Scale-free dynamics of core-periphery topography.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Systems Neuroscience

Background:

• The human brain's cerebral cortex is divided into core and periphery regions.
• Differences in timescales exist between core and periphery regions.
• Scale-free dynamics in brain activity during rest and task states are not fully understood.

Purpose of the Study:

• Investigate scale-free dynamics (pink noise) in the brain's core-periphery topography.
• Examine these dynamics during resting and task states using infra-slow frequencies.
• Clarify how power spectra features modulate across different brain regions and states.

Main Methods:

• Applied infra-slow inter-trial intervals (up to 1 minute) within the BOLD frequency band.
• Analyzed power-law exponent (PLE) in core and periphery regions during rest and task.
• Utilized a computational model and a replication dataset for validation.

Main Results:

• Found a higher resting-state PLE in the core compared to the periphery.
• Observed significant increases in PLE across both regions during task states.
• Task-related PLE increases correlated with low event rates and task periodicity (0.016-0.019 Hz).

Conclusions:

• Scale-free dynamics distinguish core and periphery brain regions during resting-state.
• Task engagement modulates these dynamics, with changes linked to slow event rates.
• Findings advance understanding of brain functional organization and dynamics.