Associate Professor of Biology
Director, Kanold Lab
Dr. Kanold studies the development and plasticity of the brain, in particular how periods of learning and plasticity are initiated and controlled. His work focuses on the development of the central auditory and visual system in particular on the role of early cortical circuits in brain wiring. He uses advanced neurophysiological, in vivo imaging, optogenetic, molecular and computational techniques.
Address: 1116 Bioscience Research Building
College Park, MD 2074
Published on Feb 5, 2014
Minimizing a person’s sight for as little as a week may help improve
the brain’s ability to process hearing, neuroscientists have found.
Hey-Kyoung Lee, an associate professor of neuroscience and researcher
at the Mind/Brain Institute at the Johns Hopkins University, along
with biologist Patrick Kanold at the University of Maryland, College
Park, are co- authors on a paper in the journal Neuron, which
examines the relationship between vision and hearing in the brain.
In this video, Dr. Lee talks about the excitement of making a new, scientific discovery– even when that discovery is unexpected.
Music experts often cite blind musicians Stevie Wonder and Ray
Charles as examples of how a lack of sight can heighten or enhance
hearing. Scientists, however, did not fully understand just how that
happened until now.
In experiments using mice, Lee, Kanold, and other researchers from
the two universities, were able to uncover how the neural connections
in the area of the brain that manages vision and hearing work
together to support each sense. These findings could help those
experiencing hearing loss regain more use of that sense.
“In my opinion, the coolest aspect of our work is that the loss of
one sense – vision – can augment the processing of the remaining
sense, in this case, hearing, by altering the brain circuit, which is
not easily done in adults,” Lee said.
“By temporarily preventing vision, we may be able to engage the adult
brain to now change the circuit to better process sound, which can be
helpful for recovering sound perception in patients with cochlear
implants for example,” she said.
In their experiments, the researchers placed healthy adult mice in a
darkened environment to simulate blindness for about a week and
monitored their response to certain sounds. Those responses and brain
activity were then compared to a second group of mice that were in a
traditional, naturally lit environment.
The researchers found a change in the brain circuitry for the mice
that experienced simulated blindness, specifically in the area of the
brain that processes sound, called the primary auditory cortex. The
primary auditory cortex allows conscious perception of pitch and loudness.
“Our result would say that not having vision allows you to hear
softer sounds and better discriminate pitch,” said Lee, an expert on
how the brain processes vision. “If you ever had to hear a familiar
piece of music with a loud background noise, you would have noticed
that sometimes it seems the beat or the melody is different, because
some of the notes are lost with the background. Our work would
suggest that if you don’t have vision you can now rescue these ‘lost’
notes to now appreciate the music as is.”
The researchers concluded that a certain set of connectors in the
primary sensory areas of the brain, called thalamocortical inputs,
are less flexible in humans later in life. When another sense also
impaired, however, those connectors can be reactivated to support the
sense that is lagging.
The University of Maryland’s Kanold, whose expertise is in how the
brain processes sound, is hopeful that the study’s findings will
apply to humans.
“We don’t know how many days a human would have to be in the dark to
get this effect, and whether they would be willing to do that,”
Kanold said. “But there might be a way to use multi-sensory training
to correct some sensory processing problems in humans.”
Presently, the changes uncovered by the group are reversible, meaning
the mice that experienced simulated blindness eventually reverted to
normal hearing after a few weeks in a normal light-dark environment.
In the next phase of their five-year study, Lee and Kanold plan to
look for ways to make the sensory improvements permanent. The pair
also said they will look beyond individual neurons to study broader
changes in the way the brain processes sounds.
Other researchers on the paper were Emily Petrus, David, Li and Hui
Wang, all from the Department of Neuroscience and the Mind/Brain
Institute at Johns Hopkins University; Adam P. Jones from the
University of Maryland’s Department of Biology and Amal Isaiah also
from the University of Maryland’s Department of Biology and the
School of Medicine.
This research was supported by the National Institutes of Health,
grant number R01-EY022720.