FEBRUARY 4, 2015—How do you “keep the beat?” Do you close your eyes and sway to the sounds? Do you watch dancers move their bodies, and do the same? Or do you tap your foot to the good vibrations?
It’s complicated, say neuroscientists at Georgetown University Medical Center. The answer may be all—or none—of the above. One thing is for certain: the scientific solution to the question will tell them a lot about these functions in terms of sensory input and functional output.
“We believe that expressing rhythm—feeling the beat—in music involves the integration of many senses—audition, motor, vestibular and vision,” says Jessica Phillips-Silver, PhD, a postdoctoral researcher in GUMC’s Laboratory of Integrative Neuroscience and Cognition, headed by Josef P. Rauschecker, PhD, professor of neuroscience. Phillips-Silver specializes in the neuroscience of music.
“We really want to understand how music resides in the brain and the body,” she says. “We want to capture a process that is at the core of what music means to humans universally.”
Balance and Rhythm
To help understand how the brain processes rhythm, Phillips-Silver and postdoctoral researcher Paula Plaza, PhD, are turning to individuals who have been blind since birth or infancy.
It’s known that hearing and touch are enhanced in the blind, taking over the brain space dedicated to vision.
“The brain is very plastic, which is why the visual cortex lights up in imaging studies of the blind,” says Phillips-Silver. “It has been reconnected to the auditory cortex to bolster that sense as well as potentially others.”
That may mean that the blind could have a leg up on musicianship given their improved capacity to hear and to touch the instruments, Phillips-Silver says. Think of Stevie Wonder, Ray Charles, Jose Feliciano, Doc Watson and many other renowned blind musicians.
But Phillips-Silver and Plaza are interested in looking at other effects of blindness on rhythm—namely, how being blind might actually impair one’s ability to feel the beat, due to loss of visual input.
“We get information about the beat when we watch musicians play or dance with each other,” Phillips-Silver says.
Plaza, who specializes in kinesiology, or the science of movement, suggests that the challenges maintaining good posture and balance faced by many with visual impairments could weaken their ability to move to the beat.
“Musicians need to be able to know where their hands are and what else is in relationship with their arms,” says Plaza. “If you have never had visual-spatial feedback, it is likely harder to move your body in the right way all the time.”
Using Sound to ‘See’
Through their research, Phillips-Silver and Plaza want to develop a model of brain plasticity in the blind, and to create interventions to help these individuals overcome recognized deficits.
For example, some balance and posture problems could be improved with a device—consisting of a headset fitted with a small camera—that scans and converts images into audible signals that the blind can use to master skills that depend on vision, Plaza says.
The research group recently launched a program that trains visually impaired people to use the device.
“Our hope is that with training that improves posture and balance over time, they won’t need to use it daily. They will be able to stand and walk and do everything they have wanted to do, without the need for professional help,” Plaza says.
Science Impacting Lives
As part of the training program, the researchers measure changes in the brain linked to plasticity. The effort ties a basic neuroscience discovery regarding brain plasticity to a clinical application that can improve people’s quality of life, says Rauschecker.
This line of research has two main objectives, he says. “One is to understand the incredible plasticity of the human brain, especially during early development; and the other is to come up with practical solutions to improve blind people’s lives.
“Over the past decades, we have made good strides towards the first goal, and we are now moving into a new phase where we think our research can really make a difference for the blind in practical terms,” Rauschecker says. “Blindness in children is still a public health problem, especially in many developing countries, and we hope, one day, to make a difference there.”
The research is supported by the NIH’s National Eye Institute (R01EY018923).
By Renee Twombly