Audio-visual sensory deprivation degrades visuo-tactile peri-personal space.

Self-perception is scaffolded upon the integration of multisensory cues on the body, the space surrounding the body (i.e., the peri-personal space; PPS), and from within the body. We asked whether reducing information available from external space would change: PPS, interoceptive accuracy, and self-experience. Twenty participants were exposed to 15 min of audio-visual deprivation and performed: (i) a visuo-tactile interaction task measuring their PPS; (ii) a heartbeat perception task measuring interoceptive accuracy; and (iii) a series of questionnaires related to self-perception and mental illness. These tasks were carried out in two conditions: while exposed to a standard sensory environment and under a condition of audio-visual deprivation. Results suggest that while PPS becomes ill defined after audio-visual deprivation, interoceptive accuracy is unaltered at a group-level, with some participants improving and some worsening in interoceptive accuracy. Interestingly, correlational individual differences analyses revealed that changes in PPS after audio-visual deprivation were related to interoceptive accuracy and self-reports of "unusual experiences" on an individual subject basis. Taken together, the findings argue for a relationship between the malleability of PPS, interoceptive accuracy, and an inclination toward aberrant ideation often associated with mental illness.