Linking brain-heart interactions to emotional arousal in immersive virtual reality

The subjective experience of emotions is rooted in the contextualized perception of changes in bodily (e.g., heart) activity. Increased emotional arousal (EA) has been related to lower high-frequency heart rate variability (HF-HRV), lower EEG parieto-occipital alpha power, and higher heartbeat-evoked potential (HEP) amplitudes. We studied EA-related brain-heart interactions (BHIs) using immersive virtual reality (VR) for naturalistic yet controlled emotion induction. 29 healthy adults (13 women, age: 26±3) completed a VR experience that included rollercoasters while EEG and ECG were recorded. Continuous EA ratings were collected during a video replay immediately after. We analyzed EA-related changes in HF-HRV as well as in BHIs using HEPs and directional functional BHI modeling. Higher EA was associated with lower HEP amplitudes in a left fronto-central electrode cluster. While parasympathetic modulation of the heart (HF-HRV) and parieto-occipital EEG alpha power were reduced during higher EA, there was no evidence for the hypothesized EA-related changes in bidirectional information flow between them. Whole-brain exploratory analyses in additional EEG (delta, theta, alpha, beta and gamma) and HRV (low-frequency, LF, and HF) frequency bands indicated a temporo-occipital cluster, in which higher EA was linked to decreased brain-to-heart (gamma→HF-HRV) and increased heart-to-brain (LF-HRV→gamma) information flow. Our results confirm previous findings from less naturalistic experiments and suggest EA-related BHI changes in temporo-occipital gamma power. ### Competing Interest Statement The authors have declared no competing interest.