Most of our motor skills are built over countless hours of practice, yet laboratory studies of motor adaptation usually involve a few hundred trials. How much do such experiments miss?
In Nature Human Behaviour, Franklin and colleagues stretched the timescale. Participants performed a simple motor adaptation task for thousands of trials over several weeks, while the team tracked adaptation, retention, transfer between limbs, decay, spontaneous recovery and generalization.
Unlike in shorter studies, participants came to compensate almost completely for the novel dynamics, and retention and spontaneous recovery kept increasing with training. The range over which the memory generalized to other movement directions also narrowed, suggesting that the motor memory was being continually tuned to the task.
The authors say that longer training produces extensive changes that brief experiments do not capture, a point that matters for research on sensorimotor control as well as for rehabilitation and skills training.
