BRAIN RULES / John Medina / 2014 / printed in July 2014
Brain Rule #1 The human brain evolved, too.
The brain appears to be designed to (1) solve problems (2) related to surviving (3) in an unstable outdoor environment, and (4) to do so in nearly constant motion.There are two ways to beat the cruelty of a harsh environment: You can become stronger or you can become smarter.
Dual Representational Theory. Stated formally, it describes our ability to attribute characteristics and meanings to things that don’t actually possess them. Stated informally, we can make things up that aren’t there. We are human because we can fantasize. We gave up on stability. We began not to care about consistency within a given habitat, because consistency wasn’t an option. We adapted to variation itself. Those unable to rapidly solve new problems or learn from mistakes didn’t survive long enough to pass on their genes. The net effect of this evolution was that rather than becoming stronger, we became smarter. It was a brilliant strategy.
It predicts interactions between two powerful features of the brain: a database in which to store a fund of knowledge, and the ability to improvise off that database. One allows us to know when we’ve made mistakes. The other allows us to learn from them. Both give us the ability to add new information under rapidly changing conditions.
started with a “lizard brain” to keep us breathing, then added a brain like a cat’s, and then topped those with the thin layer known as the cortex—the third, and powerful, “human” brain. reasoning is a uniquely human talent. It may have arisen from our need to understand one another’s intentions and motivations. This allowed us to coordinate within a group, which is how we took over the Earth.
Brain Rule #2 Exercise boosts brain power.
The chief reason for the longer life is that exercise improves cardiovascular fitness, which in turn reduces the risk for diseases such as heart attacks and stroke. Exercisers outperform couch potatoes in tests that measure long-term memory, reasoning, attention, and problem-solving skill. Essentially, exercise improves a whole host of abilities prized in the classroom and at work. Not every cognitive ability is improved by exercise, however.
The researchers consistently found that all kinds of mental abilities began to come back online—after as little as four months of aerobic exercise. In the laboratory, the gold standard appears to be aerobic exercise, 30 minutes at a clip, two or three times a week. Add a strengthening regimen and you get even more cognitive benefit. Your lifetime risk for general dementia is literally cut in half if you participate in physical activity. Aerobic exercise seems to be the key. The researchers showed you have to participate in some form of exercise just twice a week to get the benefit. For both depression and anxiety, exercise is beneficial immediately and over the long term. It is equally effective for men and women. The longer the person exercises, the greater the effect. “Kids pay better attention to their subjects when they’ve been active,”
The brain gobbles up 20 percent of the body’s energy, even though it’s only about 2 percent of the body’s weight. The three requirements for human life are food, drink, and fresh air. But their effects on survival have very different timelines. You can live for 30 days or so without food, and you can go for a week or so without drinking water. Your brain, however, is so active that it cannot go without oxygen for more than five minutes without risking serious and permanent damage. The more you exercise, the more tissues you can feed and the more toxic waste you can remove. Physical activity is cognitive candy. All we have to do is move. Most studies show a benefit from exercising only two or three times a week. Formun Altı
Fit employees are more capable than sedentary employees of mobilizing their God-given IQs.
brains were built for walking—12 miles a day! improve your thinking skills, move. gets blood to your brain, bringing it glucose for energy and oxygen to soak up the toxic electrons that are left over. It also stimulates the protein that keeps neurons connecting. exercise just twice a week halves your risk of general dementia. It cuts your risk of alzheimer’s by 60 percent.
Brain Rule #3 Sleep well, think well.
Stated formally, process S maintains the duration and intensity of sleep, while process C determines the tendency and timing of the need to go to sleep.
In general, larks report being most alert around noon and feel most productive at work a few hours before they eat lunch. They don’t need an alarm clock, because they invariably get up before the alarm rings—often before 6:00 a.m. Larks cheerfully report their favorite mealtime as breakfast and generally consume much less coffee than non-larks. Getting increasingly drowsy in the early evening, most larks go to bed (or want to go to bed) around 9:00 p.m. Larks are incomprehensible to the one in 10 humans who lie at the other extreme of the sleep spectrum: “late chronotypes,” or owls.
