Abstract

Three theories of attentional deficit were tested by means of card-sorting choice reaction time task in which stimulus complexity and response complexity were varied independently. An individual's choice reaction time was divided into movement time and decision time by regression analysis. It was found that stimulus complexity, response complexity, and movement speed were associated with significantly greater impairment in schizophrenic groups. In addition, the regression line relating decision time to response complexity was significantly steeper than the regression line relating decision time to stimulus complexity, indicating that response selection was more difficult than stimulus analysing for the schizophrenics. These finding supported Broen's (1968) partial collapse of response hierarchies, and also provided some support for McGhie's (1970) defective filter theory. But Yates' (1966) theory could not be confirmed by these results. The effect of chlorpromazine on choice reaction time performance of schizophrenia, the merit of choice reaction time task, and homogeneous grouping of schizophrenia were also discussed.