user's guide to your brain. This immersive book tackles the questions that keep you up at night: Is your smartphone wrecking your memory? Are believers' and atheists' brains different? Who's smarter: your baby or your dog? Hwo is yuor biarn albe to raed tihs crzay quseotin?
Neil deGrasse Tyson calls the human brain the most complicated object we know, and there's way too much information,
mystery, and discovery to cover in just a book. That's why It's All In Your
Head is the centerpiece of a fun, illuminating franchise spanning across digital, experiential, broadcast and more-all devoted to the awesomeness of your brain.
KEITH BLANCHARD is the author of two novels and has contributed in various capacities to a wide range of publishing and production enterprises, from The Week to Cosmopolitan,
Rolling Stone to The Drew Carey Show, The Wall Street Journal
to Yourtango.com. Most recently the chief digital officer of the World
Science Festival, Keith was the longtime editor-in-chief and creative director of Maxim.
WICKED COW STUDIOS
is a new content studio that starts first with book publishing while securing dynamic, world-class partnerships around its book content simultaneously. Wicked
Cow is also Derek Jeter's co-founder and co-publisher in Jeter Publishing, their content studio that includes a joint venture partnership with publishing giant
Simon & Schuster. Previously Wicked Cow managed beloved pop culture brands including Wiffle®, The Roberto Clemente Estate, Big League Chew,
and the Notorious B.I.G. Estate.
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|Publisher:||Wicked Cow Studios Llc|
|Product dimensions:||7.80(w) x 10.20(h) x 0.70(d)|
|Age Range:||16 Years|
Read an Excerpt
THE AMAZING BRAIN: WHAT IT WAS, IS, AND IS BECOMING
Who are you? Specifically, what are the boundaries — where does "you" stop and the outside world begin? It's not as simple as it sounds.
You might think of yourself as your contiguous set of cells, for example, but it turns out your body contains about as many bacterial cells (i.e., other life forms) as human cells. They're much smaller, sure, but there are tens of trillions of them: Do you really want to include them in your definition of you? Worse, even the cells that are yours are constantly being replaced. Defined as the sum of the cells you have now, only about 2% of "you" was a part of your body just a year ago.
But you're clearly "you." And the thing that's really unique about you, of course, is your mind.
This endlessly fascinating machine — and its squishy, compact carrying case, the brain — holds a whole lot of what's important about you: your memories and preferences, your skills and beliefs, your dreams and desires, your history of wisdom and folly. Millions upon millions of thoughts and impressions and feelings and opinions have piled up over years, packed in with incredible efficiency, yet are still changing materially every second of every day. If you lose your arms or legs or lose the use of your body below the neck, it's a terrible loss of valuable tools and capabilities ... but you're still you. If your mind begins malfunctioning, though, people might start saying things like "Grandma? Well ... she's not really here anymore."
So let's start our exploration of the mind with the brain itself: the electrically charged bag of meat in your head. If we're going to have any hope of understanding how our minds work — how ideas spring up, how memories evoke emotions, how dreams inspire action, how to fix what's broken and celebrate what's merely unusual, how to hack our own potential and capabilities for pleasure and productivity — we have to start with the wetware.
Let's peek under the hood and take a look at your brain.
Your brain weighs just under three pounds, if you're a healthy adult. (Although, if we're weighing your brain, you may not be the perfect picture of health.) It's about 60% fat and wrinkled like a walnut. Fed by thousands of miles of blood vessels, it sucks up 20% of all the energy your body takes in and boasts at least a hundred trillion electrical connections, a truly unthinkable number, equal to all the stars in a thousand Milky Way galaxies. The varying strengths and patterns and reinforcements of those connections are what represent everything you've ever known and seen and said and dreamed and imagined.
Is There a Difference Between the Right- and Left-Brain Hemispheres?
