Professor Charles Spence, Head of the Crossmodal Research Laboratory at the University of Oxford, is an experimental psychologist who popularised the term gastrophysics. The Common Table talked to him about serendipitous encounters and food that makes you cry.
Orlando Lovell: What is gastrophysics and what is it you do?
Charles Spence: I’m a psychologist by training and I’ve always been interested in the senses and applying insights about how they are connected to the design of everyday things. For the first ten years of my career, this was mostly related to technology and audio-visual interactions. One project we worked on was warning signals for car drivers that tickled parts of your brain you didn’t realise you had but made you stop more quickly. So my work is kind of neuroscience-inspired, multi-sensory design but as a psychologist, not a designer.
Over the next 20 years, I got more into the world of food and drink, which, in hindsight, is a natural place for somebody interested in the senses to end up. Some of the initial projects were funded through Unilever. They had some fruit teas that looked and smelled great but tasted of nothing. We were brought in to see, from a psychology perspective, what we could do to help improve their design. And that led to other projects, including our Sonic Chip experiments [Spence and his team found that playing the sound of a louder crunch while people bit into a crisp could enhance their perception of its freshness by 15 per cent] which won an Ig Nobel Prize for nutrition and exploded our work onto the world stage.
Basically, we took a psychology experiment, – the parchment skin illusion – which is related to the higher senses of hearing, vision, and touch – and applied it to food. No one had ever done that before. We had real people eating real food and by changing the sound of the food in real time we were able to change their experience.
Sophie Lovell: Is this what led you to work with chefs?
Charles Spence: Innovation happens very slowly in big companies. Even if you get your dream result of a warning signal that will stop all accidents, it will take 20 years from that result in the lab to appear in a car you could buy on the high street. And with in-house behind-the-scenes product innovation, for the Procter & Gambles, the Nestlés and so on, you will likely never hear about it again. Back in 2003, I was introduced to the chef Heston Blumenthal, which led to a collaboration and later with other chefs around the world. This work was much more exciting because these chefs were able to take science ideas and turn them into delicious, memorable, Instagrammable dishes in no time at all.
Heston came to the lab in Oxford: I made him a cup of tea, gave him a slice of my famous banana cake and then stuck him in our soundproof box to get him crunching. He came out saying “Wow! Sound is a forgotten flavour sense, it’s an ingredient the chef can use!” That led to his famous dish at The Fat Duck called “The Sound of the Sea”, which comes to the table with headphones for the diner to hear the sounds of the sea whilst they eat it. More recently we worked with chef Jozef Youssef of Kitchen Theory in London, on a dish based on the duck-rabbit illusion that plays with the visual senses and also with synaesthesia and the taste of colour.
Chefs have been taking the science and using it as inspiration for culinary creativity in various directions and the name for this whole thing became gastrophysics, which has different meanings depending on where in the world you are. For some, it is glorified food science, whereas, for me, it’s a combination of gastronomy and psychophysics. The gastro part is nice food, the science of very nice food. The psychophysics part is a branch of psychology where you try and systematically study perception and what drives people: what they perceive, what they choose, and how they behave. It’s normally done on a computer screen with hearing and vision. The challenge for me is trying to take those psychophysical approaches to the mind of the diner and adapt them for use.
Orlando Lovell: How does this differ from molecular gastronomy?
Charles Spence: With molecular gastronomy and modernist cuisine from the ‘80s onwards, which has been a science of spumes, foams, materials and processes, all the science is in the kitchen. But no one’s been applying the science to the dining room or the home table. That’s the part that interests me as a psychologist. Everything that you eat or drink is a result of your brain, seeing, hearing, smelling, expecting, touching. The flavour of food first comes together in your brain, not in your mouth.
Sophie Lovell: This year you co-wrote a paper on a multisensory eating experience at a restaurant called Sensorium in Milan and the emotional response it brought out in diners. In particular, a rice pudding dish accompanied by typical sounds from childhood moved some diners to tears. What were you seeking to discover with this gustatory experiment and were there any surprises?
Charles Spence: Over the last five years, we’ve been asking ourselves how we can use what we have learned from our gastrophysics studies to deliver extraordinary food experiences that go beyond the known realm of things we put in our mouths. So we’ve been looking at magic and asking: can you eat magic and if so, what does that mean?
We’ve been looking at the history of edible magic and the psychology behind it with magicians and Jozef and psychologists and exemplars have started to emerge. One kind of magical food is the aesthetic “Aha!” moment, another is awe-inducing, scary or shocking food, like a dessert we made with Jozef that looks like a beating heart.
