Having trouble with your vision? There’s an app for that. It’s called EyeMusic, and it’s the result of remarkable research at the Hebrew University of Jerusalem. It will allow you to hear shapes and colours, training your brain to process sensory information in a completely different way – and it’s rewriting what we thought we knew about how the brain works.
A report published in the 17 March edition of the journal Current Biology has surprised researchers by demonstrating that people who have been blind from birth can be trained to recognise silhouettes of the human body in various postures. The training involves around ten hours of listening to sounds. Once trained, the research subjects’ brains used sound – employing the same area as sighted people use – to recognise body postures.
This is surprising, because researchers have always assumed that the neurons used for visual processing will be reassigned in someone whose brain isn’t getting visual inputs. Received wisdom had it that they might, for instance, be used by the auditory system to enhance processing of sound signals. The idea is related to the frequent (but wrong) assertion that if you lose one sense, others become more sensitive. Studies suggest that the sense of smell is no more acute in blind people. Neither are they sharper of ear; they are perhaps marginally better at making use of auditory information, but they don’t actually hear better.
Not that making better use of sounds is to be sniffed at. There are visually impaired people who use bat-like echolocation to navigate their way through busy streets, for example. Perhaps most extraordinary is the Californian Daniel Kish. Thanks to an aggressive childhood cancer, Kish has no eyes. At the age of two he began to train himself to use the echoes of his tongue-clicks as a guide to his surroundings.
Kish can go out for a bike ride safely and hike alone through mountainous terrain. He has refined his skill to the point where his clicks and their echoes provide him with a 3D mental image of his environment. He teaches his craft to other blind people, liberating them from the severe restrictions that are so common for those without sight.
Amir Amedi’s lab in Jerusalem has a similar goal. With training, Amedi says, visual areas of the brain can process sound and touch just as successfully as they would visual inputs.
This month’s paper makes that case forcefully. Written
by Amedi’s student Ella Striem-Amit, it focuses on a region of the brain known as the extrastriate body area, which is devoted to recognising body shapes. In Striem-Amit’s adult, fully blind subjects, this area had had no training whatsoever. However, their extrastriate body area still functioned perfectly – it just needed a few hours of priming.
Amedi’s EyeMusic iPhone app runs the user through a library of sounds associated with visual patterns and shapes. Once the training is complete, sound combinations begin to suggest visual scenes.
It will take a while before you become as competent as the trainee who can play a sonic version of Guess Who? by associating sounds with facial characteristics such as hair colour, beardedness or spectacles. But it won’t take long to appreciate that your brain is a marvellously flexible organ that, with the right training, can give you the next best thing to superpowers. The app also collects performance data that will help Amedi develop his research.
Why play Candy Crush when you can idle away your time helping science give sight to the blind?