Span of apprehension performance, neuropsychological functioning, and indices of psychosis-proneness

Fifty subjects without a history of psychiatric disorder were selected from temporary employment agencies. Subjects were then assigned to two groups based solely on their performance on a forced-choice version of the span of apprehension task which previous research suggests may be associated with vulnerability to schizophrenia. The group of subjects characterized by poor performance on the span of apprehension scored significantly higher on the Schizophrenia scale of the MMPI, two indices of schizotypy--the Schizoidia and Schizophrenism scales--and an index of subclinical schizophrenic thinking, the Magical Ideation scale, than the balance of the subjects. The poor span group did not show generalized elevations on the MMPI, suggesting that there is some degree of specificity for the relationship between the span of apprehension performance and scores on indices of schizotypy and psychotic-like experiences. These results are consistent with the hypothesis that impairment in early aspects of information processing is associated with vulnerability to schizophrenic disorders. Subjects with poor performance on the span of apprehension task also scored more poorly than the balance of the group on three neuropsychological tasks: the Trail Making Test, the Digit Symbol Substitution Test, and Rey's Tangled Line task.