There are differences between the two hemispheres, but they're not nearly as profound as conventional wisdom would have you believe. It's true that your left lobe is typically more involved in language and math, and that your right side does more duty relating to spatial navigation and visuals. But both sides participate in most tasks, especially complex ones, and the idea that people more generally predisposed to logic and analytics are "left-brained" and creative dreamers are "right-brained" is lazy gibberish. A 2013 University of Utah study of more than 1,000 brains looking for just this effect found exactly nobody preferentially using one side or the other.
As a matter of fact, in some transcendently awful cases, people have had an entire hemisphere of their brain removed due to an accident or radical surgery and lived to function quite normally. The astonishing degree to which the brain is capable of dramatic rewiring is known as neuroplasticity. In fact, "rewiring," as a convenient metaphor, understates the power of what's going on. There's no real equivalent to wires in your cerebral cortex, only pathways and patterns embedded in the tissue of your brain — pathways that can and do change, for any number of reasons.
Whatever else you are, you are almost infinitely flexible.
The right and left hemispheres of your brain work in harmony to produce the smooth, graceful activities we characterize with being human. Say you want to murder a mosquito on your knee. The activity itself is directed by your motor cortex, the part of your brain that controls muscle movement. (Reach up and tap the very top of your head with both hands, then slide the fingertips down toward your ears. Beneath the hair and scalp and skull, you just outlined the motor cortex; the right motor cortex controls the left side of your body, and vice versa.) But the motor cortex is only part of this team effort. You first need the goal defined, by the frontal lobe, and information on your hand's current position, provided from the parietal lobe, and remembered details on how swatting works, from the temporal lobe, and coordination by the cerebellum, a sort of air traffic controller making sure your hand slaps that mosquito, rather than, say, knocking over your coffee mug.
"Left-brained" and "right-brained" individuals may be a myth, but left- and right-handed people are real, and their brains demonstrate intriguing, if not thoroughly understood, differences. Lefties — about 10% of the population — on average have more brain symmetry and a larger corpus callosum connecting their lobes, which may lead to better communication between the right and left sides. This can work to their advantage: They tend to recover from strokes faster than righties, for example, as their more evenly-distributed brains are better at adapting to the new reality. But they're also more susceptible to disorders like dyslexia possibly because their language processing is more distributed across the brain, which turns out to be less efficient. Right-handers' brains seem to develop along a more standard path in utero, while lefties' brains stray from the dominant developmental path. Later, as adults, lefties are more likely to be gifted mathematicians and architects, but suffer more than their share of allergies, migraine headaches, and autoimmune disorders. Righties, on the other hand, are less likely to demonstrate cognitive disabilities or behavioral problems, and earn 10-12% more income annually than lefties.
Why is Your Brain Wrinkled?
Your wrinkled brain is evolution's elegant solution for maximizing the surface area of your brain without having to build you a gigantic skull. Most of your meaningful brain activity — sensory processing, speech, and decision-making, for example — actually takes place in the outer surface of your brain, called the cerebral cortex, and that famously wrinkly surface packs a lot of processing power into a relatively small volume. This is your gray matter, and the white matter — nerve fibers that connect gray matter to other parts of gray matter — sits beneath it. Think of your cerebral cortex as a crumpled, rubbery sheet about the thickness of two stacked pennies: If you could unfold it all the way, it would be about the size of a small pillowcase (and you'd have one hell of a party trick).
This folding happens as brain growth outpaces skull growth in the womb; at birth an infant's brain wrinkliness is about the same as mom's. Lower-order animals like rats tend to have smoother brains; at the other extreme, those brainy dolphins have even more convoluted cortices than humans. That said, intelligence is a complicated affair, and more brain wrinkles don't necessarily make one human smarter than another.
The visual similarities between the wrinkles of the brain and of the walnut did not go unnoticed by the credulous ancients. According to the generally hokey theory, the Doctrine of Signatures, foods and herbs that looked like parts of the body offered special benefits to those parts; therefore, walnuts must be good brain medicine. But coincidentally, that one actually checks out: Walnuts are today considered high-value brain food that can improve memory and may help counteract age-related cognitive decline like that produced by Alzheimer's disease.
