Nervous-System-Wise Functional Estimation of Directed Brain-Heart Interplay Through Microstate Occurrences

Area of Science:

• Neuroscience
• Cardiology
• Systems Biology

Background:

• Brain-heart interplay (BHI) quantification offers biomarkers for cognitive, emotional, and autonomic states.
• Existing models for BHI often focus on single sensors or limited brain regions, lacking directional organ-level estimation.
• A system-wise approach is needed to understand the directional dynamics between brain and heart.

Purpose of the Study:

• To propose and validate a novel analysis framework for estimating directional brain-heart interplay (BHI) at the organ level.
• To quantify the directional information flow between whole-brain and heartbeat dynamics.
• To provide a system-wise perspective on BHI under cognitive and autonomic challenges.

Main Methods:

• Developed an ad-hoc symbolic transfer entropy implementation for system-wise directed functional estimation.
• Utilized electroencephalography (EEG)-derived microstate series and partitioned heart rate variability (HRV) series.
• Validated the framework on datasets involving cognitive workload (mental arithmetic) and autonomic testing (cold pressor test - CPT).

Main Results:

• Demonstrated a significant bidirectional increase in BHI during cognitive workload compared to rest.
• Observed a higher descending interplay during CPT compared to rest and recovery phases.
• Found that these BHI changes were not detected by analyzing isolated cortical and heartbeat dynamics separately.

Conclusions:

• The study validates existing literature on BHI under cognitive and autonomic conditions.
• The proposed framework offers novel organ-level insights into brain-heart interactions.
• A system-wise perspective on BHI can illuminate physiological and pathological processes not evident at lower analytical scales.