Blind people's brains 'rewire' to boost other senses

Brains of people who are born blind make new connections, resulting in a heightened sense of hearing, smell and touch as well as cognitive functions like memory and language, a new study has found.

Researchers from Massachusetts Eye and Ear Infirmary in the US used MRI multimodal brain imaging techniques 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.

In those with early blindness, the team found structural and functional connectivity changes, including evidence of enhanced connections, sending information back and forth between areas of the brain that they did not observe in the normally sighted group.

These connections that appear to be unique in those with profound blindness suggest that the brain "rewires" itself in the absence of visual information to boost other senses, researchers said.

"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," said Corinna M Bauer of Harvard Medical School in the US.

"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," Bauer added.

"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," said Lotfi Merabet of Harvard Medical School.

The study was published in the journal PLOS One.