Can the same Visual Modality Express Arousal or Valence Depending on the other Modalities it is Combined with?

Abstract

The work described in this paper explores if the same visual modality (sharpness of curvature) can be used to express different dimensions of emotions (arousal and valence) depending on the modalities it is combined with. We propose two novel approaches to visually express emotions in affective agents. Both models employ a simplistic character consisting of an abstract body modelled as a closed sequence of concatenated curves. Emotions are represented in terms of arousal and valence dimensions. In the first model, the arousal value is expressed through the sharpness of the curves that comprise the character outline, while the valence value is expressed through the curvature of the character's mouth. In the second model, the arousal value is expressed through the character's movement, while the valence value is expressed through the sharpness of the curves that comprise the character outline. Thus, sharpness of curvature is used to express arousal in the first model and valence in the second one. The paper also describes a user experiment which investigated whether the arousal and valence expressed by our models are appropriately perceived by the users or not. The results support both models and suggest that sharpness of curvature could be used to express arousal or valence if consistently combined with other appropriate modalities.