title: Let the force be with us: dyads exploit haptic coupling for coordination.
abstract: People often perform actions that involve a direct physical coupling with another person, such as when moving furniture together. Here, we examined how people successfully coordinate such actions with others. We tested the hypothesis that dyads amplify their forces to create haptic information to coordinate. Participants moved a pole (resembling a pendulum) back and forth between two targets at different amplitudes and frequencies. They did so by pulling on cords attached to the base of the pole, one on each side. In the individual condition, one participant performed this task bimanually, and in the joint condition two participants each controlled one cord. We measured the moment-to-moment pulling forces on each cord and the pole kinematics to determine how well individuals and dyads performed. Results indicated that dyads produced much more overlapping forces than individuals, especially for tasks with higher coordination requirements. Thus, the results suggest that dyads amplify their forces to generate a haptic information channel. This likely reflects a general coordination principle in haptic joint action, where force amplification allows dyads to perform at the same level as individuals.
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, Nijmegen, Montessorilaan 3, 6525 HR Nijmegen. R.vanderwel@donders.ru.nl
authors.forename: Robrecht P R D
authors.initials: RP
authors.lastname: van der Wel
authors.forename: Guenther
authors.initials: G
authors.lastname: Knoblich
authors.forename: Natalie
authors.initials: N
authors.lastname: Sebanz
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D003299:Cooperative Behavior; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007398:Interpersonal Relations; D007699:Kinesthesis; D008297:Male; D009043:Motor Activity; D009949:Orientation; D011434:Proprioception; D011597:Psychomotor Performance; D011601:Psychophysics; D014110:Touch; D055815:Young Adult