Effects of Cardiac Activity on Somatosensory Evoked High-Frequency Oscillations.

Recent neuroscience research has shed light on heart-brain interactions during diverse information processes across perception, affective, and cognitive domains. It remains unclear how the heartbeat-related interoceptive pathway affects the neural responses of somatosensory information processing. In this study, we combined EEG, ECG, and DTI to examine the effect of heart-brain interaction on cortical somatosensory processing and investigated both the cardiac phase and heart rate effects on somatosensory-evoked high-frequency oscillations (HFOs). First, we examined the somatosensory cortex activity in terms of HFOs along the cardiac cycle and observed an attenuated HFO response in the systole phase. Moreover, voluntary hyperventilation (VH) was adopted as the approach to interoceptive exposure, and a significant HFO decrease was observed after VH in both the systole and diastole phases. Then, we constructed robust fusion models to demonstrate the combined effects of cardiac activity, brain structure, and somatosensory stimulation input on the HFO response. The results showed that there was an important predictive effect of heart rate on somatosensory neural oscillations. These findings revealed the essential regulatory effect of dynamic cardiac activity on brain response during somatosensory information processing, and they may provide a better understanding of the mechanisms underlying the heart-brain interaction by integrating interoceptive and exteroceptive signals.