Too busy to read?

"Our brains crave reducing things to two or three options," said Eric Johnson, a cognitive psychologist at Columbia University who studies decision making. "So when we're faced with a lot of information, we start automatically arranging it into mental folders and subfolders and sub-subfolders."

The first humans who figured out how to write things down around 5,000 years ago were in essence trying to increase the capacity of their hippocampus, part of the brain's memory system. They effectively extended the natural limits of human memory by preserving some of their memories on clay tablets and cave walls, and later, papyrus and parchment.

The nonlinear associative nature of our brains makes it impossible for us to consciously search our memories in an orderly way. A memory only pops directly into consciousness if it is cued by some other thought or perception--some other node in the nearly limitless interconnected web. So when a memory goes missing or a name gets caught on the tip of the tongue, hunting it down can be frustrating and often futile. We have to stumble in the dark with a flashlight for cues that might lead us back to the piece of information we're looking for--Her name begins with an L ... She's a painter ... I met her at that party a couple years ago--until one of those other memories calls to mind the one we're looking for. Ah yes, her name was Lisa! Because our memories don't follow any kind of linear logic, we can neither sequentially search them nor browse them.

As proper note-taking is rarely taught or discussed, it is no wonder that almost every guide on writing recommends to start with brainstorming. If you haven't written along the way, the brain is indeed the only place to turn to. On its own, it is not such a great choice: it is neither objective nor reliable - two quite important aspects in academic or nonfiction writing.

The brain also doesn't store information neurally and objectively. We reinvent and rewrite our memory every time we try to retrieve information. The brain works with rules of thumb and makes things look as if they fit, even if they don't. It remembers events that never happened, connects unrelated episodes to convincing narratives and completes incomplete images. It cannot help but see patterns and meaning everywhere, even in the most random things (cf. Byrne, 2008). The brain, as Kahneman writes, is "a machine for jumping to conclusions"

Why is it that when you think of hash browns, your brain doesn't automatically deliver up every single time you've ever had hash browns? It's because the brain organizes similar memories into categorical bundles.

Twentysomethings take these difficult moments particularly hard. Compared to older adults, they find negative information--the bad news--more memorable than positive information--or the good news. MRI studies show that twentysomething brains simply react more strongly to negative information than do the brains of older adults. There is more activity in the amygdala--the seat of the emotional brain. When twentysomethings have their competence criticized, they become anxious and angry. They are tempted to march in and take action. They generate negative feelings toward others and obsess about the why: "Why did my boss say that? Why doesn't my boss like me?" Taking work so intensely personally can make a forty-hour workweek long indeed.

Information theory came up in Chapter 1 in discussing the number of simultaneous conversations that a person can follow, and the information processing limits of human attention being estimated at around 120 bits per second. It is a way to quantify the amount of information contained in any transmission, instruction, or sensory stimulus. It can apply to music, speech, paintings, and military orders. The application of information theory generates a number that allows us to compare the amount of information contained in one transmission with that contained in another.

Our brains come preconfigured to create categories and classifications of things automatically and without our conscious intervention.

The entire brain weighs three pounds (1.4 kg) and so is only a small percentage of an adult's total body weight, typically 2%. But it consumes 20% of all the energy the body uses. Why? The perhaps oversimplified answer is that time is energy.

As Patrick Jane of The Mentalist described it, rather eloquently, "Memory is unreliable because the untrained brain has a crappy filing system. It takes everything that happens to you and throws it all willy-nilly into a big dark closet--when you go in there looking for something, all you can find are the big obvious things, like when your mom died, or stuff that you don't really need. Stuff that you're not looking for, like the words to 'Copacabana.' You can't find what you need, but don't panic, because it's still there."

richness and associative access. Richness refers to the theory that a large number of the things you've ever thought or experienced are still in there, somewhere. Associative access means that your thoughts can be accessed in a number of different ways by semantic or perceptual associations--memories can be triggered by related words, by category names, by a smell, an old song or photograph, or even seemingly random neural firings that bring them up to consciousness.

From MRI scans of healthy adolescents and twentysomethings, we now know that the frontal lobe does not fully mature until sometime between the ages of twenty and thirty. In our twenties, the pleasure-seeking, emotional brain is ready to go while the forward-thinking frontal lobe is still a work in progress.

First, the effects of training on the brain can vary with age in several ways. The most important way is that younger brains -- those of children and adolescents -- are more adaptable than adult brains are, so training can have larger effects in younger people. Because the young brain is developing in various ways, training at early ages can actually shape the course of later development, leading to significant changes. This is "the bent-twig effect." If you push a small twig slightly away from its normal pattern of growth, you can cause a major change in the ultimate location of the branch that grows from that twig; pushing on a branch that is already developed has much less effect.

millions of neurons are constantly monitoring the environment to select the most important things for us to focus on. These neurons are collectively the attentional filter. They work largely in the background, outside of our conscious awareness. This is why most of the perceptual detritus of our daily lives doesn't register, or why, when you've been driving on the freeway for several hours at a stretch, you don't remember much of the scenery that has whizzed by: Your attentional system "protects" you from registering it because it isn't deemed important.

Two of the most crucial principles used by the attentional filter are change and importance.

THE PURPOSE OF this whole method of workflow management is not to let your brain become lax, but rather to enable it to be free to experience more elegant, productive, and creative activity.

In 2000, a neuroscientist at University College London named Eleanor Maguire wanted to find out what effect, if any, all that driving around the labyrinthine streets of London might have on the cabbies' brains. When she brought sixteen taxi drivers into her lab and examined their brains in an MRI scanner, she found one surprising and important difference. The right posterior hippocampus, a part of the brain known to be involved in spatial navigation, was 7 percent larger than normal in the cabbies--a small but very significant difference. Maguire concluded that all of that way-finding around London had physically altered the gross structure of their brains. The more years a cabbie had been on the road, the more pronounced the effect.

Recent breakthroughs in neuroscience show that our brain developed in three separate stages. First come the old brain, or "crocodile brain"--we'll call it the "croc brain" for short. It's responsible for the initial filtering of all incoming messages, it generates most survival fight-or-flight responses, and it produces strong, basic emotions, too. But when it comes to decision making, the croc brain's reasoning power is . . . well, primitive. It simply doesn't have a lot of capacity, and most of what it does have is devoted primarily to the things it takes to keep us alive. When I am referring to the croc brain, I am referring to this level. The midbrain, which come next, determines the meaning of things and social situations. And finally, the neocortex evolved with a problem-solving ability and is able to think about complex issues and produce answers using reason.

Neurobiologists also have their side of the story. They believe (roughly) that we have three brains: The very old one, the reptilian brain that dictates heartbeat and that we share with all animals; the limbic brain center of emotions that we share with mammals; and the neocortex, or cognitive brain, that distinguishes primates and humans (note that even institutional investors seem to have a neocortex).