How Can Neuroimaging Inform Our Treatment of Reading Disorders in Children With Learning Disabilities?

Abstract

Neuroimaging technology in the last two decades has allowed a direct 3 dimensional view of the processing activity in an individual’s brain while completing a particular cognitive task enabling the characterization of functional brain areas and typical processing pathways. This meta-synthesis examines current studies of the neuroimaging of reading in both typical proficient readers, and individuals with developmental dyslexia and examines how these studies can inform our treatment of reading disorders. Functional Imaging studies with fMRI, DTI, MEG, and EEG techniques have documented that the brains of individuals with dyslexia have distinct physical differences and an atypical processing of reading tasks when compared to their normal reading peers. These differences in both form and function can be determined in young pre-reading age children, enabling the early identification (with 90% accuracy) of individuals that will later struggle with the disability. Researchers in the field indicate that DD is an evolving progressive disorder beginning with a distinct phonological disorder and evolves into semantic word recognition disorder as the child ages. The underlying causes for DD that are being currently advocated are a Magnocellular/vision deficit, a cerebellar deficit, and/or a phonological deficit. Studies indicate that more than one of these deficits may be contributing factors, however 90% of individuals presenting with the DD have a phonological deficit as a major contributor making this the target area of most early interventions. Many studies have contrasted the functional scans of DD readers before, and after phonological interventions in an attempt to characterize a neuro-plastic change resulting from the intervention. These contrast studies indicate that many individuals with dyslexia will normalize their atypical processing of written information to appear to process written text much like their proficient reading peers. However, there are still many individuals with dyslexia who do not respond to interventions with normalization, but instead compensate for their atypical processing of written text by recruiting disparate areas in the brain to accomplish the same task. These researchers’ results indicate central challenge of developing interventions guided by the neurology. These interventions should target activation of a given brain system identified to be the source of the deficit in an individual’s Dyslexia with the intent to induce a neuro plastic, normalizing change in brain.