Relations between attentional deficits and clinical symptoms in schizophrenic outpatients

Information-processing impairments have been suggested to be at the core of the cognitive deficits observed in schizophrenia and may represent preclinical markers of genetic vulnerability to the illness. Of particular importance in information-processing research have been measures such as the Continuous Performance Test (CPT) and the Partial Report Span of Apprehension (SPAN) that place high momentary loads on processing resources. The relationships between the two cognitive measures and between the two measures and clinical symptoms were examined in 50 patients with either DSM-III-R schizophrenia or schizoaffective disorder. The information-processing measures were modestly correlated with each other and with an estimate of verbal, but not nonverbal IQ. The SPAN was correlated with negative symptoms and the CPT with formal thought disorder. These results provide some evidence of convergent validity but also suggest that constructs other than high momentary processing load are implicated in their sensitivity to schizophrenia.