Task-evoked metabolic demands of the posteromedial default mode network are shaped by dorsal attention and frontoparietal control networks

External tasks evoke characteristic fMRI BOLD signal deactivations in the default mode network (DMN). However, for the corresponding metabolic glucose demands both decreases and increases have been reported. To resolve this discrepancy, functional PET/MRI data from 50 healthy subjects performing Tetris® were combined with previously published data sets of working memory, visual and motor stimulation. We show that the glucose metabolism of the posteromedial DMN is dependent on the metabolic demands of the correspondingly engaged task-positive networks. Specifically, the dorsal attention and frontoparietal network shape the glucose metabolism of the posteromedial DMN in opposing directions. While tasks that mainly require an external focus of attention lead to a consistent downregulation of both metabolism and the BOLD signal in the posteromedial DMN, cognitive control during working memory requires a metabolically expensive BOLD suppression. This indicates that two types of BOLD deactiva...,
Data of 50 healthy human participants were collected using simultaneous PET/MR imaging at rest and during performance of the Tetris task (hard level).
Data are processed and include individual brain maps in MNI-space of glucose metabolism, BOLD task effects and functional connectivity.
Group-level data include intersection and statistical conjunction maps of group task effects across glucose metabolism and BOLD changes. These are provided for the Tetris task and in addition for a working memory task. Group-level CMRGlu maps for visual stimulation and right finger tapping are also provided for comparison with other tasks.
Data are provided in NIfTI format and are fully anonymized.
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