The rubber hand illusion that makes your brain lose its mind

You have deceived him many times. You deceived this famous stranger who did not know many things and made you believe anything and everything. Thanks to a few manipulations, the brain can no longer distinguish what is the real part of your body or not.

Some tests, especially the rubber hand illusion, prove that it is easy to deceive him.

Perceptual experience

In 1998, neuroscientists Matthew Botvinick and Jonathan Cohen published Nature, one of the most valuable scientific journals, whose experiment was very simple. The idea is to mislead our brain’s perception of our body with a rubber hand. At the end of this experience, the participant believes that this object is a part of his body.

Specifically, the subject should place both hands on a table, except that his left hand is covered by a panel. The scientist then places an artificial hand in front of the guinea pig, where his left hand will be. Keep in mind that the participant can no longer see his real left hand hidden by the wall. The examiner then with a brush, in the same direction and at the same time, the rubber hand (which sees the object) and his real left hand.

Through the sense of sight, the goal is to create a spatial connection between both hands. In a few minutes, the warmth performed on the rubber hand embodied the feeling that it was actually a part of his body. Then without warning, the scientist suddenly struck it with a hammer. His brain was manipulated, the object almost crying in pain.

How our brain is deceived by a rubber hand

Some parts of the brain are called body allocation or representation of one’s own body. It is about how the parietal cortex and primotor cortex work together and interconnect. Olivier Collignon, a professor at the Institute of Neurology and Psychology at UCLouvain, explains how the brain was deceived by experiments conducted by neuroscientists Matthew Botvinick and Jonathan Cohen:

” In fact, the parietal cortex integrates many sensory information from our body, including tactile information and visual information. This is exactly what happens in the plastic joint illusion. That is, we create the false visual association with the tactile association. By beating this artificial bundle, the object senses this tactile stimulus through sight, while at the same time triggering a real left hand that we do not see. First important is this visual-tactile association, which finally creates this sensation in the parietal cortex. This part of the brain sends a message to the primordial cortex, which plays an essential role in this coordination, and therefore in a limb allocation. The solution the brain invented was for this plastic organ to be part of the body. “