Abstract
Learning motor actions such pitching a baseball or kicking a football requires the person to update their motor system from sensory feedback. In order to understand the psychological mechanism of these actions, participants in the laboratory are trained to adapt to an artificial perturbation of the sensorimotor system. In the current experiment, participants completed a visuomotor adaptation task in which they learned to adjust their reach movement to account for a 45° perturbation between their movement and visual feedback. Visuomotor learning is thought to occur through an error-based mechanism in which participants adjust their reach movements by minimizing the difference between the predicted and actual visual feedback. The current study examined whether learning multiple reach movements (i.e., 15°, 30°, or 45°) affect learning rate and recall performance. Participants initially learned a small adaptation (15° or 30°), and in a second phase, participants learned a larger adaptation of up to 45°. According to the error-based model, multiple reach movements cannot be associated with the same visual stimulus as each new reach movement simply updates the prediction error. Alternatively, we hypothesized that learning different reach movements may engage separate encoding of each different motor action so that high similarity between motor memories may generate interference for new learning and recall. Consistent with our prediction, adaptation of 45° rotation was faster following the 15° rotation than 30° rotation. The findings suggest participants encode separate representations for each reach movement and this interferes with acquisition of highly similar reach movements
Meeting abstract presented at VSS 2016