Pattern of compensation of a typical participant in the: A) reinforcement group, B) reinforcement + error group, and C) error group.

<p>All experimental trials are represented in the line graph (bins 1–50), where each point represents the average of 10 trials. The circles at bin 0 represent the average of the first three trials and show each participant’s behaviour immediately after perturbation onset, which was similar across groups (see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005623#pcbi.1005623.g006" target="_blank">Fig 6</a>). For each group, the upper dashed line represents the optimal compensation (location to aim the hand) that maximizes the probability of hitting the target []. The lower dashed line represents the optimal compensation (location to aim the hand) that minimizes squared error []. It can be seen that the Reinforcement participant had a pattern of compensation that on average maximized target hits. Conversely, both the Error participant and the Reinforcement + Error participant learned a compensation that on average minimized approximately squared error. This behavior was consistent across participants. Error bars represent ±1 standard deviation.