Scientists have discovered what appears 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 surprised 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.