Left-Lateralized Contributions of Saccades to Cortical Activity During a One-Back Word Recognition Task
Author(s)Chang, Yu-Cherng C.; Taulu, Samu; Kuperberg, Gina; Khan, Sheraz; Brown, Emery Neal; Hamalainen, Matti S; Temereanca, Simona; ... Show more Show less
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Saccadic eye movements are an inherent component of natural reading, yet their contribution to information processing at subsequent fixation remains elusive. Here we use anatomically-constrained magnetoencephalography (MEG) to examine cortical activity following saccades as healthy human subjects engaged in a one-back word recognition task. This activity was compared with activity following external visual stimulation that mimicked saccades. A combination of procedures was employed to eliminate saccadic ocular artifacts from the MEG signal. Both saccades and saccade-like external visual stimulation produced early-latency responses beginning ∼70 ms after onset in occipital cortex and spreading through the ventral and dorsal visual streams to temporal, parietal and frontal cortices. Robust differential activity following the onset of saccades vs. similar external visual stimulation emerged during 150–350 ms in a left-lateralized cortical network. This network included: (i) left lateral occipitotemporal (LOT) and nearby inferotemporal (IT) cortex; (ii) left posterior Sylvian fissure (PSF) and nearby multimodal cortex; and (iii) medial parietooccipital (PO), posterior cingulate and retrosplenial cortices. Moreover, this left-lateralized network colocalized with word repetition priming effects. Together, results suggest that central saccadic mechanisms influence a left-lateralized language network in occipitotemporal and temporal cortex above and beyond saccadic influences at preceding stages of information processing during visual word recognition.
DepartmentInstitute for Medical Engineering and Science; Harvard University--MIT Division of Health Sciences and Technology; Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory; Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences; McGovern Institute for Brain Research at MIT
Frontiers in Neural Circuits
Frontiers Research Foundation
Chang, Yu-Cherng C., Sheraz Khan, Samu Taulu, Gina Kuperberg, Emery N. Brown, Matti S. Hämäläinen, and Simona Temereanca. “Left-Lateralized Contributions of Saccades to Cortical Activity During a One-Back Word Recognition Task.” Frontiers in Neural Circuits 12 (May 16, 2018).
Final published version