 Modern neuroimaging techniques such as functional magnetic resonance imaging ( fMRI ) and positron emission tomography ( PET ) have shown a correlation between both functional and structural differences in the brains of children with reading difficulties . Some dyslexics show less electrical activation in parts of the left hemisphere of the brain involved with reading , such as the inferior frontal gyrus , inferior parietal lobule , and the middle and ventral temporal cortex . Over the past decade , brain activation studies using PET to study language have produced a breakthrough in the understanding of the neural basis of language . Neural bases for the visual lexicon and for auditory verbal short @-@ term memory components have been proposed , with some implication that the observed neural manifestation of developmental dyslexia is task @-@ specific ( i.e. functional rather than structural ) . <unk> in dyslexics have provided important data which point to the interactive role of the cerebellum and cerebral cortex as well as other brain structures . 
