University of Southern California Dissertations and Theses

Cue-Dependent Amnesia

(USC Thesis Other)

Cue-Dependent Amnesia

PDF

Download a page range

Download transcript

Copy asset link

Request this asset

Transcript (if available)

Content MAHAN, Jr., John Joseph, 1943- CUE-DEPENDENT AMNESIA. University of Southern California, Ph.D., 1971 Psychology, experimental | University Microfilms, A X E R O X Com pany, Ann Arbor, Michigan THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED , CUE-DEPENDENT AMNESIA by John Joseph Mahan, Jr. 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 (Psychology) September 1971 UNIVERSITY O F S O U T H E R N CALIFORNIA THE GRADUATE SCHOOL UNIVERSITY PARK LOS ANGELES, CALIFORNIA 9 0 0 0 7 This dissertation, written by ....... JoM.J.p.a ej ?.b .. jMa jt xaa, .. Jx ......... under the direction of / i . i a . . . Dissertation C om mittee, and approved by all its members, has been presented to and accepted by The Gradu ate School, in partial fulfillment of require ments of the degree of D O C T O R O F P H I L O S O P H Y XJ Dean Date..JSe.ptemhe.j:...19.7.1... SSER/TATIO. MMITTEE JC&UZTJ... I ACKNOWLEDGMENTS I wish to express my appreciation to the members of my disser tation committee, Dr. Gary Galbraith, and Dr. Lewis Bishop. I am especially grateful to Dr. Donald J. Lewis for his guidance, and cooperation during this dissertation and throughout my three years as his research assistant. I wish to thank Dr. Anne Schell and Norman Bregman for their assistance in constructively criticizing this dissertation, and especially Marlene Hulett who has assisted me in typing and proof reading my papers since I entered college. I also wish to thank my parents, Mr. and Mrs. John J. Mahan, Sr., for their constant moral and financial support. Finally, I wish to thank my sweet wife, Dorothy Ellen, for her sincere patience and encouragement. ii TABLE OF CONTENTS Page ACKNOWLEDGMENTS.................................................. ii LIST OF TABLES................................................. iv LIST OF FIGURES......................................... v Chapter I. INTRODUCTION .......................................... 1 Brief History of the Consolidation Hypothesis . . . 1 Early Animal Research on the Consolidation Hypothesis .......................................... 3 Postulates of the Consolidation Hypothesis......... 6 Current Animal Research on the Consolidation Hypothesis .......................................... 6 An Argument Against the Consolidation Hypothesis - Cue-dependent Amnesia .............................. 10 Dissertation Purpose................................ 15 Pilot study # 1 .................................... 16 Pilot study # 2 .................................... 18 Footnotes......................................... 23 II. METHOD................................................ 24 III. RESULTS.............................................. 30 IV. DISCUSSION............................................ 42 Conclusion.......................................... 47 LIST OF REFERENCES............................................. 48 APPENDIX 52 LIST OF TABLES Table Page 1. Pilot Study #2 Experimental Design....................... 20 2. Pilot Study #2 Mean Difference Scores.............. 21 3. Experimental Design......................... 27 4. Mean Transformed Scores ..... .......... ..... 31 5. Specific Comparisons.................................... 35 iv LIST OF FIGURES Figure Page 1. Times of experimental treatment in studies of memory storage .......................................... 9 2. Mean transformed difference scores of the six different groups on test day . . . . . . . . . . . . . ........ 32 3. Reinstatement continuum: Mean transformed difference scores of Ss reinstated with various stimuli prior to ECS or sham-ECS treatment............................. 33 4. Comparison of the six groups for SD/S^ ratios on the last training day and t e s t .......... 37 5. Comparison of the six groups for SD responses on the last day of training and t e s t ............................. 38 6. Comparison of the six groups for S^ responses on the last day of training and test......................... 39 7. Comparison of tone-ECS Ss to all others on the last day of training (T-2) and test for mean SD and S responses.............................................. 40 v CHAPTER I INTRODUCTION The ability of an organism to store information, which may lead to modifications in behavior, is perhaps the most exciting phenomenon of biological science. This ability is easily observed in vertebrates, but even the small planarian "Dugesia", for example, is capable of re taining a learning experience (McConnell, 1962). The storage of a learning experience is a specialized, highly complicated, process and scientists in various fields have devoted several years to memory re search, but there still remain several unanswered questions. One very important question is concerned with how an animal's memory evolves from an initial labile state to one which is permanent. Most theorists assume that the memory in its initial state is stored differently than when it is in its permanent state, and they hypothesize that there are two memory stages: Short-term memory and long-term memory. Others (Barondes and Cohen, 1966) assume that there are three memory stages. The important point to be made, however, is that memory is assumed to transfer from one state to another. Several physiological interpretations have been offered over the years as to how memory transfer occurs, but of them all the "consolidation" hypoth esis is the most widely accepted. Brief History of the Consolidation Hypothesis The consolidation hypothesis essentially began with Mueller, and Pilzecker (1900). These men were primarily interested in the verbal- learning of humans, and they developed a technique for their studies 1 which involved the use of "nonsense" syllables (letters of the alphabet placed together so as not to form a word). While conducting their re> search they came across an interesting finding: A second-presented list of nonsense syllables caused the subject (S) to forget either all or a portion of the syllables presented on a first list, if the two lists were given relatively close together. They called this forget ting "retroactive inhibition" and assumed that it occurred because the physiological events induced by the first list were interfered with by the physiological events induced by the second list. They hypothesized that the neural processes initiated by the first list were persevera- ting and the introduction of the second list interfered with this activity. Burnham (1903) added the concept of consolidation to the neuronal- perseverating hypothesis of Mueller and Pilzecker. He theorized that the encoding of a learning experience induces perseverating neuronal processes which take some amount of time to complete their activity (fixation); if the perseverating process is interrupted no long-term storage will occur. However, if the process is completed without in terference, memory is permanently stored. Burnham's research data supported this hypothesis. He worked with retrograde amnesia*- (RA), as produced by a traumatic event, and he assumed that the RA for a learn ing experience resulted because trauma to the head was disrupting the hypothesized on-going neuronal processes. DeCamp (1915) is given credit for introducing the consolidation hypothesis to American psychologists, but several years passed before 3 the concept was studied in the animal laboratory. Early Animal Research on the Consolidation Hypothesis Duncan (1945, 1948, 1949) was one of the first to study the consolidation hypothesis using animals. He used electro-convulsive shock (ECS), a strong electrical current passed through the brain of the animal, to disrupt the memory processes and he demonstrated that the effectiveness of ECS in producing an amnesia varied as a function of the time interval between the learning experience and the convulsive shock (amnesia is operationally defined as any deficit in a S's per formance caused by the traumatic treatment). He trained rats in a special T-mase apparatus in multiple trials, one trial each day. Fol lowing each trial the animals were given an ECS treatment at various intervals. He found that rats receiving the ECS within the first 20 to 30 minutes after each trial performed much more poorly than either con trol animals (not receiving the ECS treatment) or Ss given ECS more than 1-hour after the learning trial. Duncan hypothesised that the massive electrical discharge of the ECS-induced amnesia interrupted the perseverating neural processes at 20 to 30 minutes after the training trial, but these processes had been completed by the 1-hour interval (fixation) and therefore the memory was not disrupted. Several similar experiments (see Glickman, 1961; McGaugh and Petrinovich, 1966) supported Duncan's interpretation of consolidation, but there were a few theorists who presented alternative views. Coons and Miller (1960) presented a "fear" hypothesis. They suggested that ECS is unpleasant and that what appears to be amnesia for the correct 4 response actually may be an avoidance for the consequences of the response. Since ECS was given