Two glasses sit side by side on the table, each filled midway up with red wine. On the bottom of each stem is a white piece of paper. One reads “Wine A”; the other, “Wine B.” I, along with approximately one hundred and thirty others, have a simple assignment: taste both wines and rate their tastes from one (worst) to ten (best), then write down which we think is more expensive. We aren’t allowed to comment out loud or talk with our neighbors. What—and how—will we choose? And will those rankings match the rankings and prices of the actual wines inside each glass?

This live-action experiment was conducted in early June by the Columbia University neuroscientist Daniel Salzman. His premise is that no event or object is ever experienced in perfect, objective isolation. It is instead subject to our past experiences, our current mood, our expectations, and any number of incidental details—an annoying neighbor, a waiter who keeps banging your chair, a beautiful painting in your line of sight. With something like wine, all sorts of societal and personal complications come into play, as well. We worry, for example, about whether our taste is “good.”

Salzman first became interested in wine when he was a graduate student at Stanford University studying neuroscience (Ph.D.) and psychiatry (M.D.). “I was corrupted by some people who were very serious about wine,” he told me. Together, they would host wine tastings and travel to vineyards. Over time, as his interest in wine grew, he began to think about the connections between his tastings and the work he was doing on the ways in which emotion colors the way our brains process information. “We study how cognitive and emotional processes can affect perception,” he said. “And in the case of something like wine, you have the perfect example: even before you open a bottle to experience the wine itself, you already have an arbitrary visual stimulus—the bottle and the label—that comes with non-arbitrary emotional associations, good and bad.” And those emotional associations will, in turn, affect what we taste.

The experiment I participated in is a case in point. Salzman doesn’t let us see the bottles, but he tells us a story about them. One wine, he says, is more expensive than the other. It is from a vineyard that embraces a traditional, artisanal approach to winemaking, run by a father-and-son pair. They use only organic products. Their grapes grow on a steep hill alongside peaches and cherry trees. The particular grapes in this bottle, though, come from a producer that no longer exists—one of Salzman’s personal favorites from the eighties. And then there’s the “other” wine. It’s correctly made, we learn, but without the same artisanal qualities. More commercial, more streamlined, more typical.

I can’t speak for everyone present, but at this stage in the evening my task transitions from a simple “which wine do I like more” to a “which is the artisanal.” Of course, I assume that the one I like more will be the more expensive, more carefully crafted one. I smell and taste conscientiously, smell and taste again, and scribble down my responses. I don’t particularly like either wine, I admit, but I choose Wine B as the winner. I give it a seven (honestly, it’s more of a three or four to my taste) and reward Wine A with a four (more of a one or two, but I don’t want to be mean). Naturally, I rate Wine B as the more expensive one when I hand in my card.

Expectations, argued the neuroscientists Lauren Atlas and Tor Wager in a recent review, can influence our experience in two interrelated ways. There is the conscious influence, or those things we are knowingly aware of: I’ve had this wine before and liked or hated it; I’ve been to this vineyard; I love this grape; the color reminds me of a wine I had earlier that was delicious. As our experience grows, so do our expectations. Every time we have a wine, we taste everything we know about it and other related wines. Then there are the unconscious factors: the weather is getting on our nerves, or our dining companion is; we’ve loved or hated this restaurant before; I’m mad at my boss over something he said this morning; the music is too loud, and the room is too cold. These can all affect taste, too, even though they are unrelated to the wine itself.

One of the things wine researchers like to do, in fact, is manipulate some small factor of the environment or the wine to see how perceptions of taste are affected. If we are compelled by the description of the vineyard, its owners, or its history, we are likely to pay more for a bottle. Salzman admits, after we’ve handed in our scores, that that’s the reason he gave us so much background on the wines beforehand.

Information about the vineyard at least tells us something about the wine, but even factors that don’t, like price, can have an influence. More expensive wines are often rated higher on taste than cheaper ones—but only if tasters are told the price ahead of time. In one recent study, the Caltech neuroscientist Hilke Plassman found that people’s expectations of a wine’s price affected their enjoyment on a neural level: not only did they report greater subjective enjoyment but they showed increased activity in an area of the brain that has frequently been associated with the experience of pleasantness. The same goes for the color and shape of a wine’s label: some labels make us think that a wine is more valuable (and, hence, more tasty), while others don’t. Even your ability to pronounce a winery’s name can influence your appreciation of its product—the more difficult the name is to pronounce, the more you’ll like the wine. In 1999, psychologists from the University of Leicester found that the type of music playing in a store could influence which wines were purchased: when French music was playing, people bought French wines; when German music was turned on, German wines outsold the rest. The customers remained oblivious.

Expectations seem to matter on a fundamental level: they may affect the physiology of taste itself. In one recent study, the Stanford University neuroeconomist Baba Shiv, along with his graduate student Ab Litt, designed a test to interfere with our actual taste receptors. First, they gave two groups of students identical descriptions of a wine, but for one group they added a note that described some vintages as having “unpleasant and unappealing sour undertones.” By itself, the note dramatically changed the experience of wine tasting: those who’d read it rated the wine significantly lower. Shiv and Litt then went a step further by manipulating actual taste receptors using miraculin, a glycoprotein from the so-called “miracle berry”—the fruit of the plant Synsepalum dolcificum—that alters one’s ability to taste sour notes. The miraculin was presented in the form of a dissolvable tablet that, participants were told, was a simple “chalky and tasteless” way to clear their palates for the tasting. (In a control condition, the substance was actually a calcium supplement pill.) Shiv and Litt found that the people in the sour condition now rated the wine as tastier. They couldn’t taste the sourness, so their enjoyment of the same wine increased—all because they weren’t tasting something they’d been led to expect would negatively influence their appreciation. In a second study, Litt and Shiv described the same sour undertones as a positive attribute: it would signal “palate sensitivity.” This time, people who’d read the sour description liked the wine more, and those treated with miraculin liked it less.

In one of the most prominent studies of how expectations can influence taste, Gil Morrot, a wine researcher at the National Institute for Agronomic Research in Montpellier, and his colleagues found that the simple act of adding an odorless red dye to a glass of white wine could fool a panel of tasters (fifty-four students in the University of Bordeaux’s Oenology program) into describing the wine as exhibiting the qualities associated with red wine. The tasters thought they were tasting three wines, but they were actually tasting only two. There was a white Bordeaux, a red blend of Merlot and Cabernet Sauvignon, and the same white Bordeaux colored with a red dye. When Morrot looked at the tasters’ responses, he found that they used similar descriptions in their notes on the red and colored-red wines (chicory, coal, cherry, prune, cedar, and the like), and markedly different ones when describing the white (floral, honey, peach, grapefruit, pear, banana, apple).