Once we move beyond smell to consider flavor, however, the images processed in our brains become vastly more complex. In addition to the odor signals from our noses—this coffee is good!—there will be taste signals from the mouth—oh, but it’s bitter!—as well as feelings of texture—smooth cream!—and temperature—that burned my tongue! The experience of tasting food is far more multisensory than is the case with hearing, sight, or touch, which is why it requires the most sophisticated part of our brains to process it. In fact, eating is influenced by hearing, sight, and touch as well as flavor: we prefer apples that crunch loudly, steaks that look blood-red, sauces so smooth they seem to caress the inside of our throats.
If there are 10,000 smells, the number of different flavors that our brains can potentially create is infinite. Professor Gordon M. Shepherd,
a
biologist based at Yale University, has coined the term “neurogastronomy” to explain our brain’s unique flavor system. In Shepherd’s view, complex flavor recognition is at the core of human identity, separating us from other mammals. Cats cannot even detect something as basic as sugar—they lack a taste receptor for sweetness. Humans, on the other hand, can differentiate fake maple syrup from real maple syrup, Coke from Diet Coke. Shepherd notes that the images of different flavors humans build up are processed in the prefrontal cortex, the area of the brain that is most important not only for decision making and abstract thought, but also for memory. Shepherd’s work has shown that the human brain can potentially generate any number of flavors, “since every soluble body has a special flavor which does not wholly resemble any other.”
The way our brains interpret flavors speaks to the human love of patterns. Professor Shepherd and colleagues have done experiments using fMRI and other brain-scanning technologies to show that different flavors register as different patterns in the brain. It is startling to see scans of these flavor maps and realize that there is a separate place in our brains for bananas and cheddar cheese, or that strawberries and sugar show up as dots in similar locations. The way our brains map flavor is similar to the way we perceive visual images. When we “see” something, what we are actually doing is creating an abstract 2D representation of it, with some features enhanced and others suppressed. By the same token, when we put food in our mouths, the flavor molecules that drift to our noses are turned into abstract patterns in the brain. These patterns help us to recognize the food when we taste it again. Our olfactory receptors give different patterns to the sweet and the savory, the rotten and the fresh. The receptors also modify the patterns depending on what is happening in the rest of the body: whether we are happy or depressed or nauseous.
Through these patterns, our brains make sense of the bewildering world of flavor. Take umami, the so-called fifth taste, which corresponds to the savory qualities in meat, cheese, and certain vegetables, such as tomatoes or broccoli. Umami is what gives mushrooms their oomph and the reason it’s so hard to stop pouring gravy on your potatoes. We all have neurons that are specifically tuned to umami. Yet, by itself, umami—which is made in artificial form as MSG—doesn’t really taste of much. It
is only in conjunction with other flavors that it becomes delicious. We can see this from neuroimaging studies. When glutamates are tasted in conjunction with a savory vegetable flavor, they generate far more brain activity than when the two flavors are tasted separately. The whole is more than the sum of its parts. This makes sense. Our brains are smart enough to see that a dish of Asian greens with soy sauce warrants a more sizable flavor image than the same greens and soy sauce eaten separately.
What is most significant about our flavor images is the way they lead to what scientists call “images of desire.” Once we have a memory in our heads of a flavor we love, we build up “images of desire” as we seek to acquire it again. In 2004, researchers put subjects on a bland diet and asked them to imagine their favorite foods. Just thinking about these beloved dishes created a response signal in the hippocampus, insula, and caudate—the same areas of the brain that are activated during drug craving. Canadian researchers found that people who described themselves as “chocolate cravers” showed different brain activity when eating chocolate than self-diagnosed non-cravers. The cravers’ brains continued to respond favorably to pictures of chocolate long after their bodies had reached a point of fullness. Neuroscience confirms that chocolate means more to some people than to others.
