Monday, September 24, 2012
fMRI of Dysgraphia - Lack of Automaticity and Need for Visual Monitoring
In this interesting fMRI study, good and poor child writers were compared on a task of writing a new pseudoletter. The 'good writers' (scored in the normal or higher range on WIAT writing test) showed a strong coordination between the cerebellum (motor-sensory feedback) and primary motor-sensory areas in the precental and postcentral gyrus.
Poor writers had a very different pattern. Their cerebellar activation was stronger in midline structures (trunk > fingers) and also visual areas of cortex were much more active than primary motor-sensory areas around the central gyrus. This result is very interesting - because in the clinic, we often see that students require much more visual monitoring of their letter formation (increases the labor, working memory requirement, and general tedium of writing by hand), and this greatly slows processing speed.
Sorry we haven't had time to regularly update this blog. But will let more articles trickle. I'm going to speak at the AACAP (American Academy of Child and Adolescent Psychiatry) next month and Brock at the annual meeting of the International Dyslexia Association - so our time's been swamped more than usual over our usual clinic.
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