Are blind individuals immune to bodily illusions? Somatic rubber hand illusion in the blind revisited

Behav Brain Res. 2023 Dec 20:114818. doi: 10.1016/j.bbr.2023.114818. Online ahead of print.ABSTRACTMultisensory awareness of one's own body relies on the integration of signals from various sensory modalities such as vision, touch, and proprioception. But how do blind individuals perceive their bodies without visual cues, and does the brain of a blind person integrate bodily senses differently from a sighted person? To address this question, we aimed to replicate the only two previous studies on this topic, which claimed that blind individuals do not experience the somatic rubber hand illusion, a bodily illusion triggered by the integration of correlated tactile and proprioceptive signals from the two hands. We used a larger sample size than the previous studies and added Bayesian analyses to examine statistical evidence in favor of the lack of an illusion effect. Moreover, we employed tests to investigate whether enhanced tactile acuity and cardiac interoceptive accuracy in blind individuals could also explain the weaker illusion. We tested 36 blind individuals and 36 age- and sex-matched sighted volunteers. The results show that blind individuals do not experience the somatic rubber hand illusion based on questionnaire ratings and behavioral measures that assessed changes in hand position sense toward the location of the rubber hand. This conclusion is supported by Bayesian evidence in favor of the null hypothesis. The findings confirm that blind individuals do not experien...

Source: Behavioural Brain Research - December 22, 2023 Category: Neurology Authors: Dominika Radziun Maksymilian Korczyk Marcin Szwed H Henrik Ehrsson Source Type: research