Description of brain injury in the amnesic patient N.A. Based on magnetic resonance imaging

Squire, Larry R.; Amaral, David G.; Zola‐Morgan, Stuart; Kritchevsky, Mark; Press, Gary A.

doi:10.1016/0014-4886(89)90168-4

Cited by 135 publications

(93 citation statements)

References 37 publications

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“…For example, damage to the internal medullary lamina and the mammillothalamic tract has Mori et al 1986;Squire et al 1989a). Furthermore, a recent study of Korsakoff's syndrome emphasized the importance of gliosis and neuronal loss in the anterior thalamic nuclei (Harding et al 2000).…”

Section: Discussionmentioning

confidence: 99%

The anatomy of amnesia: Neurohistological analysis of three new cases

Gold¹,

Squire²

2006

Learn. Mem.

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The most useful information about the anatomy of human memory comes from cases where there has been extensive neuropsychological testing followed by detailed post-mortem neurohistological analysis. To our knowledge, only eight such cases have been reported (four with medial temporal lobe damage and four with diencephalic damage). Here we present neuropsychological and post-mortem neurohistological findings for one patient (NC) with bilateral damage to the medial temporal lobe and two patients (MG, PN) with diencephalic damage due to bilateral thalamic infarction and Korsakoff's syndrome, respectively. All three patients exhibited a similar phenotype of amnesia with markedly impaired declarative memory (anterograde and retrograde) but normal performance on tests of nondeclarative memory (e.g., priming and adaptation-level effects) as well as on tests of other cognitive functions. Patient NC had damage to the hippocampus (dentate gyrus and the CA1 and CA3 fields) and layer III of the entorhinal cortex, but with relative sparing of the CA2 field and the subiculum. Patient MG had damage to the internal medullary lamina and mediodorsal thalamic nuclei. Patient PN had damage to the mammillary nuclei, mammillothalamic tracts, and the anterior thalamic nuclei. These findings illuminate several issues regarding the relation between diencephalic and medial temporal lobe amnesia, the status of recognition memory in amnesia, and the neuroanatomy of memory.

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Section: Discussionmentioning

confidence: 99%

The anatomy of amnesia: Neurohistological analysis of three new cases

Gold¹,

Squire²

2006

Learn. Mem.

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103

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“…had diencephalic lesions confirmed by MRI (for N.A. : Squire, Amaral, Zola-Morgan, Kritchevsky, & Press, 1989;for M.G. : unpublished observations (Osterrieth, 1944; maximum score = 36).…”

Section: Subjectsmentioning

confidence: 92%

Declarativeand nondeclarativememory in opposition:When priorevents influence amnesicpatients morethan normal subjects

Squire

McKee

1993

Memory & Cognition

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Amnesic patients and normal subjects read the names of nonfamous persons. Then, after being told that all the names were nonfamous, subjects judged the fame of names on a mixed list of new famous names, old nonfamous names, and new nonfamous names. Finally, they took a recognition memory test involving old and new nonfamous names. In this way, declarative (explicit) memory and nondeclarative (implicit) memory were placed in opposition. That is, recollection that a name had been recently presented (and was therefore nonfamous) opposed the facilitatory effect by which prior presentation ordinarily increases the tendency to judge that name as famous. Normal subjects exhibited good recognition memory and no fame-judgment effect-that is, no difference in fame judgments for new and old nonfamous names. By contrast, for the amnesic patients recognition memory was poor, but a strong fame-judgment effect occurred-that is, amnesic patients judged old nonfamous names as famous. The results provide additional evidence that the fame-judgment effect is supported fully by nondeclarative (implicit) memory and is independent of the limbic/diencephalic brain structures damaged in amnesia.

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“…Patient N.A. became amnesic, primarily for verbal material, following a stab wound to the left diencephalic region with a miniature fencing foil (Squire, Amaral, Zola-Morgan, Kritchevsky, & Press, 1989;Teuber, Milner, & Vaughn, 1968). Patient M.H.…”

Section: Experiments 1 Methodsmentioning

confidence: 99%

Relaxing decision criteria does not improve recognition memory in amnesic patients

Reber

Squire

1999

Memory & Cognition

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An important question about the organization of memory is whether information available in nondeclarative memory can contribute to performance on tasks of declarative memory. Dorfman, Kihlstrom, Cork, and Misiaszek (1995) described a circumstance in which the phenomenon of priming might benefit recognition memory performance. They reported that patients receiving electroconvulsive therapy improved their recognition performance when they were encouraged to relax their criteria for endorsing test items as familiar. It was suggested that priming improved recognition by making information available about the familiarity of test items. In three experiments, we sought unsuccessfully to reproduce this phenomenon in amnesic patients. In Experiment 3, we reproduced the methods and procedure used by Dorfman et al, but still found no evidence for improved recognition memory following the manipulation of decision criteria. Although negative findings have their own limitations, our fmdings suggest that the phenomenon reported by Dorfman et al. does not generalize well. Our results agree with several recent findings that suggest that priming is independent of recognition memory and does not contribute to recognition memory scores. 501An important and now widely accepted idea about the organization of memory is that long-term memory is not a single mental faculty (Schacter, 1987;Squire, 1982Squire, , 1992Tulving, 1985;Weiskrantz, 1990). The major distinction is between the capacity for conscious recollection offacts and events (declarative memory) and a collection of nonconscious (nondeclarative) learning and memory abilities that support skill and habit learning, classical conditioning, and the phenomenon of priming. Declarative memory is concerned with the deliberate retrieval ofrecently occurring facts and episodes, and it depends on the integrity of the medial temporal lobe and diencephalic brain systems that are damaged in amnesia. Nondeclarative memory is expressed through performance and is considered to be more automatic and less accessible to awareness than declarative memory. For example, the phenomenon of perceptual priming can occur in the absence of awareness that memory is being tested and without any deliberate effort to retrieve. Subjects

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Description of brain injury in the amnesic patient N.A. Based on magnetic resonance imaging

Cited by 135 publications

References 37 publications

The anatomy of amnesia: Neurohistological analysis of three new cases

The anatomy of amnesia: Neurohistological analysis of three new cases

Declarativeand nondeclarativememory in opposition:When priorevents influence amnesicpatients morethan normal subjects

Relaxing decision criteria does not improve recognition memory in amnesic patients

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