Poster C46, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
Knowledge Structure and Expository Texts Comprehension: A Neurocognitive Study
Chun-Ting Hsu1, Roy Clariana1, Ping Li1; 1Pennsylvania State University
Knowledge Structure (KS) refers to the textual organization of the conceptual topology, and could be quantified by graph centrality (GC), a graph-theoretic metric (ranging from 0 to 1). Lower GC indicates linear or hierarchical organization, while higher GC represents network or star-like organization. We hypothesize that expository texts with higher GC require the reader to recruit more integrative cognitive resources to integrate different pieces of information with one or several key concepts while building the KS. In this study, 50 adults read five 300-word expository texts while their eye-movements and BOLD signals were collected. For each text, beta images of content-word-fixations (representing word processing efforts) and word position parametric predictor (representing sentence comprehension processes) were regressed with the textual GC values within subject. Group-wise, GC showed positive effect on word processing in associative/integrative regions including Angular gyrus and dorsolateral prefrontal cortex (dlPFC). Positive effects on sentence comprehension were found in associative/integrative regions including bilateral dlPFC, anterior and posterior cingulate cortex. By contrast, negative correlation between sentence comprehension and GC values showed in canonical language/semantic processing regions, e.g., left anterior to posterior temporal cortex, right anterior temporal lobe, left inferior frontal gyrus, and left dorsomedial PFC. Group level regression with behavioral measures showed that when reading texts with higher GC, readers’ electronic device time per day (e.g., smartphone, internet gaming) is negatively correlated with BOLD level in the right dlPFC and right cerebellum, suggesting reading habits in this digital era might negatively impact reader’s KS integration for expository texts comprehension.
Topic Area: LANGUAGE: Other