a short time after the learning trial, and this was repeated on subsequent days, it is possible that the Ss showed a response deficit merely because the ECS treatment became aversive. Another alternative to consolidation was proposed by Adams and Lewis (1962). They presented a "conditioning" hypothesis: The con* vulsion produced by ECS becomes conditioned to the stimuli of the ex* perimental apparatus, and by "competing" with the correst response in the experimental situation, produces the decrement in performance. Multiple ECS treatments could easily establish such conditioning and therefore any amnesia (response deficit) found may be due to competing responses rather than to a disruption of the consolidation process. Hudspeth and McGaugh (1964) conducted an experiment and clearly showed that multiple ECS treatments were aversive. Rats, given multi ple ECS treatments, learned to avoid the area in the maze where the ECS had been administered. However, Hudspeth and McGaugh asserted that this finding was not necessarily contradictory to the consolidation hypothesis, but only that future experiments must be modified to ac count for such technical difficulties. Due to the suggested alternative hypotheses and the finding that multiple ECS treatments were aversive, the basic experimental paradigm of consolidation studies had to be changed and experiments like the one conducted by Thompson and Dean (1955) provided the way. They used "massed" training trials which permitted the completion of acquisition 5 in a single session. They gave a "single*' ECS treatment following this learning at various intervals. The results showed that the most severe effects of the ECS were obtained after the shortest delays used (10 and 120 seconds) but no effect was observed if the ECS treatment followed the learning by four hours. This experiment did not use spaced- learning-trials or multiple ECS treatments (which provided the basis for the above-given alternatives) and yet the consolidation hypothesis was still supported, i.e., the ECS disrupted the memory at 10 and 120 seconds but not at four hours (by which time the consolidation process had presumably been completed). Using a single training session and a single ECS treatment, Heriot and Coleman (1962) challenged the Coons-Miller and Adams-Lewis alterna tives to the consolidation hypiothesis directly. Heriot and Coleman showed that post-trial ECS can block the "disruption" of a response. Animals were trained to bar-press, in a Skinner box, for food, and on one subsequent trial in the chamber a bar-press produced a strong shock to the S. The shock was followed by an ECS treatment (or sharn- ECS) at various intervals (1, 7, 26, 60 or 180 minutes). The animals not given an ECS, or given ECS at 180 minutes, refrained from pressing the bar on a test trial, but Ss given an ECS within 60 minutes of the shock did not. This result strongly supported the consolidation hy pothesis but not the alternatives. According to either the Coons- Miller or Adams-Lewis theories, an ECS soon after the shock should en hance the animal's tendency not to press the bar, but in fact, the animals so treated showed a continuation of bar-pressing on the test trial, apparently due to forgetting of the shock. Experimenters currently doing animal research on the consolidation hypothesis have continued to follow the basic procedure set forth by Heriot and Coleman, i.e., a single training session followed by a single ECS treatment. However, before the current research is dis cussed, it might be helpful to give a brief review of the fundamental postulates intrinsic to the consolidation hypothesis. Postulates of the Consolidation Hypothesis Fixation: A primary premise of the hypothesis is that neuro- biological processes are initiated following a learning experience and this activity, including its completion, is called fixation. Fixation is "time-bound": The neurobiological processes (hypothe sised) must have some minimum amount of time in which to consolidate. If the neuronal activity is interrupted (such as in the case of ECS treatment) before sufficient time has been allotted for fixation, the memory will not be transferred to long-term storage. Disruption is permanent: If the consolidation process is dis rupted, fixation will not occur, and a permanent amnesia will result. (Note: This postulate and the one to follow, unlike the two presented above, are not universally accepted by consolidation theorists - Lewis, 1969.) Memory Stages: At least two memory stages are hypothesised: Short-term memory which is labile, and long-term memory which is permanent. Current Animal Research on the Consolidation Hypothesis 7 The postulates of the consolidation hypothesis have been derived from several different experiments. An example of research supporting the fundamental premise that a memory can be disrupted soon after a learning event is given by Madsen and McGaugh (1961). They trained rata in a step-down apparatus (see Chorover and Schiller, 1965) and followed this training with an ECS treatment. The animals were placed on a small elevated platform in the apparatus and given a mild foot- shock (FS) as they stepped from the platform onto a grid-floor. Half the animals were given ECS within a few seconds. On a retention test, given 24 hours later, the rats given only the FS tended to remain on the platform, i.e., they appeared to remember the shock. However, those animals given FS followed by ECS showed no evidence of remembering either the FS or the ECS treatment, and they readily stepped off the platform when tested. The first two postulates of the hypothesis are primarily supported by studies which show an amnesia gradient, i.e., an amnesic treatment given at short training-treatment intervals produces greater amnesia than a treatment given at long intervals, and there is some interval (sufficiently long enough) at which the treatment will not produce am nesia. Several different kinds of amnesic treatments have been used: cortical spreading depression, depressant drugs, convulsant drugs, antibiotics, electrical stimulation of the brain, hypoxia, hypothermia, and brain lesions (Agranoff, in press; Barondes, 1968; Glickman, 1961; McGaugh, 1966; McGaugh and Hera, in press); however, the most common agent is ECS. The critical time periods in "gradient" experiments may 8 be seen in figure 1. If the treatment Is given at points B, C, or D (typically less than six hours after training) a gradient of amnesia can be produced. Theorists use the amnesia gradient studies as support for the consolidation hypothesis by inductively reasoning that the neurobiological processes are open to disruption soon after learning but become less susceptible as time passes (amnesia produced at point D is less than at point B. To assure that the animals are not performing under the acute influence of the treatment, at least 24-hours are given before the animals are tested. To observe the effects of the treatment directly (pro-active effects) the treatment is administered at points A or E; this is a good way to test for possible "aversive" effects of ECS, for example. There are a few experiments that support the third postulate, i.e., amnesia, once demonstrated, is permanent (Chevalier, 1965; Geller and Jarvik, 1968; Greenough, Schwitzgebel, and Fulcher, 1968; Luttges and McGaugh, 1967), and the following quotation well describes the general consensus: "The amnesia did not decrease either as a function of time or as a function of repeated tests. Within the limits of these experiments, amnesia appeared to be permanent. Thus, amnesia produced by ECS continues to be most adequately explained as a consequence of interference with time de pendent processes underlying memory storage." (Luttges, and McGaugh, 1967) The fourth postulate is supported by theorists in different ways, but basically the following reasoning is used: Two memory stages must necessarily exist since an amnesia produced by a traumatic event, ad ministered at one point in time, does not appear when the trauma is Strength of trace o\ A I B D I / / - H - 1 day to several weeks / / E I Experimental treatment Before training Training period Po s t- Train ing period Delay- period Before Retention retention test period testing Typically less than 6 hours Typically less than 6 hours Fig. 1. Times of experimental treatment in studies of memory storage. (From McGaugh, 1969). 