New research suggests that the brain rewires itself to help enhance other senses in blind people.
According to a new study led by Massachusetts Eye and Ear, the brains of those who are born blind make new connections in the absence of visual information, resulting in enhanced, compensatory abilities such as a heightened sense of hearing, smell and touch, as well as cognitive functions like memory and language.
“Our results demonstrate that the structural and functional neuroplastic brain changes occurring as a result of early ocular blindness may be more widespread than initially thought,” lead author Corinna Bauer, Ph.D., a scientist at Schepens Eye Research Institute of Mass. Eye and Ear and an instructor of ophthalmology at Harvard Medical School, said in a statement. “We observed significant changes not only in the occipital cortex (where vision is processed), but also areas implicated in memory, language processing, and sensory motor functions.”
The researchers used MRI multimodal brain imaging techniques, specifically diffusion-based and resting state imaging, to reveal the changes in a group of 12 subjects with early blindness, defined as those born with or who have acquired profound blindness prior to the age of three. They compared their scans to a group of 16 sighted subjects in the same age range.
The team observed structural and functional connectivity changes, including evidence of enhanced connections. Information was seen going back and forth between areas of the brain on the scans of those with early blindness that they did not observe in the sighted group.
These connections appear to be unique in those with profound blindness, suggesting that the brain rewires itself in the absence of visual information to boost other senses. The researchers explained that this is because of the process of neuroplasticity—the ability of our brains to naturally adapt to our experiences.
The next step in the research will be to increase the understanding of these connections, which could lead to more effective rehabilitation efforts that will enable blind individuals to better compensate for the absence of visual information.
“Even in the case of being profoundly blind, the brain rewires itself in a manner to use the information at its disposal so that it can interact with the environment in a more effective manner,” senior author Lotfi Merabet, O.D., Ph.D., director of the Laboratory for Visual Neuroplasticity at the Schepens Eye Research Institute of Mass. Eye and Ear and an associate professor of ophthalmology at Harvard Medical School, said in a statement. “If the brain can rewire itself – perhaps through training and enhancing the use of other modalities like hearing, and touch and language tasks such as braille reading—there is tremendous potential for the brain to adapt.”
The study was published in PLOS One.