Am J Psychiatry 1997; 154:647-654
Copyright © 1997 by American Psychiatric Association
Visual information-processing impairments in deficit and nondeficit schizophrenia
JR Bustillo, G Thaker, RW Buchanan, M Moran, B Kirkpatrick and WT Carpenter Jr
Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, USA.
OBJECTIVE: Previous studies of covert visuospatial attention in
schizophrenia suggest a subtle form of right hemispatial neglect in acutely
ill patients but not in chronic, stable patients. Because of previous work
documenting various visual information-processing abnormalities in deficit
schizophrenia, the authors investigated whether the deficit/nondeficit
categorization would help clarify the presence of visual attentional
asymmetries in schizophrenia. METHOD: Performance on a covert visuospatial
attention task was examined in clinically stable outpatients with
schizophrenia (17 in a deficit subgroup and 28 in a nondeficit subgroup)
and 25 normal subjects. Peripheral cue and central cue versions of the
covert visuospatial attention task, at 100-, 200-, and 800-msec intervals
between cue and target, were administered a week apart. RESULTS: The
nondeficit patients exhibited a significant and abnormal asymmetry, with
slower reaction time to targets presented in the right visual field than in
the left visual field. This right visual field disadvantage was found with
both versions of the task, but only at the 100-msec cue-target interval.
The deficit patients were slowest in overall reaction time but, similar to
the normal subjects, showed no asymmetry. CONCLUSIONS: The results are
consistent with slower visual information processing in the left compared
to the right cerebral hemisphere in nondeficit schizophrenia. This finding
cannot be accounted for by differences between the deficit and nondeficit
subgroups in demographic characteristics, chronicity, or medication
effects, nor is it secondary to generalized cognitive impairment.
