Myomancy reader Monica, sent me details of a very interesting fMRI study on dyslexia. The researches compared a group of adult dyslexics with a control group of normal readers in the learning of a simple sequencing task. The subjects had to press one of four buttons that corresponded to a visual stimuli that appeared in a predictable pattern and they did this whilst sitting in an fMRI machine having their brains scanned. Previous studies had found that dyslexics are worse at learning this simple sequence and the researchers were interested in the differences in brain activity between the two groups.
The study found that there was a notable difference in brain activity between dyslexics and non-dyslexics. Significantly the cerebellum was more active in the dyslexics than it was in the non-dyslexics. As treatment programs such the Dore Achievement Centres focus on training the cerebellum it would seem more likely that the fast learning, non-dyslexics would show more activity in this area. The key to this counter-intuitive result is the role the cerebellum plays in learning.
Research suggests that the cerebellum plays a key role in learning by comparing what the brain expects to happen with what actually happens. As the subjects learn the sequence, the difference between expected and actual results diminishes and the work load on the cerebellum reduces. In the better developed, non-dyslexic brains, the cerebellum is more efficient at this process so sequence learning and the corresponding drop off in cerebellum activity occurs sooner.
The study concludes
Reading is a complex cognitive activity that involves functions
arising from different networks of brain structures. To achieve
reading fluency, the skill must be automatized. The cerebellum
appears to have all the potentialities to facilitate the numerous and
coordinated operations involved in proficient reading.