Cognitive constraint on the 'automatic pilot' for the hand: movement intention influences the hand's susceptibility...

Research suggests that the reaching hand automatically deviates toward a target that changes location (jumps) during the reach. In the current study, we investigated whether movement intention can influence the target jump's impact on the hand. We compared the degree of trajectory deviation to a jumped target under three instruction conditions: (1) GO, in which participants were told to go to the target if it jumped, (2) STOP, in which participants were told to immediately stop their movement if the target jumped, and (3) IGNORE, in which participants were told to ignore the target if it jumped and to continue to its initial location. We observed a reduced response to the jump in the IGNORE condition relative to the other conditions, suggesting that the response to the jump is contingent on the jump being a task-relevant event.