Adaptation to delayed visual feedback of the body movement extends multisensory peripersonal space

The space surrounding the body in which individuals interact with the environment is known as the peripersonal space (PPS). Previous studies have reported that PPS has multisensory nature. However, the relationship between the multisensory nature of PPS and an individuals' defensive actions has not been fully clarified to date. We investigated this relationship by examining the multisensory representation of PPS under situations in which visual feedback of body movements was delayed by using a virtual reality system. The results indicated that body-movement delays extended the multisensory PPS, suggesting that body-movement delays increased the potential threat of distant objects because it was necessary to prepare defensive actions sooner. The previous findings can be interpreted that PPS is modulated by the spatio-temporal relationship between people and external stimuli. This view may provide evidence of interactions between defensive and nondefensive functions of the multisensory PPS.