Rubber Hand Illusion

Body ownership, specifically arm ownership, can be experimentally manipulated using the Rubber Hand Illusion (RHI). 

RHI is a perceptual phenomenon that occurs when a person's brain is tricked into perceiving a rubber hand as part of their own body. 

In the RHI, a realistic looking rubber hand is placed next to a subject's own hand, and both hands are stroked in synchrony at the same location, with only the rubber hand being visible.

By simultaneously stroking both the rubber hand and the participant's real hand, it creates the illusion that the rubber hand is their own (attributed to their own body)

To integrate the new hand into the body representation, it is important that both the rubber hand and real hand are anatomically aligned, meaning they should be positioned in the same orientation and in parallel to each other or above one another.

Embodying the rubber hand as one's own changes the sense of location of one's own hand, and the perceived location of one's own hand typically "drifts" towards the rubber hand after inducing the illusion, which is known as proprioceptive drift.

The RHI illustrates the plasticity of our body representation, as it transiently changes how and where we perceive our hand.

RHI can also affect the foot and the entire body. RHI has been used in various research studies to investigate body perception, multisensory integration, and the brain's ability to update its body representation. It was first described by Ehrsson in 1998  paper.

Researchers have utilized the rubber hand illusion to explore various aspects of body ownership and self-perception. It has been employed in studies examining disorders like schizophrenia and body dysmorphic disorder, as well as in research related to pain perception, self-identification, and body image.

Regarding autism research, the rubber hand illusion has been employed to investigate differences in body representation and multisensory integration; whether autistics show alterations in the experience of body ownership and if their multisensory integration processes differ from NT  individuals (Casio et al, 2012)

Citation:

Ehrsson, H. H. (1998). Touching a rubber hand: feeling of body ownership is associated with the synchronous multisensory stimulation. Cognitive Brain Research, 67(2), 561-570.

Cascio, C. J., Foss-Feig, J. H., Heacock, J. L., & Newsom, C. R. (2012). Rubber Hand Illusion in Autism Spectrum Disorder: Self versus Externally Attributed Touch. Journal of Autism and Developmental Disorders, 42(11), 2420–2429. doi: 10.1007/s10803-012-1500-1