Working memory for visual features and conjunctions in schizophrenia.
The visual working memory (WM) storage capacity of patients with schizophrenia was investigated using a change detection paradigm. Participants were presented with 2, 3, 4, or 6 colored bars with testing of both single feature (color, orientation) and feature conjunction conditions. Patients performed significantly worse than controls at all set sizes but demonstrated normal feature binding. Unlike controls, patient WM capacity declined at set size 6 relative to set size 4. Impairments with subcapacity arrays suggest a deficit in task set maintenance: Greater impairment for supercapacity set sizes suggests a deficit in the ability to selectively encode information for WM storage. Thus, the WM impairment in schizophrenia appears to be a consequence of attentional deficits rather than a reduction in storage capacity.
Gold
James M
JM
Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore 21228, USA. jgold@mprc.umaryland.edu
Wilk
Christopher M
CM
McMahon
Robert P
RP
Buchanan
Robert W
RW
Luck
Steven J
SJ
D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology*; D010468:Perceptual Disorders / Q000175:diagnosis / Q000209:etiology*; D011897:Random Allocation; D012559:Schizophrenia / Q000150:complications*; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*