Amnesia
Amnesia is a condition characterized by partial or total loss of memory. It can be caused by various factors such as brain injury, trauma, or psychological disorders. Amnesia can affect both short-term and long-term memory, leading to difficulties in recalling past events or forming new memories.
5 Key excerpts on "Amnesia"
eBook - ePubAn Introduction to Cognitive Psychology
Processes and Disorders
- David Groome(Author)
- 2021(Publication Date)
- Routledge(Publisher)
...chapter 7 Disorders of memory David Groome DOI: 10.4324/9781351020862-7 Contents 7.1 Amnesia and its causes 7.2 Anterograde and retrograde Amnesia 7.3 Intact and impaired memory systems 7.4 Theories of Amnesia 7.5 Other types of memory disorder 7.6 Rehabilitation Summary Further reading 7.1 Amnesia and its causes Amnesia is the name given to disorders of memory. Amnesia normally involves severe forgetfulness which goes beyond the everyday forgetting observed in normal people, to the extent that it may interfere with the activities of normal life. We are all prone to moments of forgetfulness, but most people with intact cognitive functioning can remember quite a lot about their lives, especially their most recent experiences and events which are important to them. However, a person suffering from Amnesia may be quite unable to remember any recent events. Without an intact memory it can become impossible to keep a job, to keep up relationships with family and friends, or even to look after oneself and maintain an independent existence. In fact it is clear from the study of severely amnesic patients that memory is quite crucial to our ability to function properly as human beings. Amnesia is a very disabling condition, but it is also a disorder from which a great deal can be learned about the nature of memory function. Causes of Amnesia Amnesia may arise from a number of different causes (also known as ‘aetiologies’), which can be divided into two main groups, the organic Amnesias and the psychogenic Amnesias. Amnesia A pathological impairment of memory function. Organic Amnesia An impairment of memory function caused by physical damage to the brain. Organic Amnesias are caused by some form of physical damage (known as a lesion) inflicted on the brain. This may arise from a variety of different causes, including brain infections, strokes, head injuries, and degenerative disorders such as Alzheimer’s disease...
- Amy E. Wenzel(Author)
- 2017(Publication Date)
- SAGE Publications, Inc(Publisher)
...Elkhonon Goldberg Elkhonon Goldberg Goldberg, Elkhonon Dmitri Bougakov Dmitri Bougakov Bougakov, Dmitri Amnesia Amnesia 156 160 Amnesia Amnesia is a broad clinical term that refers to memory loss. The term has its roots in the Greek language and is formed by fusing two morphemes a, meaning “without,” and mnesis, meaning “memory.” It is common to distinguish between organic and psychogenic Amnesia. Organic Amnesia refers to memory loss due to documented or presumed brain disease. Psychogenic Amnesia refers to memory loss due to presumed psychological defense mechanisms. The review in this entry is limited to organic Amnesia, addressing the differences between Amnesia and normal forgetting. Furthermore, this entry clarifies the ambiguity stemming from the difference in the ways in which the term Amnesia is used by clinicians and neuroscientists versus by the general public, briefly relating the use of the term Amnesia to widely accepted cognitive classifications of memory. This entry also discusses two types of Amnesia: (1) anterograde and (2) retrograde. Finally, disorders that are commonly characterized by Amnesia are discussed. Amnesia Versus Forgetting Amnesia is distinguished from normal forgetting. Relatively little of what enters into a person’s memory is retained in the long-term store; most is forgotten. If you were to be asked in the afternoon of an ordinary, uneventful day what telephone calls you made that morning, you would probably give a fairly good account—you remembered. However, if you were to be asked this question about that morning a year later, the odds are you would have no recollections. This information had been stored in your memory for a while but then disappeared from it. This is normal forgetting, a highly adaptive mechanism, which ensures that only important, salient information is retained long term...
