People make thousands of decisions every day, from what clothes to wear in the morning, to what to eat and what to buy. But scientists know little about how the brain sorts through all the information it's exposed to and how it goes about making decisions. However, as Rose Hoban reports, they're learning that the brain can be easily influenced by creative marketing.

Neuroscientist Antonio Rangel from CalTech (the California Institute of Technology)calls himself a neuro-economist. He studies how people make decisions, in particular, decisions about spending. "There is a strong interest in understanding how variables such as packaging or lighting or exposure to commercials may affect the computations that the brain makes at the time it actually has to make decisions," he explains.

Rangel and his colleagues decided to examine how price affects people's expectations of quality.

So, they put people into a brain scanner and gave them some Cabernet Sauvignon to sample. "We told them they were five different wines, and we described the wines to them by price," Rangel says. "So there were a range of prices between $5 and $90, and we told them, 'Right now, you are receiving in your mouth a sip of the $5 Cabernet Sauvignon, of the $35 Cabernet Sauvignon?"

What Rangel's subjects didn't know is that in reality, there were only three different wines. When Rangel gave them sips, he lied about the price. Sometimes he told them that the expensive stuff was cheap, sometimes he told the subjects that the cheap wine was worth $90 a bottle.

Subjects consistently said that what they thought was expensive wine tasted great.

What's more, when they thought they were drinking expensive wine, Rangel was able to see in the brain scanner that their orbital frontal cortex became more active. That's the part of the brain where we feel pleasure. "So literally, for that area of the brain that encodes subjective pleasure, a more expensive wine tastes better!" Rangel concludes.

Rangel says these results confirm his hypothesis that people's expectations of how good an experience is going to be affect how much pleasure they derive from it.

This also could help explain other phenomena, such as why some people feel better when they think the pills they are taking are powerful medicines, even when they're only sugar pills.

Rangel's research is published in the journal Proceedings of the National Academy of Sciences.