Houston—(Jan. 07, 2008)—In the middle of the night, as you hear the buzzing of a mosquito, your skin begins to prickle, anticipating that the annoying insect is about to light on you. It's a common occurrence that you might take for granted. But for researcher Michael Beauchamp, Ph.D., assistant professor of neurobiology and anatomy at The University of Texas Medical School at Houston, it's a sensory mystery that he would like to solve.
Beauchamp and collaborator Tony Ro, Ph.D., associate professor of psychology at Rice University, will explore multisensory interactions in the human brain with a three-year, $750,000 grant from the National Science Foundation.
Traditionally, neuroscientists have regarded the visual, auditory and touch portions of the brain as separate areas. But new research is showing there may be connections among them. Using the latest in technology - including functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation - the researchers will study how sound and vision areas of the brain impact the sense of touch, and vice versa.
"We want to look at the way the brain takes information from the different sensory modalities and puts it together," Beauchamp said. "We know from preliminary studies that visual attention increases touch sensitivity but we don't know how the neurons from different regions are communicating."
The new research follows a previous study by Ro and Beauchamp published in the November 2007 issue of Annals of Neurology. That study, led by Ro, was based on a patient who suffered a stroke affecting only the ventrolateral nucleus of the thalamus, causing decreased sensation on the affected left side.
As the brain tried to heal in the years following her stroke, the patient reported experiencing synesthesia, when input in one sensory modality leads to a response in a second modality. When the patient heard certain sounds, she felt tingling and other sensations in the left side of her body, particularly in her left arm.
The researchers speculate that the damage resulted in neural reorganization between damaged touch nerve fibers and healthy auditory fibers near them. "When the touch region of brain was starved of input by the stroke, it may have reorganized in order to respond to sounds, using connections with the nearby auditory cortex," Beauchamp said.
In their new research, Ro and Beauchamp will continue to study the stroke patient, as well as the brains of healthy volunteers. Using the 3 Tesla scanner in the UT Imaging Center , Beauchamp will study connections between touch and sound regions of the brain.
Beauchamp and Ro have also been researching the connection between touch and sight in a visual area of the brain called MST, where the brain sees moving objects and determines how fast they are going. In a study published in the Journal of Neuroscience in August 2007, they reported that MST is also active during touch.
"We'd like to nail down why this visual area is responding to touch," Beauchamp said. "We want to find out if it's related to an action such as catching a ball, where the touch is anticipated."
To volunteer for the new study, contact utfmri@gmail.com.
Taken from: publicaffairs.uth.tmc.edu/media/
