Superordinate vs Subordinate Information

It is a common clinical observation that semantically impaired patients may classify a word or picture correctly in terms of broad taxonomic category, yet have difficulty discriminating between category exemplars (Warrington, 1975 Warrington & Shallice, 1984 Hodges et al., 1992a). A patient may state that a rabbit is an animal but not know how it differs from a dog or horse, and will make coordinate category errors in naming (e.g dog for rabbit). Our own patient, E.B. (Snowden et al.,...

The Assessment Of Verbal Shortterm Memory Function

This is the most popular and widely used test to assess short-term memory function. In the serial span technique, subjects are presented with a sequence of verbal items, which they attempt to recall in the presentation order. In the original version of the task, simple and highly familiar stimuli, such as auditorily presented digits, have been most often used. Digit span typically ranges between five and nine digits, shows slight but significant age decrements, and is affected by educational...

Mental Retardation

The most recent and widely accepted definition of mental retardation (MR) was developed by the American Association on Mental Retardation (1992) as Mental retardation refers to the substantial limitations in present functioning. It is characterized by significantly subaverage functioning, existing concurrently with related limitation in two or more of the following applicable adaptive skills areas communication, self-care, home living, social skills, community use, self-direction, health and...

Structural Brain Pathology And Retrograde Amnesia

This topic was considered in some detail by Hodges (1995) in the first edition of this Handbook, and it has also been reviewed in detail elsewhere (Kopelman 1993, 2000a Kapur, 1999). There is little doubt that large temporal lobe lesions produce an extensive RA (e.g. Cermak & O'Connor, 1983 Wilson & Wearing, 1995). Cermak& O'Connor (1983) studied a patient, S.S., who had suffered herpes encephalitis resulting in bitemporal pathology and a severe anterograde amnesia. On a test of famous...

Models Of Memory Disorders In Dementia

A few models have specially addressed the issue of the progressive development of memory disorders in Alzheimer's disease. One example is the model by Ruppin & Reggia (1995 see also Carrie, 1993), who model memory performance during progressive Alzheimer's disease, using a model of the cortex in which synapses are gradually lost. At the same time a mechanism of synaptic compensation (Bertoni-Freddari et al., 1990 DeKosky & Scheff, 1990) causes the remaining synapses to increase their...

Global Psychogenic Amnesia

A fugue state refers, in essence, to a syndrome consisting of a sudden loss of all autobiographical memories and the sense of self or personal identity, usually associated with a period of wandering, for which there is a subsequent amnesic gap upon recovery. Kihlstrom & Schacter (2000) point out that there is often a brief delay or lag between the end of the period of wandering and recovery of memory for personal identity. Fugue states usually last a few hours or days only, and they appear...

References

Aggleton, J.P. & Brown, M.W. (1999). Episodic memory, amnesia, and the hippocampal-anterior thalamic axis. Behavioral and Brain Sciences, 22, 425-489. Aggleton, J.P. & Shaw, C. (1996). Amnesia and recognition memory a re-analysis of psychometric data. Neuropsychologia, 34, 51-62. Albert, M., Butters, N. & Brandt, J. (1981). Patterns of remote memory in amnesic and demented patients. Archives of Neurology, 38, 495-500. Albert, M., Butters, N. & Levin, J. (1979). Temporal gradients in...

New Learning in Semantic Dementia

If the medial temporal lobes have a role in new learning of semantic information, then it should be possible to demonstrate new learning in semantic dementia patients in whom medial temporal lobe function is preserved. In their daily lives, patients do show evidence of new learning (Snowden et al., 1996b). One patient, on moving house, had no difficulty in learning the names of new neighbours. Another patient had no difficulty learning to use an electric toaster for the first time, despite...

Epidemiology And Prognosis Of

Two district based study found the annual incidence of TGA to be 3 100 000 (Hodges, 1991) and 5.2 100 000 respectively (Miller et al., 1987). For most patients TGA remains a unique event, as the annual recurrence rate across several years of follow-up is only 2-5 (Mumenthaler & Treig, 1984 Kushner & Hauser, 1985 Hinge et al., 1986 Miller et al., 1987 Colombo & Scarpa, 1988 Guidotti et al., 1989 Hinge & Jensen, 1990). The vast majority of patients are aged 50-70 years and the mean...

Differential Diagnosis Of

The other main conditions to be considered in the differential diagnosis of TGA are posttraumatic amnesia, transient epileptic amnesia, and transient retrograde amnesia. Concussion can lead to a transient confusional state whose clinical appearance is very similar to that of TGA, although repetitive questioning is rarely as impressive as in TGA. There are, however, cases of typical TGA following very mild head trauma. Possibly their TGA was triggered by the emotional stress of the accident...

Situationspecific Psychogenic Amnesia

Situation-specific psychogenic amnesia refers to a brief, discrete episode of memory loss, usually relating to a traumatic event in the individual's personal history this is known as dissociative amnesia in DSM-IV (American Psychiatric Association, 2000). This is important because, although controversial (Schacter, 1986a, 1986b, 1986c Kihlstrom & Schacter, 2000), clinical and forensic psychologists, psychiatrists and neurologists are often asked to assess defendants claiming amnesia for...

Script Theory and Semantic Memory Loss

The data on semantic-autobiographical interactions point to limitations of cognitive models that represent concepts purely in terms of a static network of properties of words and objects. There are other facets of performance in semantic dementia patients that are not easily accommodated by traditional semantic memory models. One of our patients, L.B., was consistently unable to name a pair of glasses on confrontation. In comprehension tests he would comment, Glasses, what's glasses I don't...

Conclusion To Memory Disorders

Nowadays, there can be no real doubt that memory belongs to the cognitive domains which show major impairment in schizophrenia, as Aleman et al. (1999) concluded in their meta-analysis. Whether in this case major means disproportionate to the general intellectual impairment also found in the disorder is a question that remains at the present time unanswered. Schizophrenic memory impairment does, however, appear to be specific in another sense, that of showing a pattern of dissociations, with...

Neurological Conditions Associated With Amnesia

Herpes simplex encephalitis (HSE) occurs as a result of virus-induced hemorrhagic lesions in the brain. In the early stages of the infectious process, patients experience a flu-like illness that is often associated with fever, headaches and lethargy. Profound confusion and disorientation may follow and patients often develop other neurocognitive problems, including aphasia, agnosia and amnesia. For some patients these problems persist so that a broad array of cognitive abilities is compromised....

Acquired Amnesia In Children

An early case of acquired amnesia in a child, following ECT, is reported by Geschwind (1974). The 10-year-old child had normal language prior to the ECT but subsequently developed both memory and language impairment. Geschwind attributed the language impairment to a retrograde amnesia which extended back into the period of language acquisition. An alternative explanation would be that the acquired amnesia and acquired dyphasia were distinct disorders. However, Geschwind argued that an acquired...

Neuropsychological Dissociations Between Visual Working Memory And Spatial Working Memory

Corsi Block

Thus far we have provided neuropsychological evidence to argue that visuospatial working memory is best viewed as an active workspace, rather than a passive memory store, and that it is somewhat distanced from perceptual processes. A range of patient data speak to the notion that visual and spatial working memory might be seen as two distinct but linked components of the cognitive system. For the purposes of this argument, it is important to clarify what we mean by visual as opposed to spatial...