Insights on embodiment induced by visuo-tactile stimulation during robotic telepresence

Abstract

Using a simple neuroscience-inspired procedure to beam human subjects into robots, we previously demonstrated by visuo-motor manipulations that embodiment into a robot can enhance the acceptability and closeness felt towards the robot. In that study, the feelings of likeability and closeness toward the robot were significantly related to the sense of agency, independently of the sensations of enfacement and location. Here, using the same paradigm we investigated the effect of a purely sensory manipulation on the sense of robotic embodiment associated to social cognition. Wearing a head-mounted display, participants saw the visual scene captured from the robot eyes. By positioning a mirror in front of the robot, subjects saw themselves as a robot. Tactile stimulation was provided by stroking synchronously or not with a paintbrush the same location of the subject and robot faces. In contrast to the previous motor induction of embodiment which particularly affected agency, tactile induction yields more generalized effects on the perception of ownership, location and agency. Interestingly, the links between positive social feelings towards the robot and the strength of the embodiment sensations were not observed. We conclude that the embodiment into a robot is not sufficient in itself to induce changes in social cognition.

Figure 1

Mean values of the embodiment scores for the ownership, enfacement, location and agency categories as measured in the Correlated and Uncorrelated visuo-tactile stimulation conditions. Note the general increase in the scores in the Correlated as compared to Uncorrelated conditions. Grey points: individual data; Black circles: means; Bars: standard errors.

Figure 2

Mean values of the Agency Score as measured in the Correlated and Uncorrelated conditions in the two visuo-motor (VMot) and visuo-tactile (VTact) experiments. Circles: averaged agency scores; Bars: standard errors.

Figure 3

Mean values of the Likeability (A) and Closeness (B) scores as measured in the Correlated and Uncorrelated conditions in visuo-motor (VMot) and visuo-tactile (VTact) experiments. Circles: averaged scores of likeability and closeness; Bars: standard errors.

Figure 4

The robot setup illustrating (left) the human subject with head mounted display being stimulated on the right cheek, (middle) the iCub facing the mirror, stimulated on the right cheek, (right) the Reeti robot in front of the mirror, stimulated on the left cheek. Timeline indicates Pre-beaming questionnaires followed by Robot 1, Post-beaming questionnaires, then Robot 2, Post-beaming questionnaires. The panel (bottom) gives the successive 1 min phases of visuo-tactile stimulations realising one correlated or uncorrelated session of robotic telepresence. Informed Consent to publish the participant images has been obtained from study participant Jocelyne Ventre-Dominey.

Figure 5

The Self-Other Closeness task as an adaptation of the single-item Inclusion of Other in the Self (IOS) scale developed by Aron et al.. The pairwise circles illustrate the self (here the participant) and the other (here the robot). On the bottom, the subjective scale of the level of Closeness.