The Relation Between Valence and Arousal in Subjective Odor Experience

Introduction: The main purpose of this study was to investigate the overall relation between the mean (at the nomothetic or group level) subjective valence and arousal ratings for odors. Although well established in other sensory modalities (e.g., visual, auditory, gustatory, tactile), this relation has not previously been investigated for odors covering a large range of the valence dimension. In addition, we evaluated the EmojiGrid (a recently introduced intuitive graphical affective self-report tool) for the affective appraisal of odors. Methods: Young and healthy participants (N = 56, 32 females) used the EmojiGrid to rate the perceived valence and arousal for 40 different and randomly presented odors, ranging in valence from unpleasant to pleasant. Results: The overall relation between mean valence and arousal can be described by a U-shaped (quadratic) form; odors scoring near neutral on mean valence have the lowest mean arousal ratings, while odors scoring either high (pleasant) or low (unpleasant) on mean valence show higher mean arousal ratings. The results for odors that were also used in previous studies in the literature agree with their earlier reported values. Conclusion: Mean arousal ratings increase with (positive or negative) emotional valence. Participants intuitively used the EmojiGrid to report their affective appraisal of odors without any verbal labels or written instructions. Implications: The current findings are relevant for various applications and environments (e.g., public, retail, entertainment) where odors are used to induce desired emotional states (e.g., relaxation, arousal) and behaviors. The EmojiGrid can efficiently be applied to assess whether specific odors evoke the desired subjective affective experiences.