You have deceived him several times. You made believe everything and anything by deluding this famous stranger regarding whom so many things are unknown. Thanks to certain manipulations, the brain can no longer distinguish what is really part of your body or not.
A few experiments, particularly that of the rubber hand illusion, demonstrate that it is easy to deceive him.
The experience that precedes the senses
In 1998, neuroscientists Matthew Botvinick and Jonathan Cohen published in Nature, one of the most prestigious scientific journals, their experiment as simple as it is brilliant. The idea is to mislead our brain as to its perception of our body with a rubber hand. At the end of this experience, the participant ends up believing that this object is part of his body.
Concretely, the subject must place both hands on a table except that his left hand is hidden by a panel. The scientist then places an artificial hand in front of the guinea pig, where his left hand might be. Remember that the participant no longer sees his real left hand concealed by the wall. The experimenter then caresses with a brush, in the same direction and at the same time, the rubber hand (which the subject is looking at) and his real left hand.
Through the sense of sight, the goal is to create a spatiotemporal link between the two hands. In a few minutes, the subject has the impression of feeling the caress performed on the rubber hand as if it were really part of his body. Then without warning, the scientist suddenly hits it with a hammer. His brain manipulated, the subject almost cries out in pain.
How our brain is fooled by a rubber hand
Certain areas of the brain deal with what is called body appropriation or representation of one’s own body. It’s regarding the parietal cortex and the premotor cortex working together and being connected with each other. Olivier Collignon, Professor at the Institute of Neurosciences and Psychology at UCLouvain, explains how the brain was tricked by the experiment conducted by neuroscientists Matthew Botvinick and Jonathan Cohen:
” In fact, the parietal cortex integrates multisensory information, including tactile information from our body and visual information. This is exactly what happens in the plastic limb illusion. That is to say, we will create a false visual association with a tactile association. By stroking this artificial limb, it is through sight that the subject will feel this tactile stimulation because at the same time we stimulate the real left hand that we no longer see. What is crucial at first is this visio-tactile association which finally creates this sensation in the parietal cortex. This brain region sends a message to the premotor cortex which itself plays an essential role in this coordination, and therefore in this appropriation of a limb. The solution found by the brain is that this plastic limb must be part of the body. “
