Bodily illusion enhances subjective fear of safety-margin violations surrounding the bodily self.

All living organisms, including humans, must flexibly adjust their defensive behaviors according to the spatial proximity of potential threats. Previous research has examined fear responses to proximal threats by manipulating distance to the body in simulated 2D or 3D environments; however, the functional role of the sense of bodily self in the interplay between fear and threat proximity remains unclear. Here, we investigated fear responses to proximal and distal fear-relevant stimuli while manipulating the sense of body ownership over a mannequin using a perceptual full-body illusion. Our findings revealed that subjective fear was more sensitive to stimulus location when participants experienced illusory ownership over the mannequin. Furthermore, we observed a significant positive correlation between illusion strength and subjective fear ratings. These findings highlight two aspects of how the sense of bodily self influences human fear experiences: enhancing sensitivity to margin-of-safety violations and amplifying anxiety in response to threat appearance.