Dynamic Neural Interactions in Word and Discourse Processing: insights from fused fMRI/EEG

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Clair Min Kyung Hong¹ (min.kyung.hong@vanderbilt.edu), Katherine Aboud; ¹Vanderbilt University

Reading comprehension requires the precise identification and decoding of individual words (word-level processing; WL) and the extraction of coherent meaning from text (discourse-level processing; DL). In this study, we investigate how these two processes interact and are represented in the brain by examining the brain’s spatiotemporal dynamics during WL and DL using a fused fMRI-EEG analysis. We examined typical adults reading single words and medical passages in MRI sessions, and in a separate session, while EEG data was collected. Using joint Independent Component Analysis, we identified distinct neural networks and their dynamic interactions during WL and DL processing. For WL processing, we observed early signals associated with left occipitotemporal and middle temporal regions for visual and orthographic processes, followed by a frontotemporal semantic network (N400). For DL processing, an inferior frontal network for semantic syntactic reappraisal and nodes of the default mode network for conceptual integration (P600) were identified. These findings underscore the brain’s processing of larger text structures and inferential reasoning in discourse comprehension. In summary, our study illuminates the dynamic neural interplay between word and discourse processing, providing insights into how the brain navigates different levels of language comprehension. These findings offer a deeper understanding of reading proficiency and potential avenues for addressing reading difficulties.

Topic Area: LANGUAGE: Other