High and Low Pitch Sound Stimuli Effects on Heart-Brain Coupling

Abstract

Abstract Purpose: This study aimed to explore the influence of sound stimulation on heart rate and the potential coupling between cardiac and cerebral activities. Methods: Thirty-one participants underwent exposure to periods of silence and two distinct continuous, non-repetitive pure tone stimuli: low pitch (110 Hz) and high pitch (880 Hz). Electroencephalography (EEG) data from electrodes F3, F4, F7, F8, Fp1, Fp2, T3, T4, T5, and T6 were recorded, along with R-R interval data for heart rate. Heart-brain connectivity was assessed using wavelet coherence between heart rate variability (HRV) and EEG envelopes (EEGE). Results: Heart rates were significantly lower during high and low-pitch sound periods than in silence (p<0.002). HRV-EEGE coherence was significantly lower during high-pitch intervals than silence and low-pitch sound intervals (p<0.048), specifically between the EEG Beta band and the low-frequency HRV range. These results imply a differential involvement of the frontal and temporal brain regions in response to varying auditory stimuli. Conclusion: Our findings highlight the essential nature of discerning the complex interrelations between sound frequencies and their implications for heart-brain connectivity. Such insights could have ramifications for conditions like seizures and sleep disturbances. A deeper exploration is warranted to decipher specific sound stimuli's potential advantages or drawbacks in diverse clinical scenarios.