Precuneus is a functional core of the default-mode network

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• The brain's functional architecture involves multiple overlapping large-scale neural networks active across different states.
• Understanding how these networks interact to guide behavior remains a challenge.

Purpose of the Study:

• To investigate state-dependent functional connectivity within large-scale neural networks.
• To identify specific brain regions that exhibit dynamic connectivity patterns between task and rest states.

Main Methods:

• Acquired functional magnetic resonance imaging (fMRI) data from 188 human subjects during three cognitive tasks and resting-state scans.
• Utilized probabilistic spatial independent components analysis (PS-ICA) to parcel brain networks.
• Employed dual-regression analysis to examine voxelwise functional connectivity changes between task and rest states, controlling for network-specific signals.

Main Results:

• Identified the precuneus as a key region with systematic state-dependent functional connectivity.
• Observed increased precuneus connectivity with the left frontoparietal network (lFPN) during cognitive tasks compared to rest.
• Found increased precuneus connectivity with the default-mode network (DMN) during rest, with a greater magnitude suggesting specialization for resting-state cognition.
• Replicated all findings across independent split samples.

Conclusions:

• The precuneus plays a pivotal role in both the DMN and broadly across various cognitive processing states.
• Demonstrated dynamic functional connectivity of the precuneus, adapting its network engagement based on cognitive demands.
• Confirmed the precuneus's involvement in orchestrating behavior through its flexible integration within large-scale brain networks.