Evidence for cerebellar dysfunction in Chinese children with developmental dyslexia: an fMRI study

Numerous studies reported that developmental dyslexia in alphabetic languages was associated with a wide range of sensorimotor deficits, including balance, motor skill and time estimation, explained by skill automatization deficit hypothesis. Neural correlates of skill automatization deficit point to cerebellar dysfunction. Recently, a behavioral study revealed an implicit motor learning deficit in Chinese children with developmental dyslexia in their left hands, indicating left cerebellar dysfunction. Using functional magnetic resonance imaging (fMRI), our study examined the brain activation during implicit motor learning in 9 Chinese dyslexic and 12 age-matched children. Dyslexic children showed abnormal activations in the left cerebellum, left middle/medial temporal lobe and right thalamus compared with age-matched children during implicit motor learning. These findings provide evidence of cerebellar abnormality in Chinese dyslexic people. Furthermore, dysfunction of the left cerebellum in Chinese dyslexia is inconsistent with the right cerebellum abnormalities that were reported by studies on alphabetic-language dyslexia, suggesting that neurobiological abnormalities of impaired reading are probably language specific.