The disengagement of covert attention and the neglect syndrome

Abstract

Parietal lesions can cause impairment of the ability to disengage attention from an ipsilateral stimulus prior to shifting the focus of attention contralaterally. The present study addresses two main questions concerning the parietal-based disengagement process. First, what is the relationship between the disengagement process, as operationalized by a cued simple reaction-time task, and the neglect syndrome? Second, is there an asymmetry in the roles of the left and right hemisphere in the disengagement of attention? We found a very strong relationship between clinical neglect and impairment of the disengagement operation across patients, and longitudinally, within patients. Furthermore, we found that right-hemisphere lesions cause greater impairment in the disengage process than do left-hemisphere lesions.