Book Notes

I started reading this book and thought, very quickly, hey, I know this stuff already. This feels very familiar.

And a few pages into the book, I realized why when my first highlight appeared: I'd read this book before.

I don't recall when I'd read the book before, as it isn't in my notes for the last 4 years, but I had read it before. After debating for a bit on whether to reread it or put it down in favor of a new book, I figured I could give it a read, and read it quickly. Was not disappointed in myself.

The brain does a lot. We are oblivious to pretty much all of it. We can, however, be aware of some of that blindness, be aware of how we are going to react even when we expect and want to react differently, be aware of how small changes can improve our lives, and be gentle with ourselves when we are strange.

This book is seven years old. While we have more research, more theories, and more data about the brain, the fundamentals are the same, which makes this a great second read, too. I'd be interested in a follow up book with curation of the latest research.

Anyway, definitely worth reading, even recommended.

As far as anyone can tell, we’re the only system on the planet so complex that we’ve thrown ourselves headlong into the game of deciphering our own programming language. Imagine that your desktop computer began to control its own peripheral devices, removed its own cover, and pointed its webcam at its own circuitry. That’s us.
Page 2

Alterations to the brain change the kinds of thoughts we can think. In a state of deep sleep, there are no thoughts. When the brain transitions into dream sleep, there are unbidden, bizarre thoughts.
Page 3

The first thing we learn from studying our own circuitry is a simple lesson: most of what we do and think and feel is not under our conscious control.
Page 4

The men were consistently more attracted to the women with dilated eyes.
Page 4

This might explain a few things for me.

Instead, they simply felt more drawn toward some women than others, for reasons they couldn’t quite put a finger on.
Page 5

In the largely inaccessible workings of the brain, something knew that a woman’s dilated eyes correlates with sexual excitement and readiness.
Page 5

How is it possible to get angry at yourself: who, exactly, is mad at whom?
Page 19

It is interesting to consider that the majority of human beings live their whole lives unaware that they are only seeing a limited cone of vision at any moment.
Page 24

One of the most pervasive mistakes is to believe that our visual system gives a faithful representation of what is “out there” in the same way that a movie camera would.
Page 24

As Mariotte delved more deeply into this issue, he realized that there is a hole in our vision—what has come to be known as the “blind spot” in each eye. To demonstrate this to yourself, close your left eye and keep your right eye fixed on the plus sign. Slowly move the page closer
Page 32

My blind spot caused me all sorts of grief after I started having migraines at nine years old. I couldn't tell migraine spots from my blind spot and had to see a few doctors to figure out what the blindness was.

But more significantly, no one had noticed because the brain “fills in” the missing information from the blind spot.
Page 33

When the dot disappears, you do not perceive a hole of whiteness or blackness in its place; instead your brain invents a patch of the background pattern.
Page 33

Unless you're having a migraine with auras, then all bets are off.

He discovered that outfielders use an unconscious program that tells them not where to end up but simply how to keep running. They move in such a way that the parabolic path of the ball always progresses in a straight line from their point of view. If the ball’s path looks like its deviating from a straight line, they modify their running path.
Page 37


Your brain is in the dark but your mind constructs light.
Page 40

Consider the way you are reading the letters on this page. Your eyes flick effortlessly over the ornate shapes without any awareness that you are translating them: the meaning of the words simply comes to you. You perceive the language, not the low-level details of the graphemes.
Page 41

The second is that the people experiencing the hallucinations are discomfited by the knowledge that their visual scene is at least partially the counterfeit coinage of their brains.
Page 45

Though, if you grew up with migraines, you kinda learn early on not to trust absolutely what you see, and always take a second look.

In this way, the brain refines its model of the world by paying attention to its mistakes.
Page 49

It will come as no surprise to you that the mere exposure effect is part of the magic behind product branding, celebrity building, and political campaigning: with repeated exposure to a product or face, you come to prefer it more. The mere exposure effect is why people in the public spotlight are not always as disturbed as one might expect by negative press.
Page 65

Another real-world manifestation of implicit memory is known as the illusion-of-truth effect: you are more likely to believe that a statement is true if you have heard it before—whether or not it is actually true.
Page 65

F'ing brain.