10 given at a later point in time. An experiment by Flexner, Flexner, and Stellar (1963) may be useful in illustrating this reasoning. They con ducted an experiment with "puromycin", a substance which interferes with celluler protein synthesis. They injected puromycin into the temporal areas of the brains of mice at various times after the mice had learned an avoidance response in a Y-mase. The mice were then tested for retention of the avoidance response three days following puromycin injection. When puromycin was injected six days or more following initial learning, it had no effect on performance in the retention test. However, when puromycin injections were given two days or less following initial learning, the mice showed no retention of the avoidance response. An Argument Against the Consolidation Hypothesis: Cue-dependent Amnesia The consolidation hypothesis is a logical construct, and it has been widely supported by numerous experiments (some of which have been presented above) that show specific behavioral changes in organisms following the administration of controlled treatments, e.g., an amnesia gradient. However, when an animal does not exhibit a behavior on a subsequent retest, it is not logically possible to ascertain whether or not it has lost the memory of the task; the animal may not have access to the memory at the time of testing or it may not be motivated to per form the learned task. It may well be that the traumatic treatment is not affecting fixation of the memory trace, but is interfering with retrieval processes. An experiment which alludes to this possibility 11 was conducted by Hine and Paolino (1969). They have shown than an an imal in a passive avoidance situation may appear to be amnesic for a given test trial, in terms of its overt behavior, but if the animal's electrocardiogram (EKG) is observed it is not different (similar heart- rate changes, indicative of fear retention) from the control S given only the FS treatment. Therefore, although the ECS-treated animal does not display a memory for the task overtly, there is still some evidence of learning. If it is hypothesized that ECS given to the animal, following a learning experience, interferes with the normal retrieval mechanisms influencing behavior, then amnesia for the memory (response deficit) should also occur if the ECS is administered long after (more than the typical six hour interval, see figure 1) the consolidation process has been completed. A good reason why amnesia has not been obtained at longer intervals (in the studies cited to support consolidation) is that the treatment did not affect the retrieval mechanisms associated with the task-memory. Therefore, to obtain amnesia at longer training- treatment intervals it is necessary to insure that the memory of the task is active at the time of treatment. A few experimenters have partially substantiated this hypothesis. Schneider and Sherman (1967) conducted an experiment and showed that amnesia could be produced in Ss 6-hours after the learning event if a task-related stimulus was pre sented prior to the ECS treatment (Chorover and Schiller, 1965, using the same passive avoidance task, found no amnesia if the training- treatment interval was longer than 30 seconds). Schneider and Sherman 12 used a step-down apparatus and trained their animals with a single FS to remain on the elevated platform when placed in the apparatus. The Ss receiving an immediate ECS (0.5-seconds) following the FS were am nesia for the task, i.e., they stepped off the platform more quickly than control Ss given only the FS. The animals receiving the ECS treatment 30-seconds or six hours after the FS, and then tested 24- hours later, showed no amnesia (confirming the findings of Chorover and Schiller, 1965). However, Ss given a second non-contingent FS at 30-seconds or six hours after the initial training trial followed by ECS within 0.5-seconds, were amnesic. Schneider and Sherman hypothe sized that the second (non-contingent) FS activated an "arousal-state" in the Ss, similar to that instated by the initial FS, and the ECS treatment administered within 0.5-seconds interfered with that memory component of the FS. Therefore, the animals were amnesic when tested. An experiment conducted by Misanin, Miller, and Lewis (1968) is even more conclusive in showing that ECS can affect a memory at long training-treatment intervals. They used a Skinner box-like lick chamber and trained water deprived rats to locate and drink from a tube which was extended into the chamber. They then presented a conditioned stimulus (CS), an 80 db white noise, and followed the CS with a FS. Animals receiving an ECS after this FS within 0.5-seconds showed an amnesia for the CS (i.e., they continued to drink) as compared to con trol Ss given only the FS, but Ss given the ECS treatment 24-hours after the training trial were not amnesic. However, When the CS was presentee (to another group of animals) 24-hours after the training FS and then 13 followed by ECS (within 0.5-seconds) the animale were aamesic. Theee reaults aupported the data obtained by Schneider and Sherman, i.e., an amne8ia was obtained at a long training-treatment interval. Miaanin, Miller, and Lewis hypothesised that the CS (given 24-hours after the training FS) reactivated the memory of the task and the ECS (given within 0.5-8econds) acted directly on that "active" memory (cue- dependent amnesia). The Misanin, Miller, and Lewis experiment obviously did not sup port the consolidation hypothesis and an almost immediate attempt to replicate the study was made by Dawson and McGaugh (1969), but they failed to obtain amnesia in those Ss given the CS-ECS treatment 24- hours after the initial training trial. However, as Misanin et al. point out, it is very important that the memory is indeed reinstated, because if the animal attends to anything else (other than the CS) prior to the ECS treatment no amnesia for the task should result. Therefore, the negative finding of Dawson and McGaugh should be con sidered carefully. Experiments conducted with goldfish partially sustain the cue- dependent amnesia hypothesis of Misanin et al. (Davis, 1968; Davis and Klinger, 1969). An amnesia was produced in the fish 24-hours after training if they were returned to the training tank prior to the am nestic-treatment. It seems quite reasonable to assume that the fish "reinstated" the memory of the task when they were returned to the training environment and the amnestic-agents disrupted the "activated" memory. 14 An experiment by Robbins and Meyer (1970) is even more conclusive I in supporting a "cue-dependent" amnesia hypothesis. They trained rats in a series of discrimination tasks (three) under either appetitive or aversive conditions. The animals were trained to discriminate between two stimuli (in an apparatus designed similarly to the maze developed by Krechevsky, 1932) in each of the three basks, but the motivating conditions for each of the three tasks did not necessarily remain the same for all Ss, e.g., one group of animals learned the first dis crimination under appetitive conditions, and the following two tasks under aversive conditions, but another group of Ss learned the first and third tasks under the appetitive condition and the second task under the aversive condition. Several different sequences of motiva ting conditions were used for different groups of animals. Upon com pletion of the third task, the Ss were given an ECS treatment and 24- hours later placed back into their respective "first" or "second" tasks. The results showed the animals to be amnesic in a particular way. If the animal was given ECS after a third-learned appetitive task, it was only amnesic for the appetitive tasks previously learned regardless of whether those tasks came first or second in the initial learning sequence. This was true for the opposite condition as well! If the third task was aversive, the animal was amnesic for only the aversive tasks in the three-task learning paradigm. Robbins and Meyer hypothesised that the memory of the task depended upon the particular motivational state, i.e., appetitive or aversive. If such a state was active at the time of the ECS treatment, an amnesia for those moti- 15 vationally-linked memories would result. An experiment by Howard and Meyer (1971) replicated these findings. Dissertation Purpose The experiments cited above do not support consolidation, but it is not clear what a better, alternative, hypothesis might be. There fore, the purpose of this dissertation was not only to challenge the theory of consolidation, but to provide empirical evidence for an al ternative interpretation, i.e., an amnesic agent disrupts the memory that is active at the time of treatment. To accomplish this purpose, three conditions had to be satisfied: (1) The learning task had to be complex; (2) an amnesia for an "old" memory had to be obtained; and (3) the amnesia obtained had to represent a "cognitive" change and not merely a gross modification of behavior. Task Complexity The task had to be complex to insure that the Ss were not merely reacting to a general behavioral change such as "disinhibition of freezing behavior" (Routtenberg and Kay, 1965; Kopp, Bohdanecky, and Jarvik, 1967). In the Robbins-Meyer study, for example, it took the Ss several trials to relearn the first or second tasks. If the ECS in duced disinhibition from freezing, the Ss might run the maze faster but there is no reason to believe that this could account for the signifi cant increase in errors obtained. Amnesia for an "old" Memory The consolidation hypothesis is directly challenged if amnesia can be obtained for a memory which has had ample time in which to fixate. Therefore, the Ss were trained in the complex task over "days" and the ECS treatment was not given for 24-hours following the comple tion of acquisition. Cognitive Change To support the cue-dependent amnesia hypothesis, it must be verified that the ECS-induced amnesia represents a memory (cognitive) change (since the ECS is assumed to disrupt an active, cue-instated, memory). Therefore, the ECS-induced amnesia had to be shown as