The Brain: The Story of You

by David Eagleman

Really, this is how love often goes. You find yourself more attracted to some people over others, and it’s generally not possible to put your finger on precisely why. Presumably there is a why; you just don’t have access to it.

Most of the time you are not aware of the decisions being made on your behalf.

We mostly walk around in our own mental worlds, passing strangers in the street without registering any details about them. But when something challenges our unconscious expectations, conscious attention comes online to try to build a rapid model of what’s happening.

A CEO is a company’s most abstract view of itself.

transcranial magnetic stimulation

This titanic complexity leaves us with just enough insight to understand a simple fact: our lives are steered by forces far beyond our capacity for awareness or control.

Your brain is like a neural parliament, composed of rival political parties which fight it out to steer the ship of state. Sometimes you decide selfishly, sometimes generously, sometimes impulsively, and sometimes with the long-view in mind. We are complex creatures because we are composed of many drives, all of which want to be in control.

One pundit suggested that the button to launch nuclear missiles should be implanted in the chest of the President’s best friend. That way, if he chose to launch nukes, he’d have to inflict physical violence on his friend, tearing him open.

The ancient Greeks suggested that we should think of our lives like chariots. We are charioteers trying to hold two horses: the white horse of reason and the black horse of passion. Each horse pulls off-center, in opposite directions. Your job is to keep control of both horses, navigating down the middle of the road.

Montague finds that the more disgusted a participant is by the images, the more politically conservative they are likely to be. The less disgusted, the more liberal.

Political persuasion emerges at the intersection of the mental and the corporal.

The dopamine acts as an error corrector: a chemical appraiser that always works to make your appraisals as updated as they can be. That way, you can prioritize your decisions based on your optimized guesses about the future.

Dopamine-releasing neurons involved in decision making are concentrated into tiny regions of the brain called the ventral tegmental area and the substantia nigra. Despite their small sizes, they have a wide reach, broadcasting updates when the predicted value of a choice turns out to be too high or too low.

The Sirens were famous for singing songs so melodious that sailors were rapt and enchanted. The problem was that the sailors found the women irresistible, and would crash their ships into the rocks trying to get to them.

By lashing ourselves to the mast we can get around the seduction of the now.

Some psychologists describe this effect as “ego-depletion,” meaning that higher-level cognitive areas involved in executive function and planning (for example, the prefrontal cortex) get fatigued.

Why do movies make us weep, laugh, gasp? To understand why you care about the actors, let’s begin with what happens in your brain when you are in pain. Imagine that someone stabs your hand with a syringe needle. There’s no single place in the brain where that pain is processed. Instead, the event activates several different areas of the brain, all operating in concert. This network is summarized as the pain matrix. Here’s the surprising part: the pain matrix is crucial to how we connect with others. If you watch somebody else get stabbed, most of your pain matrix becomes activated. Not those areas that tell you you’ve actually been touched, but instead those parts involved in the emotional experience of pain. In other words, watching someone else in pain and being in pain use the same neural machinery. This is the basis of empathy.

Susan Smith, a mother in South Carolina who in 1994 kindled the empathy of a nation when she reported to the police that she had been carjacked by a man who drove away with her sons still in the car. For nine days, she pled on national television for the rescue and return of her boys. Strangers around the nation offered help and support. Eventually, Susan Smith confessed to the murder of her own children. Everyone had fallen for her story of the carjacking, because her real act was so outside the realm of normal predictions.

The year 1915 saw the systematic killing of over a million Armenians by the Ottoman Turks. In the Nanking massacre of 1937, the Japanese invaded China and killed hundreds of thousands of unarmed civilians. In 1994, in a period of one hundred days, the Hutus in Rwanda killed 800,000 Tutsis, largely with machetes.

