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Tasty behaviour

Some multicoloured macarons

It’s hard to be good, especially when it comes to eating right. Sadly what’s tasty isn’t always what’s healthiest. Sometimes it can help to have a little nudge in the right direction. That’s what computer scientists are trying to do in three new systems. By training you, enticing you or downright fooling you, here are three inventions that use computer interaction to help users eat better.

The power of chocolate

Be honest: there’s some food you find tough to resist. It could be chips, fizzy drinks or cake. For a lot of people, the irresistible temptation is chocolate. We know it’s not good to overindulge in anything, but when that sweet, dark dessert is put in front of us we just have to take a bite. It takes a lot of willpower to resist. The problem is, scientists think willpower may be something we run out of. The strength of our will can be tired out like a muscle, and making the right choice gets more difficult the longer you hold out.

Some researchers in Germany wanted to test whether willpower could be like a muscle in another way: maybe over time you could train it. They even designed a machine to work out your willpower, and called it the chocolate machine. The chocolate machine is a dispenser filled with round chocolates. It sits on a student’s study desk, and every 40 to 60 minutes it releases one of its little sweeties. Users were free to eat one of the chocolates, but the researchers told them that to practise self-control, it would be good to put the chocolates back in the machine.

Over time, seven out of ten chocolate machine users found that their self- control got better. Most people developed strategies to help them with their willpower. Some imagined that the chocolate balls were actually just balls of wood, while others pretended that the chocolates belonged to somebody else. A few users imagined that the machine had feelings, and that by putting the chocolates back they were helping it. Overall, it seems like whenever you face a really strong temptation, it helps to imagine ways to make the temptation seem weaker.

The researchers think that their chocolate machine could be a better way to help people behave. A lot of products that try to change people’s behaviour depend on monitoring someone closely. A bit like having a parent over your shoulder, making sure you’re doing your homework. The chocolate machine’s playful design might be a better way to help someone develop their own good strategies. But now that you’ve read this far, can you resist having a chocolate?

Making students’ lives brighter (and wetter)

A lonely, unused drinking fountain in a busy university corridor inspired a group of interaction researchers based in Spain and America. Drinking water is good for you, and so is a few seconds’ rest from rushing to class. What could encourage people to stop and take a break? They needed to find a design that would work in a crowded hallway, and hopefully one that would make the whole corridor seem a little friendlier. They came up with a concept they called Gurgle.

Gurgle is an interactive light and sound display around the drinking fountain. The researchers found a light called an aquasplash, which is normally used in aquariums. It gives off a blue light that looks like wavy water. They pointed the aquasplash up from the fountain, filling the nook around the fountain with pleasant blue ripples. When someone walks past the fountain, their movement triggers the lights for just a moment, but if they then stop to take a drink the lights stay on. To add to the relaxing effect, while the person drinks they are treated to the sound of a gurgling stream coming from a speaker.

The researchers may have been proud of their setup, but they needed to find out whether it was having any effect. Did more people actually use the fountain? To find out they turned Gurgle on and off at certain times over one term, and counted how many people used the fountain. Gurgle worked: the number of people using the fountain went up by around 50% when it was turned on. They also found some buzz around campus for Gurgle. Some people went out of their way to use the fountain, and told their friends to use it too. It’s nice to know that a simple design can liven up some dull surroundings, and get people to drink more water too.

Virtually full

Here’s a surprising trick that makes you feel like you’ve had your fill of food: make the food look bigger. Researchers in Japan have developed a virtual reality system that makes you see your food as though it’s a larger portion. Once you’ve eaten it, you feel as though you’ve eaten more than you actually have. The researchers think they could use their system to help people eat less. Humans use clues to guess how much food to eat. Psychologists have found that one of the clues we use is size. If the food portion looks large compared to the objects around it, we assume the portion is bigger. For example, experiments have found that the size of a bowl can affect how much soup it takes to make someone feel full. The researchers wondered if people would eat fewer cookies if they thought the cookies were bigger than they actually were.

To get the effect they used a virtual reality system. Volunteers wore goggles with a video camera on them. The camera was connected to little computer screens inside the goggles, showing a view of what was in front of them. The goggles were also connected to a computer that could control what the volunteer saw. Researchers gave the volunteers a plate of Oreo cookies and told them they could have as many as they liked. What the volunteers didn’t know was that sometimes the virtual reality changed the size of the cookie so that it looked like they were holding a bigger (or sometimes a smaller) Oreo. The researchers then kept track of how many cookies each volunteer ate before feeling full.

The researchers found that their system worked. By changing the apparent size of the cookies, they could indeed affect how many cookies the volunteers had to eat before they felt full. And the virtual reality system did its trick flawlessly: no one suspected that the size of the food was being changed. One problem, though, was that in order to keep the illusion going, you can’t change the size of the cookie very much. If you think about it, imagine if you tried to make the cookie really huge – like the size of a pizza. You would have to deform the cookie (and the hand holding it) so much that it would be obviously fake. So computer science will have to be happy with just making our cookie binges a little bit smaller.