a "specific" memory deficit, i.e., the Ss given the cue-ECS treatment 24- hours after training should only be amnesic for those memories instated by the cue, and not for those associated with another independent stimulus. It took considerable effort to satisfy the required conditions of the experiment. In much of the research conducted on the consolidation hypothesis, stereotypic procedures are used; however, to adequately test the dissertation hypothesis an entire "new" set of procedures had to be developed. This was accomplished in two "primary" pilot studies. Pilot Study #1 METHOD Subjects Twelve male rats (Sprague-Dawley), weighing approximately 200 grams, were used for the study. The Ss were housed in individual cages and maintained on a 23-hour food deprivation schedule throughout the training and testing periods. Apparatus 17 Two Skinner boxes (equipped with a food-pellet dispenser) were used in training the Ss in a discrimination task. A Beckman brief- stimulu8 generator (type 735B) was used to deliver the ECS* Procedure The Ss were shaped to bar-press on a continuous-reinforcement schedule (CRF), and this was concluded after all Ss were responding at least 50-times in a 15-minute session. The animals were then trained in the discrimination task (each S given one 15-minute session each day). The Ss were trained to press one of the bars in the chamber when the lights in the box were "on" and to press the other bar when the lights were "off". The animals were assumed to have learned when they reached the arbitrary criterion of a 2:1 ratio, correct responses to errors respectively. Twenty-four hours after reaching criterion the Ss were assigned to one of four groups and treated as follows: (1) lights-on - ECS; (2) lights-on - NECS; (3) lights-off - ECS; (4) lights-off - NECS. The animals were given the treatment inside of the chamber. Twenty-four hours after treatment the Ss were tested in the chamber on the same discrimination task acquired in the initial learning. RESULTS AND DISCUSSION All Ss performed approximately the same in the test session, which was not surprising. A serious problem had appeared when it came time to treat the animals with ECS. To administer the ECS, small ear- clips (the brief-stimulus electrodes) were affixed to the animal's pinnae, and the Ss attended to these clips and not to the lights which | 18 {was crucial. Therefore, a different procedure was needed. Pilot Study #2 METHOD j I Sub jects | Sixteen male rats (Long-Evans hooded), weighing approximately | 200 grams, were used for this study. The housing and deprivation scheduling was the same as for pilot study #1. Apparatus The same equipment used in pilot study #1 was used for this study. Procedure The Ss were shaped to bar-press to the criterion of 50-responses i | in a 15-minute session. Following shaping, the Ss were trained in a l | | discrimination task (responding on only one bar, the second bar was not i connected to the food-dispenser). The discriminative stimulus (S®) for i responding (when a bar-press produced a food-pellet) was the "absence" ! A ! of tone; the negative stimulus (S ), signalling the animal not to j respond (when a bar-press did not produce a food-pellet), was a 200 cps tone. Learning was established in two 15-minute training sessions. All Ss were adapted with ear-clips during training so that when the i ECS-electrodes were attached for the treatment, the Ss did not attend to them. The Ss were adapted to the clips once each day, at times not contingent to the training session, for three minutes. Twenty-four hours following the completion of the second training session the Ss were assigned to one of four groups and treated as follows: (1) present 200 cps tone - ECS; (2) present 200 cps tone - NECS; (3) 19 present 2000 cps tone - ECS; (4) present 2000 cps tone - NECS (see table 1). Twenty-four hours after treatment the Ss were retested In the task. The test measure for an S was the difference between the SD/S^ ratio obtained on the test minus that same ratio on the last day of training. RESULTS AND DISCUSSION The primary results of this study may be seen in table 2. Both ECS groups, although not significantly different from each other, are significantly different from the NECS groups (p<\05). This looks like a non-specific amnesia rather than the specific one demanded by the cue- dependent amnesia hypothesis; however, after-the-fact, it seems proba ble that the 2000 cps tone may have reinstated the 200 cps tone memory via "stimulus generalization" prior to the ECS treatment and therefore an amnesia appears in both groups of Ss. Using the information obtained in the pilot studies the disserta tion experiment was initiated. The changes were: (1) adapt the ani mals to ear-clips prior to ECS treatment; (2) use a novel stimulus which will not produce stimulus generalization to the training stimulus; (3) administer the stimulus-ECS treatment in a neutral environment so that the Ss do not reinstate memories of the task other than those associated with the treatment stimulus; (4) include two additional groups of Ss which are treated with ECS or sham-ECS on the experimen ter's arm: The Ss have been consistently taken from the home-cage and placed in the training apparatus and therefore, some memory of the task should be active if the S is taken from its cage and given an ECS Table 1 Pilot Study #2 Experimental Design Group________Reinstatement Stimulus________ ECS_________n I 200 cps tone Yes 4 II 200 cps tone No 4 III 2000 cps tone Yes 4 IV 2000 cps tone No 4 Table 2 21 Pilot Study #2 Mean Difference Scores Group_____________________ Ratlo-Difference Score I -0.55 II +0.13 III -0.48 IV +0.16 22 treatment on the experimenter's arm and an amnesia for the task should |result. 23 FOOTNOTES The behavioral deficit obtained on a subsequent retest, following a traumatic event (e.g., ECS), is called amnesia. The term "retrograde" is used to describe the resultant amnesia (RA) be cause there is a gradient of amnesia following the trauma; there is greater amnesia the closer a given memory is to the traumatic event. CHAPTER II METHOD Subjects Thirty-six (Long-Evans hooded) rats, weighing approximately 200 grams at the beginning of the experiment, were obtained from Simonsen Laboratories for this study. The Ss were housed in individual cages and maintained on a 23-hour food deprivation schedule throughout the training and testing periods, and were given full access to water at all times. Apparatus Two Skinner boxes equipped with a food-pellet dispenser, dispens ing Noyes-pellets (size 4.0 mm x 3.3 mm x 45 mg), were used in this study. The boxes also had built-in speakers. Grason-Stadler program ming equipment in conjunction with two Gerbrand's variable interval programmers were used to operate the boxes. A "reinstatement" box was constructed out of plywood (12 inches high x 12 inches wide x 16% inches long). A speaker (comparable to those in the Skinner boxes) plus a seven watt (clear) light were built into one side. A simple throw-switch was used to control the audio or light stimulus presentation to the animals placed in this box. All treatments of tone or light (and contingent ECS) mentioned below were administered in this box. The reinstatement box was used to prevent the Ss from reinstating any other memory than the one dependent upon the stimulus presented. For example, if the Ss were given the treat- 24 _______________________________ 25 ment In the Skinner box, they might reinstate the memory of the task regardless of the stimulus presented, and therefore, an amnesia would result confounding the interpretation of the data. For those Ss not reinstated with the tone or light stimuli, the ECS treatment was given to the Ss while placed on the arm of the ex perimenter. Trans-pinnae ECS was supplied by a Beckman 735B Liberson Brief Stimulus Therapy Apparatus delivering 55 roa rms. rectangular waves in 0.5-m second pulses at 220 cps for 0.5-seconds. This current produced a full tonic-clonic convulsion in all Ss to which it was administered. A Heathkit sine-square generator (model 16-82) was used to deliver the 350 cps tone. For the pretraining phase of the experiment a large open box (approximately 16 inches high x 20 inches wide x 60 inches long) was used to familiarize the Ss with the Noyes pellets. Procedure Two replications were conducted in this experiment, 18 Ss in each replication, and the same procedure was followed in both instances. Upon delivery, all Ss were placed into individual cages without food. Twenty-four hours after this initial placement, all of the ani mals were put into the large open (familiarization) box with several of the Noyes pellets scattered upon the floor of the box. The Ss remained in the box for 24-hours to become familiarized with the small-pellet food. At the end-of familiarization, the Ss were once again placed back into the individual cages and randomly assigned to one of six 26 different treatment groups (see table 3). Pretraining; Twenty-four hours after completion of familiarisa tion all Ss were shaped to press bar #1 on a continuous reinforcement schedule (CRF) in 15-minute sessions (one session a day for each ani mal). Pretraining was considered complete after seven days of this shaping wherein 1007. of the Ss were