How Emotions Are Made: The Secret Life of the Brain

by Lisa Feldman Barrett

When you are suffering from some ill or insult that has befallen you, ask yourself: Are you really in jeopardy here? Or is this so-called injury merely threatening the social reality of your self ? The answer will help you recategorize your pounding heartbeat, the knot in the pit of your stomach, and your sweaty brow as purely physical sensations, leaving your worry, anger, and dejection to dissolve like an antacid tablet in water.40

When you categorize something as “Not About Me,” it exits your affective niche and has less impact on your body budget. Similarly, when you are successful and feel proud, honored, or gratified, take a step back and remember that these pleasant emotions are entirely the result of social reality, reinforcing your fictional self.

You can experience similar awe when hearing ocean waves crash against rocks on a beach, gazing at the stars, walking under storm clouds in the middle of the day, hiking deep into uncharted territory, or taking part in spiritual ceremonies. People who report feeling awe more frequently also have the lowest levels of those nasty cytokines that cause inflammation (though nobody has proved cause and effect).44

Your emotions are guided by your predictions. And as I observe you, the emotions I perceive are guided by my predictions. Emotional communication happens, therefore, when you and I predict and categorize in synchrony.46

Now a vicious cycle can ensue. When you feel fatigued due to inflammation, you don’t move as much, in order to conserve (what your brain mistakenly believes to be) your limited energy resources. You start eating and sleeping poorly and neglect exercise, which throws your budget out of balance even more, and you start to feel seriously like crap. You might gain weight, which enhances your problems because certain fat cells actually produce the proinflammatory cytokines that make inflammation worse. You might also start avoiding other people, who then cannot help balance your body budget, and people with fewer social connections also have more proinflammatory cytokines and might even get sick more often.4

About ten years ago, scientists discovered—to their astonishment—that proinflammatory cytokines can cross from the body into the brain. We also now know that the brain has its own inflammatory system with cells that secrete these cytokines. These little proteins, with their capacity to induce feelings of such misery, reshape the brain. Inflammation in the brain causes changes in brain structure, particularly within your interoceptive network; it interferes with neural connections, and even kills neurons. Chronic inflammation can also make it harder for you to pay attention and remember things, lowering performance on IQ tests.5

A chronically imbalanced body budget acts like fertilizer for disease. In the last twenty years, it has become clear that the immune system is an ingredient in far more illnesses than you might expect, including diabetes, obesity, heart disease, depression, insomnia, reduced memory, and other “cognitive” functions related to premature aging and dementia. For example, if you already have cancer, inflammation makes tumors grow faster. The cancer cells also become more likely to survive the perilous journey through the bloodstream to infect other sites in the body, a process called metastasis.

As a result of these findings, researchers are moving away from a classical view of different illnesses with distinct essences. They instead focus on a set of common ingredients that leave people vulnerable to these various disorders, such as genetic factors, insomnia, and damage to the interoceptive network or key hubs in the brain (chapter 6). If these areas become damaged, the brain is in big trouble: depression, panic disorder, schizophrenia, autism, dyslexia, chronic pain, dementia, Parkinson’s disease, and attention deficit hyperactivity disorder are all associated with hub damage.10

But stress doesn’t come from the outside world. You construct it. Some stress is positive, like the challenge of learning a new subject in school. Some is negative but tolerable, like having a fight with your best friend. And some is toxic, like the chronic stress of prolonged poverty, abuse, or loneliness. In other words, stress is a population of diverse instances. It is a concept, just like “Happiness” or “Fear,” that you apply to construct experiences from an imbalanced body budget.11

Cumulative imbalance in the body budget—say, from growing up in adversity, where you don’t feel safe or are deprived of basic necessities like nutritious food, quiet time to sleep, and so on—also changes the structure of your interoceptive network, rewiring your brain and reducing its ability to accurately regulate your body budget. All it takes are a couple of highly negative experiences for children to feel like they are living in a combat zone, reducing the size of their body-budgeting regions by the time they reach adulthood. Growing up in a family that is harsh or chaotic, with a lot of conflict or verbal criticism, increases inflammation in adolescent girls and places kids on a trajectory toward chronic disease; it’s almost as bad for the development of these networks as childhood abuse or neglect. Ditto for suffering as the target of a bully. Kids who were bullied as children show low-grade inflammation that persists into adulthood, which predisposes them to a host of psychiatric and physical diseases. These are the myriad ways that an imbalanced body budget sculpts your brain, translating into a higher lifetime risk of heart disease, arthritis, diabetes, cancer, and other diseases.14

the highest levels of circulating cytokines were found in men who expressed a lot of affect that they didn’t label. Female breast cancer survivors who explicitly label and understand their emotions also have better health and fewer medical visits for cancer-related symptoms. This means that over time, people who effectively categorize their interoceptive sensations as emotion might be better protected against chronic inflammatory processes that lead to poor health.15

This process is called nociception. And in the past, scientists believed that your brain simply received and represented nociceptive sensations and, voilà, you experience pain.

