Your brain caught at "cooking the books,"

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 have long been a topic of psychological research, and it's well known that they affect how we react to events, or how we respond to medication. But in recent years, scientists have been intensively studying how expectations shape our direct experience of the world, what we taste, feel, and hear. The findings have been surprising - did you know that generic drugs can be less effective merely because they cost less? - and it's now becoming clear just how pervasive the effects of expectation are.

The human brain, research suggests, isn't built for objectivity. The brain doesn't passively take in perceptions. Rather, brain regions involved in developing expectations can systematically alter the activity of areas involved in sensation. The cortex is "cooking the books," adjusting its own inputs depending on what it expects.

-What wine can tell us about the nature of reality