The Surprising Role of the Default Mode Network

The default mode network (DMN), a set of high-order brain regions, is linked to processing naturalistic events, but its cognitive function was unclear. Using a novel state-fluctuation pattern analysis, DMN coactivation during a short movie was selectively correlated with the cognitive state of surprise across movie events, compared to other states like emotion or vividness. This effect was specific to the DMN and not seen in dorsal attention or visual networks. Surprise also mediated DMN coactivations with the hippocampus and nucleus accumbens. These findings suggest the DMN serves as a major hub for high-level prediction-error representations.

Study at a glance

Abstract

Abstract The default mode network (DMN) is a group of high-order brain regions recently implicated in processing external naturalistic events, yet it remains unclear what cognitive function it serves. Here we identified the cognitive states predictive of DMN fMRI coactivation. Particularly, we developed a state-fluctuation pattern analysis , matching network coactivations across a short movie with retrospective behavioral sampling of movie events. Network coactivation was selectively correlated with the state of surprise across movie events, compared to all other cognitive states (e.g. emotion, vividness). The effect was exhibited in the DMN, but not dorsal attention or visual networks. Furthermore, surprise was found to mediate DMN coactivations with hippocampus and nucleus accumbens. These unexpected findings point to the DMN as a major hub in high-level prediction-error representations.