Poster E66, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
A sensorimotor network for voluntary oculomotor function in skilled reading: From cortex to brainstem
Benjamin Schloss1, Chun-Ting Hsu1, Ping Li1; 1Pennsylvania State University
Reading requires the integration of low and high level sensory and linguistic information with coordinated oculomotor sequences. This study examines how sensorimotor integration occurs in the brain during reading. Thirty adult participants read five 300-word expository texts in the MRI scanner while their eye-movements and BOLD signals were collected (see http://blclab.org/reading_brain/). Simultaneous multi-slice (SMS) fMRI data were acquired (TR = 400ms). This design greatly reduced the error in aligning the hemodynamic response function with the initial fixations on single words. Word frequency and word length were used as linear and quadratic parametric predictors of brain activity in a whole brain analysis. Our results not only replicated the quadratic effect of word length in the pontine brainstem (Schuster et al., 2016), but also showed significant quadratic effects of word length in the lingual gyri, lateral cerebellar cortex, primary motor cortex, primary auditory cortex, temporal parietal junction, and the paracingulate gyri. This network plausibly reflects the integration of linguistic (temporo-parietal areas) and visual (lingual gyri) representations of word length with a cortico-pontine-cerebellar motor circuit. Anatomical connections between primary motor cortex and the pons as well as between the pons and the cerebellum indicate the coordination and execution of oculomotor commands (Alloway & Pritchard, 2007; Schuster et al, 2016).This sensorimotor circuit is functionally interconnected during reading. Understanding of this network has significant implications for the neurocognitive mechanisms underlying individual differences in reading and typical and atypical function and development of the brain networks that support reading.
Topic Area: LANGUAGE: Other