Virtually tasty: An investigation of the effect of ambient lighting and 3D-shaped taste stimuli on taste perception in virtual reality

Taste perception is influenced by sensory information not only about the food itself but also about the external environment where the food is tasted. Prior studies have shown that both visual attributes of the environment (e.g., light colour, location) and the shape associated to food (e.g., plates, cutlery) can influence people's taste perception and expectations. However, previous studies are typically based on non-edible shapes usually shown as 2D images or presented as 3D tangible objects aimed to be perceived by subjects' hand. Therefore, the effect of mouthfeel of differently shaped foods on taste perception remains unclear. Capitalising on the advantages of virtual reality (VR) to manipulate multisensory features, we explore the effects of coloured (red, blue, neutral) virtual environments on the taste (sweet, neutral) perception of differently shaped taste samples (rounded/spiky shapes according to the Kiki-Bouba paradigm). Overall, our results showed increased ratings of sweetness when participants tasted Bouba-shaped samples (rounded) relative to Kiki-shaped samples (spiky) suggesting that tactile attributes perceived inside the mouth can influence sweetness perception. Furthermore, we concluded that lighting colour in a virtual setting might dampen experiences of sweetness. However, this effect may only be present when there is a cross-modal correspondence with taste. Based on our findings, we conclude by describing considerations for designing eating experiences in VR.