The human mind is incredibly powerful in fascinating and sometimes terrifying ways. Conmen and cult leaders know how to manipulate people by taking advantage of psychological vulnerabilities and using tricks of the mind. But there are also physical examples of how our brains can be fooled into thinking something is real that isn’t, even when we know it’s happening.
The “rubber hand illusion” is a prime demonstration of how we can manipulate our brains into experiencing physical sensations—even pain—purely through the power of visual cues and parallel touch.
The way it works is a person sits with their hands palms-down on a table, but with one arm obscured from sight by a board. A rubber hand is placed on the table within sight, visually taking the place of the hidden hand. Someone strokes the hidden real hand and the rubber hand in the exactly same way at the same time while the person watches the rubber hand, and within a minute or so, the person’s brain starts to sense the rubber hand as their real hand.
This multisensory trick is powerful. After a short time, even when the real hand is no longer being touched, watching the rubber hand being touched triggers a real physical sensation in the brain. This phenomenon is also called a body transfer illusion, and it’s quite entertaining to witness.
Watch it in action:
u201cBody transfer illusion nnThe illusion of owning a part/or entire body other than one’s own nnsight, touch and proprioception (a sense of body position) all combine to convince this person that a rubber hand is their body part 1/ud83euddf5nnud83dudd08This video has soundnhttps://t.co/p8O1GATuYvu201d
— Science girl (@Science girl)
Super trippy, right?
A group of Italian scientists measured some of the effects of the rubber hand illusion by triggering the electrical impulses in the brain that control hand movement while the person was engaged in the illusion. They found that the strength of the impulses that got through to the hidden hand dropped dramatically, indicating that the brain had reduced its readiness to use the hidden hand.
“This was very surprising for us. The effect is so strong,” said Francesca Garbarini, one of the scientists leading the study, according to The Guardian. “Because the brain no longer considers the hand as part of the body, we become less able to use it.”
The rubber hand illusion has been used to explore how people who have lost limbs might gain psychological ownership over a prosthetic limb. However, not everyone is able to experience the sensations shown in the video. One study of the rubber hand illusion found that only two-thirds of participants were actually susceptible to the rubber hand illusion; the other third were immune.
Still, it’s an incredible testament to the power of our minds to change what we think of as reality with just a few simple adjustments to our perception.