When I went to see chef Federico Rottigni at his Sensorium restaurant in Milan, he already had this dish on his Ayahuasca menu that took him by surprise because it seemed to make so many people cry. It’s a rice pudding accompanied by a complex soundscape that includes a school bell, a female school teacher talking and an old woman reminiscing. No one cried on the night I was there but it fit in for me as another kind of extraordinary experience, and with the results I’d been documenting from the sounds of the sea dish.
In London in 2014, there was a multi-sensory tasting at the Campo Viejo lab, where a synesthetic musician made soundscapes to match three wines, and the first journalist on the scene cried to a glass of wine and some matching music. This is an interesting kind of response. So when Frederico says 40 per cent of his diners are either crying or feeling like crying in response to one particular dish in this concept and they have never done it previously, I’m interested. I’m just sitting on the data he sent me last week. We experimented with 100 diners where we took out the low-frequency sounds (0 to 20 Hz) where you can’t hear a difference, but maybe you can feel the difference. We’ve done another 100 where we don’t do the ritualistic breaking of the wafer on top, and another 100 with something else. When we’ve analysed the data we will see whether there is a key variable [that makes people cry] or some interaction of different factors.
Orlando Lovell: I think we can all imagine the potential commercial value of such research for food producers, but are there non-commercial benefits that could be gained from such discoveries?
Charles Spence: That was partly the aim of the Better Life with Sourdough workshops I did with designers Maciej Chmara and Anna Rosinke at the UdK [University of the Arts] in Berlin in the spring of 2024. During the early stages of the Covid pandemic, there was a rise in the number of people baking and making bread at home – at least in Western Europe. No one knew quite what was going on there. There were various suggestions that maybe it helps the feeling of a sense of “home” or maybe the act of massaging the dough treats touch hunger, but no one’s ever tested it empirically. So we did a survey in this making, baking and tasting bread workshop and the data suggests there are significant benefits of well-being associated with bread.
I’ve also become very interested in the sensory history of ingredients such as chilli and pineapple. So far, research has been focused on the here and now. What happens when we think about the anticipation memory of things we’ve eaten, or meals we have had, and then extend that over much longer time spans? In the 1600s, pineapples were described as the world’s most delicious fruit that only the thing that King of England could eat. No one would describe them thus today. So have we changed, or has the fruit changed, or both?
You can do the same thing with the role of different herbs and spices throughout history. Spices have huge medicinal or well-being benefits, many of them also pop up in aromatherapy. So maybe there is something very interesting about olfactory well-being and scents that switches between being a well-being space, a medicinal space, and a gastronomic space. Everyone talks about the benefits of being in nature in terms of colours and sounds but nobody talks about it in terms of smell so much – except maybe in forest bathing. Maybe we can think of aromatherapy as the olfactory “nature effect” and apply it to food as a kind of nutritional medicine. What benefits will we get? Can we help dementia patients with their appetites, for example, by stimulating their olfactory memories?
Sophie Lovell: What are your thoughts on interdisciplinary practice and research with food as a medium for finding new ways of working together?
Charles Spence: For me, creativity happens when you just put people together who haven’t worked together before. When he came to our lab in 2014, the Franco-Colombian chef Charles Michel had never done psychology or statistics in his life. But put him together with a food scientist who’s a data magician, and suddenly you’ve got a whole new line of research: the gastrophysics of plating beautiful food.
It always depends a bit on who walks through the door or gets in touch. A typeface designer, Sarah Hyndman, got in touch a few years ago saying she was really interested in the taste of a typeface. I put her together with Prof Carlos Velasco and Dr Andy T. Woods in the lab, and now it’s become a whole series of studies around how typeface colour, shape and so on, can convey tastes in food.
It’s probably through mixing with these other kinds of specialists that my own research has broadened out from a very narrow focus in the lab and also away from academic psychology research being the domain of Western, educated, industrialised, rich and democratic boys and girls towards a much broader cross-cultural, cross-historical meaning of sensory stimuli and their combination.
Orlando Lovell: What in your opinion are the most pressing and fascinating upcoming food study areas?
Charles Spence: I guess it’s probably alternate sources of protein and the way we look at that through the lens of entomophagy. I did a series of studies on serving scenarios around insect-based foods, putting them in restaurants and elsewhere, to try and nudge people towards greater consumption of insects as an alternate protein source. If you can convince people about that, then you could presumably use the same approach for amoeba, bacteria or whatever else they want to feed us. Our research has mostly been insect-based in this respect, but we’ve also looked at weeds from the yard as an alternate food source, as well as vermin and jellyfish. Our relationship with certain ingredients or foods has changed dramatically at certain points in history. What can we learn from them? When it did work and how can we extend that?