Pain is an experience that occurs not only from physical damage but also when your brain predicts damage is imminent.

When you are expecting pain, like the moment just before an injection, your brain regions that process nociception change their activity. That is, you simulate pain and therefore feel it. This phenomenon is called the nocebo effect. You’re probably more familiar with its counterpart, the placebo effect, which relieves pain using a medically ineffective treatment like a sugar pill. If you believe you’ll feel less pain, your beliefs influence your predictions and tune down your nociceptive input so you do feel less pain.

A few well-known examples are fibromyalgia, migraine headaches, and chronic back pain. Over 1.5 billion people suffer from chronic pain, including 100 million in the United States who collectively pay $500 billion per year for treatment. When you include lost productivity in the price tag, pain costs the United States $635 billion each year. It is also frustratingly hard to treat, as the currently prescribed pain medications, analgesics, are ineffective more than half the time. This worldwide epidemic of chronic pain is one of today’s great medical mysteries.21

Scientists now consider chronic pain to be a brain disease with its roots in inflammation. It’s possible that the brain of a chronic pain sufferer received intense nociceptive input sometime in the past, and as the injury healed, the brain didn’t get the memo. It keeps predicting and categorizing anyway, generating chronic pain.

There is something wrong with you. Your predictive brain, which is indeed located “in your head,” is generating authentic pain that continues past the point when your body has already healed.

In general terms, that’s what I think is happening in depression. Your brain is continually mispredicting your metabolic needs. Your body and brain therefore act as if you were fighting off an infection or healing from a wound when none exists, as in

chronic stress or pain. As a result, your affect is out of whack: you experience debilitating misery, fatigue, or other symptoms of depression. Simultaneously, your body is quickly metabolizing unnecessary glucose to meet those high yet nonexistent energy needs, leading to weight problems and leaving you at risk for other metabolic-related illnesses that co-occur with depression, including diabetes, heart disease, and cancer.31

The traditional view of depression is that negative thoughts cause negative feelings. I’m suggesting it’s the other way around. Your feelings right now drive your next thought, as well as your perceptions, as predictions. So a depressed brain relentlessly keeps making withdrawals from the budget, basing its predictions on similar withdrawals from the past. This means constantly reliving difficult, unpleasant events. You wind up in a cycle of budgeting imbalances, unbroken by prediction error because it is ignored, gets tuned down, or doesn’t make it ...

It puts your budget chronically in debt, so your brain tries to cut spending. What’s the most efficient way to do that? Stop moving and don’t pay attention to the world (prediction error). That is the unrelenting fatigue of depression.32

I speculate that an anxious brain, in a sense, is the opposite of a depressed brain. In depression, prediction is dialed way up and prediction error way down, so you’re locked into the past. In anxiety, the metaphorical dial is stuck on allowing too much prediction error from the world, and too many predictions are unsuccessful. With insufficient prediction, you don’t know what’s coming around the next corner, and life contains a lot of corners. That’s classic anxiety.37

When my subjects were feeling unpleasant, I handed them rating scales to report their feeling, but only in terms of anxiety and depression. People will use whatever measure you give them to describe how they feel. If someone feels crappy and you give her only an anxiety scale, she’ll report her feelings using words for anxiety. She might even come to feel anxious as the words prime her to simulate an instance of “Anxiety.” Alternatively if you hand her a depression scale, she’ll report her feeling using words for depression and might likewise end up feeling depressed.

In people, eating sugar triggers the brain’s opioids to increase production. So eating junk food or white bread actually feels good. No wonder I love a crusty French loaf. And sugar may actually act as a mild analgesic. So, when people talk about our society being addicted to sugar, they might not be far off. I wouldn’t be surprised if people are employing high-carbohydrate food as a drug to manage their affect and feel better. Hello, obesity epidemic.47

If you sit in a chair with your legs bent, toes not touching the floor, and tap your knee just below your kneecap, the bottom half of your leg gives a little kick. Hold your hand to a flame and your arm recoils. Present a puff of air to your cornea and you blink. Each of these examples is a reflex: sensation leading directly to motion. Reflexes in your peripheral nervous system have sensory neurons wired directly to motor neurons. We call the resulting actions “involuntary” because there is one, and only one, specific behavior for a specific sensory stimulation due to the direct wiring.11

A human brain’s sensory and motor neurons, however, communicate through intermediaries, called association neurons, and they endow your nervous system with a remarkable ability: decision-making. When an association neuron receives a signal from a sensory neuron, it has not one possible action but two.

