Human gaze shifts to acoustic and visual targets.

Eye and head contributions to orienting gaze shifts have been primarily studied using visual targets. Consequently, relatively little is known about the kinematics of eye and head movements in gaze shifts to acoustic targets. Although early work in nonhuman primates indicates that orienting responses to acoustic and visual targets are similar, suggesting that a common motor program is used for stimuli of both modalities,1 supporting data have not followed. Experiments using primates, which provide for concurrent behavioral and physiological measurements, suggest that it is difficult to train them to orient to acoustic targets.2 Human subjects, on the other hand, do not require training and can be provided with specific instructions. In this study we characterize the kinematics of gaze shifts to acoustic targets using equivalent measures to visual targets for comparison.