Comprehending expository texts: the dynamic neurobiological correlates of building a coherent text representation

Abstract

Little is known about the neural correlates of expository text comprehension. In this study, we sought to identify neural networks underlying expository text comprehension, how those networks change over the course of comprehension, and whether information central to the overall meaning of the text is functionally distinct from peripheral information. Seventeen adult subjects read expository passages while being scanned using functional magnetic resonance imaging (fMRI). By convolving phrase onsets with the hemodynamic response function (HRF), we were able to identify regions that increase and decrease in activation over the course of passage comprehension. We found that expository text comprehension relies on the co-activation of the semantic control network and regions in the posterior midline previously associated with mental model updating and integration [posterior cingulate cortex (PCC) and precuneus (PCU)]. When compared to single word comprehension, left PCC and left Angular Gyrus (AG) were activated only for discourse-level comprehension. Over the course of comprehension, reliance on the same regions in the semantic control network increased, while a parietal region associated with attention [intraparietal sulcus (IPS)] decreased. These results parallel previous findings in narrative comprehension that the initial stages of mental model building require greater visuospatial attention processes, while maintenance of the model increasingly relies on semantic integration regions. Additionally, we used an event-related analysis to examine phrases central to the text's overall meaning vs. peripheral phrases. It was found that central ideas are functionally distinct from peripheral ideas, showing greater activation in the PCC and PCU, while over the course of passage comprehension, central and peripheral ideas increasingly recruit different parts of the semantic control network. The finding that central information elicits greater response in mental model updating regions than peripheral ideas supports previous behavioral models on the cognitive importance of distinguishing textual centrality.

Visualizing functional pathways in the human brain using correlation tensors and magnetic resonance imaging

“…All passages were 150 words in length, and were presented one meaningful phrase at a time (details are seen in Ref. 14). The passage-reading was interleaved with reading of unconnected words and baseline as follows: passages – baseline – passages – baseline – words – baseline.…”

Fairy Tales versus Facts: Genre Matters to the Developing Brain

“…The DMN canonically includes the dorsomedial prefrontal cortex, bilateral angular gyri (AG), the precuneus/posterior cingulate cortex, bilateral anterior temporal lobes (ATL), and the hippocampus (Buckner et al 2008). The handful of studies that have examined brain networks involved in expository comprehension (without comparing to narrative) show that language areas and restricted activation of the DMN (left-lateralized) are recruited in adolescent and adult comprehenders (Swett et al 2013;Aboud et al 2016). While originally studied in the brain at rest, the DMN (also referred to as the highly overlapping "theory of mind network") has since been found to support social, inferential, and autobiographical processes that are necessary for an individual to build an appropriate internal representation of a passage (Buckner et al 2008;Ferstl et al 2008;Mar 2011).…”

“…In the last several decades, studies have made significant headway in revealing the cognitive and neural complexities of discourse-level processes (Mar 2004;Ferstl et al 2008;Swett et al 2013;Silbert et al 2014;Aboud et al 2016), primarily through the study of stories (i.e., "narrative comprehension"). However, successful engagement in modern society involves the ability to comprehend multiple forms of discourse.…”

Neural Correlates of Coherence-Break Detection During Reading of Narratives

“…In recent years functional magnetic resonance imaging (fMRI) studies have begun to reveal a network of regions that contributes to the construction of coherent mental representations of narratives (e.g., Egidi & Caramazza, 2013;Ferstl & Von Cramon, 2001;Mason & Just, 2006;Virtue, Haberman, Clacny, Parrish, & Beeman, 2006;Xu, Kemeny, Park, Frattali, & Braun, 2005;Yarkoni, Speer, & Zacks, 2008), as well as expository texts (e.g., Aboud, Bailey, Petrill, & Cutting, 2016;Moss & Schunn, 2015;Swett et al, 2013). In a comprehensive meta-analysis of neuroimaging studies on text comprehension processes, Ferstl, Neumann, Bogler, and von Cramon (2008) showed that this type of higher level language comprehension involves activation in many brain regions.…”