Semantic and Episodic Memory and Amnesia - Essay Example

Name: ____________ Student ID: ________ Course ID: _________ Memory And Amnesia Often people confuse Amnesia with multiple personality disorder, however this is not the case. When in 1992 Conference on Abuse and Multiple Personality Disorder conducted, it was considered that sexual programs emphasize more upon psychic killers, than on oral sex. Lest they forget which victims have been robotized how, the cultists carry laptop computers with records of all past programming involving the CIA, the Mafia, Hollywood, big business, and government leaders in this respect, together with many ordinary citizens whose job was to cover up evidence of cult tortures. However the importance of Amnesia was later identified in some of the movies which appeared to be blockbusters, like Bourne Identity, 50 first dates etc. Amnesic conditions highlighted in films often bear little or no resemblance at all to reality. Since movies represent as the reflection of general public perceptions and views, doctors should be aware of all possible myths about amnesia and should act and suggest accordingly. This could be invaluable when informing patients and their relatives of a diagnosis of an amnesic condition and its likely prognosis. (BMJ) Hollywood’s recent movie discoveries, The Eternal Sunshine of the Spotless Mind (2004) and 50 First Dates (2004), head up a long tradition of movies traiting amnesic characters. No fewer than 10 silent movies were able to do so before 1926. In this context, Garden of Lies (1915), proved to be the turnover point in Hollywood highlighting the scenario when a doctor hires a new husband for an amnesic bride in an attempt to jog her memory. This movie appeared as a trendsetter for the rest of the films to come and was later followed by other amnesic conditions in films (BMJ). Bourne Identity proved to be the best example of Memory disorder in the twenty first century is not restricted to conscious recollection, but can apply to any experience that changes subsequent behavior. While focusing on Bourne Identity, we can see that Jason Bourne was affected by sensory memory disorder as well as working memory, which can be judged by analyzing his activities. Sensory Memory depends primarily on temporary ongoing activities in the brain, whereas long-term memory depends on structural changes. Memory can be measured in different ways. From least to most sensitive, these are recall, recognition, savings and priming. The successive phases in remembering are encoding, storage and retrieval. Real or Fake Amnesia Psychologists have found a way out to determine through tests if the person is suffering through real amnesia problems or is just pretending to be among one of the patients. The psychological tests consist of a series of words that the person has to remember and recall. In case he is unable to do so, he is considered as a patient of real amnesia. This is how it works actually: Suppose a person is given a list of 20 words to remember and then asked to recall them. He might be given 10 such lists, one at a time, and asked to recall each list before the next one is presented. Suppose he then plots the number of times he is able to recall the first word in the list, the number of times he is able to recall the second word, and so on, right down to the twentieth word. This plot is known as serial position curve possessing two characteristics. One is a primary effect, which is that words at the beginning of the list are recalled much better than those nearer the middle. The other is a recency effect, which is that words at the end of the list are also recalled better than those nearer the middle. There is good reason to believe that words early in the list have been transferred to long-term memory, while those at the end are still held in working memory. Evidence from this comes from the fact that the primacy and recency effects react differently to various manipulations. Suppose, for example a delay of 30 seconds occurs between presentation of the list and its recall, and that participants are required to count backwards from some number during the delay. This has no effect on the primacy effect but effectively wipes out the recency effect. Now suppose the words are presented at different rates, say 20 words in 3 seconds or 20 words in 9 seconds. Presenting the words more slowly results in an increased primacy effect but the recency effect is unchanged. Slower presentation gives more time for rehearsal of early words, which increases the likelihood that they will enter long-term memory. In this manner psychologists detect faking out amnesia in patients, and interestingly the reason for pretending is the strong influence from Hollywood movies, which makes a person to adopt amnesia. Name of test Material Test Procedure Dependant Variable Free Recall List of Items Participant reports list Number of items correctly reported Cued Recall Pairs of Items, each Consisting of a cue and Target. Given a cue participant’s reports target Proportions of targets correctly reported Recognition List of Items Participants decides whether presented items were in the list or not Proportion of correct responses Savings List to learn Participant relearns the list Improvement in learning time, or in number of trials to relearn Priming List of Items Participants perform tasks Number of time participant uses word in the list in solution of task, relative to baseline rate Anterograde amnesia is quite a common occurrence but is not restricted to events alone. H.M also faced difficulty-remembering events for up to 11 years prior to the operation. This is known as Retrograde Amnesia, which is the general term for memory loss of events preceding some brain injury or trauma. In the famous Hollywood movie “Bourne Identity”, the leading character possesses retrograde amnesia in which despite of doing every effort to regain his memory he remains unable to do so, which leads him towards frustration and depression. Semantic and Episodic Memory Long-term memory may be divided into implicit and explicit memory, further explicit memory is divided in two types: Semantic Memory and Episodic Memory. Semantic Memory is memory for information that most of us share. It includes information about what words and sentences mean. However according to Tulving’s view it includes information about the world. Semantic information is the sort of information one would expect to find in a dictionary or encyclopedia. Episodic Memory in contrast is memory for personal episodes in one’s life. Unlike Semantic memory, episodic memories refer to specific events in time and place. They represent the sort of information