European Workshop on Cognitive Neuropsychology 2017 31-Emotions and social cognition#3 Invisible body illusion reduces social space Mariano D'Angelo, Francesca Frassinetti, Giuseppe di Pellegrino First author address: University of Bologna , Bologna, Italy. First author email:

[email protected]

Introduction ​ ​ : Interpersonal space (IPS) refers to the distance individuals maintain from others during social

interactions, into which intrusion by others may cause discomfort. Recent studies on embodied cognition have suggested an interaction between bodily self-representation and socio-cognitive processing (Guterstam et al., 2015). Based on these findings, the present study investigates the novel hypothesis that a change of one’s own body representation may influence the space of interaction with other people. We predict that the experience of having an invisible body illusion should induce participants to feel themselves more protected and less exposed during another person’s approach, thus leading to a significant contraction of IPS boundaries.

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Methods: We measured IPS in healthy subjects before and after an invisible-body illusion. To asses IPS we used a comfort-distance task, in which participants were asked to stop a confederate approaching them at a position in which they felt comfortable with the other’s proximity. To rule out that the invisible body illusion may influence space perception, we also measured the reaching-space near the body, i.e. peripersonal space (PPS) through a reaching-distance task in which subjects stopped the confederate at the distance in which they thought they could reach her. In a control experiment we measured IPS and PPS before and after a tool-use paradigm to modulate PPS, without altering social IPS. The mean distances obtained in different experimental conditions were compared trough an ANOVA.

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Results: Results showed that in both experiments comfort-distance was larger than reaching-distance. More

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Discussion:Results support a close relationship between IPS and the conscious representation of the body

relevant, the experience of invisibility, affecting body image, induces a specific contraction of IPS, without affecting the perceived reaching-space around the body. In the control experiment, we found the opposite dissociation: tool-use enlarged PPS, while IPS remained unaffected. external appearance, i.e. the body image. We argued that if participants experience invisibility, their body is represented as invisible to others individual as well, which might induce participants to feel more protected and less exposed during the confederate’s approach, leading to a reduction of IPS. Since invisible body illusion selectively influence IPS and tool use modifies selectively PPS, the present findings reveal that IPS and PPS are functionally defined according to different behavioural context that involves different high-order representations of the body, used for the perception (i.e., body image), and action (i.e., body schema) of the body, respectively.

References: Guterstam et al. Scientific reports (2015) Keywords: Emotions and social cognition; normal population; group study; adults; not relevant; behavioural, Full body illusion.

Bressanone, 22-27 January 2017