Abstract
Individuals with significant hearing loss often fail to attain competency in reading
orthographic scripts which encode the sound properties of spoken language.
Nevertheless, some profoundly deaf individuals do learn to read at age-appropriate levels.
The question of what differentiates proficient deaf readers from less-proficient readers is
poorly understood but topical, as efforts to develop appropriate and effective
interventions are needed. This study uses functional magnetic resonance imaging (fMRI)
to examine brain activation in deaf readers, comparing proficient and less proficient
readers' performance in a widely used test of implicit reading. Proficient deaf readers
activated left inferior frontal gyrus and left superior temporal gyrus in a pattern that is
consistent with regions reported in hearing readers. In contrast, the less-proficient readers
exhibited a pattern of response characterized by bilateral middle frontal lobe activation
(right > left) which bears some similarity to areas reported in studies of logographic
reading, raising the possibility that these individuals are using a qualitatively different
mode of orthographic processing than is traditionally observed in hearing individuals
reading sound-based scripts. The evaluation of proficient and less-proficient readers
points to different modes of processing printed English words. Importantly, these
preliminary findings allow us to begin to establish the impact of linguistic and
educational factors on the neural systems that underlie reading achievement in
profoundly deaf individuals.