I have just read a fascinating book called “Brain Rules”1, by John Medina. The sub-heading is “12 Principles for Surviving and Thriving at Work, Home and School”. For each rule, he presents the science and then offers ideas on how the rules might apply to our daily lives, especially at work and school. The book is very easy to read and understand, and will help anyone with children or who wants to learn about the latest understanding of the brain.
Rule # 1. Exercise boosts brain power. Our brains were built for walking. To improve your thinking skills, move. Exercise gets blood to your brain, and aerobic exercise just twice a week halves your risk of dementia and cuts your risk of Alzheimer’s by 60 percent.
Rule # 2. The human brain evolved. We don’t have one brain in our heads; we have three. We started with a “lizard brain” to keep us breathing, then added a brain like a cat’s, then topped those with the thin layer of Jell-O known as the cortex – the third, and powerful, “human” brain. Going from four legs to two to walk freed up energy to develop a complex brain. Symbolic reasoning is a uniquely human talent.
Rule # 3. Every brain is wired differently. What you do and learn in life physically changes what your brain looks like – it literally rewires it. The various regions of the brain develop at different rates in different people. No two people’s brains store the same information in the same way in the same place. We have a great number of ways of being intelligent, many of which don’t show up on IQ tests.
Rule # 4. People don’t pay attention to boring things. The brain’s “attentional” spotlight can focus on only one thing at the time. This was a big shock to me. I used to be able to do three or four things at once, but as I have got older I can’t do so many things. In fact, we all can only do one thing at the time. The brain cannot multitask. We are better at seeing patterns and abstracting the meaning of an event than we are at recording detail. Emotional arousal helps the brain learn. Most importantly audiences check out after 10 minutes, but you can keep grabbing them back by telling narratives or creating events rich in emotion.
The brain naturally focuses on concepts sequentially, one at a time. You can walk and talk at the same time, but when it comes to paying attention, the brain cannot multitask. Medina speaks about a teenager doing homework, working on a laptop with an iPod in his ears blasting out, and his left hand tapping the beat. The laptop had at least 11 windows open, including two IM screens carrying simultaneous conversations with MySpace friends. Another window was busy downloading an image from Google. The window behind it had the results of some graphic he was altering for MySpace friend No. 2, and the one behind that held an old Pong game. Buried in the middle was a work-processing program holding the contents of his home work.
He would do a sentence or two, then tap out a MySpace message, then see if the download was finished, then return to his paper. Clearly, he wasn’t concentrating on the paper!! Here is what happens.
STEP 1: SHIFT ALERT
To write the paper from a cold start, blood quickly rushes to the anterior prefrontal cortex. This part of the brain works just like a switchboard, alerting the brain that it’s about to shift attention.
STEP 2: RULE ACTIVATION FOR TASK #1
Embedded in the alert is a two-part message. The first part is a search query to find the neurons capable of executing the paper-writing task. The second part encodes a command that will rouse the neurons, once discovered. This process is called “rule activation”, and it takes several tenths of a second to accomplish. The student begins to write his paper.
STEP 3: DISENGAGEMENT
While he’s typing, his sensory systems pick up an email from his girlfriend. The rules for writing a paper are different from the rules for writing to the girlfriend, so his brain must disengage from the paper-writing rules before he can respond. This happens, then the switchboard is consulted, alerting the brain that another shift in attention is about to happen.
STEP 4: RULE ACTIVATION FOR TASK #2
Another two-part message seeking the rule-activation protocols for mailing the girlfriend is now deployed. As before, the first is a command to find the email-writing rules, and the second is the activation command. Now he can pour his heart out, but as before it takes several tenths of a second simply to perform the switch.
Incredibly, these four steps must occur in sequence every time he switches from one task to another. It is time-consuming, and it is sequential. That’s why we can’t multitask.
Studies show that a person who is interrupted takes 50 percent longer to accomplish a task. Not only that, he or she makes up to 50 percent more errors.
This is why driving while talking on a mobile phone is like driving drunk. Mobile phone talkers are a half-second slower to hit the brakes in emergencies, slower to return to normal speed after an emergency, and more wild in their “following distance” behind the vehicle in front of them. In a half-second, a driver going 100 kph travels 14 metres. 80 percent of crashes happen within three seconds of some kind of drive distraction, so increasing your amount of task-switching increases your risk of an accident. More than 50 percent of the visual cues spotted by attentive drivers are missed by mobile-phone takers, who get in more wrecks than anyone except very drunk drivers.
It isn’t just talking on a mobile phone. It’s anything that distracts you. One study showed that simply reaching for an object while driving multiplies the risk of a crash or near-crash by nine times.
Rule # 5. Repeat to remember. The brain has many types of memory systems. One type follows four stages of processing: encoding, storing, retrieving, and forgetting. Information coming into your brain is immediately split into fragments that are sent to different regions of the cortex for storage.
Most of the events that predict whether something learned also will be remembered occur in the first few seconds of learning. The 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.
Rule # 6. Remember to repeat. Most memories disappear within minutes, but those that survive the fragile period strengthen with time. Long-term 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. The way to make long-term memory more reliable is to incorporate new information gradually and repeat it in timed intervals.
Rule #7. Sleep well, think well. The 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. The cells of your brain show vigorous rhythmical activity when you’re asleep – perhaps replaying what you learned that day.
People vary in how much sleep they need and when they prefer to get it, but the biological drive for an afternoon nap is universal. Loss of sleep hurts attention, executive function, working memory, mood, quantitative skills, logical reasoning, and even motor dexterity.
Rule # 8. Stressed brains don’t learn the same way. Your 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.
Under 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.
Individually, the worst kind of stress is the feeling that you have no control over the problem – you are helpless. Emotional stress has huge impacts across society, on children’s ability to learn at school and on employees’ productivity at work.
Rule #9. Stimulate more of the senses at the same time. We 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.
The 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 destination, which include that supervisor of emotions known as the amygdala.
Rule # 10. Vision trumps all other senses. Vision 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.
The visual analysis we do has many steps. The retina assembles photons into little movie-like streams of information. The visual cortex processes these streams, some areas registering motion, others registering color, etc. Finally, we combine that information back together so we can see.
We learn and remember best through pictures, not through written or spoken words.
Rule # 11. Male and female brains are different. The X chromosome that males have one of and females have two of is a cognitive “hot spot”, carrying an unusually large percentage of genes involved in brain manufacture.
Women are genetically more complex, because the active X chromosomes in their cells are a mix of Mom’s and Dad’s. Men’s X chromosomes all come from Mom, and Y chromosome carries less than 100 genes, compared with about 1,500 for the X chromosome.
Men’s and women’s brains are different structurally and biochemically – men have a bigger amygdala and produce serotonin faster, for example, - but we don’t know if those differences are significant.
Men and women respond differently to acute stress: Women activate the left hemisphere’s amygdala and remember the emotional details. Men use the right amygdala and get the gist.
Rule # 12. We are powerful and natural explorers. 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 the 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 behaviour (“Run”).
We can recognize and imitate behaviour because of “mirror neurons” scattered across the brain. Some parts of our adult brains stay as malleable as a baby’s, so we can create neurons and learn new things throughout our lives.
For anyone with children, this is as useful a book as I have come across. As one reviewer said, “Brain Rules is one of the most informative, engaging, and useful books of our time.” I strongly recommend it.
Dr Ian Brand
1 Medina, J 2009, Brain Rules, Pear Press, Seattle
The Royal Australasian College of Medical Administrators
Dr Ian Brand, , p687