Mental Practice in the Intermanual Transfer of Motor Skills

The current study compared intermanual transfer for two different handwriting tasks (familiar letters and novel symbols), following both mental and physical practice. There was substantial transfer from practice with the dominant hand to the nondominant one in both time to produce a character and size of the character produced, but there was no transfer in the reverse direction (even for novel symbols). Most importantly, there was significant transfer as a result of mental practice in production time comparable to physical practice. However, there was no transfer from mental practice when measuring character size. During mental practice, task-level variables still had significant effects whereas effector-level variables did not. Thus, asymmetrical transfer as a result of mental practice is posited to result from the transfer of task-level processes but not effector-level processes.