Larks and owls, though, cover only about 20 percent of the population. The rest of us are called hummingbirds. True to the idea of a continuum, some hummingbirds are more owlish, some are more larkish, and some are in between. It’s a fight because the brain really wants to take a nap and doesn’t care what its owner is doing.
Regardless of the cause, the nap zone matters, because our brains don’t work as well during it.
Cumulative losses during the week add up to cumulative deficits during the weekend—and, if not paid for, that sleep debt will be carried into the next week. Essentially, it comes down to whatever amount of sleep is right for you. Sleep loss takes a toll on the body, too—on functions that do not at first blush seem associated with sleep. Sleep loss hurts attention, executive function, working memory, mood, quantitative skills, logical reasoning ability, general math knowledge. Eventually, sleep loss affects manual dexterity, including fine motor control, and even gross motor movements, such as the ability to walk on a treadmill. A healthy night’s sleep can indeed boost learning significantly. Clearly, for specific types of intellectual skill, sleep can be a great friend to learning. Quite literally, the rat seems to be consolidating the day’s learning the night after that learning occurred, and an interruption of that sleep disrupts the learning cycle. A business of the future takes sleep schedules seriously. Don’t schedule meetings or classes during the time when the process C and process S curves are flatlined.
brain is in a constant state of tension between cells and chemicals that try to put you to sleep and cells and chemicals that try to keep you awake. neurons of your brain show vigorous rhythmical activity when you’re asleep—perhaps replaying what you learned that day. vary in how much sleep they need and when they prefer to get it, but the biological drive for an afternoon nap is universal. Lack of sleep hurts attention, executive function, working memory, mood, quantitative skills, logical reasoning, and even motor dexterity.
Brain Rule #4 Stressed brains don’t learn the same way.
the term “learned helplessness” to describe both the perception of inescapability and its associated cognitive collapse. a three-part definition that covers many of the bases. In their view, if all three are happening simultaneously, a person is stressed.
A measurable physiological response: There must be an aroused physiological response to the stress, and it must be measurable by an outside party
A desire to avoid the situation: The stressor must be perceived as aversive—something that, given the choice, you’d rather not experience.
A loss of control: The person must not feel in control of the stressor. our stress responses were shaped to solve problems that lasted not for years, but for seconds. They were primarily designed to get our muscles moving us as quickly as possible out of harm’s way.
These days, our stresses are measured not in moments with mountain lions, but in hours, days, and sometimes months with hectic workplaces, screaming toddlers, and money problems. Our system isn’t built for that. And when moderate amounts of stress hormones build up to large amounts, or hang around too long, they become quite harmful. Stress also affects our immune response. At first, the stress response helps equip your white blood cells, sending them off to fight on your body’s most vulnerable fronts, such as the skin.
Acute stress can even make you respond better to a flu shot. But chronic stress reverses these effects, decreasing your number of heroic white-blood-cell soldiers, stripping them of their weapons, even killing them outright. Not surprisingly, people who experience chronic stress are sick more often. They also are more likely to suffer from autoimmune disorders, such as asthma and diabetes.
One study showed that adults with high levels of stress performed 50 percent worse than adults with low levels of stress on tests of declarative memory (things you can declare) and executive function (the type of thinking that involves problem solving and self control). Those, of course, are the skills needed to excel in school, at work, and in relationships. severe stress can cause brain damage in the very tissues most likely to help you succeed in life. Depression is a deregulation of thought processes, including memory, language, quantitative reasoning, fluid intelligence, and spatial perception. stress hurts people. The problem begins when too many stress hormones hang around in the brain too long, a situation you find in chronic stress, especially learned helplessness. Whether stress becomes damaging depends on the severity of the stress, how long you are exposed to the stress, and on your body’s ability to handle stress. There’s a tipping point where stress becomes toxic. we have systems that keep us stable by constantly changing themselves. The stress system, with all of its intricacies, is one of those. The brain coordinates body-wide changes—from hormonal to behavioral changes—in response to the approach and retreat of potential threats. Marital stress at home can negatively affect academic performance in almost every way measurable, and at nearly any age. The stronger the degree of conflict, the greater the effect on performance. Depression hobbles fluid intelligence, problem-solving abilities (including quantitative reasoning), and memory formation.
