Wine tastes better if it is thought to be expensive due to a physical change in the brain, according to a study.
The researchers found that preconceived beliefs created a placebo effect so strong that it changed neural processes.
By packaging cheap wine as a fine vintage, the drinker enjoyed it in exactly the same physical way as if it was far more expensive.
"Studies have shown that people enjoy identical products such as wine or chocolate more if they have a higher price," said Bernd Webber, co-author of the report, from the University of Bonn in Germany.
"However, almost no research has examined the neural and psychological processes required for such marketing placebo effects to occur."
Participants in the study, published in the Journal of Marketing, were told they would consume five wines priced at £55 (NZD$111), £28 (NZD$56), £22 (NZD$44), £6 (NZD$24) and £3 (NZD$6) respectively, while their brains were scanned to measure their response.
The volunteers were actually only given three different wines, with two different price tags.
Another experiment used labels to generate positive or negative expectations of the taste of a milkshake.
Some consumed identical milkshakes but thought they would be either organic or regular; others consumed identical milkshakes but thought they would be either light or regular.
Participants in both demonstrated significant prejudices, both in how they rated the taste as well as in their measurable brain activity.
The brain scan readings related in part to specific areas of the brain that are associated with personality traits.
The volume of grey matter in those areas of the brain - the striatum, the posterior insula, and the dorsal medial prefrontal cortex - was found to moderate the taste according to the expectancy.
The authors were able to further determine that people who were strong reward-seekers or who were low in physical self-awareness are more susceptible to having their experience shaped by marketing techniques.
They found that the more subjects were able to focus on their internal states compared to external cues, the less responsive they were to marketing.
The study concluded: "Using a novel application of structural brain imaging in combination with behavioural experiments, we are among the first to shed light on individual difference variables that affect marketing placebo effects.
"Understanding the underlying mechanisms of this placebo effect provides marketers with powerful tools.
"Marketing actions can change the very biological processes underlying a purchasing decision, making the effect very powerful indeed."
A study in 2012 found that shoppers would pay more for a bottle of wine if it was heavier, believing them to contain higher quality wine.
Drinking wine from a heavier glass was also said to make the same wine taste better, because of the way the brain associates weight with value.