Psychology: Repression of Memories - Term Paper Example

Running head: Repression of memories is a concept much used in clinical memories. PART A :INTRODUCTION Freud originally proposed that there exists a feature of human nature whereby unwanted memories are suppressed or eliminated into the unconscious (Anderson and Green, 2001, p. 366). Though the idea of repression has been around for over 100 years, it has not been indicated what mechanism was involved. It had been associated with trauma which we find is not a cause anymore. There was also the impression that there was no biological basis for it (A biological basis, About.com). Researchers did not believe that the neurological system of the body had anything to do with repression. The brain was believed not to have any function which could do this. However recent studies on memory and attention have elicited that a biological basis is behind the chain of events (A biological basis, About.com). Executive control functions are believed to be involved. Repression has been believed to be a blessing in disguise for those who have been emotionally or psychologically traumatized (Brandon, 1998). Another concept says that suppression attempts can fail occasionally and lead to the opposite situation of more frequent unwanted thoughts through a rebound phenomenon. An abundance of this paradoxical effect can lead to psychological problems. Recollections (Eldridge, 2000), distractions caused by environmental reasons like the onset of winter or a heavy rains or cognitive origin by recent worries or bereavement (Chao, 1995) and intelligence can all cause suppression of memory . The processes in the brain are not fully understood yet. However the dorso-lateral prefrontal region and the hippocampus are known to be the brain areas which subserve suppression of memories (Davachi, 2003). PART B: REVIEWS OF THE STUDIES. Study 1: Anderson, C. and Green, C. (2001). Suppressing unwanted memories by executive control. Nature, Vol. 410, p. 366-369, MacMillan magazines Issue/question/hypothesis This study has been done to confirm that perceptual distraction, diminishing the hindrances during short and long term memory processes and stopping strong habitual responses to stimuli are the methods employed by the executive control processes of the central nervous system to prevent the embedding of unwanted memories thereby leading to repression. Four experiments were done. The first one tested whether it was the motor actions or the executive control actions which governed the act of repression by using the go/no go method in a memory retrieval task. The second experiment was to confirm whether the attempt to prevent awareness would prevent its later retrieval in a think/no think task. The third one, the same-probe test, and the fourth, the independent-probe test for the subject’s memory for the word pairs and the implications of suppression of memory were done. Methods 32 college students participated in the first 3 experiments and 16 for the fourth one. They were introduced to 40 pairs of essential words and 10 other pairs. Each person was shown a computer screen of the word and its pair for 5 seconds each. Then they were to say aloud the pair when shown a word. If they did not respond, the pair was shown on the screen. This continued till they could remember at least 20 pairs. For the suppression the pairs were not shown while for the response part, they were shown. This was followed by the think-no think task. The response pairs and the suppression pairs were used in an inter-mixed manner. In the same probe test, the participants indicated the pair. The participants were asked to name the category and the first letter of the word exhibited. 16 participants each were given the same probe and the other 16 were given the independent probe first and then followed by the other. Results Increasing inhibition was noted for all the experiments for recall of the suppressed item. However repetition improved the recall. This can be interpreted thus: frequent recall or retrieval is beneficial for later recall of the item or event. The results indicated that successful retrieval is terminated by controlling awareness. This further shows the role of the executive controlling process in the suppression. There is a suggestion that the mechanism of suppression could be by avoiding thinking about the environmental stimulus that goes with the stimulus: diversionary thought. The independent probe method which helped to isolate inhibition led to the decision that impairment of memory was seen for all occasions of initial suppression and the feature increased with repetition, whatever the type of cue provided. Conclusion The subsequent memory of an event is determined by an internal neurological process which controls the awareness of the memory and its later recall. Freud’s theory that unwanted memories are pushed out of awareness by a suppression mechanism is once again confirmed here. This suppression can be a long-lasting effect. Frequent retrieval of diversionary thoughts can sustain the effect without the purposeful intention of avoiding the memory. This implies that repression may not be a psychological defence as postulated by some researchers; it may be just part of the executive control process. Study 2 : Rassin, E., van Brakel, A. and