PHILADELPHIA (CBS) – Studies have previously claimed that if people believe a wine to be expensive, they’ll enjoy it more – even if it’s actually cheap.

But is that because we’re apt to believe anything expensive is good or because our assumption that anything expensive is good has actually changed our biology, making us experience the cheap wine the same way we would a more pricey glass?

Researchers now say they think it’s the latter.

In the study, which is published in the Journal of Marketing Research, participants were told they’d be consuming wines at five different price points ranging from $5 to $90. In reality, they only drank three different types of wine at two different price points.

Researchers found that the subjects “showed significant effect of price and taste prejudices, both in how they rated the taste [of the wines] as well as in their measurable brain activity.”

While MRI readings differed from person to person, the authors were also able to figure out that those who were “strong reward-seekers or who were low in physical self-awareness” were more likely to have their prejudices shape their experience of a product.

“Marketing actions can change the very biological processes underlying a purchasing decision, making the effect very powerful indeed,” the researchers conclude.

In other words, the placebo effect is real — and can even cause changes in our brain chemistry.