The effect of visual information on motor control in social interaction tasks

Seeing an object is important for motor control during object interaction. Which sources of visual information are important for motor control in social interaction? In a virtual environment participants hit table tennis balls served by a virtual player. We manipulated the visibility of visual information (ball, racket, body) about the virtual player and the presentation time of the animation (before, during, and after the virtual player’s stroke). We measured the shortest distance between the ball and the participants’ racket. Results: (1) The visibility of each source of information was associated with performance increases; (2) performance did not change when visual information was presented after the virtual player hit the ball; (3) the presentation of the virtual player's racket induced the largest performance improvement shortly before the virtual player hit the ball; (4) performance changes associated with seeing the virtual player’s body were independent of presentation time. In sum participants seem to use multiple sources of visual information about the interaction partner. Moreover visual information about the interaction partner is most useful when seen before the interaction partner's stroke. These results support the hypothesis that the perception of the virtual player affects the online control of own actions