Sight Is Repurposed In The Brains Of The Blind
A study published in the Proceedings of the National Academy of Sciences by cognitive scientists at the Massachusetts Institute of Technology has proposed that even in subjects who are blind from birth, the parts of the brain which we have traditionally associated with sight still find a function – rather than processing visuals, research suggests that the area instead concerns itself with language.
The study follows on from research conducted in the 1990s in which the optical nerves of ferrets were cut and reconnected to the auditory part of the brain. Results showed that amazingly the animals could still see, and the findings mimic those which showed that the visual cortices of the blind are still active when reading Braille. Naturally though, such studies would encounter severe ethical implications today.
Instead, the recent study involved monitoring the brains of permanently blind people as they were asked to listen to a series of structures with varying levels of linguistic and comprehensive difficulty. The structures ranged from things as little as single words to full sentences played forward and backward, and the highest levels of activity in the brain’s visual cortices were monitored as being in response to the higher level language demands – a fact which mirrors the activity of the part of the brain we traditionally associate with language.
The implications of the study are far reaching. The most striking conclusion we can draw is that, contrary to the popular belief of neuroscientists, the human brain does not have a section naturally ‘hard wired’ for language. Whilst it would be foolish to claim that our brains have not evolved to cope with such tasks, the fact that our visual centres seem to be able to cope with the demands of language suggests that there is far more going on than we first believed.
We could even go so far as to suggest that the brain activity of the blind touches upon an earlier developmental state, in which the areas we now see as visual were actually ready to process any kind of information before being so linked to sight.
Further studies are already underway to develop these discoveries. Scientists involved claim that a key aim is to find areas for which the brains of the blind are better attuned, and hopes are that due to the brain having to perform a wider range of functions without the help of sight, it may be possible for it to pick up on two speech streams at once. This, though, is currently mere speculation.
Rob writes for online glasses specialists Direct Sight.