The regulation of social touch and interpersonal distance during human-avatar social interactions.

Nonverbal behaviors, defined as “communication effected by mean other than words” (Knapp et al., 2014), have a deep impact on the process and outcome of our social interactions (Mehrabian & Wiener, 1967). According to the embodied cognition framework, mental processes, including high-level social and cognitive representations, are situated and embodied in our physical experiences (Barsalou, 2008; Niedenthal et al., 2005). The embodiment of social cognition constitutes the basis of social interaction: bodily-motor cues (such as facial expression, gestures, body posture, and movement) are in a reciprocal relationship (circular causality; Haken, 1977) with mental processes (affects, emotions, motivation, attitudes; Tschacher, Giersch, & Friston, 2017). Liking and attitudes toward the other are expressed primarily by nonverbal channels, often in an automatic fashion (Vogeley & Bente, 2010). On the other hand, embodied cues, such as interpersonal touch, can result in a change of attitudes toward the other person and the whole social category that him/her represents (Seger et al., 2014). This thesis aims to advance the understanding of two nonverbal behaviors that constitute the core of embodied intersubjectivity (Csordas, 2008), namely the regulation of social touch and interpersonal distance, capitalizing on the Virtual Reality (VR) technology. Indeed, the investigation of the bidirectional relationship between nonverbal behaviors and attitudes, and its physiological and neural underpinnings, has been limited by the lack of either naturalistic interactions and/or experimental control that VR can partially overcome (Pan & Hamilton, 2018). Here we aimed at developing a new paradigm to study social and intimate vicarious touch from an embodied perspective and investigate the role of affiliative and self-protective motives affecting the regulation of interpersonal distance toward virtual avatars.