13 19 ON,OFF-1 22 32 ON,OFF-2 5 7 ON,OFF-1,OFF-2 7 10 OFF-1 9 13 OFF-1,OFF-2 12 18 OFF-2 0 0 These data are visualized as a histogram in Figure 17. There was no clear example of an OFF-2 only response and the sorting resulted in six groups. These groups can be collated into three groups which are directly comparable with those first compiled by Hartline (1938) . Thus Figure 17 j i I The three histograms of this figure represent i I frequency distributions of the ganglion cells when sorted , semiquantitatively for their temporal, spatial and chro- ' I matic properties as explained in the text. I 88 % 30- 20- TOTAL 10- 1 ü. 5 CVJ r Z o <vi iL L i . o T t o z o L i . O CM I I Li . IL. O CM r li. L i . o TEMPORAL GROUPS 30- % 20- SORTEÔ lOH 0 % iv: 1 f'*, M M-L L L-s SML SPATIAL GROUPS □ ON OFF 40-1 % 304 SORTED 20-1 10 .-.'j Î / • B 86 6 GY Y YB BGY COLOR GROUPS 89 compiled, 19% of the cells were ON cells only, 49% had both ON and OFF responses and 30% had OFF responses only, con firming Hartline's findings. A more detailed, quantitative analysis of the six temporal groups is presented later in this section. ! A slightly different sorting procedure was used to I ; separate the ganglion cells on the basis of their responsive-; ness to spatial stimuli. A cell was considered to have re- ' I sponded if at least 0.6 spikes had occurred in the ON or OFF-1 period. The responses to the small, medium and large ; spots were compared. If the largest response was at least 0.6 spikes greater than another response, it was considered : to have responded differentially. If the largest response ' i was not greater by 0.6 spikes, it was considered to have responded equally with that response being compared. This I method results in seven possible groups plus an unsortable group, for both the ON and OFF -1 periods. These seven groups and their frequencies are as follows: ! 90 ON period OFF-1 period Group No. of cells Percent sorted No . of cells Percent sorted S (Small spot) 8 15% 13 23% M (Medium spot) 8 15% 6 11% L (Large spot) 10 20% 12 21% SM (Small-medium) 16 31% 12 21% ML (Medium-large) 5 10% 5 9% SL (Small-large) 0 0 2 4% SML (Equal) 5 10% 7 12% Unsorted 16 — — — 11 The frequency data for the spatial groupings are visualized' in a histogram in Figure 17. From the frequency distribu- ' tion, it would appear that the total population of 68 cells is heterogenous with respect to responsiveness to spatial - stimuli. No single spot size was clearly dominant in its < responsiveness over any other spot size. The third sorting for chromatic responsiveness was made using the same criteria which was used for sorting the spatial stimuli. As before, this procedure results in * seven groups and one unsorted group for both the ON and ; ! I OFF -1 periods. These seven groups and their frequencies | are as follows : ! 91 ON period OFF-1 period Group No. of cells Percent sorted No. of cells Percent sorted B (Blue) 5 10% 6 11% EG (Blue-green) 5 10% 8 14% G (Green) 2 4% 9 16% GY (Green-yellow) 8 16% 8 14% Y (Yellow) 9 18% 5 9% YB (Yellow-blue) 3 6% 6 11% BGY (Equal) 18 36% 15 26% Unsorted 16 — — — 11 — — — The frequency data for the chromatic groupings are visual ized in a histogram in Figure 17. In general, this data ' shows that the lack of color differentiation in the aver aged total population is due to the approximately balanced frequency of the chromatically sensitive cells and the high| number of non-chromatic cells. F. Concordance of the Semiquantitative Groupings | The individual ganglion cell assignments of the tem poral, spatial and chromatic semiquantitative sorting pro cedures described above are summarized in Table 16. If any I two cells contained the same series of grouping assign- iments, it would infer concordance and they would be func- jtionally similar and from the same group. Six pairs of 92 TABLE 16 SUMMARY OF S EMIQUANTITATIVE SORTING Temporal Spatial Chromatic 1. ON,OFF-1 ON M' OFF-1 M ON BGY OFF-1 BY 2. ON,OFF-2 SM S BY BGY 3. ON S SM BGY BGY 4. OFF-1 L ML - BG 5. ON L SML B B 6 . OFF-1 L ML - BY 7. OFF-1 SM SM - BGY 8 . OFF-1,OFF-2 - L - GY 9. ON S - Y - 10. OFF-1,OFF-2 - L - GY 11. OFF-1,OFF-2 - S - G 12. OFF-1 SM L B G 13. ON,OFF-1 SML SML BGY BGY 14. ON,OFF-1 L SML G G 15. ON,OFF-1 SM SM BG GY 16. ON L - BG - 17. OFF-1,OFF-2 - SM - BGY 18. ON,OFF-1,OFF-2 M L B B 19. ON,OFF-1 M L BG G 20. ON,OFF-1,OFF-2 M L BG G 21. ON M S Y GY 22. ON,OFF-1 L s BGY BY 23. ON ML - BGY - 24. OFF-1 - ML - BGY 25. ON SM - BGY - 2 6 . ON,OFF-1 SM S G G 27. OFF-1 SML SM BY BY 28. ON,OFF-1 SML S BGY B 29. ON,OFF-2 SML - BGY - 30. ON ML - BGY - 31. ON,OFF-1 SM SML GY BGY 32. ON S - Y - 3 3. ON,OFF-1 M* M B BG 34. OFF-1,OFF-2 - L - G 35. OFF-1,OFF-2 - S - B 3 6. ON,OFF-1 SM SL GY BGY 37 . ON SM - BGY - 38 . ON,OFF-2 S S GY GY 39. ON SM - Y - 40. ON S SM Y BY 41. OFF-1 - SML - BG 42. OFF-1,OFF-2 - L 1 BG 93 TABLE 16 (SUMMARY- OF SEMIQUANTITATIVE ^ 50RTIN §), Continued Temporal Spatial ON OFF-1 Chromatic ON OFF-1 43. ON,OFF-1 M ML BGY BY 44. ON,OFF-1,OFF-2 SML L BGY BGY 45. OFF-1,OFF-2 - L - G 46. ON S - BY - 47. OFF-1 - SM - G 48. ON,OFF-1 ML M BGY GY 49. ON,OFF-1 ML M BGY GY 50. ON,OFF-1,OFF-2 ML SM GY Y 51. OFF-1,OFF-2 - S - BY 52. ON,OFF-1 SM M GY Y 53 . OFF-1,OFF-2 - S - BY 54. ON,OFF-1 L L B BG 5 5 . ON,OFF-1 S SM GY GY 5 6. ON,OFF-1,OFF-2 S S BGY Y 57. OFF-1 - L - BGY 58 . ON,OFF-1,OFF-2 L ML BGY BGY 59. OFF-1,OFF-1 - SM - B 60. ON,OFF-1 M M BG B 61. ON,OFF-1,OFF-2 SM SL BG BGY 6 2 . OFF-1,OFF-2 - ML - BG 63. ON,OFF-1 SM M Y BG 64. ON,OFF-1 SM S Y Y 6 5 . ON,OFF-1 ML SM BGY BG 66 . ON,OFF-2 L SML GY BGY 67. ON,OFF-2 L - BGY - 68. ON,OFF-1 SM SML Y GY 94 Cells were found which exactly matched but no two pairs were exactly alike (cell numbers 9-32, 8-10, 23-30, 25-37, 34-45 and 53-51). This essential lack of concordance sug gests that the ganglion cells are greatly diversified, even though they can be satisfactorily sorted on the basis of j I j any one of the studied characteristics, i.e., temporal, j spatial or chromatic. G. Quantitative Multiparametric Groupings of the Total Population As stated above, none of the semiquantitative sorting procedures resulted in distinctive groups which could fully! account for the three main attributes studied. Factor analysis, as discussed in the Experimental Design section, * is a multiparametrie method of sorting a population into i groups, called factors. The basis of the sorting is the j Pearson correlation coefficient which quantitatively re lates similar individuals. The input for the factor | I analysis was the class interval data for the 68 individual j ganglion cells for nine conditions (three spots and three j colors). Unlike the data used for the semiquantitative sorting, which was based on number of spikes, the class interval data inherently contains information about the | number of spikes, and in addition contains information about the density of spikes and latency of the response. In addition to grouping similar cells, factor analysis 9 5 indicates those cells which are not similar and these cells are discarded. | The factor analysis procedure identified nine groups j which contained three or more cells. Seven cells were discarded. The average number of spikes, density of spikes and mean latencies for these nine groups are presented in Appendix Tables A1 to A2 7. Table 17 contains the profile data for spot size responsiveness of the nine factor groups. The Y-intercept, slope and correlation coefficients as well as the predicted values for the three spot sizes are given. Examination of this parametric data reveals that the factor analysis sorted the population of cells to some extent for temporal and spatial properties. Note that from the aver aged data, the groups were strongly responsive to one of ^ the spots and that the number of spikes in the temporal I response periods also varied considerably. The sort for I chromatic responsiveness was less strong but Group 6 showed' a strong responsiveness to blue. Examination of the Appen-! dix Tables A1 to A27 shows that many of the factor groups ; 1 had different values for density of spikes and mean latency,■ suggesting that these parameters were also taken into ' account by the sorting procedure. * Table 18 lists the cells for each factor group and their temporal, spatial and chromatic attributes which were previously assigned to them by the semiquantitative sorting I (see Table 16). It can be seen from Table 18 that all 96 TABLE 17 REGRESSION STATISTICS FOR FACTOR GROUPS ! 1 Y r PREDICTED VALUES Parameter § inter- (^correia. Time Period cept Slope coeffic.) Small Medium Large FAGTOR GROUP #1 N ON 2. 74 .16 .13 2.85 2.94 3.14 i N OFF-1 4.14 - .70 - . 88 3.64 3.21 2.32 1 N OFF-2 .15 .10 .42 .22 .28 .41 1 Density ON 105 39 .73 132 155 205 1 Density OFF-1 32 64 .97 77 116 196 1 Density OFF-2 .45 .16 . 21 .57 . 66 .87 1 Mean Time ON 113 -9 - .69 106 101 8 9 1 Mean Time OFF -1 151 -25 -.85 133 118 85 Mean Time OFF-2 709 86 .69 770 822 933 , FACTOR GROUP #2 1 N ON -.04 1.29 .80 . 86 1.64 3.2 9 1N OFF-1 .27 . 21 .69 .42 .54 .81 N OFF-2 .40 .02 .19 . 41 .43 .46 Density ON . 73 4 . 95 4 7 13 ! Density OFF-1 83 -30 - .79 62 44 6 Density OFF-2 1 . 00 1.00 1 1 1 ; Mean Time ON 250 22 . 34 265 278 306 Mean Time OFF -1 151 -16 - . 21 140 130 109 1 Mean Time OFF - 2 -32 - . 34 - .34 985 966 926 i FAGTOR GROUP #3 1 j N ON 5.20 -1 .41 -.89 4. 21 3.36 1.56 : N OFF-1 2.51 - .61 -.73 2.08 1.72 .94 N OFF-2 .30 .07 . 35 .35 .38 .47 Density ON 40 19 .62 53 65 88 Density OFF-1 18 8 . 3 5 24 28 38 Density OFF - 2 .49 .19 . 36 . 6 . 7 1.0 1 Mean Time ON 167 -36 -.89 142 121 75 I Mean Time OFF -1 178 -16 - . 30 166 156 135 iMean Time OFF - 2 696 73 .60 747 790 883 97 TABLE 17 [REGRESSION STATISTICS TOR FACTOR GROURS)^ Continued ' 1 1 1 1 Y- T Parameter § Inter (correla. PREDICTED VALUES Time Period cept Slope coefTic.) Small Medium Large FACTOR GROUP #4 1 N ON 4.43 -1 .22 - . 92 3. 57 2.84 1 1.2 9 I N OFF-1 .86 - .18 - .54 .73 .62 .38 i N OFF-2 . 87 - . 04 - .13 .84 .82 .77 Density ON 31 -1.81 -.33 29 28 26 Density OFF-1 13 -4.4 - . 71 10 7 1 Density OFF-2 3 - .15 - .13 3 3 3 Mean Time ON 185 -25.61 - . 79 167 153 121 Mean Time OFF-1 213 12.57 .37 222 230 246 Mean Time OFF-2 727 87.12 . 74 788 840 952 1 FACTOR GROUP #5 i N ON 3.58 -1 .14 - . 77 2 . 78 2.09 .63 N OFF-1 1.08 - . 24 -.56 .91 .77 .46 N OFF-2 .44 - . 06 - .44 .39 . 36 .28 Density ON -5 +14.86 . 53 6 14 34 ; Density OFF-1 . 28 3.39 .43 3 5 9 Density OFF - 2 3.04 -9. 90 -.50 2 2 1 ; Mean Time ON 367 -96.75 -1 .00 299 241 118 ■ Mean Time OFF-1 206 89.47 . 90 268 322 437 1 Mean Time OFF-2 645 104.18 .64 718 780 914 FACTOR GROUP #6 1 N ON 1.30 2.25 . 79 2.88 4.23 7.12 N OFF-1 - .14 . 70 .61 .35 . 76 1.66 N OFF-2 .05 . 27 .80 . 23 .39 . 74 Density ON -6 20.22 . 94 8 20 46 Density OFF-1 1.2 2.41 .45 3 4 7 Density OFF-2 .12 . 72 .55 1 1 2 Mean Time ON 317 -56 - .79 278 244 173 Mean Time OFF-1 189 -23 - .40 173 159 130 Mean Time OFF - 2 902 4.57 .04 905 908 914 1 98 TABLE 17 (REGRESSION STATISTICS EOR FACTOR GROUPS), Continued 1 1 Parameter ^ Y- Inter r (correla. PREDIGTED VALUES Time Period cept Slope coeffic.) Small Medium Large FACTOR GROUP #7 1 N ON .94 -.09 -.23 . 88 .83 .72 N OFF-1 -.55 3.92 .96 2.2 4.5 9.6 N OFF-2 - .36 1.90 .97 1.0 2.1 4.6 Density ON - . 6 6.43 .67 4 8 16 1 Density OFF-1 4 12.60 .91 13 20 37 ! Density OFF - 2 .13 3.48 .87 3 5 9 I Mean Time ON 332 -65.33 -.75 286 247 163 1 Mean Time OFF-1 295 -5.35 -.22 291 288 281 ! Mean Time OFF - 2 848 -28.28 -.82 828 811 775 ; FAGTOR GROUP #8 1 N ON . 73 -.17 -.52 .61 .51 .28 , N OFF-1 6.60 -.56 -.41 6.21 5.87 5.16 1 N OFF-2 -1.29 2.01 .94 .11 1.32 3.89 , Density ON .67 5.38 .35 4 8 15 i Density OFF -1 58 -7.57 -.46 53 48 38 1 Density OFF - 2 -3 4.74 .71 1 3 9 ! Mean Time ON 432 -69 -.76 384 342 254 1 Mean Time OFF -1 190 14 . 56 200 208 22 6 i Mean Time OFF-2 700 58 .49 741 775 849 i FAGTOR GROUP #9 1 N ON . 08 .09 .60 .14 . 20 .32 N OFF-1 6. 98 -.78 -.59 6.44 5.98 4.98 , N OFF-2 3.05 .41 .39 3.34 3. 