Aims: Understanding the intricacies of brain-heart interactions (BHI) is crucial for unraveling the complex mechanisms underlying emotional processing and physiological regulation. Therefore, this study aimed to understand the network physiology and BHI underlying complex emotional behavior, examine the involvement of specific brain areas, and explore the role of different frequency bands during different emotional contexts.
Method: To that end, using the DEAP dataset, EEG and PPG recordings from 10 participants were analyzed. Data from 6 selected electrodes were used to extract the brain rhythms theta, alpha, beta, and gamma. The controlled time-delay stability (cTDS) technique assessed the BHI while accounting for delays and indirect connections. Link strength was evaluated using observed cTDS percentage. High (H) and low (L) valence (V) and arousal (A) were assessed for emotional granularity.
Results: Consistent results indicated stronger connections within heart-to-brain networks across emotional states. The distribution of average link strength across different brain areas in the HAHV, LAHV, HALV, and LALV networks exhibited relative symmetry. Notably, the strength of the heart-to-brain connections indicated the influential role the heart plays in driving brain activity associated with arousal and valence. Furthermore, the beta and gamma frequency bands demonstrated stronger connection strength within the heart-to-brain networks, highlighting their relevance in the interaction between the heart and the brain.
Conclusion: The study underscores the effectiveness of the cTDS algorithm in quantifying coupling and network interactions within BHI. By elucidating the connections between the heart and the brain, this research provides valuable insights into BHI connectivity and the mechanisms involved in emotional processing. These findings have important implications for future studies exploring brain-heart networks in various emotional contexts, enhancing our understanding of the interplay between the brain and the heart.