Effects of social intention on movement kinematics in cooperative actions

Abstract

Optimal control models of biological movements are used to account for those internal variables that constrain voluntary goal-directed actions. They, however, do not take into account external environmental constraints as those associated to social intention. We investigated here the effects of the social context on kinematic characteristics of sequential actions consisting in placing an object on an initial pad (preparatory action) before reaching and grasping as fast as possible the object to move it to another location (main action). Reach-to-grasp actions were performed either in an isolated condition or in the presence of a partner (audience effect), located in the near or far space (effect of shared reachable space), and who could intervene on the object in a systematic fashion (effect of social intention effect) or not (effect of social uncertainty). Results showed an absence of audience effect but nevertheless an influence of the social context both on the main and the preparatory actions. In particular, a “localized” effect of shared reachable space was observed on the main action, which was smoother when performed within the reachable space of the partner. Furthermore, a “global” effect of social uncertainty was observed on both actions with faster and jerkier movements. Finally, social intention affected the preparatory action with higher wrist displacements and slower movements when the object was placed for the partner rather than placed for self-use. Overall, these results demonstrate specific effects of action space, social uncertainty and social intention on the planning of reach-to-grasp actions, in particular on the preparatory action, which was performed with no specific execution constraint. These findings underline the importance of considering the social context in optimal models of action control for human–robot interactions, in particular when focusing on the implementation of motor parameters required to afford intuitive interactions.

Examining ecological validity in social interaction: problems of visual fidelity, gaze, and social potential

“…For example, by changing the presence of an observer, along with the observer’s proximity and their ability to intervene in the participant’s action, Quesque et al (2013) found that the kinematic parameters of participants’ object-directed actions (in particular preparatory actions) were significantly altered. This was true even in cases where it was impossible for the observer to directly influence the action outcome.…”

Real-Time Motion Capture Toolbox (RTMocap): an open-source code for recording 3-D motion kinematics to study action–effect anticipations during motor and social interactions

“…Scientific objectives Recent kinematic studies have shown that social context shapes action planning (Becchio, Sartori, & Castiello, 2010;Quesque, Lewkowicz, Delevoye-Turrell, & Coello, 2013). Moreover, we observed in a previous study that humans are able to discriminate between actions performed under different social contexts: reach for a cup for my own use or reach for a cup to give it to someone else .…”

“…Here, we describe an example of a very simple face-to-face interactive paradigm in which two human agents exchange an object while trying to earn the most rewards possible. This software solution was used to run the study that is reported in Quesque et al (2013); it was also used to test the integration of eyetracking and 3-D movement capture .…”

“…To get an idea of the potential of the RTMocap software in conducting psychological studies, one can refer to a study published by our group (Quesque et al 2013) in which we used the software to trigger informative auditory cues to indicate who between two competing players was to pick and place a wooden object. In the present article, we provide both screenshots and exemplary data sets to illustrate the potential data that could be collected using the RTMocap software.…”

A New Computational Approach to Identify Human Social Intention in Action

“…Recent researches in cognitive psychology have suggested that even in that case movement kinematics is affected. In particular, these studies showed that when we perform an action with a social instead of a personal intention, we amplify the spatial and temporal parameters of the motor action [11]. Furthermore, an observer is able to perceive these kinematic deviants and anticipate social intention in motor actions performed by others, in order to act in a complementary way ( [9]; see [10] for a review).…”