title: Playing 'Pong' Together: Emergent Coordination in a Doubles Interception Task.
abstract: In this contribution we set out to study how a team of two players coordinated their actions so as to intercept an approaching ball. Adopting a doubles-pong task, six teams of two participants each intercepted balls moving downward across a screen toward an interception axis by laterally displacing participant-controlled on-screen paddles. With collisions between paddles resulting in unsuccessful interception, on each trial participants had to decide amongst them who would intercept the ball and who would not. In the absence of possibilities for overt communication, such team decisions were informed exclusively by the visual information provided on the screen. Results demonstrated that collisions were rare and that 91.3 ± 3.4% of all balls were intercepted. While all teams demonstrated a global division of interception space, boundaries between interception domains were fuzzy and could moreover be shifted away from the center of the screen. Balls arriving between the participants' initial paddle positions often gave rise to both participants initiating an interception movement, requiring one of the participants to abandon the interception attempt at some point so as to allow the other participant to intercept the ball. A simulation of on-the-fly decision making of who intercepted the ball based on a measure capturing the triangular relations between the two paddles and the ball allowed the qualitative aspects of the pattern of observed results to be reproduced, including the timing of abandoning. Overall, the results thus suggest that decisions regarding who intercepts the ball emerge from between-participant interactions.
authors.affiliation: Institut des Sciences du Mouvement, Aix-Marseille Université, CNRSMarseille, France; PsyCLE, Aix-Marseille UniversitéAix-en-Provence, France.
authors.forename: Niek H
authors.initials: NH
authors.lastname: Benerink
authors.affiliation: Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen Groningen, Netherlands.
authors.forename: Frank T J M
authors.initials: FT
authors.lastname: Zaal
authors.affiliation: Institut des Sciences du Mouvement, Aix-Marseille Université, CNRS Marseille, France.
authors.forename: Remy
authors.initials: R
authors.lastname: Casanova
authors.affiliation: PsyCLE, Aix-Marseille Université Aix-en-Provence, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bonnardel
authors.affiliation: Institut des Sciences du Mouvement, Aix-Marseille Université, CNRS Marseille, France.
authors.forename: Reinoud J
authors.initials: RJ
authors.lastname: Bootsma
keywords: collaboration; coordination; decision-making; interception; interpersonal coordination; joint-action; perception-action; team