Acute stress promotes brain network integration and reduces state transition variability

Area of Science:

• Neuroscience
• Cognitive Science
• Psychophysiology

Background:

• Stress is a common experience, yet its precise impact on the brain's hierarchical functional organization remains incompletely understood.
• Understanding how the brain adapts its network dynamics under acute stress is crucial for comprehending stress-related disorders and cognitive function.

Purpose of the Study:

• To investigate the dynamic changes in whole-brain functional network organization following acute social stress.
• To explore the relationship between stress-induced network alterations, physiological stress markers (cortisol), and cognitive control.

Main Methods:

• Utilized whole-brain resting-state functional magnetic resonance imaging (fMRI) to capture brain activity.
• Applied an extended nested-spectral partition method to quantify the balance between network segregation and integration.
• Analyzed dynamic transitions between segregated and integrated brain states.

Main Results:

• Acute social stress induced a shift towards a more integrated and less segregated brain network state, notably in frontal-temporal regions.
• Stress stabilized brain states by decreasing the variability in dynamic transitions between segregation and integration.
• Transition frequency correlated with cortisol levels, while transition variability related to cognitive control performance.

Conclusions:

• Brain networks exhibit increased integration and reduced variability in response to acute stress, suggesting a mechanism for efficient coping.
• Dynamic network properties are sensitive to acute stress and are linked to both physiological stress responses and cognitive functions.