title: Effects of Agent-Environment Symmetry on the Coordination Dynamics of Triadic Jumping.
abstract: We investigated whether the patterns of coordination that emerged during a three-participant (triadic) jumping task were defined by the symmetries of the (multi) agent-environment task space. Triads were instructed to jump around different geometrical arrangements of hoops. The symmetry of the hoop geometry was manipulated to create two symmetrical and two asymmetrical participant-hoop configurations. Video and motion tracking recordings were employed to determine the frequencies of coordination misses (collisions or failed jumps) and during 20 successful jump sequences, the jump direction chosen (clockwise vs. counterclockwise) and the patterning of between participant temporal movement lags within and across jump events. The results revealed that the (a)symmetry of the joint action workspace significantly influenced the (a)symmetry of the jump direction dynamics and, more importantly, the (a)symmetry of the between participant coordination lags. The symmetrical participant-hoop configurations resulted in smaller overall movement lags and a more spontaneous, interchangeable leader/follower relationship between participants, whereas the asymmetrical participant-hoop configurations resulted in slightly larger overall movements lags and a more explicit, persistent asymmetry in the leader/follower relationship of participants. The degree to which the patterns of behavioral coordination that emerged were consistent with the theory of symmetry groups and spontaneous and explicit symmetry-breaking are discussed.
authors.affiliation: Department of Education, University of Yamanashi Kofu, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Kijima
authors.affiliation: Department of Environmental Sciences, University of Yamanashi Kofu, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shima
authors.affiliation: Department of Art and Sports Educational Science, Tokyo Gakugei University Koganei, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Okumura
authors.affiliation: Research Center of Health, Physical Fitness and Sports, Nagoya University Nagoya, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Psychology, Center for Cognition, Action and Perception, University of Cincinnati Cincinnati, OH, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Richardson
keywords: joint action; leader and follower roles; social motor coordination; symmetry; symmetry-breaking