DURHAM, N.C. -- The brain's tactile and motor neurons, which perceive touch and control movement, may also respond to visual cues, according to researchers at Duke Medicine.
The study in monkeys, which appears online Aug. 26, 2013, in the journal Proceedings of the National Academy of Sciences, provides new information on how different areas of the brain may work together in continuously shaping the brain's internal image of the body, also known as the body schema.
The findings have implications for paralyzed individuals using neuroprosthetic limbs, since they suggest that the brain may assimilate neuroprostheses as part of the patient's own body image.
"The study shows for the first time that the somatosensory or touch cortex may be influenced by vision, which goes against everything written in neuroscience textbooks," said senior author Miguel Nicolelis, M.D., PhD, professor of neurobiology at Duke University School of Medicine. "The findings support our theory that the cortex isn't strictly segregated into areas dealing with one function alone, like touch or vision."
Earlier research has shown that the brain has an internal spatial image of the body, which is continuously updated based on touch, pain, temperature and pressure known as the somatosensory system received from skin, joints and muscles, as well as from visual and auditory signals.
An example of this dynamic process is the "rubber hand illusion," a phenomenon in which people develop a sense of ownership of a fake hand when they view it being touched at the same time that something touches their own hand.
In an effort to find a physiological explanation for the "rubber hand illusion," Duke researchers focused on brain activity in the somatosensory and motor cortices of monkeys. These two areas of the brain do not directly receive visual input, but previous work in rats, conducted at the Edmond and Lily Safra International Institute
|Contact: Press Office|
Duke University Medical Center