Reevaluating Strategy Development as a Discrete Step Process in Visuomotor Adaptation

In response to a changing environment, humans can adapt their movement with contributions from both implicit, or unconscious and explicit strategies. Explicit visuomotor adaptation is thought to develop gradually in a series of small incremental steps (McDougle et al. 2015). However, in some of our individual data we observed large, sudden changes in strategy comparable to insight learning. Here we investigate the timecourse of explicit learning in motor adaptation following the introduction of 5 perturbation sizes. To do so, we asked participants to report where they planned to move their hand throughout a visuomotor rotation task. This project will aim to test if 1) strategies develop in one or two discrete steps, and 2) the likelihood and magnitude of participants’ aiming strategy will increase as the rotation size gets bigger. Our findings show that most participants across all rotation groups develop an aiming strategy in discrete steps. A higher proportion of participants in the largest perturbation group adopt an explicit strategy and show greater mean aiming deviations compared to explicit learners with a small perturbation. Analysis of our previous explicit data shows that step functions provide a better fit to aiming behaviour. Investigating strategy-use at the individual level may reveal the nature of cognitive processes in a visuomotor rotation task. Having a better understanding of cognitive strategy development in motor tasks may guide future work on motor learning, and applications for support in skills training and rehabilitation.