eBook - ePub- Alan Baddeley, Michael W. Eysenck, Michael C. Anderson(Authors)
- 2020(Publication Date)
- Routledge(Publisher)
...Hence understanding its nature is important if the patient is to be helped. Attempts to explain the amnesic syndrome can operate at two separate but related levels. One of these concerns the psychological functions that are disturbed, while the other concerns their neurobiological underpinnings. We will begin with explanations of Amnesia at the psychological level, moving on later to the role of neurobiology. The 2001 film Memento chronicles the story of Leonard, an ex-insurance investigator who can no longer build new memories, as he attempts to find the perpetrator of a violent attack which caused his post-traumatic anterograde Amnesia and left his wife dead. The attack is the last event he can recall. Early hypotheses included greater susceptibility to interference leading to a retrieval deficit (Warrington & Weiskrantz, 1970), faster forgetting (Huppert & Piercy, 1979) and an incapacity for deep processing (Cermak, Butters, & Moreines, 1974), although all of these subsequently ran into problems (see Baddeley, 1990, ch. 16 for a discussion). It is, however, too soon to reject the possibility that faster forgetting, and/or susceptibility to interference may play a part in some patients, possibly reflecting further additional deficits. However, whatever the precise mechanism, it seems likely that Amnesia disrupts the capacity to associate a specific event or episode with its context, its location in time and place and that this allows individual specific memories to be retrieved. In a study using rats, Winocur and Mills (1970) observed that animals with hippocampal lesions were particularly bad at making use of environmental context in a spatial learning task, suggesting to Winocur (1978) that a failure to associate memories with context may also apply to human amnesic patients...
eBook - ePub- Jim Barnes(Author)
- 2013(Publication Date)
- SAGE Publications Ltd(Publisher)
...Finally, anterograde Amnesia can sometimes occur following damage to the structures of the diencephalon which include the thalamus, the hypothalamus, the optic tracts and the mammillary bodies, the posterior pituitary gland and the pineal gland. Korsakoff ’ s syndrome is a good example of this type of Amnesia. This condition is generally seen in individuals who consume excessive amounts of alcohol and results from a deficiency of thiamine (vitamin B1) which is thought to cause damage to the medial thalamus and possibly to the mammillary bodies (Sullivan & Pfefferbaum, 2009). RETROGRADE Amnesia Individuals with damage to the medial temporal lobes may also experience impairment of the memories that were obtained prior to the onset of Amnesia. This kind of memory loss is known as retrograde Amnesia. Generally, retrograde forms of Amnesia are assessed on a temporal basis, where information obtained far back in time (remote memory) is not affected compared to the more current memory (Jarrard, 2001). The effects of retrograde Amnesia can last a brief period, disappearing within one or two years, or can be far more enduring, spanning decades. Interestingly, even in cases of severe retrograde Amnesia, patients can still recall the facts and events of their childhood and teenage years (Kirwan, Bayley, Galvan, & Squire, 2008). PSYCHOGENIC OR FUNCTIONAL Amnesia Psychogenic Amnesia can happen as the outcome of an emotional trauma. The symptoms associated with this type of Amnesia are different from those of anterograde and retrograde memory loss. Psychogenic Amnesia is marked by severe retrograde Amnesia with little anterograde Amnesia and is not caused by damage to a specific brain structure...
eBook - ePubHuman Memory
Structures and Images
- Mary B. Howes(Author)
- 2006(Publication Date)
- SAGE Publications, Inc(Publisher)
...Knowledge of the amnesic syndrome. Knowledge of Amnesia caused by medial temporal lobe (MTL) and by diencephalic damage. Knowledge of the functions that are spared. Knowledge of the fact that different classes of concept can be lost selectively from memory. 2. Knowledge of the effects of damage to the frontal lobes. 3. Knowledge of the symptoms and causes of dementia, including Alzheimer’s disease. T he present chapter deals with various forms of abnormal functioning in memory. The field of research into cognitive disorders is known as neuropsychology. This is generally defined as the relation between damage to the brain and psychological functioning. Disorders of memory are classified as being either or organic or psychogenic in origin. Psychogenic disorders, which have a psychological origin, were covered in Chapter 14. Organic disorders, which have a physical cause, form the subject of the present chapter. Familiarity with Chapter 13, on implicit memory, will be helpful in understanding the following material. 1. The Amnesic Syndrome The amnesic syndrome, sometimes simply called Amnesia, results when certain structures of the brain are damaged. An individual suffering from this condition will not be able to form new long-term memories. That is, she may eat dinner but will then be unable to remember that she has eaten. Or she might be introduced to a new person and will not remember that this has occurred. Difficulty in learning new semantic information is also present. The amnesic person will generally have trouble remembering the past, involving the period before the trauma, as well as difficulty in forming new memories. Memory for the most recent pretraumatic events shows the greatest impairment, with remote episodes often spared. The syndrome is caused by damage to certain structures deep within the brain, particularly the diencephalon or the medial temporal lobes (MTLs), structures that form part of the limbic system...
