Automatic movement error detection and correction processes in reaching movements.

Manual aiming movements can be amended during their execution. Recent evidence suggests that error detection and correction are based on automatic and even reflexive processing of afferent information. In this study, we wanted to determine whether these processes are affected by the occurrence of successive events requiring adjustments of the originally planned movement. To reach our goal, we used a video-aiming task. For a small proportion of the trials, the cursor moved by the participant was translated laterally by 15 mm (cursor jump) soon after movement initiation. For some of the cursor-jump trials, a second cursor jump occurred 100 ms after the first one and canceled or doubled the initial cursor translation. Results showed that participants were able to cancel or double the size of the correction in response to the second cursor jump. More importantly, in double-jump trials, the correction latency for the first and second cursor jumps did not differ from that of single-jump trials. Moreover, the correction for the second cursor jump blended seamlessly with the correction for the first cursor jump. These observations suggest that the processes leading of a correction for a cursor jump do not interfere with incoming visual information.