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Abstract:
Abstract: Phonological awareness (PA) plays a crucial role in
reading acquisition. To address the role of PA in reading
impairment, 15 reading-impaired (Woodcock-Johnson single word
reading scores of <85) and 10 non-impaired control subjects
(11 to 15 years) participated in a functional magnetic resonance
imaging (fMRI) study using a phonological manipulation task.
Task-related signal change was measured as subjects engaged in a
sound deletion task that alternated with simply reading words aloud
(control task). All words were visually presented. During
phonological manipulation, areas in which activation was
significantly higher in non-impaired children as compared to the
poor readers included right cerebellum, right cingulate, bilateral
extrastriate areas and the left precentral sulcus. Additionally,
signal changes were correlated with standardized measures of single
word reading, non-word reading and receptive language skills. Areas
of overlap for all three behavioral measures found to be positively
correlated with fMRI signal included mid portions of the temporal
lobe and the occipito-temporal junction; these results are
consistent with the observation of greater activity in these areas
for controls versus impaired individuals. In addition, negative
correlations were identified in right hemisphere Brodmann's areas
9/45 and superior temporal gyrus. These results indicate that poor
reading is associated with less activity in posterior portions of
the brain during phonological processing. Furthermore, negative
correlations suggest a right frontal compensatory mechanism.
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