To anticipate pleasure in the next meal—something that can take up the greater part of the day, in my experience—is always a form of memory. And each mouthful recalls other mouthfuls you’ve eaten in the past. It stands to reason, therefore, that the flavor patterns in our brains are highly dependent on all the things we’ve tasted in the past, especially during childhood. Among North Africans who settled in France, fresh mint tea, often served in ornate teapots, is a way of life. Children grow up with that familiar herbal steam rising from the table as adults sit and talk. A particularly refreshing mint tea is served in the courtyard of the Great Mosque of Paris, a tranquil place to retreat on sweltering days in the city.
For French Algerians, mint tea is imprinted on the mind in a way that doesn’t hold true for the non-African French population. In 2009, a group of subjects, half of them “Algerian French” and half of them “European French,” were asked to smell mint and say what they thought of
it. All of them—French or Algerian—found it pleasant, and all of them correctly identified it as mint. But when gold electrodes were attached to the scalp, the Algerians showed a significantly greater level of neural activity in response to the mint than the Europeans. Because of the mint tea they drank at home, the smell induced a different cortical pattern in the brain. Put simply, mint was a flavor that resonated more with Algerians than with non-Algerians. This was an image their brains had already recognized many times before. If mint were a sound instead of a taste, you could say that the French heard the notes, but only the Algerians appreciated the music of it. Because their memories of it were more expansive, mint actually took up more of their brain.
When we are unable to obtain the flavors we remember from
childhood, it can give rise to longings so intense it is hard to think of anything else. The anosmia sufferers we met at the start of the chapter, such as Marlena Spieler, would confirm this: she hankers for the flavors that would make her feel “like Marlena” again.
Some of the most poignant examples of this flavor-yearning are the food obsessions of prisoners of war. When Primo Levi was imprisoned in a work camp near Auschwitz called Buna, he remembered that fellow prisoners not only groaned in their sleep, but licked their lips: “They are dreaming of eating; this is also a collective dream.
. . .
[Y]ou not only see the food, you feel it in your hands, distinct and concrete, you are aware of its rich and striking smell.”
Among memoirs by World War II prisoners of war, a common theme is not just hunger, but the fevered memories to which it gave rise, consisting of all the things the POWs would eat again once they were free. Very seldom did they build these dreams about the grown-up foods of sophisticated restaurants; it was the food of childhood and of home that came to mind: stodgy, filling, and safe. One British ex-POW remembered dreaming two nights in a row about “omelettes and treacle pudding.” He also remembered his bitter disappointment on waking up, since “either was as obtainable as a slice of the moon.”
Food obsession reached a particularly feverish pitch among European, American, and Australian POWs in the Far East, where the mismatch between their rations of rice and the food they longed for was enough to make them slightly unhinged. Food historian Sue Shephard writes that most of the men in the Japanese camps “regressed to a childish state.” They all hallucinated about sugar: for the British it might be chocolate éclairs, suet puddings, and steaming bowls of buttercup-yellow custard; for the Americans, Hershey bars, mother’s apple pie, and every kind of layer cake, from devil’s food to coconut. Some men refused to join in the collective discussions of food because it was too painful to be reminded of how far they were from home, but for most of them, the crazy food talk became a survival mechanism to get through the endless days of boredom and brutality. One long-term POW recalled that after the first year and a half or so, the food talk had completely supplanted daydreams about women.
Some men went so far as to write down elaborate menus and even recipes on scraps of paper. Filmmaker Jan Thompson, who spent twenty years interviewing former American POWs for her 2012 documentary
Never the Same
, found that a common theme was writing down Thanksgiving menus, reconstructed from “memories of childhood gatherings.” All memory is a distortion, and in their half-starved state, these men constructed holiday menus more lavish than any of them can have actually enjoyed as a child. In Japan, Mess Sergeant Morris Lewis felt oppressed by the responsibility of looking after his soldiers as well as himself. Sergeant Lewis kept himself “sane” by writing down an extraordinary Thanksgiving dinner menu that included Virginia Baked Ham, fried rabbit, cranberry sauce, Snowflake Potatoes, candied sweet potatoes, buttered sweet corn, buttered asparagus tip, and green stuffed olives. Then, “Assorted Cookies,” “Assorted Nuts,” “Assorted Candies,” “Assorted Ice Cream”; also “Ass. Jams” and “Fresh Ass. Fruit & Grapes.”
