The neural basis of relational memory deficits in schizophrenia.
BACKGROUND
Memory deficits are common in schizophrenia. Recent studies have demonstrated that relational memory is particularly impaired.


OBJECTIVE
To study the neural correlates of relational memory in schizophrenia using functional magnetic resonance imaging.


METHODS
Cross-sectional case-control study.


METHODS
Academic medical center. Subjects Twenty patients with schizophrenia and 17 control subjects.


METHODS
Behavioral performance and brain activity were assessed during the discrimination of previously seen and novel pairs of visual stimuli, which varied in the degree of relational memory load. We performed whole-brain and region-of-interest (hippocampus) analyses.


RESULTS
Schizophrenic subjects displayed normal activation of the presupplementary motor area and ventral prefrontal cortex, but significantly decreased recruitment of the right parietal cortex and anterior cingulate cortex when discriminating novel pairs derived from a sequence of stimuli. Discrimination accuracy was decreased in schizophrenia only when the flexible representation of a sequence was required. This selective deficit was associated with decreased activation of the right parietal cortex and left hippocampus.


CONCLUSIONS
Schizophrenia is characterized by a specific deficit of relational memory, which is associated with impaired function of the parietal cortex and hippocampus. Abnormal relational memory may be at the core of 2 prominent features of schizophrenia, ie, cognitive deficits and psychosis.
Ongür
Dost
D
Schizophrenia and Bipolar Disorder Program, McLean Hospital and Harvard Medical School, Brain Imaging Center, Belmont, MA 02478, USA. dongur@partners.org
Cullen
Thomas J
TJ
Wolf
Daniel H
DH
Rohan
Michael
M
Barreira
Paul
P
Zalesak
Martin
M
Heckers
Stephan
S
D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003072:Cognition Disorders / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology*; D008959:Models, Neurological; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013702:Temporal Lobe / Q000503:physiopathology
D010100:Oxygen