The effects of learning schedules and external visual information on implicit sensorimotor adaptation of upper limb movements.

Implicit motor adaptation is vital for maintaining accurate movements when faced with changes in the environment or our own bodies. Using both simple and complex motor tasks, this dissertation investigates the limits of implicit adaptation in upper-limb motor adaptation, and its sensitivity to visual context cues. We first demonstrate that the extent of implicit adaptation depends on how motor errors are introduced during a training paradigm. We find the largest extents of implicit adaptation when participants can adapt to small but noticeable motor errors before experiencing further perturbations to their movements. This method of error introduction led to significantly larger adaptation compared to both abruptly introducing large errors or introducing small errors in a ramped manner. Next, we determined that when adapting to opposing perturbations simultaneously, task-relevant object-shape cues that predict the presence of a given perturbation are insufficient to consistently trigger the formation of object-specific motor memories. Finally, we show that when perturbations can plausibly assign the source of errors to environment causes, context-dependent motor learning can readily occur. Overall, this dissertation highlights the adaptability of implicit motor learning, emphasizing the need to consider perturbation methods, contextual influences, and task complexity when designing effective motor learning paradigms.