Brain Rules

Book Review: Brain Rules by John Medina

Dave Kinnear1-On Leadership, Book Reviews

John Medina has pulled together all the verified scientific data (repeatable experimentation, trials, etc.) on how our brains “work” to process our sensory inputs and remember what we’ve experienced. He readily admits that this is an on-going study that will be augmented as we discover new ways the brain works and evolves.

Medina has organized the pertinent findings into what he calls “12 Brain Rules.” The hard cover version of the book (available in Kindle and paperback as well) comes with a DVD comprising videos of the meat of the brain rules. There is also a very robust website that provides support data. Briefly, Medina’s rules (or Principles) are:

  1. Exercise: Our brains were made for walking – 12 miles a day, so move. Aerobic exercise just twice a wekk halves your risk of general dementia and cuts your risk of Alzheimer’s by 60 percent.
  2. Survival: The human brain evolved, too. We don’t have one brain; we have three – “lizard brain,” the “mammalian brain” and the “Human brain” or cortex. Going from 4 legs to 2 freed up energy to develop a complex brain.
  3. Wiring: Every brain is wired differently. What you do and learn in life physically changes what your brain looks like – it literally “re-wires” itself. 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 do not show up on IQ tests.
  4. Attention: People don’t pay attention to boring things. The brain’s attentional “spotlight” can focus on only one thing at a time: NO MULTITASKING! 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. Audiences check out after 10 minutes (but you can grab them back by telling narratives or creating events rich in emotion).
  5. Short-term memory: Repeat to remember. The brain has many types of memory systems. Information coming into your brain is immediately split into fragments that are sent to different regions of the cortex for storage. You can improve your chances of remembering something if you reproduce the environment in which you first put it into your brain.
  6. Long-term memory: Remember to repeat. Most memories disappear within minutes. 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 – it can take years to end the conversation. Brains give us only an approximate view of reality because the 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.
  7. Major Brain ComponentsSleep: Sleep well, think well. The brain is in constant tension between cells and chemicals that try to put you to sleep and cells and chemicals that try to keep you awake. The neurons of your brain show vigorous rhythmical activity when you’re asleep – perhaps replaying what you learned that day. People vary in how much and when they need to sleep. But the biological urge for an afternoon nap is universal. Loss of sleep hurts attention, executive functions, working memory, mood, quantitative skills, logical reasoning and even motor dexterity.
  8. Stress: Stressed brains don’t learn the same way. 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 a huge impact across society, on children’s ability to learn in school and on employees productivity at work.
  9. Sensory Integration: 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, one influencing the other. Smells have an unusual power to bring back memories.
  10. Vision: 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 brains tell us to see and it’s not 100 percent accurate. The visual analysis we do is complex and has many steps. We learn and remember best through pictures, not through written or spoken word.
  11. Gender [uh, oh! Didn’t Larry Summers get in trouble over this?]: 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 their Y chromosome carries less than 100 genes, compared with about 1,500 for the X chromosome. 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.
  12. Exploration: We are powerful and natural explorers. Babies are models 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 and an adjoining region tells us to change behavior. We can recognize and imitate behavior because of “mirror neurons” scattered across the brain. Some parts of our adult brains say as malleable as a baby’s, so we can create neurons and learn new things throughout our lives.

The above brief summary of the twelve brain rules is well expanded upon in the book and quite nicely supported by the website and of course the DVD. Medina shines a light on to several interesting areas of how our human brain evolved. He points out how we must really start changing the way we organize our schools and our workplace if we want to maximize the human potential. And so this book not only sheds light on the science behind brain evolution but also gives us ample thought on how we might use the information to survive and thrive at work, home and school.


Click here to see the book on Amazon.