BACKGROUND: @entity2414 (WM) have been reported in @entity1 with @entity161 , but WM is a complex construct dependent on several subprocesses, including input representation (perceptual competency) and holding stimuli on-line (maintenance). A visual delayed match-to-sample task (DMST) was developed to isolate perceptual competency from maintenance during delays. It was hypothesized that @entity1 in the first episode of @entity161 would exhibit dissociable deficits in both WM domains. METHODS: Performance on the DMST was assessed in 57 @entity1 in the first episode of @entity161 or @entity914 and 22 healthy comparison subjects. In phase 1 of the DMST, a complex visual stimulus (target) was followed immediately by a forced choice between 2 test stimuli, and item difficulty (differences between the test stimuli) was titrated until each subject achieved a consistent accuracy (80%-90%) in this no-delay condition. In phase 2, a delay of 4 or 8 seconds with a mask of randomly illuminated pixels was introduced between target and test stimuli; test stimuli were fixed in difficulty level based on phase 1 titration. Main outcome measures were mean item difficulty attained in the no-delay condition and mean accuracy in matching after delay. RESULTS: Compared with controls, @entity1 attained a lower level of difficulty in the no-delay condition (P =.001) and significantly lower accuracy with delay (P =.002). CONCLUSIONS: Deficits in both domains of WM suggest abnormality in the posterior and prefrontal cortexes. These deficits can be observed in a task involving complex visual pattern stimuli using only a brief delay and are present even in unmedicated @entity1 in the first episode of illness.

Impairments in perceptual competency and maintenance on a visual delayed match-to-sample test in first-episode XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity2414 :: ('MESH:D008569', 'Disease') :: ['Deficits in working memory'] @entity161 :: ('MESH:D012559', 'Disease') :: ['schizophrenia'] @entity914 :: ('MESH:D011618', 'Disease') :: ['schizoaffective disorder']
@entity161 :: (MESH:D012559,Disease) :: ['schizophrenia']
