Abstract
Research participants (Ps) who watch a movie of another person learning to reach in a viscous, rotational force field know better how to compensate for the force field than Ps who did not see the movie. Does information derived from watching another person act directly engage learning mechanisms in the motor system (motor cortex)? If so, motor-learning-by-observing should be degraded by the application of repetitive transcranial magnetic stimulation (rTMS) to the motor cortex after observation. We applied 15 minutes of 1-Hz rTMS to the contralateral motor cortex after subjects watched a movie of another person learning a clockwise (CWFF) or counter-clockwise force field (CCWFF). After observation, all subjects were tested in a clockwise force field (CWFF). Subjects who received rTMS to M1 after watching the CWFF movie performed worse in subsequent CWFF training than controls who did not receive rTMS. In contrast, subjects who received rTMS to M1 after watching the CCWFF movie performed better in subsequent CWFF training than controls who did not receive rTMS. These results replicate earlier findings of motor learning by observing, and in addition show that both the facilitating and interfering effect of observing CWFF and CCWFF learning, respectively, can be attenuated by applying rTMS to M1. Thus, we provide direct evidence that visual information acquired simply by observing another person perform a new motor skill is translated into motor parameters used to update an internal model of that skill.
Canadian Institutes for Health Research