59 4.11 Density ON - .13 1.87 .63 1 2 5 Density OFF-1 10 11.38 .41 18 25 40 Density OFF - 2 5 1.51 .75 6 7 9 I Mean Time ON 241 23 .37 257 271 301 iMean Time OFF -1 325 -29.19 -.56 305 287 250 Mean Time OFF-2 760 25.86 .63 778 793 826 99 TABLE 18 FACTOR ANALYSIS CONCORDANCE Color Color Spatial Spatial Cell # Temporal ON OFF ON OFF Factor Group 1 1 ON,OFF-1 BYG BY M M 14 ON,OFF-1 G G L SML 15 ON,OFF-1 BG GY SM SM 19 ON,OFF-1 GY G SM S 22 ON,OFF-1 BGY BY L S 28 ON,OFF-1 BGY B SML S 33 ON,OFF-1 B BG M M 36 ON,OFF-1 GY BGY SM SL 41 OFF-1 - BG - SML 43 ON,OFF-1 BGY BGY M ML 49 ON,OFF-1 BGY GY ML M 63 ON,OFF-1 Y BG SM M 65 ON,OFF-1 BGY BG ML SM Factor Group 2 6 OFF-1 - BY L ML 30 ON BGY - L - 66 ON,OFF-2 GY BGY L SML Factor Group 3 3 ON BGY BGY S SM 26 ON,OFF-1 G G SM S 52 ON,OFF-1 GY Y SM M 55 ON,OFF-1 GY GY S SM 56 ON,OFF-2 BGY Y S S 68 ON,OFF-1 Y GY SM SML Factor Group 4 2 ON,OFF-2 B BGY SM S 9 ON Y - S - 21 ON Y GY M S 25 ON BGY - SM - 37 ON BGY - SM - 39 ON Y - SM - 46 ON BY - S - 61 ON,OFF-2 BG BGY SM SL 64 ON,OFF-1 Y Y SM S 100 TABLE 18 (FACTOR ANALYSIS CONCORDANCE), Continued Color Color Spatial Spatial Cell # Temporal ON OFF ON OFF Factor Group 5 31 ON, OFF-1 GY BGY SM SML 32 ON Y - S - 45 ON,OFF-1 Y Y S SM Factor Group 5 5 ON B B L SML 16 ON BG - L 54 ON,OFF-1 B BG L L 67 ON,OFF-2 BGY - L Factor Group 7 4 OFF -1 - BG L ML 8 OFF-1,OFF-2 - GY - L 10 OFF-1,OFF-2- - GY 1 L 12 OFF-1 B G SM L 18 ON,OFF-12 B B M L 20 ON,OFF-12 BG G M L 34 OFF-1,OFF-2 - G - L 42 OFF-1,OFF-2 - BG - L 45 OFF-1,OFF-2 - G - L 5 7 OFF -1 - BGY - L Factor Group 8 7 OFF-1 - BGY SM SM 11 OFF-1,OFF-2 - G - S 24 OFF-1 - BGY - ML 27 OFF-1 BY BY SML SM 35 OFF-1,OFF-2 - B - S 47 OFF-1 - G - SM 60 ON,OFF-1 BG B M M Factor Group 9 17 OFF-1,OFF-2 - BGY - SM 5 0 ON,OFF-12 GY Y ML SM 51 OFF-1,OFF-2 - BY - S 53 OFF-1,OFF-2 - BY - S 5 9 OFF-1,OFF-2 - B - SM 62 OFF -1,OFF- 2 - BG - ML 101 TABLE 18 (FACTOR ANALYSIS CONCORDANCE), Continued Color Color Spatial Spatial îll # Temporal ON OFF ON OFF Unsorted (Not Grouped) 13 ON,OFF-1 BGY BGY SML SML 29 ON,OFF-2 BGY - SML - 38 ON,OFF-2 GY GY S S 40 ON Y BY S SM 44 ON,OFF-12 BGY BGY SML L 48 ON,OFF-1 Y Y S SM 58 ON,OFF-12 BGY BGY L ML 102 groups contained mixed responses to these temporal, spatial,' and chromatic attributes. Even so, some attributes were , I strongly represented in some groups. The groups generated | by factor analysis were at least partially successful in sorting the population in that they took into account the j several attributes studied. ; H. Quantified Response of Ganglion Cells Sorted for Temporal Properties j i As discussed earlier, frog ganglion cells are com- j i monly described as belonging to distinctive classes or | I groups (see Review of Literature). The classification I I schemes proposed by Hartline (1938) and by Maturana et al. i (1960) are pre-eminent. However, the utility of these I classification systems is seriously limited by the quali- ! tative and non-specific nature of the criteria used to ' group the ganglion cells. These classifications are still , in wide use today. They have never been parametrically | 1 quantified in terms of their number of spikes, density of spikes and latencies. Therefore, the total population of , I I , 68 ganglion cells was subdivided into groups which closely : relate to both of these traditional classification schemes. , The specific criteria of classification were presented ; earlier in this section and their quantified responses are i j presented here. Note that this sorting procedure, unlike ' that used by Hartline (1938), divided the OFF period 103 I into an early OFF -1 and a late OFF - 2 period. These two OFF periods seemed to have distinct characteristics. There were theoretically seven possible categories of cells. However, the OFF-2 only type was never observed. There fore, this classification yielded six groups. The profile graphs of these temporal groups are shown in Figures 18, 19 and 20, and Table 18 shows the regression ! data for these graphs. In these graphs, the solid lines | I represent the regression lines for the temporal groups and j the broken lines represent the corresponding values for the total population. These graphs were constructed from data presented in Appendix Tables A2 8 .to A4 5. Although it would violate statistical independence to make probability statements about these grouped data, some differences are noteworthy. Four of the six groups had an ON response. When these four groups were compared, ; the number of spikes in the ON response was highest in { those groups where an OFF -1 response was also present. i The density of spikes was remarkably increased in the ON i response of the ON, OFF -1 group, indicating the transient nature of this response. In general, the ON response | I latency became shorter as the spot size increased. | There were four groups with an OFF-1 response. When ! these four groups were compared, the number of spikes in : the OFF-1 response was highest when an OFF - 2 response was | I I 104 Figure 18 This figure contrasts the profile graphs for the ON and ON, OFF-1 temporal groups (solid lines) with the total population of 68 cells (dotted lines). The graphs are constructed as in Figure 12, and the regression statistics I are found in Table 19 . 105 AREA OF S T IM U L U S L O G . A R E A OF S T IM U L U S JDFF-I OF S T IM U L U S N OF SPIKES LOG, A REA S T IM U L U S j 106 Figure 19 This figure contrasts the profile graphs for the ON, OFF-2 and ON, OFF-1, OFF - 2 temporal groups (solid lines) j with the total population of 68 cells (dotted lines). The I I graphs are constructed as in Figure 12, and the regression ^ statistics are found in Table 19. 107 ! DENSITY 4 0 - S T IM U L U S d e n s it y OF SPIK ES S T IM U L U S 2.5 LOG, A R E A OF S T IM U L U S I DENSITY i OF S T IM U L U S D ENSITY AREA OF STIM ULUS 108 n Figure 20 This figure contrasts the profile graphs for the OFF-1 and OFF-1, OFF - 2 temporal groups (solid lines) with the total population of 68 cells (dotted lines). The graphs are constructed as in Figure 12, and the regression statistics are found in Table 19. 1. 09J STIMULUS ON O F F -I O F F -2 CELLS STIM U LU MEAN 7 0 0 - S T IM U L U S ON O F F -2 C ELLS LOG. AREA OF STIM ULUS O F F -I O F F -2 C ELLS 1 110 1 TABLE 19 REGRESSION STATISTICS FOR THE SIX TEMPORALLY SORTED GROUPS I Parameter § , Time Period Y-intercept Slope (correlation coefficient) N ON ON GROUP 2 . 58 - .22 - .54 N OFF-1 .39 - .10 - .49 N OFF-2 .40 - . 08 -.23 Density ON 21 11 . 5 5 Density OFF -1 7 -2 -.74 Density OFF-2 0 .3 .37 Mean Time ON 222 -35 -.84 Mean Time OFF -1 153 28 .48 Mean Time OFF - 2 657 80 .39 N ON ON,OFF-1 GROUP 3.84 - .33 - .53 N OFF-1 3.47 - . 50 - .79 N OFF-2 .1 . 2 .89 Density ON 73 24 . 66 Density OFF -1 26 36 . 96 Density OFF - 2 .5 . 6 .54 Mean Time ON 178 -22 - .83 Mean Time OFF -1 175 -14 - . 63 Mean Time OFF-2 747 53 .85 N ON ON,OFF-2 GROUP 1 .39 .15 .29 N OFF-1 . 93 - . 27 -.65 N OFF-2 2.87 -.43 - .44 Density ON 8 5 .52 Density OFF -1 15 -5 - .40 Density OFF-2 9 -1 - .58 Mean Time ON 276 - 46 - .74 Mean Time OFF -1 299 -38 - .43 Mean Time OFF-2 800 73 .82 111 TABLE 19 (REGRESSION STATISTICS FOR THE SIX TEMPORALLY SORTED GROUPS), Continued Parameter § (correlation Time Period Y-intercept Slope coefficient) 1 ON,OFF-l,0FF-2 GROUP N ON 3. 71 -.22 - .41 N OFF-1 3.12 .80 . 90 N OFF-2 1. 63 .89 . 92 Density ON 21 7 .87 Density OFF-1 8 7 .75 Density OFF- 2 3 1 .77 Mean Time ON 265 -24 -.83 Mean Time OFF-1 270 -12 - .44 Mean Time OFF - 2 770 40 .82 OFF-1 GROUP N ON 0.21 . 06 .39 N OFF-1 2.27 . 96 . 88 N OFF-2 -.22 . 21 . 75 Density ON -5 8 .47 Density OFF-1 63 -9 - .55 Density OFF - 2 0 2 .51 Mean Time ON 433 -87 - .87 Mean Time OFF-1 200 12 . 61 Mean Time OFF-2 799 -7 - .09 OFF-1,OFF-2 GROUP N ON .15 - . 03 -.57 N OFF-1 4. 72 1.48 .80 N OFF-2 . 79 1.69 .94 Density ON 2 . 4 .14 Density OFF -1 13 12 .94 Density OFF- 2 2 4 .94 Mean Time ON 316 -72 -.72 Mean Time OFF-1 288 -16 -.55 Mean Time OFF-2 790 10 .24 112 present. Conversely, when the OFF-2 was absent, the den sity of spikes of the OFF-1 response was higher and the latency was shorter. In general, the number of spikes of the OFF-1 response increased linearly as the stimulus spot size increased. However, in the ON,OFF-1 group the OFF-1 response was medium spot sensitive. There were three groups with an OFF-2 response. The number of spikes in the OFF-2 response was highest in the OFF-1,OFF-2 group where there was considerable large spot sensitivity. The density of spikes in the OFF-2 response was uniformly and characteristically low. None of these six groups showed any color differences on average. Examination of the individual cells within each group revealed that the groups were mixed populations of chromatic and non-chromatic cells. In summary, this sorting procedure of the temporal responses of the ganglion cells resulted in groups, some of which showed large quantitative differences on average. As in the total population, some spatial responsiveness was observed, but no color responsiveness was seen. Indi vidual cells in each of the six groups were mixed popula tions in their responsiveness to spatial and chromatic stimuli. 113 V. DISCUSSION All of the data presented in these experiments were collected from in. vivo preparations. In all cases, the blood flow in the retina was vigorous. With one exception (Morrison, 1975), all of the data reported in the litera- i ture of direct retinal recordings of ganglion cells in the frog have been made from excised eyecup preparations (an ' in vitro method). In any event, there have been few re- , i ports in the literature of a large bank of quantified data i I which represents an average response of ganglion cells to | light stimulation. Descriptive statistics of 68 ganglion | cells’ responses to nine stimulus conditions and 36 ' ganglion cells’ responses to 21 stimulus conditions were I reported in the Results section. These values were pre- I I sented as means plus or minus their standard error. The I variability of their responses is reflected in the range of response values which is also mentioned in the Results sec tion. These data are needed in the literature to compare with data collected from dui vitro preparations and to com- I pare with samples of smaller size. ! I The responses of a single ganglion cell to nine or | 21 stimulus conditions constitute the signature of the cell, in effect its profile. These profile responses were expressed as three statistical parameters, sufficient to 114 describe the ganglion cell’s response (humber of spikes, I density of spikes and mean latency). These parameters are | essential in describing any spike train; one parameter without the other is inadequate. In other words, a profilej of a ganglion cell constitutes its responses to a number ofj j stimulus conditions as measured by sufficient statistical ; I parameters to describe the resulting response. It is common to find fragmentary reports in this respect in the literature. Collecting and comparing this type of complete ganglion cell profiles for sufficiently large samples of ganglion cells will result in a more realistic and accurate assessment of ganglion cell classes and functions. It would appear from the results presented that the I I ganglion cells of the frog retina are a functionally heter ogenous population. This heterogeneity can be interpreted in several ways. One extreme interpretation would be that ! the population is maximally heterogenous and the functional' responses of the ganglion cells would form an inseparable ■ i continuum. At the other extreme, the population of cells could be minimally heterogenous and the ganglion cells' functional responses would form a limited number of classes. On the other hand, there may be a large number of discrete | ! classes. This finding is in contrast to those of Binggeli (personal communication) and Guthrie (1976) who have ob served that the ganglion cell populations of the pigeon and rabbit are functionally homogenous. 