one would expect to find in a personal diary and are often known as autobiographical memories. Episodic memory is part of what makes each of us distinct, and is critical to our sense of self. There is evidence that the prefrontal cortex of the brain, the front portion of the frontal lobes is also critically involved in episodic memory. Part of the evidence for this is that people with damage to the prefrontal areas often show little deficit in remembering items of knowledge but suffer from what has been called source amnesia that is they might remember a fact but fail to remember when and how it was learned, even if it was learned quite recently. Cultural amnesia, the loss of cultural memory, is one of the most telling symptoms of America’s current state of mind. Each day, fewer and fewer of our nation’s long-term memories survive; each day, our country’s short-term memory grows ever shorter. This “dumbing of America” cannot be viewed simplistically as the short-term loss of social studies trivia. Instead, it must be recognized as the loss of a longer-term set of historical memories without which no civilization can prosper or long endure. Just as an individual needs memories to maintain a sense of personal identity, so a nation needs them in order to survive. Cultural Amnesia addresses this issue, combining psychological insights into the nature of memory with perspectives on the meaning of democracy and its prospects. It argues that cultural amnesia, like Alzheimer’s disease, is an insidiously progressive and destructive illness that is eating away at America’s soul. Rather than superficially blaming national memory loss on a failed educational system, the book looks beyond the schoolroom to the larger forces that conspire to alienate Americans from their past: a materialistic creed that celebrates transience, and an electronic faith that worships the present to the exclusion of all other dimensions of time. Indeed, it is these forces, more than any others, that will govern the course of American history in the twenty-first century. (Bertman, 2000, p. 82) Causes of Amnesia The absence of memory, or amnesia, can be caused by an assault upon the brain. Such an assault can take many forms. Physical Injury. The cause can be physical trauma, an injury sustained by ones brain from a blow to the head that occur at impact. For younger victims of amnesia, this is the most common cause: a closed-head injury sustained in an automobile accident. Such injuries can erase the memory of the events immediately before an accident or, sometimes, the memory of events that occurred days, months, or even years before. This aspect is focused in “Bourne’s Identity” in which Jason Bourne is first hit be many bullets after which he looses his memory. As the brain heals, many memories return, but others do not. According to one theory, the moments before the crash are the ones most readily forgotten either because memories of them have not yet taken structural form in the mind, or because the neural paths for their retrieval have not yet been laid down. Hence, of all memories, the most recent are the most fragile. Electrical Shock. But amnesia can be caused by other types of assault. An intense electrical current, for example, can figuratively burn out the wiring of the brain. Such a shock can come from inside or outside. A short circuit can occur spontaneously within the brain during a convulsion; or a jolt of current can be deliberately applied by a therapist to shock the personality into equilibrium. Either way, the electric bill is paid for in the currency of memory. Disease and Stroke. Remembrance can also be ravaged by disease by herpes simplex encephalitis, that inflames and swells the brain’s delicate tissue; or by the most devastating of mnemonic maladies, Alzheimer’s disease, that turns the brain to cellular mush. Stroke and anemia can likewise wreak havoc by robbing brain cells of life-giving oxygen. Self-Induced Oblivion Ironically, the very memories that encapsulate personal experience can be expunged by personal behavior. The alcoholic, seeking temporary oblivion in a bottle, may find it in more permanent form in Korsakoff’s syndrome, a set of symptoms first described by a nineteenth-century Russian psychologist. Confusion and disorientation are its first signs, the result of poor nutrition and thiamine deficiency that can accompany chronic alcoholism. If not treated soon enough, the outcome is permanent memory loss. Psychogenic Amnesia Memory loss can also be triggered by emotional crisis and the need to forget. In running away from an experience too painful to remember, we may bolt through an emergency exit in our consciousness, locking the steel door and the memory behind us. If the experience is terribly traumatic, we may even try to escape from our own identity. Such a condition is very rare, accounting for only about 1 percent of all amnesias, though amid the horrors of war and combat the frequency can be much higher. In time days, weeks, or months personal memory and, with it, a sense of individual identity almost always return. As time heals, the psyche gains the strength and courage to look into the mirror of the past. To focus on the role of narrative in linking autobiographical memory and self also highlights individual differences. The ways in which any given individual constructs a life narrative are influenced both by the larger cultural frameworks available for understanding what a self is and what it means to remember one’s past. Even within culture, individual pathways in the emergence of autobiographical memory are clearly evident. Developmentally, children are learning the forms and functions of autobiography through participating in conversations about the past with adults, and as adults, the way in which we share our memories with others modulates the way we think about our experiences and, ultimately, ourselves. If we take seriously the assumption that autobiographical memory is formed in social interaction, then it becomes necessary to examine the ways in which cultural constructs of the self and autobiography come to shape the kinds of interactions children and adults engage in, and thus the kinds of autobiographical selves that are formed. (Fivush, 2003, p. 10) Works Cited BMJ (British Medical Journal), MemoryLoss, accessed from < http://www.memorylossonline.com/spring2002/memlossatmovies.htm> Bertman Stephen, (2000) Cultural Amnesia: America’s Future and the Crisis of Memory: Praeger Publishers: Westport, CT. Fivush Robyn, (2003) Autobiographical Memory and the Construction of a Narrative Self: Developmental and Cultural Perspectives: Lawrence Erlbaum Associates: Mahwah, NJ. Read More