What Causes Dyslexia?
Dyslexia is caused by connectivity problems associated with language processing areas of the brain according to a new study from researchers at KU Leuven in Belgium. An article from Fox News shares the following about the study:
"The researchers scanned the brains of 23 adults with dyslexia and 22 adults without the condition as they responded to various speech stimuli. The scientists looked at how accurately the participants' brains mapped sounds to their phonetic representations.
People with dyslexia had intact representations of basic sounds, just as non-dyslexic people did, the scans revealed.
'To our surprise, and I think to the surprise of a large part of the dyslexia research society, we found out that phonetic representations were perfectly intact. They were just as robust and distinct in individuals with dyslexia as they were in typical readers,' Boets told reporters.
The researchers then investigated whether brain connectivity differed between the dyslexic and normal participants. In particular, they examined how well 13 brain areas involved in language processing were connected to phonetic representations.
The participants with dyslexia had notably worse connectivity between Broca's area, a region in the brain's frontal lobe linked to speech production, and the left and right auditory cortexes, the researchers reported online today in the journal Science. In addition, the people with the weakest connections performed the worst on reading and spelling tests.
The findings suggest dyslexia stems from a failure to connect to fundamental sound representations, rather than problems with those representations themselves, the researchers said."