115 For any functional classification of ganglion cells to be adequate, account should be taken of the main visual ! attributes which the retina monitors, i.e., contrast, chro maticity, movement, etc. Additionally, as Gordon and Hood j I (1976) point out, the classes of ganglion cells must be I quantitatively demonstrably different. Existing classifi- I cation schemes do not fulfill these criteria. i Hartline (1938) was the first to record individual j ganglion cell spiking patterns. Although this paper | explicitly reported the results of few (10) cells, a qual- ' ; i itative classification system was suggested based on the ' temporal responses of these ganglion cells, i.e., ON, OFF, and ON-OFF response classes. This pioneering class ifica- ; tion has proved to be useful and consistent. The 68 cells studied here occurred in the same frequencies reported by I Hartline, 20% ON cells, 30% OFF cells and 50% ON-OFF cells,' ! There has been no critical statistical quantification of : these Hartline classes until now. The experiments reported, here indicate that there are indeed differences in the re- | sponses of these ON-OFF classes of ganglion cells. How- | I ever, none of the groups show any significant differences j in response patterns to color stimuli. Other sorting pro - | cedures indicate that these classes are also mixed popula- ; tions in their responses to spot sizes. Therefore, while \ quantitation of the Hartline classes indicates significant ' temporal differences, the classification scheme breaks ' 116 down when chromatic and spatial responsiveness is con sidered. Barlow (1953), reporting on few cells, stated that ganglion cell receptive field properties could be cor related with the Hartline groups, suggesting that there was' some correlation of the spatial and temporal attributes. i Another classification scheme commonly used today is | that proposed by Lettvin et al. (1959). This scheme orig inally hypothesized five classes of ganglion cells. How ever, a sixth class was added by Muntz (1962) . Essentially, they hypothesized that a field of receptors, complexly I hooked up to a ganglion cell, formed an operational unit I : I which detects specific visual features such as movement and Î : I edges, as well as temporal properties. Some of the I Lettvin-Maturana classes were reported to be equivalent to the Hartline classes. Class 3 was said to be the ON-OFF cells. Class 4 was the OFF cells and Classes 1 and 6 were the small and large field ON cells, respectively. Only . Class 2 and the rarely occurring Class 5 cells were new. i I If Classes 1, 3, 4 and 6 indeed correspond to Hartline's groups as reported (Lettvin et al., 1959; Crüsser et al., i 1976), then as stated above, results presented here indi- ; cate that these classes must be mixed populations of , ganglion cells with respect to their responsiveness to j i spatial and chromatic stimuli. Unfortunately, Classes 2 i and 5 could not be sorted from the data presented here. 1 i ' ' As discussed in the Review of Literature section, several j 117 mechanistically oriented studies have raised some questions! i about the exhaustiveness and exclusivity of the six ! Lettvin-Maturana classes (Grusser et al., 1976; Brackstrom and Reuter, 1975; Keating and Gaze, 1970; Gordon and Hood, I 1976). However, taken as a whole, these reports have not been critical of this classification approach and have in fact utilized this system in their studies of frog vision. ! ! Cajal (1972) was the first to indicate that ganglion i I cells exhibit a wide range of morphological types based on j their shape, size and dendritic arborization. Various estimates of the number of types have been made since that time. Dowling and West (1972) described 15 ganglion cell I types in the ground squirrel while Griisser and Grüsser- j Cornehls (1976) described 11 types in the frog. The re - t ported small number (six) of functional classes of ganglion cells does not correlate with the larger number of morpho- j logical types reported. The results indicate that classi- I fication schemes, such as the Hartline ON-OFF classes, i which are based on only one attribute such as the temporal ; response, can arbitrarily divide a population into sub - i groups but that they are not adequate if they are based on ' i more than one attribute. The conclusion presented here, that existing classification systems only partially account for each of the main visual attributes, would suggest that there are either many more functional classes of ganglion 118 cells or that ganglion cells are not logically classifiable’ i when multiple attributes are considered. If there were ' I I more functional groups there would be a better correlation | with the larger number of morphological groups. | I The results of the multivariate factor analysis pro duced nine groups of ganglion cells with seven cells dis carded. On average, the nine groups showed considerable differences in the parameters studied (Number of spikes, density of spikes and mean latency). However, examination of the individual cells revealed that none of the groups were entirely pure populations for three attributes, tem- | I poral, spatial and chromatic, even though there was strong j I concordance for two of the attributes in several groups. j Although only partially successful as a classifying method,, the results of the factor analysis were in some ways more satisfactory than the other classification schemes previ- ! ously discussed. The average values of the nine factor j groups showed strong chromatic and spatial, as well as | I temporal concordance. The observation that the factor analysis formed groups with strong concordance would sug gest the likelihood of the existence of functional cell classes. Furthermore, the number of such classes would be greater than nine. To study such a large number of classes effectively, an appropriately large sample of ganglion cell responses would be required. 119 VI. SUMMARY I I 1. A quantified statistical description of the responses j of 68 frog retinal ganglion cells to temporal, spatial and chromatic stimuli was presented. In all cases, the resul tant spike trains were described in terms of their number of spikes, density of spikes and mean latency for three standardized periods of time. 2. It was concluded that the total population of 68 ganglion cells was heterogenous in its responses to tem poral, spatial and chromatic stimuli. 3. Classification schemes which are based on only one attribute such as the temporal response can arbitrarily divide a population of cells into subgroups, but are not adequate if they are based on more than one attribute. This conclusion would suggest that there are either many more functional classes or that ganglion cells are not logically classifiable when multiple attributes are cons idered. 4. A multiparametric factor analysis was partially j successful in sorting ganglion cells into groups, correlat-j I ing more than one attribute. Nine groups were formed, j suggesting that the number of classes is probably more thaJ I nine, and would, therefore, require a much larger sample of ( cells for an effective study. i 12 0 LITERATURE CITED Brackstrom, A.-C., and Reuter, T. 1975. Receptive field i I organization of ganglion cells in the frog retina: contributions from cones, green rods and red rods. J. Physiol. (Lond.), 246: 79-107. Barlow, H. B. 1953a. Action potentials from the frog’s retina. J. Physiol. (Lond.), 119 : 58-68. Barlow, H. B. 1953b. Summation and inhibition in the frog's retina. J. Physiol. (Lond.), 119: 69-88. Binggeli, R. L. 1975. Personal communication. Biomedical Computer Programs. 1975. Edited by W. J. Dixon. University of California Press, Berkeley, California. Birukow, C. 1939. Pukinjesches Phanbmen und Farbensehen beim Crasfrosh (Rana temporaria). Z. Vergl. Physiol., 27: 41-79. Cajal, Santiago Ramon y. 1972. Translated by Silvia A. Thorpe and Mitchell Clickstein. The Structure of the Retina. Charles C. Thomas, Springfield, Illinois. Chung, S.-H., S. A. Raymond and J. Y. Lettvin. 1970. Multiple meaning in single visual units. Brain Behav. Evol., 3: 72-101. 121 Finlcelstein, D., and 0. J. Griisser. 1965. Frog retina: detection of movement. Science, 150: 1050-1051. Gaze, R. M. 1958. The representation of the retina on the optic lobe of the frog. Quart. J. Exp. Physiol., 43: 209-214. i Gaze, R. M., and M. Jacobson. 1963. Convexity detectors I in the frog's visual system. Proc. Physiol. Soc., 169:1-3. j Gordon, J., and D. C. Hood. 1976. Anatomy and physiology ! I of the frog retina. In: The Amphibian Visual System,! I K. V. Fite, Ed., Academic Press, New York, pp. 29-86. I Granit, R. 1942. Color receptors of the frog's retina. Acta physiol. Scand., 3: 137-151. | Granit, R. 1947. Sensory mechanisms of the retina. Oxford University Press, London. Grüsser, 0. J., and H. Dannenberg. 1965. Eine und Perimeter-Apparatus zur Reitung mit bewogten visuellen Mustern. Pflugers Arch. ges. Physiol., 285: 373-378. Crüsser, 0. J., D. Finkelstein and U. Crüsser-Cornehls. I 1968. The effect of stimulus velocity on the response; of movement sensitive neurons of the frog's retina. | Pflüger's Arch. ges. Physiol., 300: 49-66. Crüsser, 0. J., U. Crüsser-Cornehls and T. H. Bullock. 1964, Functional organization of receptive fields of move ment detecting neurons in the frog's retina. Pflügers Arch. ges. Physiol., 279: 88-93. 122 Grüsser, 0. J., U. Grüsser-Cornehls, D. Finkelstein, V. Henn, M. Patutschnik and E. Butenandt. 1967. A quantitative analysis of movement detecting neurons in the frog’s retina. Pflügers Arch. ges. Physiol., 293: 100-106. Crüsser, 0. J., and U. Crüsser-Cornehls. 1968. Neurophysi- ologische Crundlagen visueller angeborener Auslosmech-| I anismen bein Frosch. Z. vergl. Physiol., 59: 1-24. 1 I Crüsser, 0. J., and U. Crüsser-Cornehls. 1973. Neuronal i J mechanisms of visual movement perception and some ps- ' chophysical and behavioral correlations. In: Handbook of Sensory Physiology, R. Jung, Ed., Vol. VII/3A, Springer-Verlag, Berlin and New York, pp. 333-429. Crüsser, 0. J., and U. Crüsser-Cornehls. 1976. Neurophys iology of the anuran visual system. In: The Frog in Neurobiology, R. Elinas and W. Precht, Eds., j Springer-Verlag, Berlin and New York, pp. 297-385. | Crüsser-Cornehls, U., 0. J. Crüsser and T. H. Bullock. I 1963. Unit responses in the frog's tectum to moving ] and non-moving visual stimuli. Science, 141: 820-822. Guthrie, M. D. 1976. A qualitative and quantitative study of the retinal ganglion cell of the rabbit (Qryctolagus cuniculus). Doctoral Dissertation, University of Southern California. 123 Harman, Harry H. 1965. Modern Factor Analysis, University of Chicago Press, Chicago. Hartline, H. K. 1938. The response of single optic nerve fibers of the vertebrate eye to illumination of the retina. Amer. J. Physiol., 121: 400-415. Hartline, H. K. 1940a. The receptive fields of the optic I nerve fibers. Amer. J. Physiol., 130: 690-699. ; I Hartline, H. K. 1940b. The effects of spatial summation | in the retina on the excitation of the fibers of the optic nerve. Amer. J. Physiol., 130: 700-711 . I I Keating, M. J., and R. M. Gaze. 1970. Observations on the | 'surround' properties of the receptive fields of frog ! I retinal ganglion cells. Quart. J. Exp. Physiol., I 55: 143-152. Lettvin, J. Y., H. R. Maturana, W. S. McCulloch and W. H. Pitts. 1959. What the frog's eye tells the frog's brain. Proc. I.R.E., 47: 1940-1951. Lettvin, J. Y., H. R. Maturana, W. S. McCulloch and I W. H. Pitts. 1961. Two remarks on the visual system ! of the frog. In: Sensory Communication, W. A. j Rosenblith, Ed., M.I.T. Press, Cambridge, Massachusetts pp. 757-776. i Liebman, P. A., and G. Entine. 1968. Visual pigments of ' frog and tadpole (Rana pipiens). Vision Res., 8: 761-775. 124 Maturana, H. R. 1959. Number of fibers in the optic nerve and the number of ganglion cells in the retina of anurans. Nature (Lond.), 183: 1406-1407. Maturana, H. R., J. Y. Lettvin, W. S. McCulloch and W. H. Pitts. 1960. Anatomy and physiology of vision in the frog (R_^ pipiens) . J. Gen. Physiol., 43: 129-175. Morrison, J. D. 1975. The responses of the retinal ganglion cells of the frog. Vision Rés., 15: 1339-1344. Muntz, W. R. A. 1962a. Microelectrode recordings from the diencephalon of the frog (R. pipiens) and a blue - sensitive system. J. Neurophysiol., 25: 699-711. Muntz, W. R. A. 1962b. Effectiveness of different colors of light in releasing the positive photostatic behavior of frogs, and a possible function of the retinal projection to the diencephalon. J. Neurophysiol., 25: 712-720. Nace, G. W., D.D. Gulley, M. B. Emmons, E. L. Gibbs, V. H. Hutchison and R. G. McKonnell. 1974. Amphibians: Guidelines for the Breeding, Care, and Management of Laboratory Animals. Nat. Acad. Sci., Washington, D.C. 125 Nilsson, S. E. G. 1964. An electron microscopic classifi cation of the retinal receptors of the leopard frog (Rana pipiens). J. Ultrastruc. Res., 10: 390-416. Nilsson, S. E. G. 1964. Interreceptor contacts in the retina of the frog (Rana pipiens). J. Ultrastruc. Res., 11: 147-165. Reuter, T. 1964. Visual pigments and ganglion cell activ ity in the retinae of tadpoles and adult frogs (Rana temporaria). Acta zool. Fenn., 122: 1-64. Reuter, T., and K. Virtanen. 1972. Border and color coding in the retina of the frog. Nature (Lond.), 239: 260-263. Sherrington, C. S. 1906. The integrative action of the nervous system. Silliman Memorial Lectures, Yale University Press, New Haven, Connecticut. Statistical Package for the Social Sciences. 1976. Edited by N. H. Nie, University of Chicago Press, Chicago. West, R. W., and J. E. Dowling. 1972. Synapses onto different morphological types of retinal ganglion cells. Science, 178: 510-512. j Witpaard, J., and H. E. ter Keurs. 