Motor learning affects visual movement perception.

In the present study we investigated whether imitation of artificial movement trajectories of meaningless objects has an effect on how these trajectories are later perceptually processed within the human brain. During observation of a sequence of artificial object movements 10 participants (experimental group) actively imitated the trajectories during motor training and 10 participants (control group) solved a working memory task without motor training. The haemodynamic responses were recorded before and after the intervention while participants observed the movements and either had to detect colour changes of one of the objects (colour task, motor-irrelevant) or had to judge whether the movement pattern could be imitated with the hands (simulation judgement task, motor-relevant). The between-group comparison of the post-intervention haemodynamic responses revealed stronger activity for the motor training than for the control group during the simulation judgement task. This activity appeared in motor-related areas (supplementary motor area and inferior parietal lobe) and in the occipito-temporal area. During the colour task, the motor training group showed stronger activity in the occipital lobe. The control group did not reveal any stronger activity than the motor training group for either task. The results suggest that motor training has task-specific effects on neural processes that are involved in perception of movements. Furthermore, they indicate that motor-related areas are triggered by observed artificial object movements, but only if a motor-relevant task is pursued.