Attention/information processing, neuropsychological functioning, and thought disorder during the acute and partial recovery phases of schizophrenia: a longitudinal study.

Schizophrenic subjects were administered the span of apprehension task, which is a measure of visual information processing; two neuropsychological tests; and measures of specific aspects of thought disorder and general clinical state. The measures were administered both when patients were acutely disturbed and when they were partially recovered. Normal control subjects were tested over a comparable 12-week interval. Improvements in both overall clinical condition and specific aspects of thought disorder occurred in the schizophrenic patients during this time. The patients, however, continued to show impaired information processing, indicating that the span of apprehension task is sensitive to schizophrenic dysfunction across wide variations in clinical state and, therefore, may be a marker of vulnerability to schizophrenia. The span of apprehension task was found to be significantly correlated with a measure of thought disorder that assesses resistance to associative distractors and two neuropsychological tests--the Trail-Making Test from the Halstead-Reitan battery and the Digit Symbol Substitution Test--during the testing session conducted while the subjects were partially recovered.