The neural correlates of target and hand vision during movement planning and execution

In the current study, electroencephalographic (EEG) data was recorded to study the impact of hand and target visibility on neural processing during both the planning and execution of upper limb reaches. Prior to each movement, participants were informed if the hand and/or the target would be available in four conditions: (1) hand and target visible, (2) hand only, (3) target only, and (4) no hand, no target. Visual evoked potentials (VEPs) were assessed after target onset (i.e., prior to the reaching movement: P2), which revealed larger positive components when vision of the target was not going to be available during the reaching movement (i.e., hand only, no hand-no target) compared to when the target would be present (i.e., hand and target, target only). Further, the motor-related evoked potentials (MEPs) observed in relation to the reaching movement onset showed that a second negative peak generated during the execution of the reaching movement was significantly greater for reaches without vision of the hand, as compared to reaches with vision of the hand. Our results indicate a sequential importance of seeing the target and the hand, prior-to and during the movement, respectively. This work provides neurophysiological evidence to better understand the utilization of vision of the hand and target during goal-directed reaching.