Shift of manual preference in right-handers following unimanual practice.

The effect of unimanual practice of the non-preferred hand on manual asymmetry and manual preference for sequential finger movements was evaluated in right-handers before, immediately after, and 30 days following practice. The results demonstrate that unimanual practice induced a persistent shift of manual preference for the experimental task in most participants, but no significant correlation between manual asymmetry and manual preference was detected. These findings are explained by proposing that manual preference is influenced by a task-specific confidence developed from the recent history of differential use of the limbs, in interaction with a generalized confidence on a single hand for performance of motor skills.