In a knowledge-based economy where intellectual dexterity is often the key to survival, that’s bad news. Yet executives often give stress the shortest shrift. Three things matter in determining whether your workplace is stressful or productive: the type of stress you experience, the balance between stimulation and boredom in your job, and the condition of your home life. Control isn’t the only factor in productivity. they need is a balance between controllability and uncontrollability.
Stress in the workplace affects family life, causing more stress in the family. Stress in the family causes more stress at work, which in turn gets brought home again. It’s a downward spiral, and researchers call it “work-family conflict.” What people do in their private life is their own business, of course. Unfortunately, what people do in their private life often affects the public. My idea envisions an educational system where the first students are not the children but the parents.
body’s defense system—the release of adrenaline and cortisol—is built for an immediate response to a serious but passing danger, such as a saber-toothed tiger. Chronic stress, such as hostility at home, dangerously deregulates a system built only to deal with short-term responses. chronic stress, adrenaline creates scars in your blood vessels that can cause a heart attack or stroke, and cortisol damages the cells of the hippocampus, crippling your ability to learn and remember. the worst kind of stress is the feeling that you have no control over the problem—you are helpless. stress has huge impacts across society, on children’s ability to learn in school and on employees’ productivity at work.
Brain Rule #5 Every brain is wired differently.
When you learn something, the wiring in your brain changes. The more activity you do, the larger and more complex it can become. What you do in life physically changes what your brain looks like. Even a cursory inspection of the data reveals remarkable variation in growth patterns from one person to the next.
“experience independent” wiring.
“Experience expectant” wiring
“experience dependent” wiring.
Learning results in physical changes in the brain, and these changes are unique to each individual. Does it make any sense that most schools expect every child to learn like every other? All else being equal, it has been known for many years that smaller, more intimate schools create better learning environments than megaplex houses of learning. too small classes restricting cultural variability and limiting classwide contributon. Theory of Mind skills give teachers critical knowledge about their students, a heightened sensitivity for when they are confused, when they are fully engaged, and when they have truly learned what is being taught. Companies could include Theory of Mind tests as they screen for leaders.
you do and learn in life physically changes what your brain looks like—it literally rewires it.
various regions of the brain develop at different rates in different people.
two people’s brains store the same information in the same way in the same place.
have a great number of ways of being intelligent, many of which don’t show up on IQ tests.
Brain Rule #6 We don’t pay attention to boring things
better attention always equals better learning. What you pay attention to is often profoundly influenced by memory. If you have an interest in a subject or a person, or something is important to you, you tend to pay more attention to things related to that subject or person. we must be aware of something for it to grab our attention.
we have the ability to detect a new stimulus, the ability to turn toward it, and the ability to decide what to do based on its nature. Emotionally charged events are better remembered—for longer, and with more accuracy—than neutral events. If you want people to be able to pay attention, don’t start with details. Start with the key ideas and, in a hierarchical fashion, form the details around these larger notions. Meaning before details.
The brain naturally focuses on concepts sequentially, one at a time. This does nothing for the nourishment of the listeners, whose learning is often sacrificed in the name of expediency. The brain is a sequential processor, unable to pay attention to two things at the same time. Businesses and schools praise multitasking, but research clearly shows that it reduces productivity and increases mistakes. decided that every lecture I’d ever give would be organized in segments, and that each segment would last only 10 minutes. Each segment would cover a single core concept—always large, always general, and always explainable in one minute. If the instructor presents a concept without telling the audience where that concept fits into the rest of the presentation, the audience is forced to simultaneously listen to the instructor and attempt to divine where it fits into the rest of what the instructor is saying.
