Switching between newly learned motor skills

Studies of cognitive flexibility suggest that switching between different tasks can entail a transient switch cost. Here, we asked whether analogous switch costs exist in the context of switching between different motor skills. We tested whether participants (23 males and 12 females) could switch between a newly learned skill associated with a novel visuomotor mapping, and an existing skill associated with an intuitive mapping. Participants showed increased errors in trials immediately following a switch between mappings. These errors were attributable to persisting with the pre-switch policy, rather than imperfect implementation or retrieval of the post-switch policy. A subset of our participants further learned a second new skill. Switching between these two novel skills was initially very challenging, but improved with further training. Our findings suggest that switching between newly learned motor skills can be challenging, and that errors in the context of switching between skills are primarily attributable to perseveration with the wrong control policy. Significance Statement A large body of work in cognitive science has established small but consistent costs when switching between different cognitive tasks, but it is unknown whether similar switch costs apply when switching between motor skills. We tested people’s ability to switch between a newly learned motor skill and an existing, well-learned one, and found a transient increase in errors on trials that immediately followed a switch. These errors were primarily due to participants persisting with their pre-switch behavior. Switching between two different newly learned skills was significantly more challenging, but switching ability improved with practice over days. These findings highlight the complexities of switching between novel motor skills, and highlight perseveration as a primary cause of errors when switching between skills.