Abstract
The purpose of this study was to examine whether social co-representation (joint action) effects (Sebanz et al., 2003), extended to a shared-task situation where response-relevant information was provided in advance to co-actors. Participants performed a modified version of the 4-choice spatial response-cueing task (Miller, 1982) in which the target could appear in one of four response positions normally assigned to the index and middle fingers of the two hands. A precue indicated full, hand, finger, ambiguous, or no information. Participants completed the task in either a solo or joint ("social") condition. In the solo condition, participants were assigned to respond to targets that appeared in one of the two positions assigned to them. In the social condition, participants were paired with a partner who was responsible for the remaining two positions. In this condition, precues also specified whether one or both partners had to engage on a given trial. In the solo condition, targets that appeared in the two unassigned positions were difficult to ignore. This difficulty in ignoring unassigned targets could explain why solo performance more closely resembled performance in a situation where the solo participant performed the entire 4-choice task. In the social condition, the other targets were assigned to a partner, making them easier to ignore. This resulted in performance that resembled completion of just half the task. We propose that co-representation was suppressed in the social condition because participants could "loaf" as the co-actor was responsible for, and responded to, the targets in the unassigned positions.Acknowledgments: This research was funded by NSERC.