THE EFFECTS OF INCREASING RESOURCE DEMAND ON VIGILANCE PERFORMANCE INADULTS WITH SCHIZOPHRENIA OR DEVELOPMENTAL ATTENTIONAL LEARNING DISORDERS - A PRELIMINARY-STUDY/

The goal of this study was to assess whether degree of information pro cessing load differentially affects vigilance performance in patients with schizophrenia as compared to normal controls or patients with oth er attentional disorders. We contrasted the performance of clinically stable outpatients with schizophrenia (n=18), with that of normal cont rols (n=17), and adults with developmental attentional/learning disord ers (n=13) on simple and demanding versions of a visual continuous per formance test (CPT). Patients with schizophrenia were significantly im paired on both versions of the CPT compared to normal controls, and sh owed a significant decline in perceptual sensitivity and significantly more omission errors with increased processing demands. Compared to a dults with developmental attentional/learning disorders, patients with schizophrenia manifested a tendency toward a decline in perceptual se nsitivity. There were no significant differences between groups on a m easure of response bias. The data support the hypothesis that patients with schizophrenia have insufficient information processing resources to cope with higher processing demands on effortful attention tasks. Further study comparing schizophrenic patients with patients who have other neuropsychiatric disorders, controlling for severity of illness, is required to determine the specificity of this deficit in schizophr enia. (C) 1998 Elsevier Science B.V. All rights reserved.