Are Bigger Brains Smarter Brains?
Yes and no. Primate brains are twice as large as you might expect for mammals of our size, and, sure enough, every chess grandmaster in history so far has been a primate. From an evolutionary perspective, these giant heads of ours are a liability: Human childbirth is painful and dangerous in the wild, and human babies are helpless and dependent for quite a long time, compared to, say, fawns. Yet for all of that, bigger brains conveyed enough of a survival advantage to take humans to the top of the food chain. Our brain has tripled in size over the last 5 million years or so — from Australopithecus through Homos habilis, erectus, and sapiens — corresponding with a gradual improvement in intelligence. Civilization and big heads may have developed in tandem, since reliable help from other nonthreatening humans made childbirth safer, which helped even more big-headed kids survive in each generation, and so on.
So far so good: In humans/hominids over the long haul, growing brains have historically correlated with growing intelligence. But the human brain is actually shrinking now, believe it or not. Our hat size seems to have peaked in the Stone Age, and since then we've lost on average about a tennis ball's worth of volume. Among the possible reasons for this shrinkage is the notion that civilization itself has made it less necessary to be super-smart to survive, which has allowed the not-so-bright to overstay their welcome in the gene pool. ("Thanks for calling tech support. Can you start by verifying that your computer is plugged in?")
Interestingly, the male brain weighs about four ounces more on average than the female brain: the equivalent of two Snickers bars. And yet there's no difference in average IQ between the genders, no matter what your drunk grandpa claims. It turns out a lot of the storied Mars/Venus differences between the male and female brains, such as the canard that men are better at math than women, appear to be based not on innate abilities but on history and socio-cultural expectations, such as keeping math-based fields closed to women for a long time. One experiment demonstrated that men are more likely to think they scored higher than they did on math tests, while women are more likely to think they scored lower; another showed that women perform better on math tests when using a pseudonym.
The bottom line on size: The surface area of your brain — not its size — is a better predictor of actual relative intelligence.
Are Humans the Smartest Animals?
Unless toads or butterflies are seriously slow-playing their hand, it seems humans are indeed at the head of the class. There are larger brains than yours in the animal kingdom, for sure, but none that can begin to compete with you on Trivia Night. What seems to matter more than brain size, in terms of intelligence, is relative brain-to-body size, as well as total neurons and other details of the brain's internal structure. For example, neurons, the brain's building-block nerve cells, are typically found in higher numbers in larger brains within any one family (like hominids, or great apes — you are smarter than your distant orangutan cousin). But when you compare across families (say, humans vs. dolphins), the different brain structures complicate the equation. Elephant brains are three times the size of ours, and they have three times the number of total neurons. Unfortunately, only 3% of them are located in their cortex, where what we call intelligence lives.
Brains generally seem to have evolved from earlier, simple structures like nerve nets, which merely propagate a sensation ("ouch!" "yum"), and help brainless animals like jellyfish respond to their environment. In vertebrates, an evolutionary process called cephalization centralized and strengthened these neural clusters into actual brains, conveying all kinds of survival advantages. But the animal kingdom is vast, and evolution has granted some animals altogether different ways to organize their intelligence. Around half of the neurons of an octopus, for example, are clustered in its eight arms. Imagine what consciousness would be like, distributed across your limbs like that. When an octopus loses an arm, the severed limb will coil and uncoil for hours, possibly feeling its own peculiar kind of disembodied pain.
How Do Thoughts Work?
Okay, buckle up — we've got to define some hardware first. As referenced in the Your Noodle In A Nutshell infographic on page 1, the four key elements of your neurological wiring are neurons, axons, dendrites, and synapses. Neurons are like little trees, with multiple outstretched branches called dendrites and a single long trunk called an axon. Axons can be microscopically small, but some overachievers are many feet long, like those of the sciatic nerve that connects your spinal cord to your big toe. The axon communicates information out to other neurons, whose dendrites receive that communication. The junctions between the axon of one neuron and the dendrites of another are called synapses, and it's across these tiny gaps that communication, at its most basic level, takes place.
