Allocation of attention for dissociated visual and motor goals

In daily life, selecting an object visually is closely intertwined with processing that object as a potential goal for action. Since visual and motor goals are typically identical, it remains unknown whether attention is primarily allocated to a visual target, a motor goal, or both. Here, we dissociated visual and motor goals using a visuomotor adaptation paradigm, in which participants reached toward a visual target using a computer mouse or a stylus pen, while the direction of the cursor was rotated 45° counter-clockwise from the direction of the hand movement. Thus, as visuomotor adaptation was accomplished, the visual target was dissociated from the movement goal. Then, we measured the locus of attention using an attention-demanding rapid serial visual presentation (RSVP) task, in which participants detected a pre-defined visual stimulus among the successive visual stimuli presented on either the visual target, the motor goal, or a neutral control location. We demonstrated that before visuomotor adaptation, participants performed better when the RSVP stream was presented at the visual target than at other locations. However, once visual and motor goals were dissociated following visuomotor adaptation, performance at the visual and motor goals was equated and better than performance at the control location. Therefore, we concluded that attentional resources are allocated both to visual target and motor goals during goal-directed reaching movements.