Photo: Oivind Hovland/Getty Images/Ikon Images

The “classical view” of emotion — a bundle of ideas dating back to the ancient Greeks — says that emotions are best described as something that happen to you. In this line of thinking, emotions are the antagonist of cool, calculated intellect; each emotion has a particular “center” in your brain and “expression” on your face.

Lisa Feldman Barrett, director of Northeastern University’s Interdisciplinary Affective Science Laboratory, has a bone to pick with this classical view, which in her new book she calls a “two thousand year old assumption.” Based on decades of her and others’ research, How Emotions Are Made: The Secret Life of the Brain, out Tuesday, is a thorough, thoughtful skewering of the classical view, something she seeks to supplant with a “constructive view,” which contends that emotions are a sort of memory-based reasoning. “Emotions are not your reactions to your world,” she tells Science of Us. “They are how you make sense of what’s going on inside your body in relation to the world.”

In the below interview, lightly edited for length and clarity, Barrett expands on how that mental construction takes place, and how that shapes everything from the treatment of cancer to how kids learn how to regulate their feelings to why time slows down when you travel.

A central claim in the book is that emotions are constructed, rather than being something that happen to you. How does that work?

From your brain’s perspective, any given sight or sound or ache can have multiple causes. Your brain is trying to figure out what the causes of the sensations are so it understands what to do about them. But the problem is, the information that it’s getting from the world and from your body is partially incomplete. It’s kind of ambiguous. Any given flash of light or sound or ache can have many different causes. So how does your brain figure out what the cause was and what to do about it? Well, it has one other source of information at its disposal, which is its past experiences.

Lisa Feldman Barrett. Photo: Mark Karlsberg / Studio Eleven/Studio Eleven

It can actually take past memories and combine them, bits and pieces of past experience and combine them. And it’s doing this in a predictive way. So, really, the way that your brain is working is, it’s taking past experience and it’s anticipating what the next moment will be like. What you see and hear and taste and so on are simulations that function as predictions, which are then confirmed or modified by sensory input from the world and from the body.

That’s kind of science-fiction-y, to say that your experience of life is a simulation.

Well, it is in a sense! It’s really that your present experience is a simulation of your past, corrected by the world.

And that’s where your concept of ‘emotional granularity’ fits in: the more fine-grained your emotional concepts are, the more precise emotions you have.

Because you have more granular experience your brain is equipped to construct more concise emotions in the moment. Right? So if you have a very fine-grained conceptual system for emotion, you know a lot about emotion, then your brain is able to construct very precise prediction in a way that’s tailored very specifically to your situation. So you’re not using stereotypes; you’re using these very fine-grained, honed, situated predictions.

I recognize I might be asking you to speculate here, but to me that seems like it explains why novel experiences cause the experience of time to slow down. Like, I travel a fair amount. So when I go to Ethiopia or to Japan, a week there feels like a month in New York.

It is speculation only in the sense that I think we don’t really completely understand all of the mechanistic processes by which this happens. There’s definitely something happening with time perception that’s very fluid. And I think it definitely is related to the amount of energy that is expended in encoding. I think the more detail that you’re encoding, the more you’re paying attention [to your surroundings], but attention from a neuron standpoint is just, some neuron is modulating the firing of another neuron. Paying attention means you have a network in your brain which controls how much prediction error you’re encoding, basically. That’s what learning is. It’s the encoding of prediction error.

The constructive view seems germane to attachment theory, the idea that people learn relationship dynamics as infants and kids and replicate those relationship styles in their adult relationships. This seems like such a strong example of this — of emotion as a learned way of interpreting a signal.

Absolutely. I mean, if you think about a little infant brain, infant brains are not structured — they’re not like miniature adult brains. An infant brain is born without the benefit of all the networks that are present in an adult brain. So you can think about a little infant brain as a set of neurons awaiting instructions on how to wire itself. And early experience really wires the brain. A brain is programmed, in a sense, to wire itself to the physical and social realities of the environment that it inhabits. It’s by virtue of these experiences that the brain acquires the knowledge that it needs to predict and therefore construct its perceptions in the future and its experiences in the future.