Axons are insulated, though not continuously so, with a fatty bubble wrap called myelin that helps these millions of "cords" pack tightly together without short-circuiting and conduct electrical signals at a suitably brisk pace. Without the magic of myelin, it's been estimated that your spinal cord would have to be as thick around as a tree trunk to work. Myelin damage can lead to crossed-signal issues; sufferers of multiple sclerosis (MS), in which the myelin deteriorates, exhibit symptoms such as blindness in one eye, numbness or tingling, and difficulty with coordination.
The last pieces of the puzzle are neurotransmitters — the chemicals that communicate between neurons by jumping the razor-thin 30-nanometer synaptic cleft between them. When a neuron "fires," the axon releases specific chemicals that spray across this teeny no-man's-land gap and are picked up by specialized receptors on the next neuron's dendrites. These chemicals are called neurotransmitters, and they do a range of exciting things.
Those are neurons, and their sequential firing, in new or remembered patterns, ultimately gives rise to conscious thought. Neurons are reasonably blank slates that specialize according to your inputs — and with some 86 billion neurons in the human brain, they can get incredibly specific: Researchers found a "Jennifer Aniston neuron," for example, that fired when a test subject was shown any picture of her, and a "Sydney Opera House neuron," and so on. The neuron patterns are so specific, in fact, that researchers recently have made strides reading people's minds simply by watching these super-specified neurons and inferring, when they fire, what the subject is thinking about. ("The subject seems to be imagining Jennifer Aniston heading into the Sydney Opera House ...")
Thought happens when sequences of firing neurons register as memories, new sensations, or creative ideas. With each individual neuron capable of connecting to tens of thousands of others, your brain has 100 trillion connections, an unthinkably vast network. If you're still imagining your brain as a supercomputer, you're severely underselling it. Measured in terms of computational capability, it's 30 times faster than the world's most powerful supercomputer today — yet stuffed into a much smaller package. If you could find a way to rent out the processing power of your head, it's been estimated you could easily earn $100,000 a day.
No wonder the brain's been called "the most complicated object in the universe."
And let's not forget, while we're wallowing in the magic, that our machine, unlike your MacBook Pro, self-assembles in the womb. The ectoderm begins to take shape as a proto-brain and spinal cord, and development takes off from there. Neurons develop at a furious pace — 250,000 every minute, at times — and migrate into the correct parts of the brain as the fetus grows. As the cerebral cortex outpaces the inner white matter in growth, it begins to crumple. The baby's brain contains virtually all the neurons it will ever have, though not all the connections, at about 40 weeks. To get all this through the birth canal, the skull famously has to finish its assembly after the squeeze through, like a miniature ship waiting to unfold its sails until it passes through the neck of a bottle.
It's all quite miraculous.(Continues…)
Excerpted from "It's All in Your Head"
Copyright © 2017 Wicked Cow Studios, LLC.
Excerpted by permission of Wicked Cow Studios.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
CHAPTER 1 The Amazing Brain: What It Was, Is, and Is Becoming, Page 3,
CHAPTER 2 Sensory Input, Illusion, and Magic: How We Know What We Think We Know, Page 21,
CHAPTER 3 Memory, Recognition, and Trying To Forget, Page 45,
CHAPTER 4 Sleep, Dreams, and the Subconscious World, Page 63,
CHAPTER 5 Disease, Disorder, and the "Broken" Brain, Page 83,
CHAPTER 6 Language, Intelligence, Creativity, and the Miracle of Genius, Page 101,
CHAPTER 7 Altered States: Your Brain On Sex, Drugs, and Rock & Roll, Page 123,
CHAPTER 8 Emotion, Faith, Spirituality, and the Rise of Cults, Page 145,
CHAPTER 9 Smart Everything, the AI Age, and What's Next, Page 165,
Glossary, Page 185,