1) The hook has to trigger an emotion.
2) The hook has to be relevant.
Happily, I found that if I made the hook very relevant to the provided content, the group moved from feeling entertained to feeling engaged.
3) The hook has to go between segments
The brain’s attentional “spotlight” can focus on only one thing at a time: no multitasking.
are better at seeing patterns and abstracting the meaning of an event than we are at recording detail.arousal helps the brain learn.
check out after 10 minutes, but you can keep grabbing them back by telling narratives or creating events rich in emotion.
Brain Rule #7 Repeat to remember.
So declarative memories are those that can be experienced in our conscious awareness, such as a list of numbers, and nondeclarative memories are those that cannot be experienced in our conscious awareness, such as the motor skills necessary to ride a bike.
The more elaborately we encode information at the moment of learning, the stronger the memory. The more closely we replicate the conditions at the moment of learning, the easier the remembering. It’s called context-dependent or state-dependent learning. The more a learner focuses on the meaning of information being presented, the more elaborately he or she will process the information. examples makes the information more elaborative, more complex, better encoded, and therefore better learned. Public speaking professionals say that you win or lose the battle to hold your audience in the first 30 seconds of a given presentation. Environment then becomes part of elaborate encoding,
The process of converting short-term memory traces to longer-term forms is called consolidation. Memory may not be fixed at the moment of learning, but repetition, doled out in specifically timed intervals, is the fixative.
repeated exposure to information in spaced intervals provides the most powerful way to fix memory into the brain.
Deliberately re-expose yourself to information if you want to retrieve it later.
Deliberately re-expose yourself to information more elaborately if you want to remember more of the details.
Deliberately reexpose yourself to the information more elaborately and in fixed, spaced intervals if you want the retrieval to be as vivid as possible.
Anything irrelevant to our survival will take up wasteful cognitive space if we assign it the same priority as events critical to our survival. In the school of the future, lessons are divided into 25-minute modules, cyclically repeated throughout the day. Subject A is taught for 25 minutes. Ninety minutes later, the 25-minute content of Subject A is repeated, and then a third time. All classes are segmented and interleaved in such a fashion. In my fantasy class, this is exactly what happens. Take math. Repetitions begin with a review of multiplication tables, fractions, and decimals. Starting in the third grade, six-month and yearly review sessions occur through sixth grade. As students’ competency grows, the review content becomes more sophisticated. But the cycles are still in place. memory is not fixed at the moment of learning, and repetition provides the fixative.
brain has many types of memory systems. Declarative memory follows four stages of processing: encoding, storing, retrieving, and forgetting. coming into your brain is immediately fragmented and sent to different regions of the cortex. The more elaborately we encode a memory during its initial moments, the stronger it will be. more elaborately we encode a memory during its initial moments, the stronger it will be. You can improve your chances of remembering something if you reproduce the environment in which you first put it into your brain. can improve your chances of remembering something if you reproduce the environment in which you first put it into your brain. memory is a collection of busy work spaces that allows us to temporarily retain newly acquired information. If we don’t repeat the information, it disappears. memories are formed in a two-way conversation between the hippocampus and the cortex, until the hippocampus breaks the connection and the memory is fixed in the cortex—which can take years.
Our brains give us only an approximate view of reality, because they mix new knowledge with past memories and store them together as one. brains give us only an approximate view of reality, because they mix new knowledge with past memories and store them together as one. The way to make long-term memory more reliable is to incorporate new information gradually and repeat it in timed intervals. way to make long-term memory more reliable is to incorporate new information gradually and repeat it in timed intervals.
Brain Rule #8 Stimulate more of the senses at the same time.
Stimulate more of the senses at the same time. two people can see the same input and come away with vastly different perceptions. Every sensory system must send a signal to the thalamus asking permission to connect to the higher levels of the brain where perception occurs—except for smell. learning abilities are increasingly optimized the more multisensory the situation is. Smell can evoke memory. Smell has the unique advantage of being able to boost learning directly, without being paired with another sense. You get the best results if the smells are congruent.
