A common belief that blind people possess unusually heightened non-visual senses now may be more than just a belief.
Credit: Bauer et al. PLOS ONE 2017
A new study led by Massachusetts Eye and Ear researchers has found that the brains of those who are born blind make new connections in the absence of visual information. This results in heightened senses of hearing, smell and touch, as well as memory and language. The report, published online in PLOS ONE, describes for the first time changes in the brains of those born with blindness that are not present in normally-sighted people.
“Our results demonstrate that the…changes, occurring as a result of early ocular blindness, may be more widespread than initially thought,” said lead author Corinna M. Bauer, Ph.D. (Schepens Eye Research Institute of Mass. Eye and Ear).
The researchers used magnetic resonance imaging (MRI) to reveal these changes in a group of 12 subjects with early blindness, and they compared the scans to a group of 16 normally-sighted subjects of the same age range. On the scans of those with early blindness, the team observed structural and functional connectivity changes, including evidence of enhanced connections not observed in the normally-sighted group.
These connections suggest that the brain “rewires” itself to boost other senses in the absence of vision. This is possible through the process of neuroplasticity: the ability of our brains to naturally adapt to our experiences, no matter at what age. The researchers hope that increased understanding of this process will lead to more effective rehabilitation efforts that will enable blind individuals to better compensate for the absence of visual information.
Senior author Lotfi Merabet, O.D., Ph.D. (Director, Laboratory for Visual Neuroplasticity at the Schepens Eye Research Institute of Mass. Eye and Ear) said, “If the brain can rewire itself – perhaps through training and enhancing the use of other modalities like hearing, touch and language tasks such as Braille reading – there is tremendous potential for the brain to adapt.”
SOURCE: Massachusetts Eye and Ear press release