Nothing is inherently tasty or repulsive—it depends on your needs. Deliciousness is simply an index of usefulness.
Page 76

Each organism has its own umwelt, which it presumably assumes to be the entire objective reality “out there.”
Page 77

Easy things are hard: most of what we take for granted is neurally complex.
Page 89

Researchers (as well as purveyors of pornography) have been able to discern a surprisingly narrow range for the female proportions that males find most attractive: the perfect ratio between the waist and hips usually resides between 0.67 and 0.8. The waist-to-hip ratios of Playboy centerfolds has remained at about 0.7 over time, even as their average weight has decreased. 22 Women with a ratio in this range are not only judged by males as more attractive, but are also presumed to be more healthy, humorous, and intelligent.
Page 91

When men ranked the beauty of women’s faces, they found the women with dilated eyes more attractive, because dilated eyes signal sexual interest.
Page 92

The Babylonian Talmud contains a passage in the same spirit: “In came wine, out went a secret.”

It later advises, “In three things is a man revealed: in his wine goblet, in his purse, and in his wrath.”
Page 103

Many people prefer a view of human nature that includes a true side and a false side—in other words, humans have a single genuine aim and the rest is decoration, evasion, or cover-up. That’s intuitive, but it’s incomplete.
Page 104

Your brain, as well, interprets your body’s actions and builds a story around them. Psychologists have found that if you hold a pencil between your teeth while you read something, you’ll think the material is funnier; that’s because the interpretation is influenced by the smile on your face. If you sit up straight instead of slouching, you’ll feel happier. The brain assumes that if the mouth and spine are doing that, it must be because of cheerfulness.
Page 134

Minds seek patterns. In a term introduced by science writer Michael Shermer, they are driven toward “patternicity”—the attempt to find structure in meaningless data.

Evolution favors pattern seeking, because it allows the possibility of reducing mysteries to fast and efficient programs in the neural circuitry.
Page 138

A popular model in the neuroscience literature suggests that dream plots are stitched together from essentially random activity: discharges of neural populations in the midbrain. These signals tickle into existence the simulation of a scene in a shopping mall, or a glimpse of recognition of a loved one, or a feeling of falling, or a sense of epiphany. All these moments are dynamically woven into a story, and this is why after a night of random activity you wake up, roll over to your partner, and feel as though you have a bizarre plot to relate.
Page 139

Consider the concept of a secret. The main thing known about secrets is that keeping them is unhealthy for the brain.
Page 145

After years of study, Pennebaker concluded that “the act of not discussing or confiding the event with another may be more damaging than having experienced the event per se.”

He and his team discovered that when subjects confessed or wrote about their deeply held secrets, their health improved, their number of doctor visits went down, and there were measurable decreases in their stress hormone levels.
Page 145

The main reason not to reveal a secret is aversion to the long-term consequences. A friend might think ill of you, or a lover might be hurt, or a community might ostracize you. This concern about the outcome is evidenced by the fact that people are more likely to tell their secrets to total strangers; with someone you don’t know, the neural conflict can be dissipated with none of the costs.
Page 146

If we hope to invent robots that think, our challenge is not simply to devise a subagent to cleverly solve each problem but instead to ceaselessly reinvent subagents, each with overlapping solutions, and then to pit them against one another. Overlapping factions offer protection against degradation (think of cognitive reserve) as well as clever problem solving by unexpected approaches.
Page 147

Some people are constitutionally incapable of keeping a secret, and this balance may tell us something about the battles going on inside them and which way they tip. Good spies and secret agents are those people whose battle always tips toward long-term decision making rather than the thrill of telling.
Page 150

When your biology changes, so can your decision making, your appetites, and your desires. The drives you take for granted (“ I’m a hetero/ homosexual,” “I’m attracted to children/ adults,” “I’m aggressive/ not aggressive,” and so on) depend on the intricate details of your neural machinery.
Page 155

Many of us like to believe that all adults possess the same capacity to make sound choices.

