Learning a specific, individual and generalizable coordination function: evaluating the variability of practice hypothesis in motor learning.

Constant and variable practice conditions have been hypothesized to lead to different learning outcomes between them but similar within. However, experiments have found that within a constant practice condition, participants can show highly individual outcomes (i.e., coordination functions). Considering the contradictory evidence on the effects of variable practice, we tested the idea that measures of the individual learned outcome would be required to provide a full explanation for results in transfer tests rather than or in addition to the group task-related conditions on which individuals practiced. Twenty-four participants were divided into three groups with different practice conditions (constant, varied distance of the target, and varied angle of the target) and for 5 days performed a task of throwing for precision to a target. Pre-, post-, and transfer tests were used to evaluate our hypothesis. The results showed that although the group measures could predict certain aspects of the transfer tests, the coordination function characteristics were required to show higher levels of explanatory power. This finding supports the view that learning involves a specific, individual and generalizable solution although there are aspects of learning that are specific to the condition of practice.