Spatial and temporal aspects of eye-hand coordination across different tasks

The way in which saccadic eye movements are elicited influences their laten cy and accuracy. Accordingly, different tasks elicit different types of sac cades, Using the tasks steps, Sap, memory, scanning and antisaccade, we ana lyzed combined eye and hand movements to determine whether both motor syste ms share control strategies. Errors and latencies were measured to examine whether changes in eye motor behavior are reflected in hand motor behavior. Directional and variable errors of eye and hand changed differently accord ing to the tasks. Moreover, errors of the two systems did not correlate For any of the tasks investigated. Contrary to errors, mean latencies of eye m ovements were organized in the same pattern as hand movements. A correlatio n of latencies indicates that both motor systems rely on common information to initiate movement. Temporal coupling was stronger for intentional tasks than for reflexive tasks.