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Query: UMLS:C0751295 (memory loss)
 3,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Confabulation and amnesia are considered disorders of episodic but not of semantic memory. To test the limits of this view, retrieval from episodic and semantic memory was investigated in eight confabulating and nine non-confabulating amnesic subjects, and in 17 matched control subjects, by using a personal and an historical version of the Crovitz [Unconstrained search in long-term memory, Paper presented at the meeting of the Psychonomic Society, St Louis, MO, 1973] cue-word test. In response to cue words such as letter or battle subjects had to describe in detail, respectively, a related event from their personal lives or from history before their birth. We found that a subset of amnesic subjects, those with presumed damage or dysfunction in the region of the ventromedial frontal cortex, would confabulate in response to these cues. Their confabulations involved semantic, historical memories, as much as episodic, personal ones: and that distortions of content were at least as common as those of time. Even when not confabulating, they had much more difficulty than other amnesic subjects in recovering memories related to these cues. In confabulating, as compared to non-confabulating, amnesic subjects, prompting led to an increase in confabulations but also to greater recovery of veridical memories. By comparison, non-confabulating amnesic subjects whose memory loss was as severe as that of the confabulators, had a milder deficit on the personal as well as the historical cue-word test. They benefited from prompting somewhat more than matched control subjects. These results suggest that confabulation is associated with impaired strategic retrieval processes resulting from damage in the region of the ventromedial frontal cortex. These strategic retrieval processes help initiate and guide search in episodic and in semantic memory and they help monitor and organize the output from those systems.
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PMID:Strategic retrieval and the frontal lobes: evidence from confabulation and amnesia. 922 62

The term "confabulation" refers to a verbal statement of fabricated, distorted or misinterpreted memories about oneself or the world, without the conscious intention to deceive. The difference between confabulation and delusion lies in the fact that the former is essentially linked with memory deficits and the latter is characterized by a firm belief in false stories. It has been established that delusion often arises from personality or emotional problems; however, the premorbid personality of confabulators has not been clarified. Confabulation is usually divided into 2 types-provoked and spontaneous. Theoretical explanations for the cognitive mechanisms underlying confabulation includes the notion that confabulation reflects the tendency of filling gaps in memory. It has also been suggested that confabulation is the consequence of memory loss and frontal dysfunction, specifically dificits in self-monitoring and/or reality monitoring. A number of studies have indicated that temporal context confusion in memory is a characteristic trait of confabulators. Recently, it has been suggested that spontaneous confabulators fail to suppress previously activated memory traces or currently irrelevant memory traces, which intrude into ongoing thinking. In addition, it has been indicated that confabulation can be attributed to problems in the regulation of autobiographical recollection. This account may explain why confabulators focus on particular themes and why the content of confabulations is distorted toward more positive and optimistic self-representations. Lesions involving the basal forebrain and the orbitofrontal cortex may lead to confabulation. In particular, patients with severe or chronic spontaneous confabulation appear to have multiple lesions involving the basal forebrain and the orbitofrontal cortex, including the striatum or the dorsolateral prefrontal cortex. Cognitive rehabilitation methods such as keeping a diary, re-orientation, and self-monitoring training are reported to reduce the severity of confabulation.
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PMID:[Memory deficits and confabulation]. 1864 24