People with the reading disability dyslexia may have brain differences that are surprisingly wide-ranging, a new study suggests.
Using specialized brain imaging, scientists found that adults and children with dyslexia showed less ability to “adapt” to sensory information compared to people without the disorder.
And the differences were seen not only in the brain’s response to written words, which would be expected. People with dyslexia also showed less adaptability in response to pictures of faces and objects.
That suggests they have “deficits” that are more general, across the whole brain, said study lead author Tyler Perrachione. He’s an assistant professor of speech, hearing and language sciences at Boston University.
The findings, published in the Dec. 21 issue of the journal Neuron, offer clues to the root causes of dyslexia.
Other studies have found that people with dyslexia show differences in the brain’s structure and function.
“But it hasn’t been clear whether those differences are a cause or consequence of dyslexia,” Perrachione explained.
The chicken-and-egg question is tricky, because years of reading, or years of reading disability, affect brain development.
Perrachione said his team thinks it has discovered a cause of dyslexia — partly because the reduced adaptation was seen in young kids, and not only adults.
A researcher who was not involved in the study called it “groundbreaking.”
“Frankly, researchers have struggled with understanding the brain bases of dyslexia,” said Guinevere Eden, director of the Center for the Study of Learning at Georgetown University Medical Center in Washington, D.C.
Scientists have known that brain structure and function look different in people with dyslexia, Eden said, but they haven’t known why.
“This study makes an important step in that direction,” she said. “It gets to the true characteristics of the properties of the neurons