On wakefulness fluctuations as a source of BOLD functional connectivity dynamics

Area of Science:

• Neuroscience
• Brain Imaging
• Sleep Research

Background:

• Human brain functional connectivity is dynamic, fluctuating with internal states and external demands.
• The neurobiological significance of these dynamics during rest remains unclear.

Purpose of the Study:

• To investigate the neurobiological significance of functional connectivity dynamics during rest.
• To identify discrete patterns in brain connectivity associated with different states of consciousness.

Main Methods:

• Whole-brain dynamic functional connectivity was measured using magnetic resonance imaging (MRI).
• Coarse-grained clustering was applied to identify discrete connectivity states.
• Electroencephalography (EEG) was used for validation in healthy subjects and narcolepsy patients.

Main Results:

• MRI-based dynamic connectivity analysis revealed discrete states associated with wakefulness and sleep.
• EEG validation confirmed these findings and identified drowsiness as a potential confound in previous studies.
• Results were consistent with a large collaborative database.

Conclusions:

• Dynamic connectivity states, when analyzed at a coarse temporal scale, reflect fluctuations in wakefulness.
• Wakefulness level is a crucial factor to consider in studies of transient functional connectivity.
• The identified states offer insights into the neurobiological underpinnings of consciousness during rest.