Visual object working memory function and clinical symptoms in schizophrenia.
OBJECTIVE
The presence of working memory deficits suggests abnormalities of prefrontal cortex (PFC) in schizophrenia. Although much is known about spatial working memory deficits in schizophrenia, including its potential as a phenotypic marker, it is unclear whether object working memory is similarly affected. Our goal was to examine nonspatial, object working memory function in relation to clinical symptoms.


METHODS
We assessed object working memory and clinical symptoms in 28 schizophrenia patients during acute psychotic episode and 4 months later during partial remission. Delayed-matching-to-sample tasks for familiar object (DMTS-F) and novel shapes (DMTS-N) were used. Symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). 33 age-matched normal subjects were also tested over the same time period.


RESULTS
Acutely psychotic patients showed deficits in both DMTS-F and DMTS-N. Four months later, their DMTS-F performance improved significantly but deficits in DMTS-N were still present. During acute psychosis, symptoms correlated with DMTS-F but not with the DMTS-N. Four months later, negative symptoms correlated with both tasks.


CONCLUSIONS
Object working memory as measured by DMTS-N was impaired in schizophrenia patients during both acute and chronic states. When schizophrenia patients were in partial remission, object working memory was associated with negative symptoms.
Park
Sohee
S
Department of Psychology, Vanderbilt University, Wilson Hall, 111 21st Ave South, 37Nashville, TN 37240-0009, USA. sohee.park@vanderbilt.edu
Püschel
Jörg
J
Sauter
Barbara H
BH
Rentsch
Markus
M
Hell
Daniel
D
D000208:Acute Disease; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology*; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology*; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*