Temporal integration limits of stereovision in reaching and grasping

Even though there have been extensive investigations of the temporal integration limits of binocular vision in perceptual tasks, relatively little is known about temporal integration limits during the completion of visuomotor tasks. To assess the temporal integration limits of binocular disparity within the action domain, accuracy of reach kinematics in a reaching and grasping task under continuous binocular and monocular viewing conditions were compared with those obtained under alternating monocular viewing conditions with interocular delays ranging from 14 to 58 ms. Even the shortest of the interocular delays resulted in larger grip apertures than those in the continuous monocular and binocular viewing conditions. The short temporal integration interval of stereovision obtained in this study cannot be accounted for by differential visual feedback in the binocular and interocular delay conditions, nor is it likely to be a consequence of visual disruption due to the interocular delays. Our findings suggest that the visuomotor system has little tolerance to interocular delay.