1975. Reclass if ication, of retinal ganglion cells in frog, based upon tectal I endings and response properties. Vision Res., 1^: j 1333-1338. I 126 127 Appendix Figures Al to A9 These figures present the frequency distributions of the values of the responses for the number of spikes, den sity of spikes and mean latency for the ON, OFF-1, and OFF-2 time periods. The abscissa indicates the range of values obtained, which varies from graph to graph. A constant value indicator is found on each abscissa to aid in graph-to-graph comparisons. The ordinate indicates the number of cells. The scale of the ordinate also varies from one graph to another. The value of each mark (H) is 1 unless indicated in the upper right region of the graph, j The distributions for light spots are from the total popu- j lation of 68 cells, while the annular distributions are from the 36 cell subset. 128 o 2.5° O 5° 2.t 2,^x5° 2 . 5 x 2 2 " ^x 2^ o 2.5’x 22° B l u e (432 nm) H H H HH H HH H HHHMH HHMHH HHHHH H HHMHH HH HHHHHHHHHHH 0“ H H H H HH HHH HHH H HHH H H HHHHHHHH H HHHHHHHHHHHH 1.5 H H “ 10 1.6 12 29 0 H H H H H H HH HHH HHHHH HHHHHH 5 19 H H H H H H H H H HHHH H HHHHHH HH HHHHHHHHHH H HH 0 H H H HH HH HHH H HHHHHHH HHHHHHH 1.3 Ô - H H ' h H H H , H HH H H HH CJ" H H H H H H H H H HH H H 0” 12 1.3 . H H HH HHH H HHHHH H 11 1.3 H H H HHHHH HHHHH H 13 G R E E N (502 nm) YE L L O W (5 7 2 n m ) 0 H H H H H H HH H M HH HHHH H HHHHHHH H H HHHHHHHH HHH H 1.9 H H H H HH HH HH HH HH HH HH HH HH HHHHH HH H HHHHHHHHHH 1.7 HHHHH HHHHHH HHHHHHHHH 13 " 1 1 HHH HHHHH MHHHHHHHH 0 10 H H H H H HH HH HH HH HH 1 . 1 H HH H HH HH HHHH HH HHHH 0 ■T H -8 1.3 HHH H H H HHHHHHHHHHH O' H H H H H H HH HH HH HH H H HH HHH H H MHHHHHHHH H H 8 H H H H H H HHH HHHH 1 . 6 H H H HHHHH HH H H H HH HHHHHHHHHHHHHHH 0 H "7 H H H H H H HHH H HHH H HHHH HHH HHHH HHH 1.4 H H HH HHHHHHHHH HHHHH p ; 0 M H H HH H HH H HH H HH H 1.8 HHH H H HHHHH H H HHHHHHHHHHHH H H H H HHH H H HHH H H HHHHHH H H H HHHHHHHHHH HH H O' H H HHHH HHHHHH y-G 1 . 1 HHHHHHHHHHHH H H H H H HH H H M M HH 1 . 2 0“ HH HHH HH H HHHHHHH H H H HH HH H HH H H H HHHHHHHHH H HHHHHHHHHHHH HH O" Appendix Figure A1 Number of Spikes in the ON period B l u e (432 nm) G R E E N ( 5 0 2 n m ) YE L L O W (5 7 2 n m ) I O 2,5° O 5° 2,^x^ © 2.^ X 5x22° © 2f e 2.5’ x22® H MH H HH HH H H HH 1.9 HH HH 1.6 H H H H 1.3 HH HHH H H H HHH HHH HHHH H HHH HHMHH HHHHH H HHH HH HHHHH H HHHHHHHH HHHHHH HHHHHHH HHHHHHHHH H H HHHHHHH HHH H H HHHHHHH HH H H H H HHHHHHHHHH H HH 0 ------1 ---------------------- "20 -------- 79 H ^ H ^ H H H H H HH ^ n HH 1.8 HH H HH 1.8 HH H HH H 1.7 HHH HH H HH H HHH HH H HH H HHHH HH H HHHH HHHH HHHHH HHHH HHHH H H HHHHH HHHH H HHHHHHHHHHH H H HHHHHH HHHHH H HHHHHH HHHHHH HH ---------------------------------------18 H ^ ----------1 9 " 7 --------------- H H H H H H _ H 2.3 H H H 1.8 H H 2.3 H M H M HHH H MH H HHH HHHH HHHH HHH HHHH HHHH HHH HHHH HHHHHH H HHH H HHHHH HH H H HHHHHHHHHHH H HH HHHHH H H H ^ H --------- 15 ° 5 H H H H H - H H HH 1 .1 HH H HH HHH HHH HHHH HHH HHH H HHHH HHH HHH H HHHH H HHH H HHH H HHHH H H HHHHHH HHHHH H HHHH HHHHH H HHHHHH H H H HHHHH HH HH H H O ’ ----------- Î ----------1 1 H ° H 5 15 0-7 - 7 - 1 1 H H HH H , _ HH H H 13 H 1.2 HH 1 .1 M M H H HH HH HH HH H HH HHH HHH H HH HHHH HHH H H HHH HHHHHH. HHHHH H HHH H HHHHHH H H HHH HHHHH H H H HHH HHHH M H O ’ ------g ------------- ’14 0 " " 5 16 722 H H H H H H M H H 1.3 H HH 1,1 H H 1.2 HH H HHH H H M H HHH HHHH HHH HHH HHHH HHH HHH HHHH H H HHHH H M H HHH HH HHHHHH H HH H HHHHHH H HHH HHHHHHHHH H H H ^ 14 0” ” g-------------’ 17 H H H H H H HH H 1.4 H 1.2 HHH H HH HHH H HHH HHH H HHH HHHH HHH HHHH HHHH - HHH HHHH HHHH H HHH H HHHHHH HH HH H HHHH H HHHH H HHHHHH HH H 0” ” g” ----------- -17 ---- ’ 20 Appendix Figure A2 Number of Spikes in the OFF-1 period 130 o 2.5" O 5 " © 2.d*x5x22' 0 I © 25^x22^ B l u e (432 nm) 3.1 HH H H H H HH HH H HHHHH H H H H H H H H H H HHHH HHHHHHH 3.0 HHH - i — 5 "Si5 ■ " B 3.3 H H H H H H H HHH HHHHHHH "T— 5 0 "15 1.7 H H H HHHHH HHHHHH 0" H H H H H H H H HH H HHHHH H HH H 1.5 H H H H H H H H H H H H HHHHHHH HHHH 1 .4 ■ " 8 H H H H H H H H H H HHH H HHHHH H H H 1 . 6 0 10 G R E E N (502 nm) Y E L L O W (572nm) 3.4 0 H H H H H H HH HH HHH H HHHHH ^r 1 3 H H H H H H H HH H H HH HHHHHH 3.0 G " '5 10 H 3.9 H H H H HH HHH H 0 16 2 . 1 H H H HHHHH H H 12 H H H H H HHH HHHHHHH G' H H H H H H H H H H H H H H HHHHH H H 1.8 H H H H -T-6 1. 6 2 . 1 HHHH H G"--- H H H H H HH H HHHH 3.1 HHHHHH HH F ~6 H H H H 3.2 H H H HHH HHHHH HHHHH H 0 -7---------------------- 5 1 1 H H H H 3.5. H H H H HHH HHHHH H HHH Is H H H 1.5 H H H H H H H H HH HHHHHH HHM HH H G* H H H H H H H H H H H H HHHHHH HH H ^ H H H H H H H M M H M H H HHHHHHHH H H 1 . 6 1 . 6 G H H H H H H H H HH H H H H H H H H H HHHH HHHH H H 1.3 G ' Appendix Figure A3 Number o£ Spikes in the OFF-2 period 131 o 2.5° O 5° 2,^x5° © 2 . ^ X 5X 22° ^x 2f 2.5’x22® B l u e (432 nm) H H H 2.6 H H H H H H HHH H HHH H HHH H ^ ïo 276 H H H H H H H H H HH H HM H M HHH HH 0 " 50 H H H H H H H H H H H H HH H HHH H HHHH 3 .1 316 1.9 o-Tæ" 1.3 H H H H H H H H HH M HH H HHHHH H HHHHHH H H H 0 I 50 H H H H H H K H HHH HHH HHH HHHHH '316 1 . 1 H HHHH 0 " '50 '2 5 3 GREEN (502 nm ) YE L L O W (5 7 2 n m ) H H HH H M H H HH H HH H HH H HHH H HHH H HHH H HHHHHHH 0— S' — 1.7 H HHHH H 270 H HH HH 1.8 H HH H HH M HH H HH H HHHHH H HHHHHHH HHHHH HH (Tiæ H H H M H HH H M H H HH " - 9 0 2 1.6 HH HHH HHHH HHHH H HHHHH HHHHHHH H ■344 CTlgo" '402 1.4 H H H H H H H HH H HH H HHH H HHHHH HH HH H ■416 H H H H H H H H H H H HH H H H HH H H H HH H H H HH H H H HHH H H H HHH H H M HH H Hhh HH H H H HHHHH 0 " 241 O ' H H H H h H H H 1.2 H H H HH H HH HH H HH H H H H HHH H H H H H HHHH H H H HH H H HHHHHHH H H HHHHH 0 “ " " 2 3 0 O ' Y Ô — 1.4 '253 1.2 HH H 316 H M H M H H H H M H H HH H HHHHH 0” H H H H 2 .2 H H H HH H HH H HH H HHH H HHHHH 3.1 r I 224 O 1373 H H H H HHH H HHHH H HHHHH '50 H H H H H H H H H H H H HHHHHHHH 2 . 1 HH H 1344 O'- t s o -------------"270 O"' H H H H M H H 1.4 H H H H H H H H H H H HH H HH H HH H HH H H HH H HHHHH H H H HH 1.7 H H 264 0-iBo 1,5 HHHH 253 H H H H H 1.3 H H H HH H M H H HH H HH H H HHHHHH HH 0 " W — 247 H H H H H H H H HH H HHH H HHH H H H HHHH H H 1.3 387 Appendix Figure A4 Density of Spikes in the ON period 132 o 2.5° G 2^ # 2.d'x5° © 2.^ X 5x22° 0 0 2.5’x22° 1 I B l u e (432 nm) G R E E N ( 5 0 2 n m ) YE L L O W (5 7 2 n m ) H H M H H M H 2 .9 H 2 .9 M H 2.6 H H HH H H M H HH HH M H H HH M HHH M H H HHH H H HHH H HHH M HHH H HH H HHHHH M HHHHH M H 0 0 ” " ’S ” ’ " 2 8 7 0 g ) 3 5 9 M H H H H H H ^ H H 3 .6 H 2 .5 M 3 .4 M H H H H M HH M HHH H HH H HHH H HH H HH H HHH H HH H HHHH H H HHHH H H H HHH HH d - T g E ---------------------------------3 2 5 O' ■ T 5 Ô '"-------------------------------2 6 7 d - T g o -------------------------------------316 H H H H H H M M _ H H ^ ^ HH 2 .9 M 2 .7 M H 2.1 HH HH HH HH HH M H HH HH HHH HHH H HM M M M HHH H HH HHH M HHH HH H HHMHH H HHHHH H 0 1 5 0 861 0 *5Q 4 7 4 6 6 9 H H H H H H 1 .6 H H HH HH H 1*5 H M HH H HH H HH M H HH H HHH H H H HH H HHH H HHH H HHHH H HHH H H HHH H HHHH H H H HHHHH HHH H H HHHH H hhh d "SQ ■■ 2 8 7 O' '50 2 8 7 0 ' i " W ------------------"1 5 6 H H H H H H H : 1.2 : 1.3 ' : . h 3 H HH H H HH H HH H H H HH H HHHH H HHH h hhh , H HHHHH H H HHHH H H . M HHHH ! H HHHHHH H H HHHHH HH HH H M HHHH HH H H ' d ■ " I5 Ô ' Ï8 7 d -T5 Ô - ------------------------2 6 7 d i æ " — - -----------------373 ! H H H 1 H H M , H H H ^ ! H 1.1 H 1.4 HH 1.4 H H H HHH H HH H H HHH H HH H HH HHH H HH H H H HH HHH H HHHHH H H HH H HHH H HHHHHHHH H H HHHH H HH HHH H H H d % Ï 2 9 d " " I g r 2 3 0 0 I 5 Ô 6 6 0 H H H H H H H M H ^ _ HH 1.1 H 1.5 H H 1.3 H H H H H HH H H H H M H H H H HH H HH H H HH H H HH H HHHHH H H HHHH H HHH H H HHHHH H H H H HHHH HH H H H HHHHHH H H H d " ■ g j------------------------" ^ 6 O 'ig ô ---------------------— 3 5 9 d l g ô " ---------------------------"3 8 0 Appendix Figure A5 Density of Spikes in the OFF-1 period 133 o 2.5° O 5° 2©x5° © 2 .g x 5 x 2 2 ° © 2.5’x 22° B l u e (432 nm) GR E E N (502 nm ) YE L L O W (5 7 2 n m ) M H H M H H H H 2,9 H M M M M H 2,9 M H M M M M M H M HM H MH H HH H M M H H M H HHH H M M M H 0 "" 10 "”33 M H 0 H H —-j- 10 H H 3,0 H M H H 2.6 M M H H H H H H M H H H M HH H M H MH H HHH H HH M M HHH M HHMM CT H “ io^"‘ ' " 2 1 0 "”"’ H -1 H H H H H 2^ H H 2.7 H H H H H H HH H H H HH H H H HH H M H M M H HH H HH H HHH ' H HH1 M H HHHH d " i6 H - H d " " ' H 10 H H H H 1.6 H H 2.0 H H H H H H H H H H H H H H H M H H HH H H H HH H M H HHH M 0 H © 34 d"" H Î6 "26 H H H H H H 1.3 H H 1.4 M H H H HH H H H H HH H HHH H HH H HHH H HH H HHH H HH H HHHH H HHHH 0 10 * "15 d " " H H H H H H 1 . 1 H H H H H H 1.3 HH H HH H HH H HH H HH H HHHH H HH H HHHH H HH H HHHH H HHHH H HHHH H HHHH 0 H 1 C ) 15 H d H H H H H 13 H H H H H 1.7 H H H H H H H H H H H H H H H H HHHHH H HH H HHHHH H HHHHH I E " ------------2 0 d h o " "20 ■25 18 27 M H H 3 .1 H H H H H H HH H HH M HH H HHH d “ ” — — r — M 10 M M M 2 .5 H H M M H H M HH H M M M H M M M H HHH 0 " " " --------1 — 10 H H H H M H 2.7 H H M H M M H M H H MH H HHH 23 129 O 10 H H H H H 1 .7 H H H H H H H H H H HH H HHH d " " p i 11 "57 1.5 H H H H HH HH HH HH HHHH 0 ’ i" 18 1.5 H HH HH HH HHH HHHH 0 1.5 0~ ? 13 H H IH "13 Appendix Figure A6 Density 6£ Spikes in the OFF-2 period 1-3 4 B l u e (4 32 nm) G R E E N ( 5 0 2 n m ) Y E L L O W ( 5 7 2 n m ) o 2.5“ O 5“ 2'i 2.^x5" H H H H H H M HHHHH HHHHH H HHHHHH HHHH 1.8 35 H H : 1-5 HHH HHH HHH H HHHHHHH H HHHHHHHH HHHHH HHH 38- H H H H H H H HH HHHH HHHHHH H 2.0 36- H H H H HHHH HHHH HHHH H HHHHHHH HHH 2 3-%o "525 2.^ X 5x22" H H H H HHH HHH HHH HHHH HH HHHHHHH H 'M4 H H H H H H HH HHHH HHHHHHH HHHHHHH 1 . 8 : - 5 2 7 54-l^E H M H H H H HH HH HHH HHHHH H 2.4 44“ 3 œ " 2 1 1 2 H M ■ M 1.9 H H HH HH HHHHH HHHHHHH HH HHHHH H H HH HH HH HH HH HH HHHHH HHHHHH HHHHHHHHH H HH 1.5 "512 3 5 - - - i y 6 H H H H H HH HH H HHHHH HHHHH HHHHHHH ^Too" •472 H H HH HH HH HH HHH HH HHH HH H H HH M 35" 1284 H H HH HH HH HH HH HH HHH HHHH H 2.0 "298 35^-iTOO HH HH HH HH HH HH HHHH HHHHH HHHHHHHHHHH H H 4o--Tœ~" H H H H HHH HHH HHH HHHH H H HHHH HHHHH ■^84 1.5 "292 H H H H HH HH H HH H HHHHH MHHHMH 35"- 1 — 100 1 . 1 H H ""4 5 1 1 . 1 H H ■""381 5x 2^ H H HH HH HH HHH HHHH H HHHHHHH H ■405 H H H H H HHHH HHHH H HHHHHHH 1 . 2 2.^x2^ 4 2-1j5'o‘ HH HH HH HH HH HHH HHH H HHHHHHH H HH HHH HHH HHH HMHH HHHHH HHHHH H "529 hhh HH Appendix Figure A7 Latency of Spikes in the ON period HH HHH HHHHH HHMHH H HHHHHHHH H 35— 1 100 "306 H H H H H H H H H HHHHHH H 1.5 "3 0 6 4 0 7 135 o 2.5“ B l u e (432 nm) G R E E N ( 5 0 2 n m ) Y E L L O W ( 5 72nm) 2f I M H H H H H H H H M H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 538ng55---- H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 1.3 900 535" „ïœ 1.5 H H H H H 5 3 5 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H ”^6Ô0 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 1.4 H M M M M H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 535--%oo“*^‘--- H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H M l ' ” ë 5 ô H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H t '1.5 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 1 . 2 ’T)16 540 H H H H H H H H H H M H 600 'Ë63 1 . 6 H H H H H H H M H H H H H H H H H H H H H H H H H H H H H H 1.6 'S72 535"T'f 1 . 6 1000 M H H H H H H H H H H H H H H H H H 966 H H H M H H H H H H H H H H H H H H H H H H H H H 1 . 2 1027 H H H H H H H h h h H H H H H H H H H H H H H H H H H H ”712 535-^5 - 0 H H H H H H H H H H H H H H H H H M H H H H H H H H H 5 3 5 " H H H H H H H H H ■ H H H H H H H H H H H H H H H H H H H h 9 0 5 53 51 600 10 21 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 1030 H H H H H H H H H M H H H H H H H H H H H H H H H H H H H 53S-T 600 H "962 600 "978 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H 1.5 H H H H H “ " “ ■■“ “969 H H H H H H H H H H H H H H H . H H H H H H H H H H H H H 5 3 5 ' 6 0 0 H "994 H H H H H H H H H H H H H H H H H H H H H H H H H H “1025 5 3 5 1 600 985 H H H H H H h h h h h h h H H H H H H H H H H H H 5 3 5 “ l 600 952 H H H H H H H H H H H H H H H H H H H H h h H M H h h %33 Appendix Figure A8 Latency of Spikes in the OFF-1 period .135 B l u e ( 432 nm) GREEN(502nm) Y E L LOW(572nm) O 2.5“ O 5“ 2^ 2,^x5" H M H 1 . 1 HHH H H H HH 1 . 