Attention and eye movements in schizophrenic, affective disorder, and normal subjects

Previous work is reviewed that relates to and lends support to three basic ideas. First, behavioral and physiological work has shed light on those cortical and subcortical areas that are involved in the generation of saccadic eye movements, smooth pursuit eye movements, and spatially directed visual attention. Second, the abnormal behavior of schizophrenic patients in general motor tasks, language tasks, and attention tasks has often been attributed to an attentional deficit; at the same time, abnormal smooth pursuit eye movements in schizophrenic patients cannot be accounted for by an attentional deficit. Third, some research has suggested that schizophrenia may involve a frontal lobe deficit.; A model is proposed that attempts to relate saccadic eye movements and spatially directed visual attention. Based on these ideas, a particular hypothesis is proposed and tested in the present study. Specifically, schizophrenic patients who have abnormal smooth pursuit eye movements may demonstrate behavioral deficits on cortical or voluntary tasks of saccadic eye movements and spatially directed visual attention, and demonstrate behavioral disinhibitions on subcortical or automatic tasks of saccadic eye movements and spatially directed visual attention.; To test such a hypothesis, schizophrenic, bipolar and normal subjects groups were tested on a series of tasks. There were three saccadic eye movement tasks (an anti-saccade, saccade, and gap task), two spatially directed attention tasks (endogenous and exogenous task), and a smooth pursuit tracking task. Results from each of the experiments are discussed. In addition, performance on the smooth pursuit tracking task is compared to performance on each of the tasks to determine the relation between abnormal pursuit eye movements and performance on the various saccadic eye movement and attention tasks.