A structural–functional basis for dyslexia in the cortex of Chinese readers

Developmental dyslexia is a neurobiologically based disorder that affects 5–17% of school children and is characterized by a severe impairment in reading skill acquisition. For readers of alphabetic (e.g., English) languages, recent neuroimaging studies have demonstrated that dyslexia is associated with weak reading-related activity in left temporoparietal and occipitotemporal regions, and this activity difference may reflect reductions in gray matter volume in these areas. Here, we find different structural and functional abnormalities in dyslexic readers of Chinese, a nonalphabetic language. Compared with normally developing controls, children with impaired reading in logographic Chinese exhibited reduced gray matter volume in a left middle frontal gyrus region previously shown to be important for Chinese reading and writing. Using functional MRI to study language-related activation of cortical regions in dyslexics, we found reduced activation in this same left middle frontal gyrus region in Chinese dyslexics versus controls, and there was a significant correlation between gray matter volume and activation in the language task in this same area. By contrast, Chinese dyslexics did not show functional or structural (i.e., volumetric gray matter) differences from normal subjects in the more posterior brain systems that have been shown to be abnormal in alphabetic-language dyslexics. The results suggest that the structural and functional basis for dyslexia varies between alphabetic and nonalphabetic languages.

John Gabrieli, a neuroscientist at the Massachusetts Institute of Technology in Cambridge who also works on dyslexia, is especially intrigued by the region that the researchers fingered as the culprit in Chinese dyslexia. It isn't the part associated with symbol recognition,he says. Instead, the area is associated with working memory — a higher stage of processing.

If alphabetic dyslexia takes certain forms,
reversing letters and such, assuming that's
a correct stereotype of the anomalies seen,
then what forms of mistakes do the logographic
dyslexics exhibit? Symbol recognition isn't
involved? So they just can't remember
where each stroke goes? I don't get it.

encopresis of the testes is wit for the dumbfounded here...

Ah, that explains it.
Thank you.

i'm feeling Saucier for you.

Let me know
how it goes.

Just pigeons.