2 HHHH HH HHHH HHHH HH HHHH HHHH HH HHHH H HHHH HHHH H HHHHHHH H HHHH H HH HHHH H H HHHHHHH H H H HH HHHHHHHHH HHH H HHHHHHH H H 1 0 3 9 --T fl0 5 " 1394 1039^ 1-100 1392 1 0 3 7 % 0 — H 1651 H H H H H _ H _ _ H 1,7 H 1.3 H 2 .0 H H H HH HHH H HH H HHH M H HH H HHHH HH HH H H HHHMH H H H HHH H HHHHH HHHHH H HHHHH HH H HH H HHHHHH 1 0 4 5 -1 — - Î627 IO397ÔÔ' ^ 2 1039^^qq Î6 3 H H H H H M 1.4 H H H HHH HHH HH HHH HHH HHH HHHH H HHH HHH HHHHHH H HHHH H HHH HHHHHH H H H HHHHH HH H HHHH HHHHHHHH H HHHH H HHHHHHHHHHH H HHH HHHH H HH HHHH HH ------------------------"1656 IO37T— ---------------Î735 104175Ô""' T64e HH H HH H M H HH HHH H H HH H HHHHH HHHH HHH H HHHHH HHHH HHH HH HHH H HHHHHH H T ^ o HHHHHH H H H 1041 Ij^QQ 1634 1056^100 1563 H H H H HH HH H H HH HH HH HH H HH HH H HHHHH H HH H H HHHHHH H HHHHHH H H H H M HHHH HHHH HHHHHH H H H H. 1044 TjiQQ "1594 10391 1100 1717 1037" I 1100 1449 104 2 H H H HH H H H HH HHH HHHHHH H *^100 H HH HH HH HHHH H HHHHHH HH HHHH HHHH HHHHHH H H H H "1526 104 F I H H HH HHH HHHH H HHHHHHHH H H 1100 HH HHH HHHH HHHH HH "l"362 10421 1100 1503 M H H HH H HH H HHHH 1042' ^100 H HH Ï547 1049'^']QQ 1561 104'f-fioo' H "1479 I Appendix Figure A9 I Latency of Spikes in the OFF-2 period -13 7 Appendix Tables Al to A2 7 These tables present the parametric averages for the nine factor groups for frequency of spikes (number of spikes), density of spikes, and the mean time of occurrence of the spikes. The abbreviations used are found in Table 2 of the Results section. 13 8 : _____ I APPENDIX TABLE Al FREQUENCY OF SPIKES Response of 12 Frog Ganglion Cells of Factor Group #1 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 12 6.1±1 . 6 2.6±1 . 6 3.4±1.3 O.llO.l 1-2 12 7.5±3.1 3.3±1. 6 4.0±2.3 0.210.5 1-3 12 6.3± 2 . 8 3.0±1.8 3.2±1 .4 0.110.1 2-1 12 7.7±2.9 3 . 8±2.0 3.7+1.6 0.310.6 2-2 12 8.0±3 . 5 3.9±1.8 3 . 4±1. 5 0.712.0 2-3 12 6.8±2.2 3.6±2 . 0 3.0±1.1 0.210.4 3-1 12 5.9±2.4 3.1+1.6 2.4±1.3 0.411.2 3-2 12 5.6±1. 7 3.1±1.5 2.411.1 0.210.3 3-3 12 5.9±2 . 5 3.4±1.6 2.011.1 0.511.2 1-0 (36) 6 . 6±2 . 6 3.0±1. 6 3.511.7 0.110.3 2-0 (36) 7.5±2.8 3.7±1.9 3.311.4 0.411.2 3-0 (36) 5.8±2.2 3.2±1 . 5 2.311.1 0.311 .0 0-1 (36) 6.6±2 . 5 3 . 2 + 1.8 3.211.5 0.310.8 0-2 (36) 7.0±2 . 9 3.4±1.6 3.311.8 0.311.2 0-3 (36) 6.3±2.4 3.4±1.8 2 . 711 . 3 0.310.7 0-0 (108) 6.7±2 . 6 3.3±1.7 3.111.5 0.310.9 Mean Values ± Standard Deviation 139 APPENDIX TABLE A2 DENSITY OF SPIKES Response of 12 Frog Ganglion Cells of Factor Group #1 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Conditions GC On Off-1 Off-2 1-1 12 96±87 76162 0.210.4 1-2 12 148±87 66171 0.310.8 1-3 12 110±72 1061113 0.110.3 2-1 12 152±112 98193 1.3i2 . 5 2-2 12 216±126 111195 2.115.3 2-3 12 160±113 1161106 0.310.5 3-1 12 167±125 2091228 0.912.2 3-2 12 207±141 1951144 0.411.0 3-3 12 2211113 1981211 0.811.7 1-0 (36) 118183 83184 0 . 2iO . 5 2-0 (36) 1751117 109196 1.213.4 3-0 (36) 1981125 2001192 0.711.7 0-1 (36) 1381110 1281154 0.811.9 0-2 (36) 1901121 1241118 1.012.3 0-3 (36) 1641109 1401153 0.411.1 0-0 (108) 164 114 131 141 0.7 2.2 Mean Values ± Standard Deviation 140 APPENDIX TABLE A3 MEAN TIME OF OCCURRENCE OF SPIKES Response of 12 Frog Ganglion Cells of Factor Group #1 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Conditions GC Mean On Mean Off-1 Mean Off-2 Observations On Off-1 Off 1-1 12 119+52 626+59 1247188 11 12 4 1-2 12 102±54 636±70 12391142 11 12 3 1-3 12 100±42 624+95 12071103 11 12 3 2-1 12 111±65 644±116 13161232 11 12 5 2-2 12 92±30 609±95 1444±146 11 12 5 2-3 12 97±68 618+66 1377150 11 12 4 3-1 12 98±48 575±26 1514167 11 12 4 3-2 • 12 85±58 573+22 14231165 11 12 3 3-3 12 85±53 601±85 1307198 11 12 5 1-0 (36) 107±49 629174 1233199 33 36 10 2-0 (36) 100±56 624193 13871164 33 36 10 3-0 (36) 89±52 583+53 14051136 33 36 12 0-1 (36) 109±55 615180 13561184 33 36 13 0-2 (36) 93±48 606172 13831163 33 36 11 0-3 (36) 94±54 614181 13051103 33 36 12 0-0 (108) 99±52 612177 13471153 99 108 36 Mean Values ± Standard Deviation - 14f APPENDIX TABLE :A4: FREQUENCY OF SPIKES I ! Response of 3 Frog Ganglion Cells of Factor Group #2 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 3 2.4±1.6 1.4±2.1 0.5±0.2 0.5±0.6 1-2 3 2.0±0.6 1.1±1.3 0.4±0.5 0.5±0.6 1-3 3 2.1±0.9 1.3±1.4 0.5±0.4 0.3±0.3 2-1 3 2.5±1.3 1.6±1. 8 0 . 5 ± 0 . 5 0 . 3 ± 0 . 6 2-2 3 2.8±2.0 2.1+2.4 0.3±0.2 0.4±0.4 2-3 3 3.2±1.9 2.1±2.6 0.6±0.4 0.5±0.5 3-2 3 5.6±1.0 4.0+2.1 1.1±0.9 0.6±0.9 3-3 3 5 . 3 ± 0 . 5 4.0±1.5 0.9+0.9 0.4±0.5 1-0 (9) 2.2±0.9 1.3±1.4 0.5±0.3 0.7±0.5 2-0 (9) 2.8±1.5 1.9+2.0 0.5±0.4 0.4±0.4 3-0 (9) 4.9±1.2 3.6 ±1 . 5 0.8±0.8 0.5±0.6 0-1 (9) 2.9±1.3 1.9±1.6 0.5±0.4 0.4±0.5 0-2 (9) 3.5± 2 . 0 2.4±2.2 0.6±0.7 0.5±0.6 0-3 (9) 3.5±1.8 2.4±2.0 0.7±0.5 0.4±0.4 0-0 (27) 3.3 + 1.7 2.3±1.9 0.6+0.5 0.4±0.5 Mean Values ± Standard Deviation 142 APPENDIX TABLE A5 DENSITY OF SPIKES Response of 3 Frog Ganglion Cells of Factor Group #2 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Conditions GC Den On Den Off-1 Den Off-2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 3±6 4±5 4 + 6 4±5 5±7 8±6 9±1 12±6 14 ±6 58±75 96±166 45±70 55±89 8±12 50±81 0±0 13±13 11±6 1±1 1±1 1±1 1±1 1±1 1±1 1±1 1±1 1 + 1 1-0 2-0 3-0 (9) (9) (9) 4±5 6±5 12±5 66+101 3 7 ± 6 5 8±10 1±1 1±1 1±1 0-1 0-2 0-3 (9) (9) (9) 6±5 7±6 9±7 38±65 39±94 35 + 58 1±1 1±1 1±1 0-0 (27) 7±6 37±71 1±1 Mean Values ± Standard Deviation 143 ‘ “ I APPENDIX TABLE A6 MEAN TIME OF OCCURRENCE OF SPIKES Response of 3 Frog Ganglion Cells of Factor Group #2 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Conditions GC Mean On Mean Off-1 Mean Off-2 On Off-1 Off 1-1 3 302+28 636±124 1449±53 2 3 2 1-2 3 269+46 678+122 1510±75 3 2 2 1-3 3 168±118 666±141 1573±162 3 3 2 2-1 3 309±34 698±223 1498±0 3 3 1 2-2 3 251±4 684+214 1393+140 3 3 3 2-3 3 360±69 618+95 1395±71 3 3 2 3-1 3 296±34 604±91 1388±3 3 3 2 3-2 3 307±57 619 + 2 1557±174 3 2 2 3-3 3 287±5 568+20 1368±56 3 3 3 1-0 (9) 240±91 658±112 1511±100 8 8 6 2-0 C9] 307±61 667+166 1415±91 9 9 5 3-0 (9) 296±34 595±55 1438±124 8 8 6 0-1 (9) 302±28 646+142 1435±54 8 9 5 0-2 (9) 276+44 664±137 1487±130 9 7 6 0-3 C9) 272±108 617+95 1445±130 9 9 6 0-0 (27) 282+69 641±122 1457±109 26 25 17 Mean Values ± Standard Deviation 1 4 4 APPENDIX TABLE A7 FREQUENCY OF SPIKES Response of 6; Frog Ganglion Cells of Factor Group #3 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 6 5.2±6 . 3 3.0±3 . 0 1.6±2.2 0.5il.l 1-2 6 6.6±4 . 5 4.5 ±3 . 0 2.0±1.6 O.liO.2 1-3 6 7.5±3.1 5.0±1.7 2.4±1 .4 0.2i0.4 2-1 6 4.3±4.0 2.8±2.4 1.0±0.9 0.5i0.9 2-2 6 6.3±4.1 3.1±2.3 2.0±1 .3 0.6il.l 2-3 6 6.7±4 . 6 3 . 8±2 . 5 2.5 ±1.5 0.4i0.4 3-1 6 2.3±2.6 1.5±1. 5 0 . 5 ± 0 . 5 0.4i0.7 3-2 6 3.2±3.2 1.7±1 .8 1.Oil .1 0.4i0.7 3-3 6 3.2±2.9 1.4±1.4 1.2±1.2 0.5i0.7 1-0 (18) 6.4±4.6 4.2±2.6 2.Oil.7 0.2i0.7 2-0 (18) 5.8±4.1 3.4±2.3 1.8il.3 0.5i0.9 3-0 (18) 2.9±2 . 8 1.6±1.5 0.9il.0 0.4i0.7 0-1 (18) 3.9±4.5 2.4±2.4 l.Oil.4 0.5i0.9 0-2 (18) 5.4±4 . 0 3 . 3±2 . 6 1.6il.3 0.4i0.7 0-3 (18) 5.8±3.9 3.4±2.4 2.Oil.4 0.4i0.6 0-0 (54) 5.0±4.1 3.0±2.4 1.6il.4 0.4i0.7 Mean Values ± Standard Deviation 145 APPENDIX TABLE A8 ] DENSITY OF SPIKES t Response of 6 Frog Ganglion Cells of Factor Group #3 1 to 9 Stimulus Conditions, Presented Individually or i as a Total Group and Sorted for Shape and Color j 1 Stimulus N Den Den ! Den Conditions GC On Off-1 Off-2 1 1-1 6 29±27 13±13 1±2 1-2 6 37±33 18+18 1±3 1-3 6 48±36 37±54 0±0 2-1 6 78±37 11±9 1+1 ; 2-2 6 88±59 53±82 i±2 : 2-3 6 96±140 26±38 Oil 1 3-1 6 68 ±6 6 10±16 lii 3-2 6 84±65 59±73 li2 3-3 6 92±79 45±66 lii : 1 1-0 (18) 38±31 23±34 li2 2-0 (18) 87±84 30±52 li2 3-0 (18) 81±67 38±58 lii 0-1 (18) 58±49 11±12 1 li2 : 0-2 (18) 69±56 43±63 li2 ‘ 0-3 (18) 79±92 36±51 lii 0-0 (54) 69±67 30±49 li2 ' Mean Values ± Standard Deviation 146 _I n APPENDIX TABLE A9 MEAN TIME OF OCCURRENCE OF SPIKES Response of 6 Frog Ganglion Cells of Factor Group #3 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Mean Mean Mean Off-2 Observations Conditions GC On Off-1 On Off-1 Off 1-1 6 155±20 716±45 1222±127 6 6 3 1-2 6 159±39 640±48 1204±215 6 6 3 1-3 6 146+44 659±50 1349±0 6 6 1 2-1 6 100±20 677+95 1243±133 6 6 3 2-2 6 99 + 26 640±71 1364±15 6 6 2 2-3 6 115±153 628±49 1213±166 6 6 3 3-1 6 97 + 31 717+146 1267+128 5 5 3 3-2 6 74±9 575±19 1483±164 6 6 2 3-3 6 71 + 12 622±53 1416±141 6 6 3 1-0 (18) 153+34 672+56 1233±153 18 18 7 2-0 (18) 105+35 648±73 1262±131 18 18 8 3-0 (18) 80 + 21 633+99 1376±152 17 17 8 0-1 (18) 118+36 702±96 1244±114 17 17 9 0-2 (18) 111+45 618+57 1329±190 18 18 7 0-3 (18) 111+49 636±50 1319+162 18 18 7 0-0 (54) 113±43 651±78 1293±153 53 53 23 I Mean Values ± Standard Deviation 14-7 , APPENDIX TABLE AlO FREQUENCY OF SPIKES Response of 9 Frog Ganglion Cells of Factor Group #4 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 9 5.4±4.4 3.4±1.7 0.8±1.3 1.212.8 1-2 9 4.3+3.1 3.1±2.0 0.5+0.7 0 . 711.6 1-3 9 5.5+2.6 3.7±1.9 1.2±1 . 2 0.611. 0 2-1 9 9.1+3.5 2.8±1.0 0 . 3 ± 0 . 5 1. 012.0 2-2 9 3.8±2.8 2.6±1. 5 0.5±0 . 7 0.611.3 2-3 9 5.4±3.6 3.9±2.0 0.6±1 .1 0.911.8 3-1 9 3.3 ±3.6 1.0±0.9 0.310.8 1.112.0 3-2 9 2.1±2.8 1.2±0.9 0.410.9 0.511 . 2 3-3 9 2.6±2.7 1.4±1.0 0.611 .0 0.711.4 1-0 (27) 5.1±3.4 3.4+1.8 0.811.1 0.811.9 2-0 (27) 4 . 4 ± 3 . 3 3.1±1.9 O.SiO.8 0.811.7 3-0 (27) 2.4±3.0 1.2±0.9 0.4 + 0.9 0.811. 5 0-1 (27) 3.9±3.9 2.4±1.9 0 . 5 + 0 .1 1.112.2 0-2 (27) 3.4±3.0 2.3±1.7 0.510.8 0.611.3 0-3 (27) 4 . 5±3.2 3.0±2.0 0.811.1 0.711.4 0-0 (80) 3.9 3.4 2.6 1.9 0.6 0.9 0.8 1.7 Mean Values ± Standard Deviation 148 APPENDIX TABLE All DENSITY OF SPIKES Response of 9 Frog Ganglion Cells of Factor Group to 9 Stimulus Conditions , Presented Individually as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Conditions GC On Off-1 Off - 2 1-1 9 34±32 5±8 4±11 1-2 9 27±23 18±47 1±4 1-3 9 23±16 8±10 4±8 2-1 9 28±29 7±14 3±7 2-2 9 31±23 7±10 2±4 2-3 9 32 + 23 4±6 3±5 3-1 9 25±36 1±3 3±4 3-2 9 31±29 2±3 3±6 3-3 9 20±20 2±4 2±3 1-0 (27) 29±24 11±28 3±7 2-0 (27) 31±24 6±10 3±5 3-0 (27) 25±29 2±3 2±5 0-1 (27) 29±31 5±10 3±8 0-2 (27) 30±25 9±28 2±5 0-3 (27) 25±20 5±7 3±6 0-0 (81) 28±26 6±17 3±6 Mean Values ± Standard Deviation - 149 APPENDIX TABLE Al2 MEAN TIME OF OCCURRENCE OF SPIKES Response of 9 Frog Ganglion Cells of Factor Group #4 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Mean Mean Mean Observations Conditions GC On Off-1 Off-2 On Off-1 Off 1-1 9 189154 7521158 1258190 9 6 5 1-2 9 163132 7181115 1285+106 9 5 3 1-3 9 179126 7111117 1203161 9 7 3 2-1 9 147134 7241128 1427160 9 5 3 2-2 9 125123 7391163 14401123 9 4 2 2-3 9 144126 7501143 13271115 9 4 3 3-1 9 141±67 700±192 14671121 9 3 4 3-2 9 112138 7801184 13591333 9 5 3 3-3 9 124+45 764±105 14741155 9 4 3 1-0 (27) 177+40 7271125 1251186 27 18 11 2-0 (27) 139+29 7371135 13931122 27 13 8 3-0 (27) 126151 7551152 14361195 27 12 10 0-1 (27) 159156 7311147 13701132 27 14 12 0-2 (27) 133137 7461146 13521215 27 14 8 0-3 (27) 149+39 7351115 13351155 27 15 9 0-0 (81) 147146 7381133 13541160 81 43 29 Mean Values ± Standard Deviation :i50 APPENDIX TABLE A13 1 FREQUENCY OF SPIKES 1 i Response of 3 Frog Ganglion Cells of Factor 1 Group #5 ! to 9 Stimulus Conditions, Presented Individually or ; as a Total Group and Sorted for Shape and Color 1 Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 3 2.3±1.0 1.410.7 0.510.5 0.310.3 1 1-2 3 4.4±2.4 3.011.7 0.910.6 0.510.5 1-3 3 6.3±2.1 4.410.6 1.411.2 0.510.5 1 2-1 3 3.0±2.5 1.811.5 0.710.6 0.410.4 2-2 3 2.511.8 1.711.3 0.510.5 0.310.3 2-3 3 3.211.9 2.111.1 1.Oil.0 0.210.2 3-1 3 1.111.8 0.510.9 0.310.3 0.410.6 3-2 3 1.411.2 0.910.8 0.310.4 0.310.3 3-3 3 1.710.7 0.710.6 0.811.0 0.210.2 1-0 (9) 4.312.4 2.911.6 1.010.8 1 0.410.4 2-0 (9) 2.911.8 1.911.1 0.710.6 0.310.3 ' 3-0 (9) 1.411.2 0.710.6 0.410.6 0.310.4 I 0-1 (9) 2.111.7 1.311.1 0.510.5 I 0.410.4 0-2 (9) 2.812.1 1.911.5 0.510.5 0.410.4 0-3 (9) 3.712.5 2.411.7 l.Oll.O 0.3+0.3 0-0 (27) 2.912.1 1.811.5 0.710. 7 0.310.3 Mean Values ± Standard Deviation , 151 APPENDIX TABLE Al4 DENSITY OF SPIKES Response of 3 Frog Ganglion Cells of Factor Group #5 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Conditions GC Den On Den Off-1 Den Off-2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 5±2 12±11 13±2 8±4 8±1 9±5 6±10 78±132 23±19 3±4 3±2 4±2 3 + 3 4 + 4 4 + 7 2±2 3 + 2 23 + 20 3±4 1±2 5±5 1±1 1 + 1 1±1 0 + 1 1±1 2+1 1-0 2-0 3-0 (9) (9) (9) 10±7 8±3 36±74 3±2 4 + 4 9±15 3 + 4 1±1 1 + 1 0-1 0-2 0-3 (9) (9) (9) 7±6 32 + 74 15±12 2±3 3±3 10±14 1±2 1±1 3±3 0-0 (27) 18±43 5 ± 9 2±2 Mean Values ± Standard Deviation 1 5 2 - APPENDIX TABLE Al 5 MEAN TIME OF OCCURRENCE OF SPIKES Response of 3 Frog Ganglion Cells of Factor Group #5 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Mean Mean Mean Observations Conditions GC On Off-1 Off-2 On Off-1 Off 1-1 3 296+27 805+116 12141195 3 2 2 1-2 3 292+23 758±147 13471238 3 3 2 1-3 3 309±20 732±120 1116138 3 3 2 2-1 3 238+38 881±110 12261138 3 2 2 2-2 3 239+79 761+182 13471318 3 2 2 2-3 3 250+49 839±104 12331170 3 2 2 3-1 3 123 + 0 937±71 131010 1 2 1 3-2 3 122±81 923±5 13431232 2 2 2 3-3 3 107+37 9451110 1599148 3 2 2 1-0 (9) 299±22 7601114 12251173 9 8 6 2-0 (9) 242+51 8271119 12691183 9 6 6 3-0 (9) 115+44 901173 14391188 6 6 5 0-1 (9) 246+67 874+98 12381126 7 6 5 0-2 (9) 229±89 8061138 13461205 8 7 6 0-3 (9) 222+95 7951110 13161239 9 7 6 0-0 (27) 232±83 8231117 13041193 24 20 17 Mean Values ± Standard Deviation 153 APPENDIX TABLE A16 j FREQUENCY OF SPIKES Response of 4 Frog Ganglion Cells of Factor Group #6 to 9 Stimulus Conditions , Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 4 3 . 