This word “assorted” is heartrending, coming from a man whose diet had been reduced to abject monotony. Prison can famously expand the imagination. After all this time without cookies, nuts, candies, or ice cream in any form, Sergeant Lewis was planning a meal where all of these treats were freely offered in multiple varieties. He had returned to that old childhood pipedream of being given free rein in a candy store.
POW yearnings for childhood foods were like an exaggerated version of the food nostalgia we all feel. The thing you are seeking to recover is not just the flavor in itself, but all the things that went with it: your family sitting round the table, the feeling of being cared for, the freedom from responsibility. This is why it’s possible to long for bad food, too, just because of the happy connotations it may have. Not everyone grows up with a mother who turns out perfect apple pies. POW Russell Braddon, a “cheeky young Australian gunner” who spent three years in Japanese camps, was thrilled to get a card from his sister. It arrived sixteen months after she first posted it, and it had to be short because the limit was twenty-five words:
Dear Russ, Mum’s puddings are still as lumpy as ever. Oodles of love from us all. Pat.
Braddon later said that this letter told him “all I wanted to know”: that his family did not accept he was dead, and that “the old household jokes about my mother’s rather abandoned cooking still flourished.”
The childhood foods that we ache for are very specific to
the place and the time where we grew up. The American POWs did not dream of “sweetness” in the abstract but of candied sweet potatoes and pie. Psychologist E. P. Köster is a Dutch psychologist, a professor emeritus at the University of Utrecht, who works on the knotty question of why we choose some foods and not others. Köster is particularly preoccupied by the role of memory in shaping our gastronomic desires. His work spans the cutting edge of both psychological thought and consumer science. In 2009, he lamented the fact that among many consumer scientists, there was such “lack of understanding of the ‘fundamental insights from psychology.’” Köster regrets that consumer research tends to be founded on the assumption that our food choices are rational and conscious, when most of the time, they are anything but.
He traces his own strong preference for dark Bourneville chocolate made by Cadbury’s—which, during the war, was the main brand of dark chocolate in Britain—to his memories of being thirteen years old in 1944,
when the German-occupied Netherlands was suffering from extensive starvation. One day Köster was out riding his bicycle when a British RAF plane circled overhead. He saw one of the pilots throw a pack containing three bars of Bourneville from the cockpit. He quickly grabbed them before anyone could stop him. “On the way back,” he said, “I slowly sucked morsels of one bar. It was heaven. The other two bars I shared with my brother and we ate them for days, a little each day. For the rest of my life I have longed for the taste of that chocolate and whenever I came to Britain the first thing I did was to buy a bar of it. I admit that there may be finer chocolates than Cadbury’s, but for me there is no chocolate more delicious.”
Childhood food memories, like family jokes, are often untranslatable to outsiders. If I gave you a small dinner plate containing three mounds, one of cottage cheese, one of chopped apple, and one of raisins, you might think me a little odd. You might wrongly suspect me of trying to put you on some kind of low-carb or gluten-free diet. But if I served this to my sister, she would understand at once that I was giving her a nice bedtime snack, just like the ones my mother made for us when we crept downstairs in our pajamas because we couldn’t get to sleep.
The importance of shared childhood food memories for bonding families together can be seen among expats who carry their “homeland” with them in the form of ingredients smuggled in suitcases. In Greece, they sometimes refer to this desire for the food of home as a “burning of the lips.” When Greeks move abroad, their mothers will often send care packages of food containing such treats as “oregano, thyme, mountain tea, locally produced honey, figs, almonds, hard cheese and dried dark bread rings.” At college, I had a Greek friend named Athena, like the goddess, who received the most wonderful parcels from her mother, with slabs of sweet halva and vast bags of the freshest, crunchiest pistachios. She laid them out in exotic pottery dishes. Somehow Athena’s student room always felt different from the rest of ours, though underneath, it was the same scruffy bedsit. Surrounded by her foods from home, she had the air of someone who was never alone.