making at least 50 correct respon ses in the session. Training: On day eight, training was started. All Ss now had to learn to discriminate between no tone, which was the discriminative stimulus (S®) for the bar-press response, and the 350 cps tone, which was the negative stimulus (S^ ) signalling the S not to respond. The Ss were reinforced on a CRF schedule for correct responses. No food pellets were issued for a bar-press response on bar #1 when the tone was on, and never for a bar-press response on bar #2. The tone stim ulus was programmed on a variable-interval of 25-seconds (VI-25). The training sessions, of which there were two (day-eight and day-nine), were 15-minutes in duration. (Note: during pretraining and training the Ss were adapted to ear-clips, in the reinstatement box, once each day for 3-minutes at times not contingent to the S's training session.) Treatment: Twenty-four hours after completion of training all Ss were treated according to the six group experimental design shown in table 3. Ss in group I were taken from their cages and placed into the reinstatement box with the ECS-electrodes attached. After the animals had all four feet on the floor of the box, the 350 cps tone was turned on. The tone was presented for five seconds, immediately after 27 Table 3 Experimental Design Group___________ Reinstatement Stimulus_________ ECS_______n I 350 cps tone Yes 6 II 350 cps tone No 6 III 7-watt light Yes 6 IV 7-watt light No 6 V experimenter's arm Yes 6 VI experimenter'8 arm No 6 28 (0.5-seconds) which the Ss were given the ECS treatment. Both the stimuli and the ECS were administered manually by the experimenter. Ss in group II were treated identically to those in group I except that they were given sham*ECS. Ss in group III were treated like those in group I except that they were presented the seven-watt light stimu lus instead of the 350 cps tone. Group IV Ss were treated just like the Ss in group III except that no ECS was given. Animals in groups V and VI were placed on the experimenter's arm and given ECS or sham- ECS respectively. All Ss were returned to their home cages after treatment. Testing: On the eleventh day, 24-hours after treatment, all Ss were placed back into the Skinner boxes (one at a time for a 15-minute session). Each animal responded ideosyncratically, i.e., some Ss were high responders, others were low responders, and still others were in- between; therefore, a "difference" score was used to control for this variability so that the treatment effects could more easily be seen: The ratio of the total number of responses to the number of error- responses (Blough, 1966; Hoffman, 1965) on the last day of training was subtracted from the same ratio, for a given animal, obtained on test day. Individual differences in motivation (responding) were controlled, therefore, and the differences found reflected primarily the treatment administered. A transformed score was developed for ease of statisti cal analysis only. To derive the transformed score +1.00 was added to the difference score and then multiplied by 100 (see below). A low transformed score indicated amnesia. 29 SD(test) + (test) - Sp(training) + (training) ■ Difference Score A & S (test) S (training) (Difference Score 4- 1.00) ■ Transformed Score Kote: Ss responding at a low level (responding a total of 59 times or less in the 15-minute test session) were removed from the study because ratios are no longer meaningful when they are based upon an exceptionally small number of total responses; a few "chance" responses throw the ratio out of alignment. Ratios only become repre sentative when an adequate response sample is available. For example, an S might respond only in the first few minutes of the session making a total of only 10 responses with just one error to produce a high ratio of 10.00, but there is no way of knowing what the ratio would be if the S continued to respond during the entire testing session; Ss responding throughout the session produce much more stable ratios. CHAPTER III RESULTS Six of the Ss responded below the ratio cut-off score of 60 and therefore they were removed from the study. These Ss were in the fol lowing groups: Two Ss removed from group IV; two from group V; one from group II; and one from group VI. The method of "unweighted means" was used in the analysis of variance to cope with the problem of un equal numbers of Ss within the six different treatment groups (the raw data and the analysis of variance table are presented in appendix 1 and 2 respectively). The performance of the Ss during training was compared to chance behavior (chance was defined as an equal rate of responding in both the S» and S^ periods and was calculated to be 1.37 by taking the ratio of the total time on the tape programmer to the time allotted for the S stimulus; for the ratio measure see Blough, 1966) and it was found that the Ss had indeed learned (p<^ .001). Therefore, a definite memory had been established. The primary results of the experiment, showing the effects of ECS on retention, may be seen in table 4 and in figures 2 and 3 below. Figure 2 shows that the control Ss given no-ECS and group III Ss given light-ECS improve in the test session, i.e., they have scores higher than 100 (a transformed score of 100 would indicate no change in per formance, see formula above); however, Ss in the arm-ECS group are slightly below 100, indicating that they are moderately amnesic, and Table 4 Mean Transformed Scores Group Mean transformed score I (tone-ECS) 61.17 II (tone-NECS) 134.00 III (light-ECS) 117.67 IV (light-NECS) 135.00 V (arm-ECS) 90.00 VI (arm-NECS) 121.40 CM CO 140 . i | 120 . 100 Transformed 80 . Scores 60 . 40 20 i ! I II III IV V VI tone-ECS tone-NECS light-ECS light-NECS arm-ECS arm-NECS j | ! Fig. 2. Mean transformed difference scores of the six different groups on test day. CO CO 140 120 100 Transformed Scores 60 Light Ana Tone Reinstatement continuum: Mean transformed difference scores of Ss reinstated with various Fig stimuli prior to ECS or sham-ECS treatment 34 the Ss in the tone-ECS group are considerably below 100, and therefore, are strongly amnesic. Figure 3 clearly shows that all of the ECS- treated groups perform more poorly than the no-ECS groups. However, the amnesia is greatest for those Ss presented with the tone stimulus prior to ECS. The analysis of variance performed on this data showed that there was a significant ECS effect (p<^ .025). To test the main hypothesis of the dissertation (presented under the heading "disserta tion purpose") specific planned comparisons were made. The result of the planned comparisons may be seen in table 5. There is definitely a "memory" effect. Not only is group I signifi cantly different from groups II, IV, and VI but it is also signifi cantly different from groups III and V. A memory deficit occurred when a previous "discriminative" stimulus was presented prior to ECS, but no amnesia occurred if a novel stimulus (a stimulus not used in the train ing of the discrimination task) was presented prior to the ECS treat ment. However, mild amnesia occurred when the animal was taken from its cage and given an ECS treatment on the experimenter's arm. This leads to an interesting possibility, i.e., a reinstatement gradient (see figure 3). What this seems to imply is that merely taking the animal out of the cage and placing it on the arm of the ex perimenter reinstates some portion of the task-memory (remember that placing the S on the experimenter's arm during training was always as sociated with the task) and consequently there is an amnesia produced for the discrimination task. However, this amnesia is not as great as that found in Ss reinstated with the 350 cps tone stimulus. 35 Table 5 Specific Comparisons Comparison Significance Group I vs Group III p < .005 Group I vs Group V p< .025 Group III vs Group V p < .025 Group IV vs Group VI None Group I vs Mean of Groups II, IV, & VI p < .001 Group III vs Mean of Groups II, IV, & VI None 36 Interaction among the groups was probable. The control group with the lowest mean-score (group VI) is not significantly different from the control group with the highest mean-score (group IV). Therefore, an interaction is likely because all three of the ECS-treated groups were significantly different from each other. This interaction may readily be seen in figure 3 also. Additional information is obtained by the analysis of the sD/si^ ratio scores. The Ss in the tone-ECS group were the only animals significantly different from the others (p<^.05) when tested (see figure 4). That this difference is due to the experimental treatment is indicated by the fact that no significant differences were found between the groups for this ratio score on the last day of training. By looking at the raw S® and scores for the various groups, it may be inferred that the change in ratio (SD/S^ ) for the tone-ECS Ss is primarily due to the reduction of S® responses; the S^ responses re main relatively constant: It may be further seen (in figure 5) that the tone-ECS group has a sharp decrease in S® responses (although not statistically significant) on test day as compared to the last day of training; however, in figure 6 it may be seen that there is almost no change at all in the number of S^ responses for this group. The arm- ECS Ss have a slight reduction in both their S® and S^ responses. An even clearer picture of the response deficit in the tone-ECS Ss is shown in figure 7; a comparison is made between tone-ECS Ss and all others for mean S® and S^ responses on the last day of training (T-2) and test. On T-2 all Ss make more S® responses than S^ responses; cn 1.54- IV (light-NECS) 1.48- 1.42' III (light-ECS) V (arm-ECS) VI (arm-NECS) 1.37. 