Allocentric Full Body Illusion extends Peripersonal Space

Body Self-Consciousness (BSC) is based on a multisensory integration (MSI) process, in which bodily signals and information entering the space immediately surrounding the body - the Peripersonal Space (PPS) - are integrated. The PPS contributes to the development of self-presentation and plays a critical role in shaping how people interact with the surrounding physical and social environment. Alterations in the PPS have been found to be associated with conditions characterised by abnormal anxiety responses or altered states of the BSC, suggesting a possible role in the maintenance of pathological behaviour. Thus, previous research has explored the possibility of manipulating PPS through body illusions. In the present study, we investigated whether a full-body illusion (FBI) presented from an allocentric spatial frame was able to extend the PPS boundary. Participants performed the first run of the PPS task and were then presented with the FBI, followed by a second run of the PPS task for both synchronous and asynchronous conditions. Results showed that PPS increased after the synchronous FBI compared to baseline. As the PPS reflects a change in the MSI, future studies should investigate whether PPS enhancement and allocentric FBI can positively influence body experience in conditions characterised by BSC alterations, such as eating disorders, as well as their effects on the way people interact with their physical and social environment.