Abstract The present study tests the hypothesis that voluntary lateral eye movements produce heightened arousal in the contralateral hemisphere. A task which can be performed using either the semantic or the non-semantic cognitive mode was presented to subjects who were directing their gaze either to their right or their left. Forty right-handed subjects preferred the non-semantic mode more often while gazing to the left than while gazing to the right. No such effect was detectable with left-handed subjects. It is concluded that hemispheric activity can be affected by voluntary lateral gaze.