Digitizing the chemical senses: Possibilities & pitfalls

Abstract

Many people are understandably excited by the suggestion that the chemical senses can be digitized; be it to deliver ambient fragrances (e.g., in virtual reality or health-related applications), or else to transmit flavour experiences via the internet. However, to date, progress in this area has been surprisingly slow. Furthermore, the majority of the attempts at successful commercialization have failed, often in the face of consumer ambivalence over the perceived benefits/utility. In this review, with the focus squarely on the domain of Human-Computer Interaction (HCI), we summarize the state-of-the-art in the area. We highlight the key possibilities and pitfalls as far as stimulating the so-called 'lower' senses of taste, smell, and the trigeminal system are concerned. Ultimately, we suggest that mixed reality solutions are currently the most plausible as far as delivering (or rather modulating) flavour experiences digitally is concerned. The key problems with digital fragrance delivery are related to attention and attribution. People often fail to detect fragrances when they are concentrating on something else; And even when they detect that their chemical senses have been stimulated, there is always a danger that they attribute their experience (e.g., pleasure) to one of the other senses-this is what we call 'the fundamental attribution error'. We conclude with an outlook on digitizing the chemical senses and summarize a set of open-ended questions that the HCI community has to address in future explorations of smell and taste as interaction modalities.

Gustatory interface: the challenges of ‘how’ to stimulate the sense of taste

“…A systematic review and discussion of the possibilities and pitfalls around stimulating the chemical senses (taste and smell) was recently presented by Spence et al [23], providing a solid foundation for future work. Here, we extend the discussion by reviewing the specificities of gustatory interfaces using both chemical and electrical/thermal stimulation approaches.…”

Multisensory Technology for Flavor Augmentation: A Mini Review

“…For instance, Kabaq 4 is an AR food program that offers restaurants the option of presenting their customers with 3D visions of the food that they serve, before ordering. As for VR, whilst some researchers are exploring the possibility of virtual flavors via digitally controller electric and thermal taste sensations, such systems are currently of very limited use/potential (see Spence et al, 2017, for a critique). That being said, there is potential to design experiences in VR that target the user’s flavor expectations (e.g., before going to a restaurant or buying a product).…”

Development and Testing of a Small-Size Olfactometer for the Perception of Food and Beverages in Humans

“…Besides its very high technological level and the miniaturizations of its components, this olfactory device allows only a limited series of odors to be presented and still produces some degree of clutter for the wearer. As recently pointed out by a number of authors (Obrist et al, 2016;Spence et al, 2017), in order to obtain good results in chemosensory digitization, it is necessary to take into account both technical and psychological limitations of an olfactory display. Moreover, the effectiveness of these devices should depend on the similarity of the human responses to the stimuli elicited by the device, concerning those occurring under natural emissions of odors (e.g., see the Smell Synthesizer of the Museum of Food and Drink's MOFAD Lab; Berenstein, 2015).…”

“…The implementation of devices able to simulate a real flavor experience by means of trigeminal and tactile taste stimulation has proven to be a difficult task. Technical difficulties associated with the digitization of flavors and odors have likely contributed to the reduced commercial success of the devices that have been developed so far for this purpose (see Spence et al, 2017, for a detailed review). As consequence, it is still hard nowadays to effectively use smell by means of an olfactometer device, especially under conditions of multisensory stimulus presentation (Sanders and McCormick, 1993; see Barfield and Danas, 1995;Nakaizumi et al, 2006;Nakamoto, 2012).…”