Becoming an expert in anything, whether it’s wine tasting or mathematics, changes the way you perceive the world.
Expertise is less about knowledge and more about observing things that elude novices. Through training, experts learn to see, taste, smell, and hear things that the rest of us can’t, therefore allowing them to perceive the world differently. This became clear to me after spending a weekend in conversation with an expert winemaker in Napa Valley.
Wine tasting is a peculiar profession (and not just because critics spit $50 mouthfuls into a bucket). Sommeliers can sound like they’re speaking in a strange foreign language. Wines are said to possess “roundness, generosity, and depth.” Their aromas are berrylike (strawberry, raspberry, blueberry, blackberry, whatever berry), further containing hints of tobacco, vanilla, leather, and plum. Other aroma labels don’t sound like they belong in food, like “pencil shavings,” “petrol,” and—wait for it—“cat’s piss.”
But all these things cannot possibly be in a glass of wine, can they?
The lyrical waxing of wine experts is hard to buy in its sincerity. Even poets like Kingsley Amis mocked their manners: “When I find someone I respect writing about an edgy, nervous wine that dithered in the glass, I cringe. When I hear someone that I don’t respect talk about an austere, unforgiving wine, I turn a bit austere and unforgiving myself … You can call a wine red, and dry, and strong and pleasant. After that, watch out…”
Lots of people think of wine tasting as a scam. But wine tasting is a true scientific art—it’s just that words sometimes get in the way of it being taken seriously. Gasoline-smelling wines do not contain petrol per se—we hope—but often share compounds with another substance with a recognizable aroma. The brains of sommeliers learn how to link categories of sensory experience (i.e., “this smells like petrol”) to qualitative categories of specific chemical compounds. Aged Riesling, for example, contains TDN (short for 1,1,6-trimethyl-1,2-dihydronaphthalene), a compound with the aroma of petrol. TDN is a result of carotenoids (organic pigments found in many foods, including grapes) breaking down, a process accelerated by higher temperatures. Many odd wine descriptors, including “rubber hose” and—yes—“cat’s piss,” can be identified as a specific chemical compound by expert noses. In the case of cat’s piss, it’s the compound pyrazine found in Sauvignon Blanc.
Wine has several hundred aroma compounds, which is more molecular information than most of our brains have the ability to compute. Sommeliers have learned how to direct their sensory spotlight to identify specific compounds in a complex mixture. They have trained themselves to be extremely good at discriminating and identifying individual aromas and aroma patterns. The best wine experts can identify a vintage down to its specific vineyard and even year with a virtuosity that can occasionally take less than a minute.
Acquiring this skillset not only makes sommeliers a knowledgeable (if not sometimes exasperating) dinner-party guest. It actually alters the structure and activity of their brains.
Comparing the brain of a mathematician with that of a sommelier, we find remarkable similarities. In both cases, the cellular density of white and gray matter in designated areas increases. Whether it’s sniffing Syrah or performing calculus, the acquisition of expertise makes parts of the brain thicker. In mathematicians, for example, one of the most prominent changes in the density of gray matter is found in the superior frontal gyrus, an area also linked with the coordination of self-awareness and, most intriguing, laughter. In comparison, changes in sommeliers’ brain volume were found in the right insula and entorhinal cortex, areas that are notably involved in memory processing. Such changes in neural density give those areas enhanced cortical connectivity and signaling speed, as the synaptic connections by which neurons communicate become more tightly packed. A consequence of increased neural density is that dedicated specialized areas of the brain better integrate and orchestrate otherwise widespread neural activity. Expertise of any kind results in a more sophisticated communication architecture of the brain.
But here’s the paradox. When an expert’s brain grows, they also use less of it. The more proficient you are at wine tasting, the less activity we’ll see in your brain’s fMRI recording, as reported in a scientific study from 2014. If you’re processing more information, though, how are you using your brain less? This observation is less puzzling if you compare your brain to the body of an athlete. You’ll need to put in less overall effort to lift weights if your body is trained to do so routinely. With practice, some brain activities become “automatized” and, according to the neuroscientist Christof Koch, resemble a “zombie agent”—meaning these processes require less and less conscious effort and attention.
So do sommeliers become merely better at memorizing patterns, like in the legendary study of hippocampi in London cab drivers, or do they also get better at the sensory part of smelling itself? The answer is both. Notably, a sommelier’s skill is not exclusively a method of memory (this is what a Cabernet Sauvignon typically smells like, and that is the aroma profile of a Barolo). Training further enhances their ability to be more receptive to aromas in a mixture: the sensitivity to odors changes with repeated exposure.
Whether it’s sniffing Syrah or performing calculus, the acquisition of expertise makes parts of the brain thicker.
Yet the real surprise is this: The previously mentioned 2014 fMRI study on expert sommeliers suggests that sensory expertise modifies your experience of reality—it affects not just the ability to identify and recall things on a cognitive level, but also consciousness itself. During tasting, the scientists observed activation in the brain stem of experts but not in novices. This finding (which is still being further explored) implies a difference in how sensory information is integrated into the cortical cognitive activity of experts and novices. Engaging with your perception on an analytical level thus makes a difference in the quality of your experience by fine-tuning your brain to its input (and having it reorganize its neural story to match).
Hold that thought: You get more control of the quality and content of your own conscious experience … by thinking while drinking wine.
And yet we hesitate to trust sommeliers’ abilities. That’s because of our outmoded views of mind and brain, particularly our understanding of the senses. The philosopher René Descartes, the influential source of so many misled thoughts about the mind, famously claimed that you could not trust your senses. He believed that the existence of illusions proved the unreliability of perception, and that it is impossible to establish a difference in the experience of dreams and reality.
Descartes’ skepticism led him as far as to doubt whether our entire experience may just be a hallucination induced by an evil demon. And you can’t trust your senses to reflect reality, neither by referring to what you see and hear or smell, nor by any other empirical observation. (Although demons are said to come with a pungent odor.) For Descartes, the only assurance of our material existence was the use of pure analytic reason—I think, therefore I am. The irrefutable truth from which all other truths must follow.
Except Descartes was wrong. Our senses do not “deceive” us. They are built on experience. That experience can vary through our engagement with the world, and therefore different people see, taste, hear, smell, and feel the world differently. There isn’t one shared reality that all conscious beings observe; the wine tastes different to all of us, despite the drop in our glass being from the same bottle. The dress is black and blue. I heard Laurel, not Yanny.
This shows how perception is markedly dynamic. That insight amounts to more than saying that you create your own reality. As sensory expertise enrichens the content of conscious awareness, you perceive more of the world, not just differently.
The acquisition of expertise broadens your perspective—and not only on the particular thing you specialize in. Acquiring expertise has the hidden benefit of developing a cognitive meta-skill: you learn how to learn. Such a skill provides a scaffold—both sensory and cognitive—to approach learning about other areas you may not be sufficiently familiar with. Knowing one thing well allows you to branch out to other things without getting lost in the process. Knowledge develops with experience, and experience develops with knowledge. Or as Eleanor Roosevelt said: “When you are genuinely interested in one thing, it will always lead to something else.”