학술논문

Hippocampal abnormalities and memory deficits: New evidence of a strong pathophysiological link in schizophrenia
Document Type
Author abstract
Source
Brain Research Reviews. April, 2007, Vol. 54 Issue 1, p92, 21 p.
Subject
Schizophrenia -- Analysis
Language
English
ISSN
0165-0173
Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.brainresrev.2006.12.008 Byline: Patrice Boyer (a)(b), Jennifer L. Phillips (a), Francois L. Rousseau (a), Susan Ilivitsky (a) Keywords: Schizophrenia; Cognition; Long-term memory; Episodic memory; Hippocampus; Contextual binding Abstract: The central goals of this manuscript are (1) to better characterize what appears to be the most parsimonious account of schizophrenic long-term memory impairment in the neuropsychological literature: a contextual binding deficit rooted in the medial temporal lobes; (2) to link this deficit to concrete abnormalities at the level of the hippocampus; and (3) to suggest that this deficit could lead to the functional impairment experienced by schizophrenia patients in their daily lives. As far as long-term memory is concerned in schizophrenia, there seems to be a general agreement to conclude that explicit mechanisms are disturbed compared to relatively spared implicit mechanisms. More precisely, both subsystems of explicit memory (i.e., episodic and semantic) appear to be dysfunctional in this patient population. Errors during the encoding processes could be responsible for this dysfunction even if retrieval per se is not totally spared. Recently, a number of studies have suggested that impairments in conscious recollection and contextual binding are closely linked to episodic memory deficit. Since the hippocampal formation is considered to be the central element in the neural support for contextual binding and episodic memory, we have conducted an extensive review of the literature concerning the hippocampal formation in schizophrenia. Emerging evidence from varying disciplines confirm the coherence of the different anomalies reported concurrently at the neuroanatomical, neurodevelopmental, biochemical, and genetic levels. It seems highly probable that the synaptic disorganization in the hippocampus concerns the regions crucial for encoding and contextual binding memory processes. The consequences of these deficits could result in schizophrenia patients experiencing major difficulties when facing usual events which have not been encoded with their proper context. Author Affiliation: (a) Schizophrenia Research Unit, University of Ottawa Institute of Mental Health Research, 1145 Carling, Ottawa, Ontario, Canada K1Z 7K4 (b) Paris7 University, 1 Place Jussieu, Paris, France, 75005 Article History: Accepted 20 December 2006