The cerebellum does not affect reading ability in people with dyslexia, according to a study that challenges a controversial theory.
The cerebellum is a brain structure traditionally involved in motor function.
This new study disputes that theory and could lead to improved treatment of dyslexia, according to scientists from Georgetown University Medical Center in Washington, D.C.
"Prior imaging research on reading in dyslexia had not found much support for this theory … but these studies tended to focus on the cortex," explained study first author Sikoya Ashburn, a PhD candidate in neuroscience.
Evidence never very strong
"Therefore, we tackled the question by specifically examining the cerebellum in more detail. We found no signs of cerebellar involvement during reading in skilled readers or differences in children with reading disability," Ashburn said in a Georgetown news release.
In the study, the researchers used functional MRI to monitor brain activation in 23 children with and 23 children without dyslexia while they read. The results showed that the cerebellum is not engaged during reading in typical readers and does not differ in children who have dyslexia.
"The evidence for the cerebellar deficit theory was never particularly strong, yet people have jumped on the idea and even developed treatment approaches targeting the cerebellum," said senior study author and neuroscientist Guinevere Eden, She is a professor in the Department of Pediatrics at Georgetown and director of its Center for the Study of Learning.
The study was published in the journal Human Brain Mapping.
The findings could help refine models of dyslexia and assist parents of children who are struggling with reading to make informed decisions about which treatment would be best for their children, the researchers said.
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