Assessment of EEG-PPG Cross Frequency Coherence under Evoked Emotional Arousal

Abstract Emotion influences the daily activity of human life. The complex interaction between the central nervous system (CNS) and peripheral nervous system (PNS) contributes to emotional experiences. Various studies have investigated this interaction during sleep, meditation, deception, and cognition. However, research focusing exclusively on emotion-related interactions is limited. In this work an attempt has been made to assess the CNS and PNS interaction by analyzing Electroencephalogram (EEG) and Photoplethysmogram (PPG) signals during emotional arousal induced by audio-visual stimuli obtained from the DEAP database . EEG signals are divided into four frequency bands: theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (30-45 Hz). The envelope of EEG and PPG signals is then computed to determine cross-frequency coherence (CFC). TheWilcoxon Rank-sum test is employed to assess the statistical significance of CFC in low (LA) vs. higharousal( HA) for various electrodes. Results indicate that CFC can discriminate the LA vs HA. Higher CFC is found in HA compared to LA for the beta and gamma bands, while the opposite trend is observed in the theta and alpha bands. The FP1, FC1, and T7 are found to be statistically significant (p < 0.05) in differentiating LA with HA. Therefore, this study offers insights into CNS-PNS interaction during emotional arousal.