1.Si ll (tone-NECS) 1.25 - S /S Ratios 1.19. 1.13- 1.07 ■ 1.01 - .95 - .89 - .83 - Last Training Day- Test Fig. 4. Comparison of the six groups for S /S ratios on the last training day and test. 00 <n SD Responses VI (arm-NECS) 90 84 78 I (tone-NECS) 72 IV (light-NECS) III (light-ECS) 66 60 54 (ann-ECS) (tone-ECS) 48 42 36 Last Training Day Test Fig. 5. Comparison of the six groups for SD responses on the last day of training and test. o\ <n 76 . 70 64 Responses 58 52 . 46 . 40 . . ; VI (arm-NECS) II (tone-NECS) I (tone-ECS) III (lig}it-ECS) V (arm-ECS) IV (light-NECS) Last Training Day Test Fig. 6. Comparison of the six groups for S^ responses on the last day of training and test. Mean Responses 80 70 60 D S (all others) (tone- ECS) 50 D (all others) (tone- ECS) T-2 Test Fig. 7, Comparison of tone-gCS Ss to all others on the last day of training (T-2) and test for mean S and S^ responses. 41 however, on test the tone-ECS Ss greatly reduce their SD responses. Finally, aside £rom the analyses previously conducted, a further analysis was performed on the responses made by the Ss on bar #2 in the test session. Bar #2 responses were never reinforced and yet it was found that Ss in group III (light-ECS) made significantly more respon ses on this bar (p<\05) than the Ss in any of the other groups. It is not well understood why this occurred and no interpretation is offered. CHAPTER IV DISCUSSION The important findings of this experiment were: (1) Both the tone-ECS Sa and the arm-ECS Ss were amnesic for the task, but the light-ECS Ss were not amnesic; (2) the tone-ECS Ss were significantly more amnesic than the arm-ECS Ss; (3) the ECS-induced amnesia was pro duced 24-hours after the animals reached criterion on the discrimina tion task. Cue-dependent Amnesia It is our assumption that ECS affects a memory which is active at the time of treatment (Misanin, Hiller, and Lewis, 1968). The animals in this experiment showed a strong amnesia, on a subsequent test ses sion, if the training stimulus (350 cps tone) was presented prior to the ECS treatment; however, no amnesia was produced if a novel stimulus (seven watt light) was presented prior to ECS. Thus a definite memory is being acted upon by the ECS; otherwise, these two groups of Ss should both be amnesic since the motivational state of the organism (as defined by Robbins and Meyer, 1970) was the same. Robbins and Meyer hypothesized that the motivational cues (i.e., whether or not the ani mal had just completed a trial in an aversive or appetitive task) prior to the ECS treatment was crucial for the amnesia; however, this hypoth esis is not supported here since both the tone-ECS and the light-ECS Ss were trained under the same appetitive conditions. The "motiva- tional-cue" hypothesis is also not supported in this experiment because 42 43 the difference between ratios, the measure used for the statistical analysis, controlled for differences in motivation. For example, an S might make more total responses on test than on the last day of training, but the ratio score need not vary, i.e., the Ss should still make a proportionate amount of errors to total responses, and the dif ference between two such ratios could only reflect a "cognitive" change and not a motivational one. The cue-dependency hypothesis is given even more support by the fact that the animals given ECS on the ex perimenter's arm, although less amnesic than the Ss in the tone-ECS group, were more amnesic than the Ss in the light-ECS group. Ss treated on the arm of the experimenter were quite possibly reinstating something of the task (since being taken out from the cage and placed on the arm always accompanied being placed in the training apparatus) prior to the ECS treatment, and therefore amnesia resulted. However, presentation of the light (in the reinstatement box) might have reasonably interfered with activation of a task-related memory, and therefore the ECS treatment did not produce amnesia in these Ss. These results sustain the data obtained by Hisanin, Miller, and Lewis (1968), i.e., amnesia was produced 24-hours after training by presenting the Ss with a training "cue" prior to the ECS treatment. Discrimination Task The discrimination task used in this experiment was developed for particular reasons. To support a cue-dependent amnesia hypothesis it was necessary to show that ECS would produce amnesia when the training stimulus was presented prior to the treatment but not when a novel 44 I stimulus was presented; however, as discovered in Pilot Study #2, the training and novel stimuli had to be sufficiently different from each other to prevent stimulus-generalization (see Jenkins and Harrison, 1960). Therefore, a tone was used for one stimulus and a light for the I other. A tone was used as the training stimulus because data from Pilot Study #2 showed that the animals quickly learned the discrimina tion between tone and no-tone, and the Ss noticeably attended to the tone when it was presented in the reinstatement box. The tone was used as the because of past research. Hunt and Brady (1951) investigated the effects of ECS on a conditioned-emotional response (CER) by training rats to lever-press for water reinforcement in an operant chamber. When the Ss achieved a stable rate of respond ing, a CER was established in a different apparatus and this emotional response transferred to the lever-pressing situation in the chamber. After six ECS treatments (given to the Ss once each day) none of the experimental animals showed any evidence of retaining the CER, either in the original training situation or in the operant chamber. Hunt and Brady assumed that the ECS was acting specifically on the CER because the bar-pressing performance of the experimental animals remained the same, i.e., the rate of responding did not change. It was desirable for this current experiment to show a specific (cue-dependent) deficit for the task, and therefore the tone stimulus was assigned the S^ function in the discrimination task since the S^ is similar to the conditioned stimulus (CS) used in the Hunt and Brady study, i.e., both stimuli evoke non-responding. The importance of having the stimulus 45 evoke non-responses can be infered from other studies also. For ex ample, Posluns and Vanderwolfe (1970) found that if the ECS treatment followed an S's training in a task which required movement no RA could be produced. They trained the animals in a one-trial escape task and discovered that ECS given 1-second after learning did not produce am nesia, and in an active avoidance task they administered ECS 30-seconds after learning and found no deficit. However, if the ECS treatment was administered after one-trial passive avoidance training they were able to obtain RA. They concluded that ECS acts as a disinhibitor of move ment, i.e., the animal becomes more active following the ECS treatment, and therefore in one-trial escape and active avoidance the S's behavior is facilitated but in one-trial passive avoidance (where the animal must inhibit movement) his behavior is impaired (amnesia results). This dissertation experiment does not have a one-trial task, but the tone-stimulus was used as the S^ due to possible generalizations, i.e., perhaps amnesia can only be found in multi-trial appetitive tasks when the S is supposed to refrain from responding. The resultant amnesia in the tone-ECS Ss can be explained by as suming that the tone-stimulus (when presented 24-hours after training) activated the task memory and the ECS affected that reinstated memory. It is difficult to assess how the ECS produces the amnesia, but a strong possibility is that amnesic-agents produce extinction in a single trial. When a discrimination is formed the SD and S^ stimuli take on special significance depending upon the reinforcement contingencies, i.e., an SD indicates when a bar-press will yield a food pellet, and a S^» 46 indicates when a bar-press will not produce a pellet (see Blough, 1966). When the S is trained to discriminate between these two types of stimuli it soon learns to respond when the S& is presented and to withold responding when the is presented; however, if in subsequent training sessions the SD responses are extinguished, i.e., a bar-press during the S® presentation no longer produces a food pellet, the only behavioral change will be a reduction of responses during the S® period since responses during the presentation have already been extinguished (see Keller and Schoenfeld, 1950). In figure 7 a com parison was made between tone-ECS Ss and all others for mean S® and responses on the last day of training (T-2) and test: on T-2 all Ss make more S® responses than S^ responses but on test the tone-ECS Ss reduce their S® responding to the level of responding. The reduction of S® responses by the tone-ECS Ss was