Scientists have discovered what emerge to be a fundamental reason why people are dyslexic.Using MRI scans to monitor the brains of people who present with the condition, and those who don’t, researchers found a “really pronounced” difference in responses to a series of visual and audio cues. The brains of people without dyslexia were more able to recognise repeated words or images in a process known as “neural adaptation”, while a “neural signature” was identified among dyslexics, whose brains displayed lower levels of “plasticity” – or response ability.
The researchers were amaze to find such a broad range of effects but speculated that dyslexia only shows itself when people try to read because this is a relatively demanding task.While humans have evolved to be skilled verbal communicators, writing is a relatively recent occurrence in our history, particularly as something that most people in society do.One of the researchers, Professor John Gabrieli, of the Massachusetts Institute of Technology, said: “You learn something upon the initial presentation that makes you better able to do it the second time, and the ease is marked by reduced neural activity. Because you’ve done something before, it’s easier to do it again.”
Scans of the brains of people with dyslexia showed this conversion process was not as effective – their brains were more exercised to understand the same information, the academics reported in the journal Neuron. Speaking to The Independent, Professor Gabrieli said: “There are different ways to struggle to read, but for many individuals with dyslexia, we suspect this might be the route pathway – the beginning would be this broader reduction in [brain] plasticity that only manifests itself when the demands for plasticity are highest.”
He added the study suggested a potential new way to reduce effects of dyslexia by artificially increasing the plasticity of the brain.However Prof Gabrieli said the techniques used to do this – involving electromagnetic stimulation of the brain – were at an experimental stage and had not been tried for the condition.“We’d love if it would have implications for helping people, but we know that’s far away,” he said.Prof Tyler Perrachione, of Boston University – the lead author of the study – said: “Adaptation is something the brain does to help make hard tasks easier [but] dyslexics are not getting this advantage.“I am surprised by the magnitude of the difference. In people without dyslexia, we always see adaptation, but in the dyslexics, the lack of adaptation was often really pronounced.