It’s a nice idea, but it’s wrong.
Page 157

As far as we can tell, all activity in the brain is driven by other activity in the brain, in a vastly complex, interconnected network. For better or worse, this seems to leave no room for anything other than neural activity—that is, no room for a ghost in the machine. To consider this from the other direction, if free will is to have any effect on the actions of the body, it needs to influence the ongoing brain activity. And to do that, it needs to be physically connected to at least some of the neurons. But we don’t find any spot in the brain that is not itself driven by other parts of the network. Instead, every part of the brain is densely interconnected with—and driven by—other brain parts. And that suggests that no part is independent and therefore “free.” So in our current understanding of science, we can’t find the physical gap in which to slip free will—the uncaused causer—because there seems to be no part of the machinery that does not follow in a causal relationship from the other parts.
Page 166

However, at this point, no one can see a clear way around the problem of a nonphysical entity (free will) interacting with a physical entity (the stuff of the brain).
Page 167

To help a citizen reintegrate into society, the ethical goal is to change him as little as possible to allow his behavior to come into line with society’s needs.
Page 182

Poor impulse control is a hallmark characteristic of the majority of criminals in the prison system.
Page 182

If it seems difficult to empathize with people who have poor impulse control, just think of all the things you succumb to that you don’t want to. Snacks? Alcohol? Chocolate cake? Television? One doesn’t have to look far to find poor impulse control pervading our own landscape of decision making. It’s not that we don’t know what’s best for us, it’s simply that the frontal lobe circuits representing the long-term considerations can’t win the elections when the temptation is present. It’s like trying to elect a party of moderates in the middle of war and economic meltdown.
Page 182

Recall the patients with frontotemporal dementia who shoplift, expose themselves, urinate in public, and burst out into song at inappropriate times. Those zombie systems have been lurking under the surface the whole time, but they’ve been masked by a normally functioning frontal lobe.
Page 184

The same goes for the mentally retarded or schizophrenic; punitive action may slake bloodlust for some, but there is no point in it for society more broadly.
Page 189

Biological explanation will not exculpate criminals. Brain science will improve the legal system, not impede its function. 36 For the smooth operation of society, we will still remove from the streets those criminals who prove themselves to be over-aggressive, under-empathetic, and poor at controlling their impulses. They will still be taken into the care of the government. But the important change will be in the way we punish the vast range of criminal acts—in terms of rational sentencing and new ideas for rehabilitation. The emphasis will shift from punishment to recognizing problems (both neural and social) and meaningfully addressing them.
Page 190

Effective law requires effective behavioral models: understanding not just how we would like people to behave, but how they actually behave.
Page 191

Visual illusions reveal a deeper concept: that our thoughts are generated by machinery to which we have no direct access.
Page 194

The dethronement led to a richer, deeper understanding, and what we lost in egocentrism was counterbalanced in surprise and wonder.
Page 196

(It is also the case that a virtuous actor can have minimal temptations and therefore no requirement for good brakes, but one could suggest that the more virtuous person is he who has fought a stronger battle to resist temptation rather than he who was never enticed.)
Page 197

All of this leads to a key question: do we possess a soul that is separate from our physical biology—or are we simply an enormously complex biological network that mechanically produces our hopes, aspirations, dreams, desires, humor, and passions? 7 The majority of people on the planet vote for the extrabiological soul, while the majority of neuroscientists vote for the latter: an essence that is a natural property that emerges from a vast physical system, and nothing more besides.
Page 203

As soon as your drink is spiked, your sandwich is sneezed upon, or your genome picks up a mutation, your ship moves in a different direction. Try as you might to make it otherwise, the changes in your machinery lead to changes in you. Given these facts on the ground, it is far from clear that we hold the option of “choosing” who we would like to be.
Page 209

Who you turn out to be depends on such a vast network of factors that it will presumably remain impossible to make a one-to-one mapping between molecules and behavior (more on that in the moment).
Page 209

If there’s something like a soul, it is at minimum tangled irreversibly with the microscopic details.
Page 209

In other words, a lower level of social acceptance into the majority correlates with a higher chance of a schizophrenic break. In ways not currently understood, it appears that repeated social rejection perturbs the normal functioning of the dopamine systems.
Page 211

In my view, the argument from parsimony is really no argument at all—it typically functions only to shut down more interesting discussion. If history is any guide, it’s never a good idea to assume that a scientific problem is cornered.
Page 222

Keep in mind that every single generation before us has worked under the assumption that they possessed all the major tools for understanding the universe, and they were all wrong, without exception.
Page 223

“Vision after early blindness.”
Page 230 incognito for interactive demonstrations of how little we perceive of the world. For excellent reviews on change blindness, see Rensink, O’Regan, and Clark, “To see or not to see”; Simons, “Current approaches to change
Page 230

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