Positive/negative symptomatology and experimental measures of attention in schizophrenic patients

In a search for an external validation of the negative syndrome construct and the attentional impairment item on Andreasen's scale, 49 unmedicated schizophrenic patients were administered the Span of Apprehension Test and a Continuous Performance Test with two levels of difficulty. This schizophrenic sample performed significantly more poorly on the attentional tests than a comparable group of 27 healthy control subjects. Depending on the difficulty of the test we found a number of significant correlations between the SANS composite score and the pertaining attentional impairment item on the one hand and experimental indices of attentional functioning on the other hand, which might corroborate the psychopathological assumptions. The implications of these results for further attempts to validate clinical concepts of the positive/negative dichotomy by experimental means will be discussed.