(Thanks to the Progressive Review News for a pointer to this article)
GRAPE EXPECTATIONS AFFECT WINE TASTING
BOSTON GLOBE - Scientists at Caltech and Stanford recently published the results of a peculiar wine tasting. They provided people with cabernet sauvignons at various price points, with bottles ranging from $5 to $90. Although the tasters were told that all the wines were different, the scientists were in fact presenting the same wines at different prices. The subjects consistently reported that the more expensive wines tasted better, even when they were actually identical to cheaper wines.
The experiment was even more unusual because it was conducted inside a scanner - the drinks were sipped via a network of plastic tubes - that allowed the scientists to see how the subjects' brains responded to each wine. When subjects were told they were getting a more expensive wine, they observed more activity in a part of the brain known to be involved in our experience of pleasure.
What they saw was the power of expectations. People expect expensive wines to taste better, and then their brains literally make it so. Wine lovers shouldn't feel singled out: Antonio Rangel, the Caltech neuroeconomist who led the study, insists that he could have used a variety of items to get similar results, from bottled water to modern art. . .
Expectations can even play havoc with experts. A few years ago, Frederic Brochet, a cognitive psychologist at the University of Bordeaux, conducted a rather mischievous experiment. He invited 54 experienced wine tasters to give their impressions of a red wine and a white wine. Not surprisingly, the experts described the wines with the standard set of adjectives: the red wine was "jammy" and full of "crushed red fruit." The white wine, meanwhile, tasted of lemon, peaches, and honey. The next day, Brochet invited the wine experts back for another tasting. This time, however, he dyed the white wine with red food coloring, so that it looked as if they were tasting two red wines. The trick worked. The experts described the dyed white wine with the language typically used to describe red wines. The peaches and honey tasted like black currants.
According to Brochet, the lesson of his experiment is that our experience is the end result of an elaborate interpretive process, in which the brain parses our sensations based upon our expectations. If we think a wine is red, or that a certain brand is better, then we will interpret our senses to preserve that belief. Such distortions are a fundamental feature of the brain.