Multisensory Integration of Signals for Bodily Self-Awareness Requires Minimal Cognitive Effort

Multisensory integration is considered a crucial mechanism underlying the sense of body ownership, but the everyday experience of feeling our own bodies seems automatic and effortless, which implies that the process of integrating multisensory signals for bodily self-awareness may require minimal cognitive effort. To test this, we developed an n-back rubber-hand illusion. The n-back component refers to tracking the identity of the rubber-hand fingers being stroked as the illusion is induced. This embedded n-back task allowed us to parametrically manipulate the levels of cognitive load while maintaining the integrity of the rubber-hand illusion. Across two experiments, we show that the strength of hand embodiment is sensitive only to the multisensory congruency of signals (as elicited by the finger stroking on the rubber hand) but not to the increasingly higher load placed on the performance of the n-back tasks. These results suggest that multisensory representation of self is robust to cognitive depletion and requires minimal effort.