Dynamic reconfiguration of the default mode network during narrative comprehension

The default mode network (DMN) reconfigures moment by moment to encode information about a changing environment, as shown by a new method called inter-subject functional correlation (ISFC). ISFC isolates stimulus-dependent correlations between brains exposed to the same stimulus, separating them from intrinsic neural processes and noise. In an fMRI experiment, subjects listened to an auditory narrative or temporally scrambled versions. ISFC revealed DMN correlation patterns locked to each narrative segment and specific to its meaning. These patterns were highly replicable across groups, and DMN coupling strength predicted memory of narrative segments, linking brain network dynamics to stimulus features and behavior.

Study at a glance

Abstract

Does the default mode network (DMN) reconfigure to encode information about the changing environment? This question has proven difficult, because patterns of functional connectivity reflect a mixture of stimulus-induced neural processes, intrinsic neural processes and non-neuronal noise. Here we introduce inter-subject functional correlation (ISFC), which isolates stimulus-dependent inter-regional correlations between brains exposed to the same stimulus. During fMRI, we had subjects listen to a real-life auditory narrative and to temporally scrambled versions of the narrative. We used ISFC to isolate correlation patterns within the DMN that were locked to the processing of each narrative segment and specific to its meaning within the narrative context. The momentary configurations of DMN ISFC were highly replicable across groups. Moreover, DMN coupling strength predicted memory of narrative segments. Thus, ISFC opens new avenues for linking brain network dynamics to stimulus features and behaviour.