exactly what would be expected if the Ss were extinguished over several trials. It seems quite possible, therefore, that the ECS treatment acted like extinction except that it completed the process in a single trial. This hypoth esis might seem to be incorrect since the tone-stimulus presented just prior to the ECS treatment was the S^ and not the S®, i.e., the S^ responses should have gone up and the S® responses should not have changed. However, it can easily be assumed that, although tone-onset and presentation were indeed the , tone-offset was the S® since it immediately preceded the reinforcement conditions and ECS extinguished that aspect of the stimulus. Extinction of a novel stimulus, i.e., light, would have no effect on the performance of the discrimination 47 task, and therefore, amnesia is not observed on test day for those animals. The ratio measure used in this experiment was borrowed from dis crimination studies by Blough (1966) and Ferster and Hammer (1966). The proportion of errors (S^ responses) to the total number of respon- ses (Su + S responses) can be used as a measure of learning, and the difference between two such ratios (for a given animal) produces an excellent index of retention; if the S makes more errors in proportion to total responses on test than it does on the last day of training then the difference score will be negative indicating forgetting (amnesia), but if the S performs about the same or makes even fewer errors to total responses on the test session than on the last training session the difference score will be positive indicating retention or learning. Conclusion ECS affects the memory of an organism that is active at the time of treatment. Presentation of a novel stimulus prior to ECS produces no amnesia whereas presentation of a meaningful (training) stimulus prior to ECS produces a very specific amnesia in rats. An hypothesis of "cue-dependency" is offered to account for these results; the con solidation hypothesis is not supported. « | Adams, H. I Adams, H. Agranoff, Barondes, Barondes, Blough, D Burnham, 1 Chevalier Chorover, Coons, E. 48 LIST OF REFERENCES E., and Lewis, D. J. Electroconvulsive shock, retrograde amnesia, and competing responses. Journal of Comparative and Physiological Psychology, 1962, 55, 299-301. E., and Lewis, D. J. Retrograde amnesia and competing responses. Journal of Comparative and Physiological Psychology, 1962, 55, 302-305. B. W. Effects of antibiotics on long-term memory formation in the goldfish. In W. K. Honig & P. H. R. James (Eds.), Animal Memory. New York: Academic Press, in press. S. H. Effect of inhibitors of cerebral protein synthesis on "long-term" memory in mice. In D. H. Efron (Ed.), Psychopharmacology: A review of progress, U.S. Government Printing Office, Washington D.C. PHS Publ. No. 1836, 1968, 905-908. S. H., and Cohen, H. D. Puromycin effect upon successive phases of memory storage. Science, 1966, 151, 594-595. S. The study of animal sensory processes by operant methods. In W. K. Honig (Ed.), Operant Behavior: Areas of Research and Application. New York: Appleton-Century- Crofts, 1966. F. H. Retroactive amnesia: Illustrative cases and tentative explanation. American Journal of Psychology, 1903, 14, 382-396. J. A. Permanence of amnesia after a single posttrial electroconvulsive seizure. Journal of Comparative and Physiological Psychology, 1965, 59, 125-127. S. L., and Schiller, P. H. Short-term retrograde amnesia in rats. Journal of Comparative and Physiological Psychology, 1965, 59, 73-78. E., and Miller, N. E. Conflict versus consolidation of memory traces to explain "retrograde amnesia" produced by ECS. Journal of Comparative and Physiological Psychology, 1960, 53, 524-531. 49 Davis, R. E. Environmental control of memory fixation in goldfish. Journal of Comparative and Physiological Psychology, 1968, 65, 72-78. Davis, R. E., and Klinger, J. D. Environmental control of amnesic effects of various agents in goldfish. Physiology and Behavior. 1969, 4, 269-271. Dawson, R. G., and McGaugh, J. L. Electroconvulsive shock effects on a reactivated memory trace: Further examination. Science. 1969, 166, 525-527. DeCamp, J. E. A study of retroactive inhibition. Psychological Monographs, 1915, 19, 84. Duncan, C. P. The effect of electroshock convulsions on the maze ha bit in the white rat. Journal of Experimental Psychology, 1945, 35, 267-278. Duncan, C. P. Habit reversal induced by electroshock in the rat. Journal of Comparative and Physiological Psychology, 1948, 41, 11-16. Duncan, C. P. The retroactive effect of electroshock on learning. Journal of Comparative and Physiological Psychology, 1949, 42, 32-44. Ferster, C. B., and Hammer, G. E. Synthesizing the components of arithmetic behavior. In W. K. Honig (Ed.), Operant Behavior: Areas of Research and Application. New York: Appleton- Century-Crofts, 1966. Flexner, J. B., Flexner, L. B., and Stellar, E. Memory in mice as affected by intracerebral puromycin. Science, 1963, 141, 57-59. Glickman, S. E. Perseverative neural processes and consolidation of the memory trace. Psychol. Bull., 1961, 58, 218-233. Heriot, J. T., and Colman, P. D. The effects of electroconvulsive shock on retention of a modified "one-trial" conditioned avoidance. Journal of Comparative and Physiological Psychology, 1962, 55, 1082-1084. Hine, B., and Paolino, R. M. Retrograde amnesia: Production of skeletal but not cardiac response gradient by electro convulsive shock. Science, 1970, 169, 1224-1226. 50 Hoffman, H. S. Theory construction through computer simulation. In W. F. Prokasy (Ed.), Classical Conditioning; A symposium. New York: Appleton-Century-Crofts, 1965, 107-117. Howard, R. L., and Meyer, D. R. Motivational control of retrograde amnesia in rats: A replication and extension. Journal of Comparative and Physiological Psychology, 1971, 1, 37-40. Hudspeth, W. J., McGaugh, J. L., and Thompson, C. W. Aversive and amnesic effects of electroconvulsive shock. Journal of Comparative and Physiological Psychology, 1964, 57, 61-64. Hunt, H. F.» and Brady, J. V. Some effects of electro-convulsive shock on a conditioned emotional response ("anxiety"). Journal of Comparative and Physiological Psychology, 1951, 44, 88-98. Jenkins, H. M., and Harrison, R. H. Effect of discrimination train ing on auditory generalization. Journal of Experimental Psychology, 1960, 59, 246-253. Keller, F. S., and Schoenfeld, W. N. Principles of Psychology. New York: Appleton-Century-Crofts, 1950. Kopp, R., Bohdanecky, Z., and Jarvik, M. E. Long temporal gradient of retrograde amnesia for a well-discriminated stimulus. Science, 1966, 133, 1547-1549. Krechevsky, I. "Hypothesis" versus "chance" in the presolution period of sensory discrimination learning. Psychological Review, 1932, 3, 27-44. Lewis, D. J. Sources of experimental amnesia. Psychological Review, 1969, 76, 461-472. Luttges, M. W., and McGaugh* J* !*• Permanence of retrograde amnesia produced by electroconvulsive shock. Science, 1967, 156, 408-410. McConnell, J. V. Memory transfer through cannibalism in planarians. Journal of Neuropsychiatry, 1962, 3, 42-48. McGaugh, J. L. Time-dependent processes in memory storage. Science, 1966, 153, 1351-1358. McGaugh, J. L. Facilitation of memory storage processes. In S. Bogoch, (Ed) The future of the brain sciences, New York: Plenum Press, 1969, 355-370. 51 McGaugh, J. L., and Herz, M. J. Memory Consolidation, Albion Publishing Company, In press. McGaugh, J. L., and Dawson, R. G. Modification of Memory Storage Processes. Behavioral Science. 1971, Vol. 16, No. 1, 45-63. Madsen, M. C., and McGaugh, J. L. The effect of ECS on one-trial avoidance learning. Journal of Comparative and Physiological Psychology, 1961, 54, 522-523. Misanin, J. R., Miller, R. R., and Lewis, D. J. Retrograde amnesia produced by electroconvulsive shock after reactivation of a consolidated memory trace. Science, 1968, 160, 554-555. Mueller, G. E., and Pilzecker, A. Experimentelle Beitrage zur Lehre vom Gedachtnis. Zeitshrift fur Psychologie, 1900, Suppl. No. 1. Posluns, D., and Vanderwolfe, C. H. Amnesic and disinhibitory effects of electroconvulsive shock in the rat. Journal of Comparative and Physiological psychology, 1970, 73, 291-306. Robbins, M. J., and Meyer, D. R. Motivational control of retrograde amnesia. Journal of Experimental Psychology, 1970, 84, 220-225. Routtenberg, A., and Kay, K. E. Effect of one electroconvulsive seizure on rat behavior. Journal of Comparative and Physiological Psychology, 1965, 59, 285-288. Schneider, A. M., and Sherman, W. Amnesia: A function of the temporal relation of footshock to electroconvulsive shock. Science, 1967, 159, 219-221. Thompson, R., and Dean, W. A. A further study on the retroactive effect of ECS. Journal of Comparative and Physiological Psychology, 1955, 48, 488-491. 52 APPENDIX RAW TRANSFORMED SCORES Tone-ECS Light-ECS Arm-ECS 89 236 77 36 65 79 82 140 140 11 95 _64 104 69 i - 360 45 101 Y - 90.00 i - 367 * “ 706 Y - 61.17 Y - 117.67 Tone-NECS Light-NECS Arm-NECS 130 82 169 114 110 76 136 177 119 195 171 151 95 * » 540 _92 * » 670 Y - 135.00 * « 607 Y - 134.00 Y » 121.40 ANALYSIS OF VARIANCE (UNWEIGHTED MEANS) SUMMARY TABLE Source o£ Variance df SS MS F Significance A 1 2,472 2,472 6.52 p < .025 B 2 719 359 0.95 -- AB 2 992 496 1.31 -- S/AB 24 9,099 379

