title: The default modes of reading: modulation of posterior cingulate and medial prefrontal cortex connectivity associated with comprehension and task focus while reading.
abstract: Reading is a fundamental human capacity and yet it can easily be derailed by the simple act of mind-wandering. A large-scale brain network, referred to as the default mode network (DMN), has been shown to be involved in both mind-wandering and reading, raising the question as to how the same neural system could be implicated in processes with both costs and benefits to narrative comprehension. Resting-state functional magnetic resonance imaging (rs-fMRI) was used to explore whether the intrinsic functional connectivity of the two key midline hubs of the DMN-the posterior cingulate cortex (PCC) and anterior medial prefrontal cortex (aMPFC)-was predictive of individual differences in reading comprehension and task focus recorded outside of the scanner. Worse comprehension was associated with greater functional connectivity between the PCC and a region of the ventral striatum. Better comprehension was associated with greater functional connectivity with a region of the right insula. By contrast reports of increasing task focus were associated with functional connectivity from the aMPFC to clusters in the PCC, the left parietal and temporal cortex, and the cerebellum. Our results suggest that the DMN has both costs (such as poor comprehension) and benefits to reading (such as an on-task focus) because its midline core can couple its activity with other regions to form distinct functional communities that allow seemingly opposing mental states to occur. This flexible coupling allows the DMN to participate in cognitive states that complement the act of reading as well as others that do not.
authors.affiliation: Department of Psychology, University of York Hesslington, North Yorkshire, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Smallwood
authors.forename: Krzysztof J
authors.initials: KJ
authors.lastname: Gorgolewski
authors.forename: Johannes
authors.initials: J
authors.lastname: Golchert
authors.forename: Florence J M
authors.initials: FJ
authors.lastname: Ruby
authors.forename: Haakon
authors.initials: H
authors.lastname: Engen
authors.forename: Benjamin
authors.initials: B
authors.lastname: Baird
authors.forename: Melaina T
authors.initials: MT
authors.lastname: Vinski
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Schooler
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Margulies
keywords: comprehension; default mode network; medial prefrontal cortex (MPFC); mind wandering; posterior cingulate cortex; reading; self-generated thought