کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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334573 | 546591 | 2010 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The role of hippocampus dysfunction in deficient memory encoding and positive symptoms in schizophrenia The role of hippocampus dysfunction in deficient memory encoding and positive symptoms in schizophrenia](/preview/png/334573.png)
BackgroundDeclarative memory disturbances, known to substantially contribute to cognitive impairment in schizophrenia, have previously been attributed to prefrontal as well as hippocampal dysfunction.AimsTo characterize the role of prefrontal and mesolimbic/hippocampal dysfunction during memory encoding in schizophrenia.MethodNeuronal activation in schizophrenia patients and controls was assessed using functional magnetic resonance imaging (fMRI) during encoding of words in a deep (semantic judgement) and shallow (case judgment) task. A free recall (no delay) and a recognition task (24 h delay) were performed.ResultsFree recall, but not recognition performance was reduced in patients. Reduced performance was correlated with positive symptoms which in turn were related to increased left hippocampal activity during successful encoding. Furthermore, schizophrenia patients displayed a hippocampal hyperactivity during deep encoding irrespective of encoding success along with a reduced anterior cingulate cortex (ACC) and dorsomedial prefrontal cortex (DMPFC) activity in successful encoding but an intact left inferior frontal cortex (LIFC) activity.ConclusionsThis study provides the first evidence directly linking positive symptoms and memory deficits to dysfunctional hippocampal hyperactivity. It thereby underscores the pivotal pathophysiological role of a hyperdopaminergic mesolimbic state in schizophrenia.
Journal: Psychiatry Research: Neuroimaging - Volume 183, Issue 3, 30 September 2010, Pages 187–194