An examination of the rapid automatized naming-reading relationship using functional magnetic resonance imaging

Rapid automatized naming (RAN) has been established to be a strong predictor of reading. Yet, the neural correlates underlying the RAN-reading relationship remain unknown. Thus, the purpose of this study was to determine: (a) the extent to which RAN and reading activate similar brain regions (within subjects), (b) whether RAN and reading are directly related in the shared activity network outlined in (a), and (c) to what extent RAN neural activation predicts behavioral reading performance. Using functional magnetic resonance imaging (fMRI), university students (N=15; Mean age=20.6 years) were assessed on RAN (letters and digits) and single-word reading (words and non-words). The results revealed a common RAN-reading network that included regions associated with motor planning (cerebellum), semantic access (middle temporal gyrus), articulation (supplementary motor area, pre-motor), and grapheme-phoneme translation (supramarginal gyrus). We found differences between RAN and reading with respect to percent signal change (PSC) in phonological and orthographic regions, but not in articulatory regions. Significant correlations between the neural RAN and reading parameters were found primarily in motor/articulatory regions. Further, we found a unique relationship between in-scanner reading response time and RAN PSC in the left inferior frontal gyrus. Taken together, these findings support the notion that RAN and reading activate similar neural networks. However, the relationship between RAN and reading is primarily driven by commonalities in the motor-sequencing/articulatory processes.