8 ± 5 . 3 3.114.7 0.410.7 0.410.8 1-2 4 3.9±4.4 3.314.0 0.310.4 0.310.6 1-3 4 2.2±2.5 1.712.6 0.210.3 0.410.5 2-1 4 5.8±5.9 4.915.1 0.8i0 . 8 O.llO.l 2-2 4 6.617.7 5.015.5 1 .3 + 2.3 0.310.2 2-3 4 4.213.2 3.613.3 0.410.5 0.210.2 3-1 4 13.4110.2 9.917.7 2.613.1 0.910.9 3-2 4 8.314.9 6.313.7 2.312.2 0.711.4 3-3 4 5.712.8 4.913.3 OlO 0.811.5 1-0 (12) 3 . 313 . 9 2.7+3.6 0.3+0.5 0.410.6 2-0 (12) 5.515.4 4.514.4 0.811.4 0.210.2 3-0 (12) 9.117.0 7.015.3 1 .312.3 0.811.2 0-1 (12) 7.718.0 6.016.2 1.3 + 2.0 0.410.7 0-2 (12) 6.315.6 4.914.2 1.011.7 0.410.8 0-3 (12) 4.013.0 3.413.1 0.210.3 0.510.9 0-0 (36) 6.015.9 4.714.7 0.811.6 0.410 . 8 Mean Values 1 Standard Deviation 154 n APPENDIX TABLE A17 DENSITY OF SPIKES Response of 4 Frog Ganglion Cells of Factor Group #6 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Conditions GC Den On Den Off-1 Den Off-2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 9±13 12±12 6±10 18±17 16±12 20±15 37±14 58±23 44±27 4±9 2±4 0±0 8±12 3±6 6±8 14±14 7±11 0±0 1±1 0±1 111 010 313 011 214 213 213 1-0 2-0 3-0 (12) (12) (12) 9111 18114 46122 2l5 518 7111 111 112 213 0-1 0-2 0-3 (12) (12) (12) 2.211.8 2.912.7 2.312.4 0.911.1 0.410.7 0.210.5 112 213 112 0-0 (36) 24122 519 112 Mean Values i Standard Deviation 1 5 5:' APPENDIX TABLE A18 MEAN TIME OF OCCURRENCE OF SPIKES Response of 4 Frog Ganglion Cells of Factor Group #6 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Mean Mean Mean Number of Observations Conditions GC On Off-1 Off-2 On Off-1 Off-2 1-1 4 297±47 6961127 136310 3 2 1 1-2 4 286150 615117 149510 3 2 1 1-3 4 2031128 7051177 1387170 3 2 2 2-1 4 276150 643183 13281244 4 4 2 2-2 4 243132 632172 13411312 4 4 4 2-3 4 284189 7051185 15091179 4 4 2 3-1 4 201158 639135 12791132 4 4 4 3-2 4 143140 684195 15491150 4 3 2 3-3 4 152136 56510 1427174 4 1 2 1-0 (12) 262185 6721107 1408171 9 6 4 2-0 (12) 268159 6601117 13801248 12 12 8 3-0 (12) 165149 646168 13831161 12 8 8 0-1 (12) 255164 652171 13051141 11 10 7 0-2 (12) 219172 645170 14231152 11 9 7 0-3 (12) 214198 6851159 14411108 11 7 6 0-0 (36) 229179 658199 13871182 33 26 20 Mean Values ± Standard Deviation .156 APPENDIX TABLE A19 FREQUENCY OF SPIKES Response of 10 Frog Ganglion Cells of Factor Group #7 to 9 Stimulus Conditions , Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 10 3.8 ±3.4 0.8±1.2 1.8±1.7 1.1±1.3 1-2 10 4.9±3.4 0.6±1.1 2.8±2.4 1.5±1 .1 1-3 10 3.3±2.9 0.7±1.0 1.5±1.7 1.1±1.1 2-1 10 7.2±4.9 1.5±2 . 5 4.2±3.9 1.5±1.3 2-2 10 9.8±5 .1 1.1±2.0 6.7±4.5 2.0±1.7 2-3 10 5.9±4.4 0.7±1.5 3.5+3.5 1.7±1.2 3-1 10 14.2±7.9 0.9±1.8 9 . 2 ± 5 . 5 4.2±4.5 3-2 10 14.6±8.1 0.5±0.9 8.9±4.7 5.2±4.9 3-3 10 15.5±9.6 0.5±0.8 10.4±6.6 4.6±4.2 1-0 (30) 4.0±3 . 2 0.7±1.1 2 . 0±2 . 0 1.3±1.1 2-0 (30) 7.6±4.9 1.1±2.0 4.8±4.1 1.7±1.4 3-0 (30) 14.8±8 .3 0.7±1.2 9.5±5 . 5 4.6±4.4 0-1 (30) 8.4+7.1 1.1±1.9 5.0±5 . 0 2.3±3.0 0-2 (30) 9.7±6.9 0.8±1.4 6.T±4.6 2.9±3.3 0-3 (30) 8.2+8.1 0.7±1.1 5.1±5. 8 2 . 5 ± 3 . 0 0-0 (90) 8.8±7.3 0.8±1.5 5.4+5.1 2.5±3.1 Mean Values ± Standard Deviation :15% APPENDIX TABLE A20 DENSITY OF SPIKES Response of 10 Frog Ganglion Cells of Factor Group # to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Conditions GC On Off-1 Off-2 1-1 10 4±6 12±24 2±2 1-2 10 4±6 12±15 4±7 1-3 10 8±18 13±30 1±1 2-1 10 7±10 24±20 3±2 2-2 10 8±12 28±15 4±4 2-3 10 2±4 12±8 8±11 3-1 10 29±43 37±24 8±7 3-2 10 11±24 32±15 10±8 3-3 10 10±22 40±23 9±8 1-0 (30) 5±11 13±23 2±4 2-0 (30) 5±9 22±16 5±7 3-0 (30) 17±32 36±25 9±8 0-1 (30) 13±27 24±25 4±5 0-2 (30) 7±15 24±17 6±7 0-3 (30) 7±16 22±29 6±8 0-0 (90) 9±20 24±24 6±7 Mean Values ± Standard Deviation H i] APPENDIX TABLE 21 MEAN TIME OF OCCURRENCE OF SPIKES Response of 10 Frog Ganglion Cells of Factor Group #7 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Mean Mean Mean Observations Conditions GC On Off-1 Off-2 On Off-1 Off-2 1-1 10 331+94 798171 13501144 6 8 9 1-2 10 291±179 8021126 1341190 5 9 8 1-3 10 381±73 777166 1317181 7 9 8 2-1 10 237±145 7681116 1307183 7 10 10 2-2 10 134+156 765197 12811104 8 10 10 2-3 10 305±145 8261109 13111137 5 10 10 3-1 10 181±201 795176 12721102 5 10 9 3-2 10 155±84 779166 12701105 4 10 10 3-3 10 175±95 771190 1294159 5 10 8 1-0 (30) 339+116 792190 13371106 18 26 25 2-0 (30) 253±145 7861701 13001107 20 30 30 3-0 (30) 171+88 781176 1277190 14 30 27 0-1 (30) 2531128 786189 13101112 18 28 28 0-2 (30) 2321150 781196 12941102 17 29 28 0-3 (30) 2981131 791191 1308198 17 29 26 0-0 (90) 2611137 786191 13041103 52 86 82 Mean Values ± Standard Deviation 159 APPENDIX TABLE A2 2 FREQUENCY OF SPIKES Response of 7 Frog Ganglion Cells of Factor Group #8 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 7 7.8±6.9 0.510.7 7.116.8 0.310.4 1-2 7 8.3±7.0 0.411.0 7.516.6 0.410.5 1-3 7 5.113.7 0.410.7 4.513.9 0.110.2 2-1 7 7.916.2 0.911.8 6.015.4 1.011.6 2-2 6 6.616.4 0.912.0 4.313.9 1.312.6 2-3 7 8.116.3 0.510.9 6.615.6 1.Ol2 . 0 3-1 7 8.718.0 0.310.4 5.314.6 3.213.4 3-2 7 6.5i5 . 6 O.llO.l 5 .115 . 3 3.412.5 3-3 7 10.8110.5 0.210.4 5.3i4 . 9 5.3i5 . 8 1-0 (21) 7.115.9 0.410.7 6.415.8 0.310.4 2-0 (20) 7.616.0 0.811.5 5.714.9 I.I1I.6 3-0 (21) 8.718.1 0.210.3 5.214.7 3.3i4 . 3 0-1 (21) 8.216.7 0.511.1 6 .115 . 5 1.512.4 0-2 (20) 7.216.1 O.51I.2 5.715.4 1.011.9 0-3 (21) 8.017.4 0.410.7 5.514.7 2.213.9 0-0 (62) 7.816.6 0.5il. 0 5.815.1 1.612.9 Mean Values ± Standard Deviation 160 1 APPENDIX TABLE A2 3 DENSITY OF SPIKES Response of 7 Frog Ganglion Cells of Factor Group #8 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Conditions GC Den On Den Off-1 Den Off-2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 2±5 9±17 3 ± 5 8±11 7±10 7±13 42±108 0±1 2 ± 4 39 + 33 44±42 47±65 621101 621112 611102 29121 25124 48181 113 212 OlO 315 214 313 8110 315 18120 1-0 2-0 3-0 (21) (20) (21) 5110 7111 15163 43146 62199 34149 112 314 10114 0-1 0-2 0-3 ( 20) (21) (21) 17162 6111 419 43161 42165 52180 417 213 7114 0-0 (62) 9 + 37 4 616 8 5i9 Mean Values i Standard Deviation 161 APPENDIX TABLE A24 MEAN TIME OF OCCURRENCE OF SPIKES Response of 7 Frog Ganglion Cells of Factor Group #8 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-2 Number of Observations On Off-1 Off-2 1-1 7 417+47 696163 1225192 3 7 3 1-2 7 375+141 704152 11691107 3 7 5 1-3 7 311±52 691157 14091116 2 7 4 2-1 7 380±107 700160 12401108 3 7 5 2-2 6 332±129 718186 13231120 3 5 3 2-3 7 385+136 717152 11911117 3 7 5 3-1 7 1711143 693151 14701143 4 7 5 3-2 7 298174 724163 13871254 2 7 5 3-3 7 272190 757+76 12551114 2 7 6 1-0 (21) 400184 697155 12631174 8 21 12 2-0 (20) 3651111 711157 12401116 9 19 13 3-0 (21) 2281120 724167 13511188 8 21 16 0-1 (20) 3081154 696156 13251163 10 21 13 0-2 (21) 3401111 715158 12931187 8 19 13 0-3 (21) 3601108 722165 12751139 7 21 15 0-0 (62) 3331126 711160 12901161 25 61 41 Mean Values 1 Standard Deviation 162 APPENDIX TABLE A2 5 FREQUENCY OF SPIKES Response of 7 Frog Ganglion Cells of Factor Group #9 to 9 Stimulus Conditions , Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Conditions GC Total On Off-1 Off-2 1-1 7 9.1±4.8 0.1±0.1 6.4+5.0 2.6±2.3 1-2 7 11.8±8.9 0±0.1 7.5±5 . 8 4.3±3.9 1-3 7 7.1±5.2 0.2±0.3 4.9±3.2 2.0±2.2 2-1 7 11.2±6.9 0.2±0.2 6.3±6.2 4.7+1.9 2-2 7 9.7±8.4 0.4±0.9 5 . 3 ± 6 . 5 4.0±3.1 2-3 7 11.0±7.4 0.2+0.5 7.1±5.7 3.7 + 3.7 3-1 7 9.1±10.3 0.2±0.6 4 . 6±5.6 4.3±4.8 3-2 7 9.0±10.4 0.4+0.9 4.5±4. 8 4.0±6 .1 3-3 7 9.5±9.6 0.3±0.7 5.6±7.9 3 . 5 ± 2 . 4 1-0 (21) 9.3±6 . 6 0.1±0.2 6.3±4 . 7 2.9±2 . 9 2-0 (21) 10.6+7.2 0.3±0 . 6 6.2±5.9 4.1±2.9 3-0 (21) 9.2±9.6 0.3±0.7 4.9±6.0 3.9±4.4 0-1 (21) 9.8±7.3 0.2±0.4 5.8±5.4 3.8±3.2 0-2 (21) 10.2±8.9 0.3±0.8 5.8±5.6 4.1±4.3 0-3 (21) 9.2±7.4 0.3±0.5 5 . 9 ± 5 . 7 3.1±2.8 0-0 (63) 9.7±7.8 0.2±0.5 5 . 8 ± 5 . 5 3.7±3 . 5 Mean Values ± Standard : Deviation 163^ APPENDIX TABLE A26 DENSITY OF SPIKES 1 Response of 7 Frog Ganglion Cells of Factor Group #9 ! to 9 Stimulus Conditions, Presented Individually or as a 1 Total Group and Sorted for Shape and Color i Stimulus N Den Den Den 1 Conditions GC On Off-1 Off-2. 1-1 7 3±7 21±24 5±4 1-2 7 0±1 22±20 8±6 1-3 7 2±3 14±7 5±6 2-1 7 1±2 19 + 21 8±4 2-2 7 2±4 25±30 8±6 2-3 7 2±4 28±32 7±7 3-1 7 1±2 34±25 10±11 3-2 7 8±16 40±44 9±9 3-3 7 2±3 46±45 8 ±6 1-0 (21) 2±4 19±18 6±5 2-0 (21) 1±3 24±27 8±5 3-0 (21) 3±10 40±37 9 + 9 0-1 (21) 2±4 24 + 23 8 + 7 0-2 (21) 3 ±10 29±32 8±7 0-3 (21) 2±3 29±33 7±6 0-0 (63) 2 ±6 28 + 29 8±7 Mean Values ± Standard Deviation 164 APPENDIX TABLE A27 MEAN TIME OF OCCURRENCE OF SPIKES Response of 7 Frog Ganglion Cells of Factor Group #9 to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus N Mean Mean Mean Observations Conditions GC On Off-1 Off-2 On Off-1 Off- 1-1 7 264±208 819±49 1279±65 4 7 7 1-2 7 253±142 825±65 1271+65 2 7 7 1-3 7 392±111 725±82 1286±88 4 7 7 2-1 7 207±143 821±82 1306±64 4 7 7 2-2 7 358±86 788±91 1298±97 2 7 7 2-3 7 348±27 818±106 1277±99 2 7 7 3-1 7 290±160 764±128 1370±154 2 7 7 3-2 7 220±166 743±126 1360±199 3 7 7 3-3 7 237±155 721±97 1279±80 4 7 7 1-0 (21) 314±159 806±67 1278±70 10 21 21 2-0 (21) 280±126 809±90 1294±85 8 21 21 3-0 (21) 243±141 742±113 1337±151 9 21 21 0-1 (21) 247±159 802±91 1318±106 10 21 21 0-2 (21) 269±133 786±99 1310±132 7 21 21 0-3 (21) 322±133 771±100 1281±85 10 21 21 0-0 (63) 280±142 786±96 1303±109 27 63 63 Mean Values ± Standard Deviation aev Appendix Tables A28 to A45* These tables present the parametric averages for the six temporal groups for frequency of spikes (number of spikes), density of spikes, and mean time of occurrence of ■ I the spikes. The abbreviations used are found in Table 2 i of the Results section. APPENDIX TABLE A28 FREQUENCY OF SPIKES Response of 13 Frog Ganglion Cells of A Priori Group #1, the "On" Type, to 9 Stimulus Conditions j Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N ■ N N N N Conditions GC Total On Off-1 Off-2 1-1 13 2.4±1.4 2 . 0±1. 3 0.2±0.2 0.2±0.5 1-2 13 2.6+1.9 2 . 2±1. 6 0.2±0.4 0.1±0.3 j 1-3 13 3.6± 2 . 3 2.8±2.1 0.6± 0 . 7 0.2±0.5 2-1 13 2.4±2.0 2.2±1. 8 0.1±0.2 0.7±0.1 2-2 13 2.7±1 .8 2.4±1.6 0.3+0.5 0.5±0.1 1 2-3 13 3.0±1. 9 2.7±1.9 0.3±0.5 0.6±0.1 1 3-1 13 2.6±4 . 6 2.0±3.7 0.3±0.6 0.2±0.4 3-2 13 2.0±2 .3 1.9±2.3 0.0±0.1 •o7±o.i : 3-3 13 1.9+1.6 1.8±1. 6 0.0±0 .1 ,08±0.2 1-0 (39) 2.8±1.9 2.3+1.7 0.3±0.5 0 . 2 ± 0 . 4 2-0 (39) 2.7+1.9 2.4±1.7 0 . 2±0 .4 0.6±0.1 3-0 (39) 2.2±3.0 1.9±2.6 0.1±0.3 0.1±0.2 1 0-1 (39) 2.5±2.9 2.1±2.4 0.2±0 .4 0.2±0.4 ! 0-2 (39) 2.4±2 . 0 2.2±1.8 0.2±0.4 0.1±0.2 1 0-3 (39) 2.8±2.0 2.4±1.9 0.3±0.5 0.1±0.3 0-0 (117) 2.6±2.3 2.2±2.0 0.2±0 .4 0.1±0.3 ! Mean Values±Standard Deviation 167 APPENDIX TABLE A29 DENSITY OF SPIKES Response of 13 Frog Ganglion Cells of A Priori Group #1, the "On" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Den Den Den Condition GC On Off-1 Off-2 1-1 13 22±31 3±8 0.4+0.8 1-2 13 22±23 7±21 0.2±0.5 1-3 13 19±20 5±8 0.7±2.0 2-1 13 26±35 6 + 13 0.1±0.3 2-2 13 54±66 3±8 0.1±0.4 2-3 13 61±102 3±7 0.1±0.3 ■ 3-1 13 58 + 86 3±6 2.0±3.0 3-2 13 37±39 0±0 0.2±0.6 3-3 13 43±57 0 + 1 0.3±0 . 6 1-0 (39) 21±24 5 + 14 0.4±1.0 2-0 (39) 47±73 4±9 0.1±0.3 3-0 (39) 46±63 1±4 0.7±2.0 0-1 (39) 35±57 3±9 0.7±1.0 0-2 (39) 38±47 3±13 ■ * 0.2±0.5 0-3 (39) 41±69 3±6 0.3±1. 0 0-0 (117) 38±58 3 + 10 0.4+1.0 Mean Values ± Standard Deviations 168 APPENDIX TABLE A3 0 MEAN TIME OF OCCURRENCE OF SPIKES Response of 13 Frog Ganglion Cells of A Priori Group #1, the "On" Type, to 9 Stimulus Conditions, i Presented Individually or as a Total Group and Sorted for Shape and Color Number of Stimulus Conditions N GC Mean On Mean Off-1 Mean Off-2 Observations On Off-1 Off 1-1 13 225+80 7141147 1264+101 12 7 5 1-2 13 199±80 6751107 13381222 12 6 2 1-3 13 192±74 6711107 1342192 12 9 3 2-1 13 174±78 637181 13081216 13 7 4 2-2 13 144±63 6611107 1608190 13 6 2 2-3 13 163±78 7081166 14141185 13 6 4 3-1 13 146±70 7041180 13571139 11 5 6 3-2 13 123±49 8131190 13881255 13 4 4 3-3 13 141±64 6631138 1487+168 13 4 4 1-0 (39) 205±77 6861117 1302+116 36 22 10 2-0 C39) 160172 6671118 14101203 39 19 10 3-0 (39) 136160 7251169 14031179 37 13 14 0-1 (39) 182181 6831134 1313+146 36 19 15 0-2 (39) 154171 704+138 1430+220 38 16 8 0-3 (39) 165173 6811128 14211155 38 19 11 0-0 (117) 167175 6891131 13761173 112 54 34 Mean ValuestStandard Deviations 169 APPENDIX TABLE A31 FREQUENCY OF SPIKES Response of 22 Frog Ganglion Cells of A Priori Group #2, the "On, Off-1" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Condition GC Total On Off-1 Off-2 1-1 22 5 . 