How people mentally represent their body appearance (i.e., body image perception-BIP) does not always match their actual body. BIP distortions can lead to a detriment in physical and emotional health. Recent works in HCI have shown that technology can be used to change people's BIP through visual, tactile, proprioceptive, and auditory stimulation. This paper investigates, for the first time, the effect of olfactory stimuli, by looking at a possible enhancement of a known auditory effect on BIP. We present two studies building on emerging knowledge in the field of crossmodal correspondences. First, we explored the correspondences between scents and body shapes. Then, we investigated the impact of combined scents and sounds on one's own BIP. Our results show that scent stimuli can be used to make participants feel lighter or heavier (i.e., using lemon or vanilla) and to enhance the effect of sound on perceived body lightness. We discuss how these findings can inform future research and design directions to overcome body misperception and create novel augmented and embodied experiences.

Driving is a task that is often affected by emotions. The effect of emotions on driving has been extensively studied. Anger is an emotion that dominates in such investigations. Despite the knowledge on strong links between scents and emotions, few studies have explored the effect of olfactory stimulation in a context of driving. Such an outcome provides HCI practitioners very little knowledge on how to design for emotions using olfactory stimulation in the car. We carried out three studies to select scents of different valence and arousal levels (i.e. rose, peppermint, and civet) and anger eliciting stimuli (i.e. affective pictures and on-road events). We used this knowledge to conduct the fourth user study investigating how the selected scents change the emotional state, well-being, and driving behaviour of drivers in an induced angry state. Our findings enable better decisions on what scents to choose when designing interactions for angry drivers.

The Sense of Agency (SoA) is crucial in interaction with technology, it refers to the feeling of 'I did that' as opposed to 'the system did that' supporting a feeling of being in control. Research in human-computer interaction has recently studied agency in visual, auditory and haptic interfaces, however the role of smell on agency remains unknown. Our sense of smell is quite powerful to elicit emotions, memories and awareness of the environment, which has been exploited to enhance user experiences (e.g., in VR and driving scenarios). In light of increased interest in designing multimodal interfaces including smell and its close link with emotions, we investigated, for the first time, the effect of smellinduced emotions on the SoA. We conducted a study using the Intentional Binding (IB) paradigm used to measure SoA while participants were exposed to three scents with different valence (pleasant, unpleasant, neutral). Our results show that participants' SoA increased with a pleasant scent compared to neutral and unpleasant scents. We discuss how our results can inform the design of multimodal and future olfactory interfaces.

It has long been known that our sense of smell is a powerful one that affects emotions and behaviors. Recently, interest in the sense of smell has been growing exponentially in HCI. However, the potential of smell to inspire design is still underexplored. In this paper, we first investigated crossmodal correspondences between scents and selected features relevant for design (clustered in sensory, bodily, and qualitative features). Then, we created a set of cards (EssCards) to visually summarize the key findings to inspire designers. We carried out two preliminary design exploration sessions using the EssCards. Based on our findings, we discuss how to inspire and challenge design opportunities around the sense of smell and reflect upon applications for smell as inspirational material for designing future interactions and experiences.

Sound delivery is a key aspect of immersivity in virtual and augmented reality (VR/AR), with studies hinting at a correlation between users’ ability to locate sounds around them and the ‘feeling of being there’. This is particularly true for WebVR, a method of delivering immersive experiences through a local web browser that has recently captured attention in multiple industries. In WebVR, audio is the main spatial cue. Designers need to select the correct number of sound sources so that users perceive the location of incoming sound correctly. Information on how users localize sound is essential. Sound localization experiments, so far, have been run only in empty spaces or closed rooms, without clear indications for designers in WebVR. Thus, in this study, we investigate sound localization directly through WebVR. To do so, we designed a traditional empty room for training and a city-like virtual environment for testing purposes. In our paper, we also discuss key design parameters, differences in perception for vertical and horizontal directions, the impact of training, and the role of changing virtual environments. In addition, we introduce and test a new sound cue along with the traditional pink noise sound to measure and explore the impact of different sound cues in different environments. The results demonstrate the potential of exploring sound localization using WebVR, and our study will support the development of virtual experiences in human-computer interaction that may be able to reach a large number of participants using a local web browser.