Exploratory aspects of variability in learning a novel skill

Movement variability has been typically thought as detrimental, but it also plays a positive role for perception and action. One positive aspect is that it allows exploring different task solutions. Using a virtual throwing task [1], we examined how participants explore task solutions as they become more skilled. Naive subjects practiced 240 throws a day for 11 days - one group (N=13) had an easy target location and another (N=10) a difficult one. We hypothesized that participants in both groups would initially explore the task result space early in learning to find a solution and then fine-tune this solution over practice. We also hypothesized that once participants learn to reduce intrinsic noise, they would explore different solutions within the result space. Consistent with our hypothesis, participants in both groups found an initial task solution region. Only subjects in the easy target group, however, increased in variability to continue exploring the result space, as they were able to reduce their noise to a low level faster than the difficult target group. These results support the prior finding that participants initially seek most error-tolerant regions [1] and our hypothesis that exploration increases as expert participants reduce noise.