5 ± 2 , 7 2.712 .1 2.711.9 0 . 210.3 1-2 22 7.3±3.2 3.712.0 3.412.7 0.210.4 1-3 22 6.5±2.1 3.611.8 2.711.4 0.210.3 2-1 22 7.1±4.1 3.712.6 3 .112.5 0.310.5 2-2 22 7.7±4.4 4.012.5 3.212.4 0.511.4 2-3 22 7.2±3.0 3.811.9 3.012.3 0.310.4 3-1 22 6.0±6.0 3.013.9 2.412.7 0 . 6H . 3 3-2 22 5,2±3 . 6 2.812.4 2.011.4 0.511.4 3-3 22 5.5±3.9 2.812.2 1.911 . 7 0.812.1 1-0 (66) 6.4±2.8 3.312.0 2.912.1 0.210.3 2-0 (66) 7.3±3 . 8 3.912.3 3.112.3 0.410.9 3-0 (66) 5.6±4 . 5 2.912.9 2.112.0 0.611.6 0-1 (66) 6.2±4.4 3.213. 0 2.712.4 0.310.8 0-2 (66) 6.8±3. 9 3.512.3 2.912 .3 0.411.2 0-3 (66) 6.413.1 3.412.0 2.611.9 0.411.3 0-0 (198) 6.4i3 . 8 3.412.4 2.712.2 0.411.1 Mean ValuesiStandard Deviation 17G APPENDIX TABLE A3 2 DENSITY OF SPIKES Response of 22 Frog Ganglion Cells of A Priori Group #2, the "On, Off-1" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color .Stimulus N Condition GC Den On Den Off-1 Den Off-2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3.3 22 22 22 22 22 22 22 22 22 62±75 99±90 75±70 112±109 147±134 103±106 103±117 142±136 142+127 47±56 43±58 69±96 59±81 77±89 74±93 119±193 117±140 123±177 0. 5±1 1.8±5 0.9±2 1 .0±1 1.8±4 0.4±0 3.5±12.2 1.6±2.4 1.3±3.0 1-0 2-0 3-0 ( 66) (66) (66) 78±79 1211117 1291126 53172 70187 1201169 1.113.3 1.112.7 1.917.4 0-1 0-2 0-3 (66) (66) (66) 92H02 1291122 1071106 751127 791104 881128 1.717.2 1.514.0 0.912.2 0-0 (198) llOilll 81H20 1.414.9 Mean ValuesiStandard Deviation 171 APPENDIX TABLE A33 MEAN TIME OF OCCURRENCE OF SPIKES Response of 22 Frog Ganglion Cells of A Priori Group #2, the "On, Off-1" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-2 On Off-1 Off-2 1-1 22 174±96 672±80 12381113 22 22 9 1-2 22 162±94 . 671±97 13091182 22 22 10 1-3 22 150±80 656+92 12741163 21 22 8 2-1 22 155±105 683±122 12961161 22 22 11 2-2 22 136+86 633±95 13611182 22 21 11 2-3 22 157±110 649±91 13361112 22 22 10 3-1 22 141±90 647±131 13811195 20 21 10 3-2 22 116±84 628±107 13871159 21 22 7 3-3 22 104±72 6421103 13681147 22 21 10 1-0 (66) 162±90 667189 12751153 65 66 27 2-0 (66) 149±100 6551104 13311153 66 65 32 3-0 (66) 120±82 6391113 13781163 63 64 27 0-1 (66) 157±97 6681112 13071166 64 65 30 0-2 (66) 138±89 6441100 13491173 65 65 28 0-3 (66) 136±91 649194 13301140 65 65 28 0-0 (198) 144±92 6541102 13281160 194 195 86 Mean Values±Standard Deviations 17(2 APPENDIX TABLE A3 4 FREQUENCY OF SPIKES Response of 5 Frog Ganglion Cells of A Priori Group #3, the "On, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Condition GC Total On Off-1 Off-2 1-1 5 5.2i6. 0 1.812.2 0.610.5 2.813.5 1-2 5 5.315.1 1.511.5 0.710.7 3.0i3. 0 1-3 5 3.913.9 1.611.5 1.311.7 l.lll.l 2-1 5 4.813.3 1.Oil.0 0.410.2 3.312.7 2-2 5 3.812.5 l.lil.0 0.410.2 2.312.1 2-3 5 4.813.6 2.012.0 0.410.5 2.512.5 3-1 5 3.211.4 1.311.0 0.110.04 1.711.0 3-2 5 3.712.6 2.212.0 0.510.5 1.011.2 3-3 5 4.511.9 2.011.9 0.310.3 2.211.3 1-0 (15) 4.814.8 1.611. 6 0.911.0 2.312.7 2-0 (15) 4.513.0 1.411.4 0.410.3 2.712.3 3-0 (15) 3.812.0 1.811.6 0.310.3 1.6H..2 0-1 (15) 4.413.9 1.411.4 0.410.3 2 . 612.5 0-2 (15) 4.313.4 1.611.5 0.510.5 2.1+2.2 0-3 (15) 4.413.1 1.811.7 0.611.0 1.9H.7 0-0 (45) 4.413.4 1.611. 6 0.510.7 2.212.2 Mean ValuesiStandard Deviation 173 APPENDIX TABLE A35 DENSITY OF SPIKES Response of 5 Frog Ganglion Gells of A Priori Group #3, the "On, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Condition GC Den On Den Off-1 Den Off - 2 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 15±15 6±8 7±9 13±18 25±34 14 + 14 12±8 18±12 26 + 20 5±7 32 + 63 5 ± 8 2±3 7±12 3±4 0.6±1 7±11 4 + 6 10±14 7±6 6±9 10±9 7±6 6± 7 6±5 5±7 5±3 1-0 2-0 3-0 (15) (15) (15) 9±11 17 + 22 18±15 14±36 4 + 7 4 + 7 7±10 8 + 7 5 ± 5 0-1 0-2 0-3 (15) (15) (15) 13±13 16±21 16 + 16 3±5 15±37 4 + 6 8±9 6±6 6 + 6 0-0 (45) 15 + 17 7±22 7±7 Mean Values±Standard Deviation 174 APPENDIX TABLE A36 MEAN TIME OF OCCURRENCE OF SPIKES Response of 5 Frog Ganglion Cells of A Priori Group #3, the "On, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Conditions GC Mean On Mean Off-1 Mean Off-2 On Off-1 Off 1-1 5 256±106 874±101' 1368±205 4 4 4 1-2 5 220+48 687±62 1414±75 4 4 4 1-3 5 209±33 810±48 1282±134 4 4 4 2-1 5 222±114 810±136 1441±96 5 5 5 2-2 5 208+110 700+146 1374±219 5 5 5 2-3 5 289+141 663±57 1360±40 5 3 4 3-1 5 142+82 683+107 1495±127 5 5 5 3-2 5 185±104 707+174 1517±171 5 5 5 3-3 5 126±93 740±193 1461±84 5 5 5 1-0 (15) 228+67 791±105 1355±145 12 12 12 2-0 (15) 240+119 734+134 1390±142 15 13 13 3-0 (15) 151+90 710±152 1491±125 15 15 15 0-1 (15) 203+106 783+135 1439+145 14 14 13 0-2 (15) 202+88 699+130 1436+171 14 14 14 0-3 (15) 208+119 744+135 1375+115 14 12 13 0-0 (45) 205+102 742+134 1417+146 42 40 40 Mean Values ± Standard Deviation 17 5 APPENDIX TABLE A37 FREQUENCY OF SPIKES Response of 7 Frog Ganglion Cells of A Priori Group #4, the "On, Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Condition GC Total On Off-1 Off-2 1-1 7 9.8±4. 2 3 . 5 ± 2 . 9 3 . 6 ± 2 . 2 2.7±1.8 1-2 7 9.2±2. 5 3.3±3 . 0 3.5±2.0 2.4±1.7 1-3 7 9.1±2.8 3.0±2.3 4 . 1±2 . 6 2.1±1.4 2-1 7 10.2±4.1 4.2±2.8 3.5+3.2 2.5±1.1 2-2 7 10.6±3.4 3.9±1.9 4.2±3.2 2.4±0.7 2-3 7 10.7±3.8 3.4±2.7 4.5±2 . 5 2.8±1.7 3-1 7 13.0±7.5 3.2±1.4 5.3±4.4 4.4±2.7 3-2 7 11.7±6.8 3 .0±1. 5 5.1±4.1 3.6±3 . 3 3-3 7 12.0±6.2 2.8±1.3 5.2±4.0 4.0±2.4 1-0 (21) 9.4±3.1 3.3 + 2.6 3.7±2.2 2 . 4 ± 1. 6 2-0 (21) 10.5 ±3.6 3.8±2.4 4.1±2.9 2.6±1.2 3-0 (21) 12.2±6.5 3.0±1. 3 5.2+4.0 4.0±2.7 0-1 (21) 11.0±5.4 3 . 6 ± 2 . 4 4.1±3.4 3.2±2 .1 0-2 (21) 10.5±4.5 3.4±2.1 4.3±3.1 2.8±2.1 0-3 (21) 10.6+4.4 3.0±2.1 4 . 6 ± 3 . 0 3.0±2.0 0-0 (63) 10.7 4.7 3.4 2.2 4.3 3.1 3.0 2.0 Mean Values±Standard Deviation 176 APPENDIX TABLE A38 DENSITY OF SPIKES Response of 7 Frog Ganglion Cells of A Priori Group #4, the "On, Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented individually or Sorted for Shape as a Total Group and Color and timulus N Den Den Den idition GC On Of f -1 Off-2 1-1 7 23±26 11 + 9 6±4 1-2 7 24±30 13±12 4±3 1-3 7 25±36 15±15 3 + 2 2-1 7 33±3 5 16±16 5 ± 2 2-2 7 32±36 21±22 4±1 2-3 7 29±30 15±12 5±3 3-1 7 33 + 30 21±14 7±4 3-2 7 43±33 38±46 6±5 3-3 7 36±27 21±16 7±4 1-0 (21) 24±29 13±12 4.3 2-0 (21) 32±32 18±16 5±2 3-0 (21) 38±29 27±29 7±4 0-1 (21) 30±29 16 + 13 6±4 0-2 (21) 33±32 24 + 31 5±4 0-3 (21) 30 + 30 17±14 5 + 3 0-0 (63) 31±30 19±21 5±3 Mean ValuestStandard Deviation 17% APPENDIX TABLE A39 MEAN TIME OF OCCURRENCE OF SPIKES Response of 7 Frog Ganglion Cells of A Priori Group #4, the "On, Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N Number of Observations Mean Mean Mean Condition GC On Off-1 Off-2 On Off-1 Off 1-1 7 246±99 755165 1340186 7 7 7 1-2 7 234±111 772175 12861105 6 7 7 1-3 7 262+130 753151 1292189 7 7 7 2-1 7 232±110 755188 1349139 7 7 7 2-2 7 247±132 744195 1354156 7 7 7 2-3 7 223±131 770177 12961139 7 7 7 3-1 7 212±114 780188 1398176 7 7 7 3-2 7 1781102 724187 1372182 7 7 7 3-3 7 2151130 712169 1376164 7 7 7 1-0 (21) 2481109 760162 1306192 20 21 21 2-0 (21) 2341119 756183 1333189 21 21 21 3-0 (21) 2011111 739183 1382173 21 21 21 0-1 (21) 2301103 763178 1362171 21 21 21 0-2 (21) 2191114 747184 1337189 20 21 21 0-3 (21) 2341126 745168 13211105 21 21 21 0-0 (63) 2281113 7521113 1340190 62 63 63 Mean ValuestStandard Deviations 178 APPENDIX TABLE A4 0 FREQUENCY OF SPIKES Response of 10 Frog Ganglion Cells of A Priori Group #5, the "Off-l" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Condition GC Total On Off-1 Off-2 1-1 10 3 . 7 ± 6 . 0 0.310.5 3.316.0 0.210.2 1-2 10 4 . 0 ± 5 . 6 0.H0.2 3.415.6 0.410.8 1-3 10 2.8±3.0 0.310.6 2.313.0 0. 2iO.2 2-1 10 4.7±4. 9 0.510.8 3.815.0 0.410.7 2-2 9 3.5±4.0' 0 . 2iO.2 2.913.8 0.410.5 2-3 10 4 . 6 ± 5 . 3 0.310.4 3.615.1 0.710.9 3-1 10 6.7±7.8 0.5i0 . 8 4.415.3 1.813.1 3-2 10 5 . 8 ± 5 . 8 0.210.5 5.2i5 . 6 0.410.5 3-3 10 7.1±8.6 0.410.7 4.7i4. 9 2.0i4 . 7 1-0 30 3.5±4 . 9 0.210.4 3.0l4.9 0.210.5 2-0 29 4.3±4.7 0.310.5 3.514.5 0.510.7 3-0 30 6.5± 7 . 2 0.410.7 4.815.1 1.413.2 0-1 30 5.0±6. 2 0.410.7 3 . 815 . 2 0.8H.9 0-2 29 4.4±5.1 0.210.4 3.915. 0 0.410.6 0-3 30 4.8±6.2 0.310.6 3.614.4 0.912.8 0-0 89 4.8±5.8 0.3l0. 5 3.814.8 0.712.0 Mean ValuestStandard Deviation .179 APPENDIX TABLE A41 DENSITY OF SPIKES Response of 10 Frog Ganglion Cells of A Priori Group # the "Off-1" Type, to 9 Stimulus Conditions, Presented Individually or as Sorted for Shape and a Total Group Color and Stimulus N Den Den Den Condition GC On Off-1 Off-2 1-1 10 1±2 48150 0.210.3 1-2 10 3±6 55191 317 1-3 10 2±4 5 0i66 0.611 2-1 10 5±7 70189 0.811 2-2 9 2±5 48191 7i2 2-3 10 2±4 59191 7111 3-1 10 43±95 25122 519 3-2 10 2±3 29122 112 3-3 10 2±5 55170 10119 1-0 30 2±5 51169 2i4 2-0 29 3 ±6 59188 317 3-0 30 16±56 36145 5112 0-1 30 16156 47161 216 0-2 29 215 44173 215 0-3 30 214 55174 6113 0-0 89 7133 49169 319 Mean ValuestStandard Deviation ■18 0 APPENDIX TABLE A42 MEAN TIME OF OCCURRENCE OF SPIKES Response of 10 Frog Ganglion Cells of A Priori Group #5, the "Off-1" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations imulus ditions N GC Mean On Mean Off-1 Mean Off-2 On Off-1 Off 1-1 10 405146 7121119 13471158 3 9 5 1-2 10 3821142 7021125 12521210 4 9 5 1-3 10 3241193 7061115 13961224 4 9 4 2-1 10 2911141 6981120 12251106 6 10 6 2-2 9 3001102 7131125 12611140 4 8 5 2-3 10 3781125 7461141 12211161 4 10 7 3-1 10 1551104 7241122 13511157 5 10 6 3-2 10 262180 7341101 13011220 3 10 7 3-3 10 206165 7331134 12451107 4 10 6 1-0 (30) 3671138 7071115 13271191 11 27 14 2-0 (29) 3181123 7191126 12331132 14 28 18 3-0 (30) 199190 7301116 12991167 12 30 19 0-1 (30) 2671144 7111116 13061146 14 29 17 0-2 (29) 3191115 7171113 12751186 11 27 17 0-3 (30) 3021146 7291128 12701167 12 29 17 0-0 (89) 2941135 7191118 12841164 37 85 51 Mean ValuesiStandard Deviation 181, APPENDIX TABLE A43 FREQUENCY OF SPIKES Response of 12 Frog Ganglion Cells of A Priori Group #6, the "Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Stimulus N N N N N Condition GC Total On Off-1 Off-2 1-1 12 7.6 ±4 , 8 0.110.2 5.814.6 1. 6H . 5 1-2 12 9 , 5±7.6 O.liO.l 6.815.2 2.613.3 1-3 12 5.4±4.1 0.210 . 2 4.013.3 1.211.6 2-1 12 10.0±5.9 O.liO.l 6.615.0 3.312.3 2-2 12 11.5±6.2 O.liO.l 7.715.4 3.812.7 2-3 12 9.3±6.4 O.liO.l 6.615.1 2.612.8 3-1 12 13.0±8.4 O.liO.l 8.116.1 4.814.6 3-2 12 13.119.4 O.liO.l 7.815.3 5.315.6 3-3 12 14.5110. 2 O.OiO.l 9.418.1 5.113.6 1-0 (36) 7.515.8 0.110.2 5.614.5 1.812.3 2-0 (36) 10.216.0 0.11.1 7.015.1 3.212.6 3-0 (36) 13.5+9.1 O.liO.l 8.416.5 5.114.6 0-1 (36) 10.216.7 0.110.1 6.815.2 3.313.3 0-2 (36) 11.417.8 0.110.1 7.415.2 3.914.1 0-3 (36) 9.718. 0 0.110.2 6.716.1 2.913.1 0-0 (108) 10.417.5 0.110.1 7.015.5 3.413.5 I Mean ValuestStandard Deviation I 182 APPENDIX TABLE A44 DENSITY OF SPIKES Response of 12 Frog Ganglion Cells of A Priori Group #6, the "Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color imulus N Den Den Den dition GC On Off-1 Off- 1-1 12 3±7 24±27 413 1-2 12 0±1 24±19 718 1-3 12 6±16 21±26 3i5 2-1 12 0±1 25±22 714 2-2 12 3±8 32±22 715 2-3 12 0±1 22±25 718 3-1 12 5±14 43±24 1219 3-2 12 5±12 42±32 1118 3-3 12 0±0 48±45 1117 1-0 (36) 3±10 23±24 416 2-0 (36) 1±5 26 + 23 716 3-0 (36) 3±11 44±34 1118 0-1 (36) 3±9 31±25 7i7 0-2 (36) 3±9 32±26 8i7 0-3 (36) 2±10 31±35 718 0-0 (108) 2±9 31±29 8i7 Mean ValuestStandard Deviation .183 i APPENDIX TABLE A45 MEAN TIME OF OCCURRENCE OF SPIKES Response of 12 Frog Ganglion Cells of A Priori Group #6, the "Off-1, Off-2" Type, to 9 Stimulus Conditions, Presented Individually or as a Total Group and Sorted for Shape and Color Number of Observations Stimulus N Mean Mean Mean Conditions GC On Off-1 Off-2 On Off-1 Off-2 1-1 12 2881172 775156 12601114 6 11 12 1-2 12 1841121 790186 1279197 4 12 12 1-3 12 381194 736160 13141106 7 12 11 2-1 12 1671134 787172 1288178 4 12 12 2-2 12 1901158 771164 1311188 6 12 12 2-3 12 2321132 792189 13681111 3 12 12 3-1 12 1761135 7541104 13281169 3 12 12 3-2 12 1121125 735194 13261184 3 12 12 3-3 12 1311136 740172 1274170 3 12 11 1-0 (3 6) 3021147 767171 12841105 17 35 35 2-0 (36) 1931136 784174 1289192 13 36 36 3-0 (36) 1401118 743189 13101149 9 36 35 0-1 (36) 225H54 772180 12921126 13 35 36 0-2 (36) 1701133 765183 13051128 13 36 36 0-3 (36) 2891149 756177 1285197 13 36 34 0-0 (108) 2281150 754179 12941117 39 107 106 Mean ValuestStandard Deviation 184 UMI Number; DP23585 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. DiSSMtalififli Pkbl sbtng UMI DP23585 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346