Diederen, E. (2003). Suppressing unwanted memories: Where there is a will, there is a way. Behaviour Research and Therapy, Vol.41, p. 727-736 Pergamon Issue/question/hypothesis This study focused on determining if the expectations of the manipulations for suppression efficacy had any influence on the actual suppression. Methods The participants were 85 graduates of which 69 were women. The conditions addressed were a no-instruction control condition, a suppression condition, a suppression-works condition and a suppression-does-not work condition. All the participants heard an audio-taped story and were asked to identify the main character and then divided into groups. The no-control group was free to think whatever they liked in the next two hours. The suppression condition group also was free to think what they like but they were not to think about the story. The suppression works condition group were additionally told that it is possible to suppress memory and that this research is based on that. The suppressions-does-not-work group were additionally told that it has been found that suppression of memories does not work though there have been claims. The participants were first asked about the emotional violence in the story and the main character. Then after two hours, short questionnaires were given for answering within half an hour. Then they were asked to answer 2 final questions. The emotional story had been about a person who on his way to an interview had a road accident which killed the child of the other driver. The unpleasantness of the story was recorded with the visual analogue scale graded from 0(not at all unpleasant ) to 100 (very unpleasant). The 13-item questionnaire was based on the story. The first question indicated the story-related intrusions. The second decided to what extent suppression was attempted. The perceived efficacy was graded by a scale in the third question. The next item was on their estimation of the memory of the story (estimated accuracy). The next four questions were together classed as the metamemory variable. The next three items contributed to the snapshot likeness variable. The questions asked in the morning were repeated again here as the last 2 questions. The participants were asked how much suppression of memory they had marked as whether they forgot faster or remembered better or did not know. Chi square analysis showed that the no-instruction control condition group was most convinced about the suppression theory. All the participants in the suppression-does-not-work group did not believe that suppression had a memory undermining effect. The suppression works group actually believed that their attempts to suppress memory was most successful. The story-related thoughts were most seen in the suppression-does-not-work group. The estimated accuracy, metamemory, snapshot likeness and recall difficulty which contributed to perceived memory showed no effect on the suppression. The actual or free recall memory was also not affected. The suppression works group showed a decreased unpleasantness after suppression. The results showed that perceived suppression efficacy was determined by expectations of suppression efficacy. The expectations also influenced the stimulus-related thoughts and emotional impact of the stimulus. The groups which were convinced about the suppressive effect and the other which were not, did not have different levels of memory as expected before the study. Metacognitions about suppression varied from actual recollection accuracy. This is different from what other researchers have found: that memory is affected by metacognition. However emotional impact was diminished by the suppression works. This study being a laboratory model of situations may differ to some extent from real-life situations where people want to suppress traumatic experiences. The influence of expectations may be greater in real life. Rassin’s study results differ greatly from many other studies. Conclusion People who are really convinced about suppression are more successful in the effort than others in their attempts. The suppression reduces the emotional impact of unpleasant memories. Manipulations like written or oral instructions can influence expectations. Induced expectations influenced the efficacy of suppression. Participants who were informed about the possibility of successful suppression had more effective suppressions. They had lesser intrusions and thought that the stimulus was not aversive unlike the participants who were told about the suppression being counter-productive and that the stimulus did not produces suppression as is thought. Actual accuracy was not influenced by the expectations. Explicit memory was not influenced by suppression as evidenced by the no-instruction control group. Study 3 Anderson, M.C., Oschner, K.N., Kuhl, B., Cooper, J., Robertson, E., Gabrielli, S.W. et al. (2004). Neural systems underlying the suppression of unwanted memories. Science, Vol. 303 p. 232-235 Issue/Question/Hypothesis/ This study is to understand the areas of the brain where the repression of unwanted memories occurs, to confirm that an active forgetting process exists and to establish a neurobiological model for motivated forgetting Methods The fMRI or functional magnetic resonance imaging was used to scan the activated areas of the