Scans of the brains of people with dyslexia showed this adaptation 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 alleviate 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.”
About one in 10 people in the UK, some 6.3 million people, are estimated to have dyslexia.
In addition to making reading and spelling more difficult, it can affect short-term memory, maths and co-ordination. However it does not affect general intelligence or reasoning.