Tricking Your Taste Buds

Research shows that expectations can affect the taste of what you eat.

Not a fan of Brussel sprouts? New research shows that our expectations may be able to change the way food tastes to us.

We often speak of unpopular foods like Brussel sprouts or chopped liver as being acquired tastes. Now, brain research from the University of Wisconsin shows just how subjective our tastes really are. The study, published in the March 2006 issue of Nature Neuroscience, found that people could not only be duped into believing a bitter beverage tastes better than it actually does, but that the trick decreases the activity in the "taste" region of the brain. The findings also show that this taste region may be larger than previously thought.

In past research, brain scans performed on Old World monkeys showed that the taste region of their brain, called the primary taste cortex, always gave the same response to a specific taste, regardless of how hungry the monkeys were when they tasted it. This suggested that the primary taste cortex codes for the objective qualities of taste. But many human experiments-like clinical trials where patients felt less pain after taking a placebo-confirmed that in other senses, our expectations could change our perceptions.

Neuroscientist Jack Nitschke and his colleagues wanted to find out if our sense of taste could be similarly manipulated. The researchers placed college students under a brain scanner, and measured brain activity as the subjects rated five different tastes: very bitter, bitter, neutral, pleasant, and very pleasant. The bitter tastes were made from quinine-the chemical that gives tonic water its bite-while the pleasant tastes were different concentrations of sugar water.

Each trial began with a visual cue-a plus sign, for instance, before the very pleasant taste-so that the subjects knew what taste to expect. But on some trials, the researchers played a game of switcheroo, showing the "bitter" cue before doling out a "very bitter" sample. The trick worked: when subjects were misled to believe the sample would taste better, they rated it higher. Moreover, the subjects didn't realize they had been fooled. "We asked them afterwards," Nitschke says, "and not a single one knew."