brain while the think-no think model was implemented. Word pairs were used as in the first study by Anderson and Green (2001). The tests of response, suppression, same-probe and independent probe tests were done here. Results It was found that forgetting occurs due to inhibition of the response. The brain areas more active during suppression was found to be the bilateral dorsolateral and ventrolateral pre-frontal cortex, Brodman’s area stronger on the left, anterior cingulate cortex, pre-supplementary motor area, dorso-lateral pre-motor cortex, intra-parietal sulcus, bilateral Brodman’s area and putamen. The pre-frontal regions are more concerned with the suppression rather than the memory retrieval. The regions sub-serving the executive control functions are the areas important for suppression. The reduced activation of the hippocampus was also related to the suppression of recollection. Hippocampal activation during suppression trials has been related to the memory inhibition and is predicted by activation of the pre-frontal cortex. Increased activation of the dorso-lateral pre-frontal cortex is the only area which when activated could predict memory inhibition. This has been substantiated by studies where lesions of the pre-frontal cortex showed memory inhibition. Increased activation of the hippocampus is associated with memory retrieval. In the process of suppression of recollection of an unwanted experience, the pre-frontal cortex and hippocampus are related. Conclusion Dorso-lateral pre-frontal cortex is the area associated with suppression of memory. The stopping of retrieval of memory is a more complicated process requiring more areas in the brain to execute. The control of traumatic injuries is not easy. However the intrusive memories of the trauma and the emotional response can be diminished over time. The cumulative inhibitory effects of the suppression has been noted. It has not been found whether the suppression can produce amnesia which is a more long-lasting effect. The suppression has been shown to be an active process which people can use to prevent memories they do not wish to remember. This is called forgetting. The model of the voluntary repression of Freud has been shown by this study. PART C: CONCLUSION Freud’s hypothesis that unwanted memories are excluded from awareness in a process called repression forms the basis of all the three studies selected for discussion. The first study was done to confirm that perceptual distraction, diminishing hindrances during short and long term memory processes and stopping strong habitual responses to stimuli are the methods employed by the executive control processes of the central nervous system to prevent the embedding of unwanted memories thereby leading to repression (Anderson and Green, 2001) .The results showed that executive control processes could provide a model for repression. The second study focused on determining if the expectations of the manipulations for suppression efficacy had any influence on the actual suppression (Rassin et al, 2003). It was found that induced expectations influenced the perceived efficacy of suppression and thought frequency but the accuracy of recollections was not associated. The third study was done to understand the areas of the brain where the repression of unwanted memories occurs, to confirm that an active forgetting process exists and to establish a neurobiological model for motivated forgetting (Anderson et al, 2004). It was found that the dorso-lateral pre-frontal cortex is the area associated with suppression of memory. The stopping of retrieval of memory is a more complicated process. Controlling unwanted memories has been associated with the increased activation of the dorso-lateral pre-frontal cortex. The diminished hippocampal activation and the impaired retention of the memories also are found associated. The concept of forgetting has been found to be associated with both the pre-frontal cortex and right hippocampus activations. An active forgetting processs exists and there could be a model for investigating into motivated forgetting. Whether suppression of memories has any relationship to amnesia has to be investigated. This study suggests that there could be a relationship. Part D : References: A biological basis for repressed memories, Nov. 6th , 2005, Retrieved on 6/5/09, About.com Anderson, C. and Green, C. (2001). Suppressing unwanted memories by executive control. Nature, Vol. 410, p. 366-369, MacMillan Magazines. Anderson, M.C., Oschner, K.N., Kuhl, B., Cooper, J., Robertson, E., Gabrielli, S.W. et al. (2004). Neural systems underlying the suppression of unwanted memories. Science, Vol. 303 p. 232-235 Brandon, S. (1998). Recovered memories of childhood sexual abuse: implications for clinical practice, British Journal of Psychiatry, April 98, p. 302 Chao, L.L. and Knight, R.T. (1995). Human pre-frontal lesions increase distractability to irrelevant sensory inputs. Cognitive NeuroScience, Vol. 6, p. 1605-1610. Davachi, L. et al. (2003). Proc. National Academy Science, USA, Vol. 100, p. 2157. Eldridge, L.L. et al. (2000) Nature Neuroscience, Vol. 3, p. 1149 Rassin, E., van Brakel, A. and Diederen, E. (2003). Suppressing unwanted memories: Where there is a will, there is a way. Behaviour Research and Therapy, Vol.41, p. 727-736 Pergamon Read More