In Psychology Today's blog Evolved Primate, social psychologist Daniel R. Hawes describes an experiment where wine tasters rated the same wine differently depending on how much they thought it cost. The tasters said the $90 wine was superior to the $10 wine, findings that were confirmed by fMRI scanning machines showing the activity in their brains:
When tasting the wine out of the $10 bottle, the medial orbitofrontal cortex—an area of the brain that is strongly related to experiences of pleasure—showed only very little activity. When the exact same wine was poured out of a $90 bottle however, this brain area showed levels of activation which indicate that the participants were indeed drawing much more enjoyment from the same wine this time around. In other words, the price tag seemed to have a real physiological influence on the taster's taste experience.
Hawes points out that the placebo effect is at work here: Expecting something to taste good, perhaps under the influence of a higher price, might make it taste better than if there were no expectations. How often do you think price influences your perception of a food's deliciousness?