Vanderbilt University psychology department researchers Anna Wang Roe, Li Min Chen and Robert Friedman have identified responses in the brain to a touch illusion that shed new light on how the brain processes sensory information and call into question long-held theories about the nature of the "map" of the body in the brain.
Walter Penfield is credited with first establishing in 1957 that a map of the human body exists in the brain, with specific areas of the cortex processing information from different body areas. Researchers have long hypothesized this map is a topographic map of the physical body.
"What is surprising about this paper is we found the cortical map reflects our perceptions, not the physical body," Roe said. "The brain is reflecting what we are feeling, even if that's not what really happened." The team completed the research at Yale University before moving to Vanderbilt this fall.
Roe's research used a well-documented illusion called the tactile funneling illusion to explore how the brain processes touch. With this illusion, an individual perceives simultaneous touches to multiple locations on an area of skin as a single touch at the center of that area. Although the perception of this illusion has been studied for decades, researchers did not know how it was processed by the brain.
Roe's team first tested the funneling illusion in humans by stimulating adjacent fingers. The human subjects confirmed that they experienced a sensation between the two fingers when both were touched simultaneously. The team then used a technique called in
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Contact: Melanie Catania
melanie.catania@vanderbilt.edu
615-322-6397
Vanderbilt University
31-Oct-2003