Can passive arm movement affect adaptation to visuomotor rotation?

Through active motor experience, humans are capable of adapting to even unfamiliar environments. However, little is known about motor learning in the absence of active motor intention such as passive movements by rehabilitation robots. To clarify this question, we investigated whether passive arm movements by a robotic manipulandum affect the motor learning of arm-reaching tasks under unfamiliar visuomotor rotation. Experimental results suggest that passive motor experience has positive effect on acquisition of motor skills for the visuomotor rotation, even though it is significantly small compared with active motor learning. Furthermore, experimental result shows that the effect of passive motor experience can be maintained even after a day.