Abstract
Practice improves the speed at which we can perform a task, but also leads to habitual behavior. Behavioral, computational, and neurobiological evidence has suggested that these two effects of practice might be related; however, it remains unclear whether skill improvement and habit formation are two aspects of the same learning process, or are separate processes that occur in parallel. Using a visuomotor association task in human participants, we directly assessed the effects of practice on both the speed of response selection, and whether or not response selection became habitual. We found that response selection could become fully habitual within four days of practice. In contrast, the speed of response selection improved continuously with practice over twenty days. We conclude that skill learning occurs largely independently of habit formation, suggesting a distinct neural basis.
