Book Summary

The Skinny

You're divided. In some ways, one might argue that you are one being. Yet, in other ways you are a series of connected modules that often times work together, and other times to opposite ends. You're mind and body are divided, but connected. The left and right hemisphere of your brain or separate, and, at the same time, work together as one. The old, often referred to as, "reptilian brain" and the newer additions to your brain such as your neocortex are also divided but connected. And last but not least, the hundreds of automatic processes going on inside you and your one controlled process (the thing your using to read this passage) are separate but connected.

Chapter 1

Human thinking depends greatly on metaphor. We understand new or complex things in relation to things we already know. For example, it's hard to think about life in general, but if I say "life is a journey", the metaphor guides you to better understanding. Learn the terrain, pick a direction, find some good traveling buddies, and enjoy the trip. People have and still today use metaphors to describe the mind. Buddha compared the mind to a wild elephant.

"In days gone by this mind of mine used to stray wherever selfish desire or lust or pleasure would lead it. Today this mind does not stray and is under the harmony of control, even as a wild elephant is controlled by the trainer"

Plato used a metaphor where the self was a chariot, and the calm, rational part of the mind holds the reins.

"The horse that is on the right, or nobler, side is upright in frame and well jointed, with a high neck and a regal nose;...he is a lover of honor with modesty and self-control; companion to true glory, he needs no whip, and is guided by verbal commands lone. The other horse is a crooked great jumble of limbs...companion to wild boasts and indecency, he is shaggy around the ears--deaf as a post--and just barely yields to horse-whip and goad combined.

Freud said the mind is divided into three parts: the ego (the conscious, rational self); the superego (the conscience, a sometimes too rigid commitment to the rules of society); and the id(the desire for pleasure, lots of it, sooner rather than later). Nowadays, people say the mind is like a driver in a car, or a computer executing a program. This is fundamentally flawed in that it completely ignores Freud's unconscious. Metaphors can also mislead. If the brain were like a computer you could program it to do whatever you want, with a decision-making process based solely on rational thought, then why would people continue to do things they know are bad for them. The metaphor of trying to control an elephant is more accurate. Being the driver trying to tell the elephant to turn, stop, or change direction,. We can impose our will, but the elephant gets a say, too. We assume ourselves to be one being in one body, but in some ways we are each more like a committee whose members have been thrown together to do a job, but who often find themselves working at cross-purposes.

First Division: Mind vs. Body

Our intestines are lined by a vast network of more than 100 million neurons; these handle all the computations needed to run the chemical refinery that processes and extracts nutrients from food. This gut brain is like a regional administrative center that handles stuff the head brain does not need to bother with. You may expect it to take orders from the head brain. However, this gut brain possess a high degree of autonomy, and continues to function well even if the vagus nerve, that connects the two together, is cut. This gut brain triggers anxiety in the head brain when it detects infections in the gut, leading you to act in more cautious ways that are appropriate when you're sick. And it reacts in unexpected ways to anything that affects its main neurotransmitters, such as acetylcholine and serotonin. Hence, many of the initial side effects of Prozac.

Second Division: Left vs. Right

A second division was discovered when a surgeon, Joe Bogen, began to cut peoples' brains in half. He was actually trying to help people with epileptic seizures, by cutting the corpus callosum, a large bundle of nerves that connects the left and right hemisphere of the brain. He tried this out on a few patients and it seemed to work. To make sure there were no unintended consequences of this surgery, the surgical team brought in a young psychologist, Michael Gazzaniga, to see what the potential after-effects were. The brain divides its processing of the word into its two hemispheres--left and right. The left hemisphere takes in information from the right half of the world (that is, receives transmissions from the right arm and leg, the right ear, and the left half of each retina) and sends out commands to the right side of the body. The right hemisphere does the same thing, just the mirror opposite. In other ways the two sides are specialized. The left hemisphere is specialized for language processing and analytical tasks. In visual tasks, it is better at noticing details. The right hemisphere is better at processing patterns in space, including the face. (That's the origin of the popular and oversimplified idea about artists being "right-brained" and scientists being "left-brained"). Michael Gazzaniga used this division of labor to present information to each half of the brain separately. He told the patients to stare at a dot and then flashed an image just to the right or left of the dot, so quickly they couldn't move their gaze. If flashed to the right it would register on the left side of each retina, which then sent neural information to the left hemisphere. Gazzaniga would then ask, "What did you see?" Because the left hemisphere as full language capabilities, the patient would respond, "A hat". If flashed to the left, the image was sent to the right hemisphere which doesn't control speech. When asked what they saw, they would respond by saying "nothing". However, when they were asked to point to the image they saw, they would, with their left hand, point to the hat. The finding was that people will readily fabricate reasons to explain their own behavior. The left hemisphere will give a running commentary on what's being done, even if the language center has no access to the real causes or motives for the behavior. This shows that the mind is a series of modules that can work independently, and even at cross-purposes. Side Note: check out alien hand syndrome. It really makes you think

Third Division: New vs. Old

Your brain probably started off with just a hindbrain, midbrain, and forebrain. Overtime as the behaviors and body became more complex, things kept getting added to the front, expanding the forebrain more than any other. In more social mammals, especially primates, a new layer of neural tissue developed and spread to surround the old limbic system. This neocortex is the gray matter of human brains. The front of the neocortex is interesting, because it doesn't seem to be dedicated to any specific task like interpreting sounds or moving your hands. Instead, it's available to make new associations and to engage in thinking, planning, and decision making. The neocortex seems to not only have given us the ability to think and reason, but also to have expanded the range and complexity of our emotions. The lower third of the prefrontal cortex is called the orbitofrontalcortex because it's just above your eyes (orbito is Latin for eye). This region is one of the most consistently active regions when determining the pros and cons/reward and punishment in a situation. The neurons here also fire like crazy when there is an immediate possibility of pain, pleasure, loss or gain. Studies have shown the importance emotions. When a person's orbitofrontal cortex is damaged, their lives essentially fall apart. You would think they become hyper-rational, as they can see through the "fog" of emotion, but, in reality, they have trouble making even the simplest decisions. They can't set goals or pick something because they don't see a reason to. Emotions helps us to make decisions by making somethings immediately pop out as interesting or enjoyable and then we can use a more rational side to sort out the pros and cons of the 2-3 choices remaining.

Fourth Division: Controlled vs. Automatic

There are really two processing systems at work in the mind at all times: controlled and automatic processes. Controlled processing is limited--we can think consciously about one thing at a time only-- but automatic processes run in parallel. If your mind performs a hundred operations at once, all but one of those hundred must be done automatically. Controlled processing requires language. You can have bits and pieces of thought through images, but to plan something complex , to weigh the pros and cons of different paths, or to analyze the causes of past successes and failures, you need words. No one knows when we began developing language, but no one denies its usefulness. Whenever it began, we know that language, reasoning, and conscious planning were the most recent "upgrades" to our brains. Since their such new additions, you could say there are still some "bugs" in the software update. The automatic processes on the other hand work fantastically. They've been through thousands of "product-cycles". This is why we can make computers that can beat us at chess, and perform math calculations far faster than we can, but most bi-pedal robots couldn't traverse a mountain to save their life. Returning back to the original metaphor of the rider and the elephant, the rider and the elephant have their own intelligence. They both can work well together or at cross-purposes. The addition of the rider (the ability to think, plan ahead, and contemplate) also made the elephant (everything else including; gut feelings, automatic reactions, emotions, and intuitions) more intelligent .