Default mode network mediates low-frequency fluctuations in brain activity and behavior during sustained attention

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Behavioral Science

Background:

• Low-frequency fluctuations (<0.1 Hz) in sustained attention are critical in cognitive neuroscience and clinical research.
• These fluctuations are associated with cognitive and behavioral lapses.
• The neural underpinnings and behavioral relevance of attention fluctuations remain unclear.

Purpose of the Study:

• To investigate the neural source of spontaneous fluctuations in sustained attention.
• To determine the relationship between neural and behavioral fluctuations during sustained attention tasks.
• To explore the role of the default-mode network (DMN) in attention dynamics.

Main Methods:

• Analysis of two independent functional Magnetic Resonance Imaging (fMRI) and behavioral datasets.
• Examination of low-frequency neural fluctuations (fMRI) within the default-mode network (DMN).
• Correlation analysis between neural fluctuation amplitude and behavioral fluctuation (reaction time) across different frequency ranges.

Main Results:

• Neural fluctuations in the default-mode network (DMN) mediate behavioral (reaction time) fluctuations during sustained attention.
• Increased DMN fluctuation amplitude correlated with behavioral fluctuation in the 0.01-0.1 Hz range.
• Findings were consistent across auditory and visual attention tasks and replicable across independent datasets.

Conclusions:

• The default-mode network (DMN) is a key neural source of spontaneous fluctuations in sustained attention.
• This research reframes the understanding of DMN's role, extending beyond task-deactivation.
• The study highlights the dynamic temporal relationship between brain activity and behavior during attention.