Multimedia principle: Students learn better from words and pictures than from words alone. Temporal contiguity principle: Students learn better when corresponding words and pictures are presented simultaneously rather than successively.
Spatial contiguity principle: Students learn better when corresponding words and pictures are presented near to each other rather than far from each other on the page or screen.
Coherence principle: Students learn better when extraneous material is excluded rather than included.
Modality principle: Students learn better from animation and narration than from animation and on-screen text
Spangenberg knew from prior work that the male nose responds positively to the smell of rose maroc (spicy floral notes), the female nose to vanilla. What if he pumped rose maroc into the air of the men’s section at a clothing store and vanilla into the women’s section? Spangenberg hit pay dirt, generating twice the sales throughout the store. Smell also can be used to differentiate a brand. Also match the odor to the “personality” of the object for sale, the article suggests. Research shows that the less complex the smell (the fewer interacting ingredients), the more likely it is to drive sales. Simpler smells drive sales 20 percent more than complex smells, or no smells at all. But what if you pair a smell with each lesson, as in my Brut experiment?
absorb information about an event through our senses, translate it into electrical signals (some for sight, others from sound, etc.), disperse those signals to separate parts of the brain, then reconstruct what happened, eventually perceiving the event as a whole. brain seems to rely partly on past experience in deciding how to combine these signals, so two people can perceive the same event very differently.
Our senses evolved to work together—vision influencing hearing, for example—which means that we learn best if we stimulate several senses at once.
Smells have an unusual power to bring back memories, maybe because smell signals bypass the thalamus and head straight to their destinations, which include that supervisor of emotions known as the amygdala.
have an unusual power to bring back memories, maybe because smell signals bypass the thalamus and head straight to their destinations, which include that supervisor of emotions known as the amygdala.
Brain Rule #9 Vision trumps all other senses.
WE DO NOT SEE with our eyes. We see with our brains. Visual processing doesn’t just assist in the perception of our world. It dominates the perception of our world. Some process only the color information in a visual signal; others, only edges; others, only motion. the more visual the input becomes, the more likely it is to be recognized—and recalled. Text and oral presentations are not just less efficient than pictures for retaining certain types of information; they are far less efficient. Animating presentations is another way to capture the importance not only of color and placement but also of motion. Simple two-dimensional pictures are quite adequate; studies show that if the drawings are too complex or lifelike, they can distract from the transfer of information. “Less text, more pictures”
Seeing is by far our most dominant sense, taking up half of our brain’s resources. What we see is only what our brain tells us we see, and it’s not 100 percent accurate. learn and remember best through pictures, not through written or spoken words.
Brain Rule #10 Study or listen to boost cognition.
music training also aids social cognition. People with music training are better able to detect the emotional information in speech. Empathy skills and other prosocial behaviors improve.
Brain Rule #11 Male and female brains are different.
Brain Rule #12 We are powerful and natural explorers.
Some people have tried to harness our natural exploratory tendencies by using “problem-based” or “discovery-based” learning models.
Babies are the model of how we learn—not by passive reaction to the environment but by active testing through observation, hypothesis, experiment, and conclusion.
Specific parts of the brain allow this scientific approach. The right prefrontal cortex looks for errors in our hypothesis (“The saber-toothed tiger is not harmless”), and an adjoining region tells us to change behavior (“Run!”). parts of our adult brains stay as malleable as a baby’s so that we can create neurons and learn new things throughout our lives.
Brain Rules Summary
survival The human brain evolved, too.
exercise Exercise boosts brain power.
sleep Sleep well, think well.
stress Stressed brains don’t learn the same way.
wiring Every brain is wired differently.
attention We don’t pay attention to boring things.
memory Repeat to remember.
sensory integration Stimulate more of the senses.
vision Vision trumps all other senses.
music Study or listen to boost cognition.
gender Male and female brains are different.
exploration We are powerful and natural explorers