One important realization, I think, is that your brain, in wiring itself, its job isn’t primarily to create thoughts and feelings and perceptions for you. Your brain’s job, really, if it can be said to have a job, is to regulate your body. It’s to keep all of the systems in your body in balance. The analogy I like to use is, just as a large company has a financial office that regulates the revenues and expenditures so it develops budgets for different accounts — your brain basically acts like the financial office of your body. It manages a budget for all the accounts in your body. For glucose, salt, water, temperature, all of these things.

[But] an infant can’t regulate its own nervous system. It requires caregivers to do that. The earliest experiences that a brain receives for wiring itself come from the interactions with the caregiver, who is regulating the baby’s body budget. This is how an infant learns how to do it themselves, and part of that learning involves not just the actions that a caregiver will take, but also the words that are spoken and the sensations that derive from those words and those actions.

The constructive view is a way of understanding how early experiences get under the skin, get embedded, and essentially become embodied in the brain’s wiring to set the brain on a particular developmental trajectory that eventually becomes the adult brain.

You say that depression is this “body budgeting” gone awry.

Many illnesses are body budgeting gone awry. But in depression’s case, what usually happens is you’ve overspent. So either you’ve spent too much of your resources or you haven’t replenished them. Maybe you’re not sleeping adequately. Maybe you’re not eating properly. Maybe you’re not exercising well. Maybe you’re under constant stress, meaning that your brain believes that you need more glucose than you actually do. So it’s flushing your system with cortisol so you can get glucose into your system as fast as possible. But you don’t really do anything with it. So it’s kind of like impulse buying. Your brain is predicting that you need this glucose. But then it’s predicting a threat, so it’s predicting that you need to run, but then you don’t. You just sit there like you’re in a meeting and you’re being criticized by someone or you feel threatened by someone. You’re flushed with cortisol, you’re flushed with glucose, but you’re not using the glucose. So you’ve squandered your resources, essentially.

If this kind of thing goes on for long enough, where you’re spending extravagantly and you’re not replenishing, you’re gonna go into debt, just like you would with money. But when you go into debt, biologically into debt, then your immune system starts to get involved because your brain thinks that your body is sick. Once your immune system kicks in and believes that your body is sick when it isn’t really, then any number of diseases can manifest themselves.

Going off your point about the brain constructing experience out of signals from the world and the body — how does interoception, or your felt sense of your interior, inform that process? Does greater interoception produce some greater emotional granularity? Is this a lever in which we can become more, say, emotionally intelligent?

That is certainly a hypothesis that people have. I think there are multiple paths to increased emotional granularity. So I think the more distinctions that you make, the more opportunity you have to make finer-grained categories and concepts. So I don’t think that interoceptive sensitivity increasing on its own, independent of anything else, is sufficient for producing increasing granularity. But I think it’s necessary. Meaning, the more variation you can detect, the more opportunity you have for making finer-grained categories and concepts. But I think without words, without an increase in vocabulary, I think it’s very hard to have an increase in the granularity in emotion concepts. So it’s not impossible, I just think it’s really tricky.

And you know, you can see this in everyday life. When people undergo treatment for cancer, for example, they have a huge variety of what we would call interoceptive sensations that they have no language for. And this is actually a huge problem in the treatment of cancer.

Wow, really?

In English, we have a fairly substantial vocabulary for emotion. But we don’t really have an equivalently elaborated vocabulary for physical sensations. And in medical circles, but particularly in circles where people are receiving treatment or they have a disease that increases the range of their physical sensations, they don’t have a language for it.

They can’t be communicated and also they don’t know how to make sense of them. So they don’t know, is this my anxiety? Does this mean my treatment isn’t working? Does it mean my treatment is working? What do I know? It’s just not clear. It’s noise. But it’s scary noise because they’re uncertain and they don’t know what it means.

I’ve long been struck by neuroscientist Antonio Damasio’s contention that what we call wisdom results from having a more fine-grained sense of one’s embodied states. How does that fit in here?

I think your body definitely is a source of wisdom. It’s not because it carries around in it biological fingerprints of emotion that you learn to recognize, or that there’s some objective reality that you learn to recognize. Your body is a source of wisdom because it contains information that your brain can learn so that it can construct better. So it can construct your perceptions in a more functional way. It can tailor your actions in a way that’s more precise to the situation, as opposed to using a stereotype. So it lets you be more efficient and it lets you be more functional. I think that’s what wisdom is, really. It’s knowing what to do and how to do it.