Barrett on the Human Brain

In the past, I have written here about the theory of psychology. One weak point about it is that it’s a lot of, well, theory. However, what if there was an underlying physical reality to it, i.e. to how our brains develop and work? I recently read two books by Lisa Feldman Barrett. I think she provides this much-needed connection.

I would like to divide this post into three broad themes I found in Barrett’s writings. Her more recent, shorter and accessible book is Seven and a Half Lessons About the Brain. It piqued my interest sufficiently to read her older but more expansive book on the topic: How Emotions Are Made. Barrett is a researcher in neuroscience and a professor of psychology at Northeastern University.

Theme 1: Brain is not for Thinking

Well, that should catch anyone’s attention, doesn’t it? Barrett notes that brains evolved for organisms with complex organ systems, as a way to manage the complexity of such systems. The main job of the brain is to assign a body budget and manage the budget, known as “allostasis”. We add to our body budget when we nourish, sleep, or are in a caring environment. We are depleted when we are hungry, thirsty, tired, ill, or stressed out.

What we call our “mood” is our brain’s summary of the current state of the body budget. The brain does not have an elaborate way of communicating the state of the body, so it instead gives an admittedly crude summary. Most animals are better at being aware of this and taking corrective actions; however, humans in the 21st century have to re-learn this skill. I have seen my grandparents being aware of their body on a day-to-day and even hour-to-hour basis. They would notice any unease and adjust their food, sleep or work based on it.

Redefining brain’s role is a welcome U-turn from the traditional Western canon: the Cartesian “I think therefore I am”. It restores the primacy of the body and re-embodies our existence. This is closer to Eastern holistic medicine, such as the Ayurveda in India. It’s time we started taking care of our bodies, and not seeing them as vessels to hold our brain.

Theme 2: Brains Wire Themselves to Their World

This statement packs a punch and needs some unpacking.

The first important bit here is that human brains come to the world unfinished. Then, as they grow up in their specific family and culture, the brain adapts its connections to survive and thrive in that specific world. Barrett notes a physical basis to it; she calls it “tuning and pruning” of actual neural connections in the brain as a child grows.

Is there a biological advantage to an unfinished infant brain and prolonged childhood? Yes. It provides for an additional dimension of evolution: it allows for imbibing of culture. Genetic evolution takes time, dependent as it is on mutations. Culture is faster as a protective layer. Consider our traditional cultural elements: the rituals, unwritten rules and behavior, etc. They are there to protect the child and the community, provided the original context in which they were developed has persisted.

A drawback, however, is that a brain that is so well adapted to its niche may struggle when taken to a different world: perhaps a different culture, or in the later decades of its existence when there are a lot of accumulated changes. (The same problem afflicts computers as well. In machine learning, the analogous situations are called over-fitting and model drift respectively. More on this in a bit.)

A second, perhaps more severe, drawback is that this creates many different realities. If you bring people who grew up immersed in two different cultures together, they may not experience the world the same way. This can cause misunderstanding, hatred, bigotry, and war. If done consciously, it may also help us coexist and understand each other. When I was growing up, India had an allowance for travel within the country to promote national unity. Today, we need a similar program for international travel; however, what we have in reality are restrictions and encumbrances in the name of passports and visas.

The next important bit here is the importance of the world to the brain. We are influenced by people around us, and some of these people may not even exist today. They may be talking to us from a book written hundreds of years ago. It is very important to be aware of this so that we can select for good influences for our brain; and also so that we can be a good influence to the people around us.

Clearly, we have a neurological basis for why our current algorithm-driven filter-bubble worlds are not good for our minds or our society.

Theme 3: Brain is a Prediction Machine

Human brain predicts all the time, and bases those predictions on what it has sensed before. To predict, it assigns categories to what it senses, and then picks the category with the highest probability. All this, of course, happens very fast and often automatically.

This is probably the most insightful theme in the book and has massive implications.

First, this means our brain will misfire when it is experiencing something new. I mentioned earlier the situation of an immigrant or an older person. Both such people can be stressed because their brain cannot make sense of the world they are currently in. In the case of an immigrant, it may improve over time, but changes tend to be accumulative and predictions become harder as one ages. This is the quintessential problem of old age: of dealing with and adapting to change, i.e. mispredictions. Mispredictions may be the neurological basis for what we call “familiarity-seeking” in psychology.

Second, our brain’s predictions can only be as accurate as the number of categories it knows. If you train a computer to distinguish only between cats and dogs, and you then show it a cow, it will only try to predict in terms of cats and dogs. Barrett calls the categories “concepts”: the more concepts our brain knows, the better it can attempt to distinguish and predict. This is the neurological basis to knowledge: the hope is that knowledge gives you enough concepts to train your brain and classify your (future) experiences. Sadly, the education I received was hopeless when it came to psychology. I wish I’d learned in my teens some of the concepts I know today.

Barrett goes on to call emotions also as concepts: it helps to know a variety of emotions, perhaps going out into other cultures and languages. It also follows based on the previous theme that the same experience may bring different emotions to different people, depending on how the brain is wired. Guessing someone’s emotions is hard, especially if you don’t know the person well.

Third, this brings to the fore a distinction between our senses and our experience. Our senses only feed data to our brain; it is the brain that ultimately has the say on whether to consider that data or throw it away. In other words, our brain may be ignoring sensory input when making predictions. This is why optical illusions can be so confusing. At one point, Barrett draws a diagram, a continuum with “pure sensing” on one end and “pure prediction” on the other end. Meditation is pure sensing; day-dreaming is pure prediction. Meditation can be a ritual to reinstate sensing to our brains and give a break to its default predicting behavior.

Fourth, this tells us that we cannot be “here and now” all the time. That would be very expensive for the brain and unnecessary most of the time. It is a lofty ideal, an aspirational goal perhaps, but practically infeasible. If the underlying sensory data brings no new information because it is the same as past experiences, the brain has an advantage in conserving energy by using past predictions.

Fifth, this means we can trick our brain to distinguish against categories with no physical existence by creating abstract concepts. Barrett calls this “social reality”. A lot of activism is often about questioning or upending existing social reality. Or think of concepts like patriotism, purity, heaven. Social reality can bring us together but can also rip us apart. One has to be careful with them.


Barrett provides solid research evidence to psychological theory. I personally find her writing to be a CBT (Cognitive-Behavioral Therapy) of the highest order. She provides a scientific model on how the brain works and allows us to think about its ramifications. She lays out the strengths and weaknesses.

We live in a world that’s increasingly non-local. We move a lot, meet mostly strangers, and our relationships are mostly transactional. This is very different from the world we evolved in. One can harken back to old days, but it may be more progressive and enlightening to read Barrett to increase our self-awareness instead.

Lisa Feldman Barrett, Seven and a Half Lessons About the Brain, 2020

Lisa Feldman Barrett, How Emotions are Made: The Secret Life of the Brain, 2017

See also