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Could the study of how our senses interact with each other — like color and sound, or color and taste — someday help improve our health, as well as just being kind of cool?
Absolutely, says Charles Spence. Spence heads the Crossmodal Research Laboratory at Oxford University. He studies the senses to help chefs improve customers' dining experiences and food companies develop healthier products.
We caught up with Spence recently to quiz him on his latest experiments. Here's an excerpt from our interview, edited for length and clarity.
Q: So what exactly is it that you do?
A: I'm an experimental psychologist interested in the senses. I'm interested in knowing how they speak to each other in the brain and what rules our brains use to combine the information going in our eyes and ears and so on.
What really drives our research is: how can that information be applied or used to design better products or packaging or experiences?
Q: So why does that work?
A: Each of our senses are kind of noisy transducers of information. But when you start combining two senses, there's a big advantage... it's incredibly unlikely that by chance you thought you heard something, at the same time your visual system mistakenly told you there was something to see.
Q: So why did you decide to start studying taste?
A: Perhaps the most multi-sensory of all our experiences is food and drink. It's something that we have multiple times every day. It's something where when one of the senses isn't quite right, the whole experience is ruined: A perfect meal should be hot and it's cold. You have to have every sense pulling together.
Q: So how do you pull them together in the kitchen?
Well, the best example would be our perception of a flavor: a drink is very often driven by the eye - the color that we see, the intensity of the color.
As fruit ripens, it goes from green to orange to red and becomes less sour to more sweet. Our brains pick up on that correlation. So when we see that food or drink and it is the appropriate red hue and intensity, then it will taste sweeter.
A: What food companies want to do is reduce the sugar, salt, and fat, but have as little change in the actual perceived taste as possible. So it's healthier for you but it tastes almost as good as it ever did.
But if we [only] lower the salt or the sugar, people just won't buy it. So the challenge is to try and use the psychology and the neuroscience about how vision changes taste and flavor.
Q: So how do you do that?
In the case of drinks, by using the appropriate shade and intensities of red coloring, you can deliver about 11 percent more perceived sweetness than if the drink is some other color. So that's important in making healthier products, but also increasingly important in the aging population. They're tending to eat unhealthier food with more sugar and more salt in order to keep food more flavorful for them.
I can remember my grandmother spooning in five teaspoons of sugar into her big cup of tea. Why did she do that? Because her taste buds were in decline. And she needed that much sugar to give her the same flavor as I got as a young person. And if you're over 70 you probably need 5 times as much salt to give you the same saltiness perception as young person.
Q: So you can add color for sweetness. What about salt?
That's much harder. There aren't really colors associated with saltiness.
But what happens if we take a slice of bread, and rather than having the salt evenly distributed through the piece of bread, we put all the salt just around the edge. Well, when you first bite into it, it will taste salty and will you notice a difference when you get to the middle of the piece of bread and actually, the salt's gone? No. Because your perception of the food or drink is determined by the first taste. [You could] enhance salt perception but with a reduced amount of salt.
Q: You also mentioned chefs and fun...
Another thing I enjoy working a lot on is sound... We think it's all in the food but we're trying to help chefs to see how much all these other [sensory] cues make a difference — the plate it's served on, the waiter, the cutlery, the weight of the tablecloth, the chair you sit in, the music in the background.
We did an experiment to try and demonstrate this last summer at a cooking school in London. We gave one group of chefs on one side of the table the dark chocolate mousse.
On the other side we gave them a crushed meringue with strawberries and lemon and icing sugar and then played different pieces of music while they ate one dessert or another...
Carnival of the Animals has a lot of rapid, high-pitched tinkling piano, and the chefs [eating the meringue] enjoyed the dessert more.
But when Pavarotti was belting it out, it [the music] was much more congruent with the coffee-chocolate dessert.
Q: So what's next?
We're hopefully setting up an event in September in London - a pop up dining restaurant for charity. And there they'll be some great food ... there will also be magicians playing with you or food or both. Also they'll be stalls with psychologists, myself and some of my group there, giving you things to taste, and creating illusions and doing experiments on you.
Q: We'll have to check back in and see how that goes. Thanks!
A: Thank you.