We generally believe that illusions are our brain tricking us. However, recent research published in the journal Science has indicated that our perception of illusions is not the brain tricking us, but is in fact the result of how the brain is organized.

Researchers at Vanderbilt University have identified responses in the brain to a 'touch illusion' which shed light on how the brain maps the body. It has already been established that the brain constructs a map of the body, with specific areas of the cortex processing information from separate body areas.


One of the researchers, Anna Wang Roe, explained the results. "What is surprising about this paper is we found the cortical map reflects our perceptions, not the physical body," she said. "The brain is reflecting what we are feeling, even if that's not what really happened."


The research team used a well-documented illusion, called the 'tactile funneling illusion' - in which a person feels simultaneous touches to multiple locations on an area of skin as a single touch at the center of that area- to explore the manner in which the brain processes touch sensations.


Using monkeys as subjects, the team found that touches on separate fingers produced brain responses in identifiable areas of the cortex. However, when the subject was touched simultaneously on both fingers, a single, separate cortical location - between the two other areas - responded, explaining the perceived location of the illusion.

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