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Abstract:
Abstract: Rapid naming of letters and objects is a strong
predictor of reading skill. The present study used functional
magnetic resonance imaging (fMRI) to investigate the functional
neuroanatomy of rate-modulated naming and articulation. For the
experimental task (naming) eleven participants named aloud letters
and objects at three different rates (1.11, .92 or .89 hz), with
one rate and one stimulus type (letters or objects) presented per
functional run. Within each run, the control task (articulation)
required saying the same word aloud in response to a nonsense
stimulus presented at the same rate as the meaningful stimuli. The
articulation task was designed to isolate brain activity associated
with seeing a stimulus and speaking aloud, whereas the naming task
additionally included lexical, phonological, and in the case of
objects, semantic retrieval. Considering naming controlled for
articulation, the magnitude of fMRI signal significantly increased
with both object and letter naming rate in several bilateral
spatially distinct cerebellar regions. Other areas modulated by
naming rate included left cuneus (area 17), right parahippocampal
gyrus (area 38), right superior temporal (area 22), right inferior
frontal (area 45), left inferior frontal (area 47), and left
superior frontal (area 8) regions. Because differences between
naming and articulation were considered, the cerebellum and these
other regions may play an important role in rapid lexical,
phonological and semantic retrieval. Support: NICHD.
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