MANUAL AND SACCADIC REACTION-TIME WITH CONSTANT AND VARIABLE PREPARATORY INTERVALS IN SCHIZOPHRENIA

Saccadic reaction time (RT) has been shown to be unimpaired in schizop hrenia. Could this be due to its not requiring controlled information processing? The authors gave 49 schizophrenia patients and 34 controls manual and saccadic RT tasks with preparatory intervals of 1, 3, and 5 s given in regular and irregular sequences. If saccades require main ly automatic processes, they should not be affected by variations in t he preparatory interval that are mediated by controlled processing. Th e manual task showed typical slower RT and larger preparatory interval effects in patients than in controls. Although the saccadic task show ed significant effects of both the preparatory interval and the prepar atory interval on the preceding trial similar in kind to those in manu al RT, there were no group differences in these or in RT. The results are attributed to greater stimulus-response compatibility in the sacca dic task, which puts fewer demands on working memory.