The role of visual error and reward feedback in learning to aim to an optimal movement endpoint

When presented with a target circle horizontally overlapped by a penalty circle, participants initially aim closer to the penalty circle than optimal and with experience and feedback shift their endpoint horizontally to the optimal endpoint. Our purpose was to determine whether solely reward feedback or reward feedback in combination with visual error feedback of the movement and final movement endpoint is necessary for participants to learn to aim to the optimal endpoint. Participants received money for hitting the target but lost money for hitting the penalty region. In a critical No Feedback group, the target/penalty configuration would disappear on movement initiation, but participants were told the number of points received or lost after each trial. Similar to groups receiving various amounts of visual error feedback (target never disappeared, or reappeared upon screen contact), participants in the No Feedback group shifted the endpoint horizontally with experience, but they vertically undershot the horizontal meridian that contained the optimal endpoint. The region of the vertical undershoot, although suboptimal, was associated with less variance in the value of the expected outcomes. We suggest that reward feedback encourages participants to aim toward this less risky region, whereas receiving full visual error feedback leads participants to aim to the more advantageous horizontal meridian. (PsycInfo Database Record (c) 2020 APA, all rights reserved).