Dynamic similarity promotes interpersonal coordination in joint action
Bardy, Benoit G.
Di Bernardo, Mario
Journal of The Royal Society Interface
The Royal Society
Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Human movement has been studied for decades, and dynamic laws of motion that are common to all humans have been derived. Yet, every individual moves differently from everyone else (faster/slower, harder/smoother, etc.). We propose here an index of such variability, namely an individual motor signature (IMS) able to capture the subtle differences in the way each of us moves. We show that the IMS of a person is time-invariant and that it significantly differs from those of other individuals. This allows us to quantify the dynamic similarity, a measure of rapport between dynamics of different individuals' movements, and demonstrate that it facilitates coordination during interaction. We use our measure to confirm a key prediction of the theory of similarity that coordination between two individuals performing a joint-action task is higher if their motions share similar dynamic features. Furthermore, we use a virtual avatar driven by an interactive cognitive architecture based on feedback control theory to explore the effects of different kinematic features of the avatar motion on coordination with human players.
This work was supported by the European Project AlterEgo FP7 ICT 2.9-Cognitive Sciences and Robotics, grant number 600610. The research of K.T.-A. was supported by grant no. EP/L000296/1 of the Engineering and Physical Sciences Research Council (EPSRC).