Linked assets

University of Southern California Dissertations and Theses

Conceptually similar

PDF

Cue Dependent Active Memory And Ecs Produced Memory Occlusion

PDF

Habituation Of The Multiple Unit Discharge Response To White Noise Stimulation In The Unanesthetized Rabbit

PDF

Monocular Acquisition And Interocular Transfer Of Two Types Of Discriminations In Normal And Corpus Callosally-Sectioned Guinea Pigs

PDF

Visual Evoked Potentials, Laterality Of Eye Movements, And The Asymmetry Of Brain Functions

PDF

Operant Discrimination Of An Interoceptive Stimulus In The Urinary Bladder Of Intact And Dorsal Root Transected Female Rhesus Monkeys

PDF

The Use Of The Orienting Reflex To Test The Zeaman And House Theory Of Attention

PDF

Signal Processing Time And Aging: Age Differences In Backward Dichoptic Masking

PDF

Biofeedback Control Of The Eeg Alpha Rhythm And Its Effect On Reaction Time In The Young And Old

PDF

Electrophysiological Properties Of Reaction Time And Aging

PDF

An Assessment Of The Relevance Of Cortical Theta-Rhythm For Memory Processes In The Rat

PDF

Psychomotor Performance And Change In Cardiac Rate In Subjects Behaviorally Predisposed To Coronary Heart Disease

PDF

Ucr Diminution As A Function Of Isi

PDF

Simple Auditory Reaction Time Of Young Adult And Elderly Subjects In Relation To Perceptual Deprivation And Signal-On Versus Signal-Off Conditions

PDF

Death Anxiety In Leukemic Children

PDF

The Effects Of Ether And Electroconvulsive Shock On One Trial Appetitive And Adversive Learning

PDF

Modality and serial position effects in immediate and delayed recall

PDF

The Effect Of Irrelevant Environmental Stimulation On Vigilance Performance

PDF

The role of cues in the arousal of anxiety

PDF

The Modification Of Partial Reinforcement Effect As A Consequence Of Electrical Stimulation Of The Caudate Nucleus In Cats

PDF

The Effect Of Anxiety And Frustration On Muscular Tension Related To The Temporomandibular-Joint Syndrome

Asset Metadata

Creator Mahan, John Joseph, Jr. (author)

Core Title Cue-Dependent Amnesia

Degree Doctor of Philosophy

Degree Program Psychology

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

Tag OAI-PMH Harvest,psychology, experimental

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Lewis, Donald J. (committee chair), Bishop, Louis B. (committee member), Galbraith, Gary C. (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c18-541611

Unique identifier UC11362187

Identifier 7200570.pdf (filename),usctheses-c18-541611 (legacy record id)

Legacy Identifier 7200570.pdf

Dmrecord 541611

Document Type Dissertation

Rights Mahan, John Joseph, Jr.

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