Linked assets

University of Southern California Dissertations and Theses

Conceptually similar

PDF

The innervation of the teeth and periodontium of the rat

PDF

Cation localization in growth hormone and prolactin cells of the rat pars distalis

PDF

A study of Japanese students at the University of Southern California, 1946-1980: vocational impact of American academic experience on Japanese students after returning to Japan

PDF

Studies on the cytology of bacteria and yeasts by means of ultraviolet photolysis

PDF

Studies on the bacterial oxidation of saturated fatty acids and their derivatives

PDF

Studies of two naturally occurring compounds which effect release of acetylcholine from synaptosomes

PDF

Nude mouse grown human nephroblastomas

PDF

Chemical and immunological studies on a heterophile antigen extracted from bovine erythrocyte stroma

PDF

Studies on the aerobic oxidation of fatty acids by bacteria

PDF

Numerical analysis of ecological survey data

PDF

The interaction of learners' spatial ability aptitudes with filmic schematic operations

PDF

A histochemical and morphological investigation of the developing human aorta

PDF

The role of microbes in the formation of the tubeworm fouling community in Fish Harbor, Los Angeles Harbor, California

PDF

Light and electron microscopic observations on glial cells of developing and adult human retina and optic nerve head

PDF

Resocialization of older adults to work roles through worklife autobiography

PDF

Endocrine aspects of aggression and dominance in champanzees of the Kibale Forest

PDF

Lab coats in the dream factory: science and scientists in Hollywood

PDF

Electrophysiological and behavioral activity accompanying self-stimulation (a comparative study of the hypothalamus and septum)

PDF

The relationship between cultural-value orientation and achievement in three learning environments: Lecture, small-group, and self-study

PDF

Self-perceived job satisfaction and dissatisfaction of urban elementary classroom teachers

Asset Metadata

Creator Cummings, Peter Francis (author)

Core Title Studies of frog retinal ganglion cell responses to temporal, spatial and chromatic stimuli

School Graduate School

Degree Doctor of Philosophy

Degree Program Anatomy

Degree Conferral Date 1978-01

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag anatomy,biology,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c30-204649

Unique identifier UC11228234

Identifier DP23585.pdf (filename),usctheses-c30-204649 (legacy record id)

Legacy Identifier DP23585.pdf

Dmrecord 204649

Document Type Dissertation

Rights Cummings, Peter Francis

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA