Can your brain be tricked into claiming a rubber hand as its own?
In short: By synchronising a paintbrush stroke on your real hand and a fake one, researchers can hijack your sense of self. This phenomenon, known as the body transfer illusion, demonstrates how powerful sensory input can override your fundamental knowledge of where your body ends and the world begins.
First reported by Botvinick and Cohen in 1998, the rubber hand illusion relies on the integration of visual and tactile signals. In a classic 2004 study, participants had their real left hand hidden while observing a lifelike rubber hand. Participants felt the prosthetic limb belonged to them as a paintbrush moved across both hands simultaneously, frequently indicating the artificial hand when prompted to find their actual one. This occurs because bottom-up perceptual mechanisms, such as visual input, temporarily override the top-down knowledge that the rubber object is foreign.
Neuroimaging provides a window into this neurological hijacking. Functional MRI scans during these experiments show increased activity in the parietal lobe, followed by the premotor cortex—the area responsible for planning movements. This suggests the parietal cortex processes the visual and tactile data, which is then transmitted to the premotor cortex to create the feeling of ownership. The illusion is so potent that when a needle is moved toward the rubber hand, the anterior cingulate cortex—a region activated by anticipated pain—is triggered, causing subjects to move their real hand to avoid the threat.
The mechanism of this illusion is currently a subject of scientific debate. While some researchers, such as Lush in 2019 and 2020, argued that the effect might be driven by suggestion, hypnosis, or participant expectations, others like Slater and Ehrsson argued in 2022 that the primary driver is multisensory integration. Interestingly, certain substances can alter this balance; ketamine and dextroamphetamine have been shown to enhance the illusion, even when sensory inputs are asynchronous, potentially by increasing the salense of visual input at the expense of temporal discrepancies.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: Body transfer illusion
To cite this card, link to https://intellectplus.co.uk/app/music-body-transfer-illusion.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in Illusions · More in Music · Latest · A–Z · All topics