It can stimulate or inhibit a motor neuron. Therefore, the same sensory input can yield different outcomes on different occasions.

Here’s where the law is out of sync with science, thanks to the classical view of human nature. The law defines deliberate choice—free will—as whether you feel in control of your thoughts and actions. It fails to distinguish between your ability to choose—the workings of your control network—and your subjective experience of choice. The two are not the same in the brain.14

They are not even your reactions to the world. They are your constructions of the world.

Contracting a muscle is a movement. Freezing is a behavior because it involves multiple, coordinated muscle movements. The feeling of fear is an experience that may or may not occur together with behaviors like freezing. Circuitry that controls freezing is not circuitry for fear. This egregious scientific misunderstanding, along with the phrase “fear learning,” has sown confusion for decades and turned what’s effectively an experiment on classical conditioning into an industry of fear.46

It’s one thing to observe that a rodent’s anterior cingulate cortex increases its activity when a neighbor is in pain. It’s quite another to say the rodent is feeling empathy. A simpler explanation is that the two animals are just influencing each other’s body budgets, as so many creatures do.50

Our challenge is to understand animal minds for their own sake, not as inferior human minds. The latter idea comes from the classical view of human nature, which implies that chimps and other primates are less evolved, diminished versions of ourselves. They’re not. They’re adapted to the ecological niche that they live in. Chimps have to forage for food and modern humans largely do not, so a chimp brain is wired to identify and remember details, not to build mental similarities.53

The neurons within every cortex are wired to compress information into efficient summaries, creating a conceptual system that shapes action and experience. Many of these features are present in other mammals, and some truly ancient aspects of your nervous system are even shared with insects.

Complexity is a metric to describe any structure that efficiently creates and transmits information. A system with high complexity can create many new patterns by combining bits and pieces of old patterns. You can find complex systems in neuroscience, physics, mathematics, economics, and other scholarly disciplines.6

The ingredients are three aspects of the mind that we’ve encountered in this book: affective realism, concepts, and social reality. They (and perhaps others) are inevitable and therefore universal, barring illness, based on the anatomy and function of the brain.

Affective realism, the phenomenon that you experience what you believe, is inevitable because of your wiring. The body-budgeting regions in your interoceptive network—your inner loudmouthed, mostly deaf scientist with a megaphone—are the most powerful predictors in your brain, and your primary sensory regions are eager listeners. Body-budget predictions laden with affect, not logic and reason, are the main drivers of your experience and behavior. We all think a food “is delicious” as if the flavor were embedded in the food, when flavor is a construction and the deliciousness is our own affect. When a soldier in a warzone perceives a gun in someone’s hands when no gun is present, he might actually see that gun; it’s not a mistake but a genuine perception. Judges who are hungry during parole hearings render more negative decisions.

The second inevitability of the mind is that you have concepts, because the human brain is wired to construct a conceptual system. You build concepts for the smallest physical details, like fleeting bits of light and sound, and for incredibly complex ideas like “Impressionism” and “Things Not to Bring on Airplane Rides.” (The latter includes loaded guns, herds of elephants, and your boring Aunt Edna.) Your brain’s concepts are a model of the world that keeps you alive, serves to meet your body’s energy needs, and ultimately determines how well you propagate your genes.

We are performing a synchronized dance of prediction and action, regulating each other’s body budgets. This same synchrony is the basis of social connection and empathy; it makes people trust and like each other, and it’s crucial for parent-infant bonding.15

Your personal experience, therefore, is actively constructed by your actions. You tweak the world, and the world tweaks you back. You are, in a very real sense, an architect of your environment as well as your experience. Your movements, and other people’s movements in turn, influence your own incoming sensory input. These incoming sensations, like any experience, can rewire your brain. So you’re not only an architect of your experience, you’re also an electrician.

Firestein opens Ignorance with an old proverb, “It is very difficult to find a black cat in a dark room, especially when there is no cat.”

Social reality is the human superpower; we’re the only animal that can communicate purely mental concepts among ourselves. No particular social reality is inevitable, just one that works for the group (and is constrained by physical reality).

Ironically, each of us has a brain that creates a mind that misunderstands itself.

In this cyclic manner, society’s stereotypes about race, which are social reality, can become the physical reality of brain wiring, thereby making it seem as if the cause of poverty were simply genes all along.18