New findings by a team of researchers at York University indicate that individuals with early vision loss exhibit a larger volume in the auditory parts of the brain, as well as evidence of cross-modal plasticity, over those with typical sight.
The research was recently published in the journal NeuroImage: Clinical under the title “Evidence of multisensory plasticity: Asymmetrical medial geniculate body in people with one eye.” The study was led by York U PhD student Stefania Moro, with contributions from York PhD candidate Larissa McKetton and York Professor Jennifer Steeves.
The team studied a unique group of patients with early visual deprivation to examine how the brain develops after the loss of an eye. Patients in the study had cancer of the retina that was diagnosed between birth and the first few years of life.
“The study allowed us to look at how changes in sensory input to the brain during development affects the maturation of the sensory structures of the brain,” says Steeves, an associate professor in psychology and biology. “We previously studied auditory function in those with vision loss, and found that it’s good or sometimes even better than those with typical sight, but here we are looking at what’s going on in the brain to support their sensory abilities.”
In this study, the team researched a subcortical structure of the auditory brain. They found, in their patient group, that it presents as asymmetrical and larger than expected in the hemisphere that supports language and some other auditory functions.
Another interesting finding, says Steeves, is the possibility that the auditory brain in those with sight deprivation in one eye can take over some of the visual “real estate” in the brain.
“You would think you’d have limited space for the auditory brain to grow, but that’s not the case,” she says.
Those who had more plasticity in their visual system also had more plasticity in their auditory system, they found.
The research will continue, and the team plans to look at long-term effects of neuroplasticity.
By Ashley Goodfellow Craig, YFile deputy editor