Haptic texture affects the kinematics of pointing movements, but not of eye movements

Discrepant findings on the degree of eye-hand coupling suggest its dependence on the task. One task characteristic modulating this coupling may be the relevance of certain target attributes for each motor system. We tested this assumption by comparing eye and hand movements towards targets of different haptic texture, a target attribute which is behaviourally relevant only to the hand, not the eye. Pointing to a slippery target (fur) resulted in longer hand movement time than to a rougher target (sandpaper). This effect was due to an increased ratio of time spent in deceleration. In contrast, eye movement time was invariant across different haptic target textures. Thus, information about target texture is used differently by eye and hand.