The nature of deficit among paranoid and nonparanoid schizophrenics in the interpretation of sentences: an information processing approach.

Compared paranoid and nonparanoid schizophrenics to normal controls on a sentence verification task. The task permitted separation of times taken for central scanning and comparison operations and for operations associated with response selection and response execution. Neither group of schizophrenics took more time than normal controls for the latter operations; however, both groups of schizophrenics took longer at central scanning and comparison. Performance on this task was compared to previous results in which schizophrenics were similar to normals on times for central scanning and comparison, but took longer for non-central aspects of processing. It was condluded that the present deficit at the central processing level was attributable to deficient short-term memory of the encoded version of the sentence during the scanning and comparison operations. The absence of differences in the time taken for the non-central operations was ascribed to the exclusion of sentence encoding from the present latency times.