Abstract
For goal-directed movements like throwing darts or shooting a soccer penalty, the optimal location to aim depends on the endpoint variability of an individual. Currently, there is no consensus on whether people can optimize their movement planning based on information about their motor variability. Here, we tested the role of different types of feedback for movement planning under risk. We measured saccades toward a bar that consisted of a reward and a penalty region. Participants either received error-based feedback about their endpoint or reinforcement feedback about the resulting reward. We additionally manipulated the feedback schedule to assess the role of feedback frequency and whether feedback focusses on individual trials or a group of trials. Participants with trial-by-trial reinforcement feedback performed best. They were less loss-aversive, had the least endpoint deviation from optimality, and showed more consistent performance at the group level. This combination of reduced between-participant variability and the improved alignment with optimality suggests that reinforcement feedback about a single movement is particularly effective to optimize movement planning under risk.