In a fascinating piece of brain research, Swedish scientists have been able to convince people that they have three arms.
The new study consisted of five experiments on 154 men and women, and the research was conducted at the Karolinska Institutet in Stockholm. Scientists had the test participants sit with their right arm on a table, and their left arm hidden.
A prosthetic right hand was placed next to the person’s real hand, while a piece of material was draped over the participant’s right shoulder covering everything but the forearms of both the artificial and real right arms. If a test participant looked at their right hand, it looked like they had two of them.
In one of the tests, scientists stroked the fingers of the real right hand and the fake one at the same time with different paint brushes. During the test, participants were told to look at the fake hand. Afterward, the participants said they had felt like they had two right hands.
Scientists explained that the brain has the ability “to experience an extra third arm,” according to MSNBC.com. Even though we are born with two arms, the brain can easily be fooled into believing that its body has an extra arm.
Apparently, when the brain sees an artificial arm next to a real one, it wonders which one is really its. And what happens is that the brain accepts both hands.
This odd research may have a pracical application, according to MSNBC.com.
“The findings, for example, may benefit stroke patients who need an artificial arm because one side of their body is paralyzed,” the website reported. “Scientists would better understand how patients can control this extra arm and experience it as their own.”