What allows a diminished emotional reaction to harming another person? The neurosurgeon Itzhak Fried points out that when you look across violent events all over the world, you find the same character of behavior everywhere. It’s as though people shift from their normal brain function to act in a specific way. In the same way a physician can look for coughing and fever with pneumonia, he suggested that one can look for and identify particular behaviors that characterize perpetrators in violent situations – and he named this “Syndrome E”. In Fried’s framework, Syndrome E is characterized by a diminished emotional reactivity, which allows repetitive acts of violence. It also includes hyperarousal, or as the Germans call it, Rausch – a feeling of elation in doing these acts. There’s group contagion: everybody’s doing it, and it catches on and spreads. There’s compartmentalization, in which somebody can care about his own family, and yet perform violence on someone else’s family.

the result is not fundamentally about religion – it’s about which team you’re on.

The brilliance of the blue eyes/brown eyes exercise was that Jane Elliott switched which group was on top. That allowed the children to extract a larger lesson: systems of rules can be arbitrary. The children learned that the truths of the world aren’t fixed, and moreover they’re not necessarily truths.

“Moore’s Law” forecast that as transistors became smaller and more precise, the number that could fit onto a computer chip would double every two years, exponentially increasing computing power over time.

Human Brain Project is an ambitious research mission that collects data from neuroscience laboratories across the globe – this includes data on individual cells (their contents and structure) to connectome data to information about large-scale activity patterns in groups of neurons.

The goal of the Human Brain Project is to achieve a simulation of a brain that uses detailed neurons, realistic in their structure and their behavior.

Consider the possibility this way: what if there is nothing special about biological neurons themselves, and instead it’s only how they communicate that makes a person who they are? That prospect is known as the computational hypothesis of the brain. The idea is that the neurons and synapses and other biological matter aren’t the critical ingredients: it’s the computations they happen to be implementing. It may be that what the brain physically is doesn’t matter, but instead what it does.

“Instead of trying to produce a program to simulate the adult mind, why not rather try to produce one which simulates the child’s?” – Alan Turing, 1950. There are twenty-nine identical iCubs in research labs all over the globe, each one part of a common platform that can merge their learning.

Searle argued this is just what is happening inside a computer. No matter how intelligent a program like iCub seems to be, it’s only following sets of instructions to spit out answers – manipulating symbols without ever really understanding what it’s doing.

To understand human consciousness, we may need to think not in terms of the pieces and parts of the brain, but instead in terms of how these components interact. If we want to see how simple parts can give rise to something bigger than themselves, look no farther than the nearest anthill. With millions of members in a colony, leaf-cutter ants cultivate their own food. Just like humans, they’re farmers. Some of the ants set forth from the nest to find fresh vegetation; when they find it, they chew off large pieces that they hump back to the nest. However, the ants don’t eat these leaves. Instead, smaller worker ants take the pieces of leaves, chew them into smaller pieces, and use these as fertilizer to grow fungus in large underground “gardens”. The ants feed the fungus, and the fungus blossoms into small fruiting bodies which the ants later eat. (The relationship has become so symbiotic that the fungus can no longer reproduce on its own; it relies entirely on the ants for its propagation.) Using this successful farming strategy, the ants build enormous nests underground, something spanning hundreds of square meters. Just like humans, they have perfected an agricultural civilization.

This phenomenon, known as “emergence”, is what happens when simple units interact in the right ways and something larger arises.

In his framework, Tononi suggests that a conscious system requires a perfect balance of enough complexity to represent very different states (this is called differentiation) and enough connectivity to have distant parts of the network be in tight communication with one another (called integration).

Uploading may not be all that different from what happens to you each night when you go to sleep: you experience a little death of your consciousness, and the person who wakes up on your pillow the next morning inherits all your memories, and believes him or herself to be you.

“Once upon a time, I, Chuang Tzu, dreamt I was a butterfly, fluttering hither and thither, to all intents and purposes a butterfly. I was conscious only of following my fancies as a butterfly, and was unconscious of my individuality as a man. Suddenly, I awoke, and there I lay, myself again. Now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly dreaming that I am a man.”