Modulating Virtual Affective Elicitation by Human Body Odors: Advancing Research on Social Signal Processing in Virtual Reality

Human sensory systems are capable of encoding emotion-related signals during social interactions (e.g., fearful or happy facial expressions). In this regard, many emotion elicitation procedures have been reported within the scope of social signal processing research. Most of these procedures rely on socially relevant stimuli, such as emotional face images, videos, and, more recently, virtual reality (VR) scenes. Unfortunately, procedures involving cross-modal interactions beyond visual and acoustic stimuli, such as olfaction, are still scarce. In this sense, neuroscience supports a close link between the olfactory and affective systems. Moreover, experimental research has reported faster appraisals of emotional face images when congruent valence-laden artificial scents were presented (e.g., positive scent-happy face; negative scent-fearful face). Interestingly, recent findings indicate that emotion-related human-body odors (HBOs) might also modulate affective appraisals during a neutral virtual reality experience. However, whether and how emotion-related HBOs modulate affective VR experiences requires further examination. Here, an approach to this research question is proposed from a Virtual Reality-based Behavioral Biomarker (VRBB) experimental framework. Concretely, in the first place, a novel affective elicitation procedure based on social-emotional VR is introduced, wherein electro-dermal activity (EDA), heart-rate variability (HRV), electroencephalography (EEG), and affective appraisals, will be accounted for. In a second step, the modulating role of HBOs will be investigated regarding those measures. This work presents the envisioned model, details of the devised VEs, and a research design to test concrete hypotheses.