Selection of the hand path in obstacle avoidance

Participants performed rapid hand movements to a goal position avoiding a central obstacle either to the right or to the left, depending on the pitch of the acoustical go-signal. We used a dot probe paradigm in order to analyze the deployment of visual attention in the field during the motor preparation. Briefly after the go-signal but still before the hand movement actually started a visual transient was flashed either on the planned pathway of the hand to the left or right of the obstacle (congruent trials) or on the opposite, movement-irrelevant side (incongruent trials). The P1/N1-components that were induced by the onset of the dot probe were enhanced in congruent trials where the visual transient was presented on the planned path of the hand. The results indicate that during movement preparation attention is allocated to the planned trajectory the hand is going to take around the obstacle.