Sophie Lovell: Serendipity plays an interesting role in the eating experience, especially at a good restaurant and it is something that is not often discussed. You might have an idea of the taste of what you have ordered but it is not until you put it in your mouth that a revelation may occur. What is the role and importance of serendipity in the eating experience in your view?
Charles Spence: I don’t know, whether I’d used the term more in respect to the research around food than the eating experience per se. In part because it doesn’t sound very scientific – it doesn’t sound very measurable or predictable. I do worry sometimes that in order to do the experiments that psychologists do, you have to repeat the same thing again and again to get enough data, and by doing the same thing, again and again, it fundamentally changes the thing you’re trying to study. Maybe many interesting phenomena can only happen once, like the surprise of a dish the diner thinks is one thing but actually, it’s something else. You can’t really repeat that.
Those sorts of one-off, unpredictable occurrences are not amenable to research either because you can’t write a grant around it and say “In five years’ time I will serendipitously find X”. I never apply for grants. The whole notion of having to predict what you’re going to be doing five years hence just takes away innovation completely. I like serendipity because it’s one of these things that you know can’t be planned but it is valuable nonetheless. We don’t have a lab at the moment because the building was closed due to asbestos and I think it has made us more flexible, allowing us to respond to whatever comes along. For example, Chat GPT creating foods wasn’t even a thing two or three years ago now suddenly it is and we’re ready to study it because we don’t have a backlog of things we’re meant to be doing for the next half-decade.
When we were doing those first experiments for Unilever on the fruit teas that looked and smelled great but tasted of nothing, the obvious solution was to add sugar, which they didn’t want to do. At the same time, we happened to be working with Heston Blumenthal who was serving a beetroot pastille at the end of a meal and a beetroot orange jelly at the beginning – so there were two purple jelly things at two points in the meal. In one case, it tasted definitely blackcurrant-ey in the other, it was clearly beetroot-ey. They had figured out in the kitchens that fruit acids could change the diners’ brains’ response to the colour. If the jelly contains fruit acids (malic and citric acid) the mind thinks it must be a fruit and without them, it becomes beetroot. No one in the scientific literature had ever mentioned that at all. So we went straight back to the lab and started systematically adding fruit acids to coloured drinks to see how we could enhance that taste perception. That was a serendipitous finding.
Orlando Lovell: It sounds like quite an unconventional way of working for a scientist.
Charles Spence: My department (and I have to be in a department) only likes psychology students. It’s not willing to take a punt on a chef for a PhD or a product designer or an architect or anything interesting (to me). So maybe that also sort of forces these external collaborations, because I’ve given up trying to get those people into the department.
If I had people in my lab crying after my experiment, I’d be in trouble and hauled up in front of the ethics board, but an artist can induce crying, deal with it and not worry about the ethics. Hence, when Federico Rottigni observed that people were crying in his restaurant, no one was concerned. It’s fine. So that’s shifting the focus: if you don’t call it an experiment, it becomes an experience or performance. That sort of liminal space in between allows you to do things that you can’t perhaps do otherwise.
I used to think that if I did the experiment and published a paper that showed the graph and its significance, the world would change. But no one reads scientific papers, and if they do they ignore them, unless they fit with their intuitions. My most impactful work, in hindsight, seems to have been with experiences like the Singleton Sensorium experiment in 2013 in London, where 500 people tasted whisky in changing environments. Being at that experience and seeing from your scorecard that you changed what you said about the whisky three times in the space of 15 minutes, has a direct impact. Experiences like that motivate people to do things differently. You have to shift out of the traditional scientific mindset to try and influence or effect change.
Professor Charles Spence is an experimental psychologist, Head of the Crossmodal Research Laboratory at the University of Oxford and coiner of the term gastrophysics. He is interested in how human brains process and respond to sensory information such as smell, taste, sight, hearing, and touch especially in relation to food. His research focuses on how a better understanding of the human mind will lead to the better design of multisensory foods, products, interfaces, and environments in the future. In 25 years he has written over 1200 scientific articles and won numerous awards.
Images: Laila Snevele is a sensory food designer who specialises in sensory experiences for chefs to implement sensory knowledge in their gastronomic storytelling. She uses speculative design as a tool to arrive at ideas for the future. Her Sensetopia” series imagines a future where human senses can be tailored to specific needs – sensing sugar levels in food, radio waves, UV light, and air pollution, for example – using AI and robotics to create sense-enhancing wearables. She cites the work of Charles Spence as one of the main inspirations for the path of her design work.