Brain Rules - John Medina

Brain Rules - John Medina

Video Book Summary

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Book Summary Notes

Brain Rules

“Because we don’t fully understand how our brains work, we do dumb things."

"We try to talk on our cell phones and drive at the same time, even though it is literally impossible for our brains to multitask when it comes to paying attention."

"We have created high-stress office environments, even though a stressed brain is significantly less productive than a non-stressed brain. Our schools are designed so that most real learning has to occur at home." 

"Taken together, what do the studies in this book show? Mostly this: If you wanted to create an education environment that was directly opposed to what the brain was good at doing, you probably would design something like a classroom. If you wanted to create a business environment that was directly opposed to what the brain was good at doing, you probably would design something like a cubicle. And if you wanted to change things, you might have to tear down both and start over."

"Blame it on the fact that brain scientists rarely have a conversation with teachers and business professionals, education majors and accountants, superintendents and CEOs. Unless you have the Journal of Neuroscience sitting on your coffee table, you’re out of the loop."

"This book is meant to get you in the loop.”

Optimal Environment

  • The human brain functions best in very specific ways..  
  • Unfortunately the environments most of us are expected to perform in aren't optimal for those ways!
  • Fortunately John is going to show us exactly how we can change that environment to help us get the most out of ourselves

There are 12 rules in this book that if applied will help you learn, think and perform your best!

I'm just going to go over a few of the ones I think are the most important and easiest to change here but recommend you pick up the book if you want a full look into the 12 rules!

The Rules

“My goal is to introduce you to 12 things we know about how the brain works.  I call these Brain Rules."

"For each rule, I present the science, introduce you to the researchers behind it, and then offer ideas for how the rule might apply to our daily lives, especially at work and school. The brain is complex, and I am taking only slivers of information from each subject—not comprehensive but, I hope, accessible.”

The Rules

1. Survival - The human brain evolved, too.

2. Exercise - Exercise boosts brain power.

3. Sleep - Sleep well, think well.

4. Stress - Stressed brains don’t learn the same way.

5. Wiring - Every brain is wired differently.

6. Attention - We don’t pay attention to boring things.

7. Memory - Repeat to remember.

8. Sensory Integration - Stimulate more of the senses.

 9. Vision - Vision trumps all other senses.

10. Music - Study or listen to boost cognition.

11. Gender - Male and Female brains are different.

12. Exploration - We are powerful and natural explorers.

Apply The Rules

Most of us probably know intuitively which of these rules we're not performing best on..  

Which of these rules do you need to pay more attention too?

How can you setup your environment to make sure your brain can perform at it's highest level?


“All of the evidence points in one direction: Physical activity is cognitive candy."  

"Civilization, while giving us such seemingly forward advances as modern medicine and spatulas, also has had a nasty side effect. It gives us more opportunities to sit on our butts. Whether learning or working, we gradually quit exercising the way our ancestors did."

"Recall that our evolutionary ancestors were used to walking up to 12 miles per day. This means that our brains were supported for most of our evolutionary history by Olympic-caliber bodies."

"We were not sitting in a classroom for eight hours at a stretch. If we sat around the Serengeti for eight hours—heck, for eight minutes—we were somebody’s lunch. We haven’t had millions of years to adapt to our sedentary lifestyle. That lifestyle has hurt both our physical and mental health.”


So much research is now out there about how connected the body and the mind are..

  • The stress of the mind is the stress of the body and vice versa..  
  • Having a body that supports your brain by helping it create useful neurotransmitters and by dissipating stress chemicals is extremely important!

How do you feel after a full day of sitting?  

  • Most of us know that after just one day of sitting for a whole day we feel like cognitive junk.. 

Thinking is harder..  Maybe we're moody or grouchy!

  • Now imagine that adding up for 50-60 years! 
  • It's no wonder people are lined up and ready to retire..

What can you do to mitigate the effects of sitting?

  • Here are a few tips!
  • 1 Hour of sitting = 10 Mins of targeted stretching 
  • Set a 30 Minute Move Timers
  • Outside of work get up and move with a hobby!


“One study showed that a highly successful student can be set up for a precipitous academic fall just by getting less than seven hours of sleep a night."

"Take an A student used to scoring in the top 10 percent of virtually everything she does. If she gets just under seven hours of sleep on weekdays, and about 40 minutes more on weekends, her scores will begin to match the scores of the bottom 9 percent of individuals who are getting enough sleep.”

Sleep as a Cognitive Enhancement

Sleep is probably the one thing most of us 'know' we should be optimizing in order to optimize our brains..

  • From this study here we can see that even if we're above average but we don't sleep as much as we should we're going to be below average..
  • Now this is for students but we can use this for a proxy in our own lives..  Work, creativity and learning all hinge on getting good nights of sleep!

How many hours of sleep do you get in a night?

  • For me I know I aim to get 9 hours of sleep a night..  Now it doesn't always happen!  
  • But I know if I aim for 9 hours I will reliably get 8 hours of sleep..  

Some sleep 'hacks' that I've found helpful!

  • Shut off electronics at least an hour before bed and maybe read fiction
  • Do about 10-20 minutes of light stretching after shutting off electronics
  • Take some magnesium and CBD before bed
  • 100% dark and cool room


“As a professor, I’ve noticed a change in my student’s abilities to pay attention to me during a lecture."

"They have a habit of breaking out their laptops while I’m talking. Three researchers at Stanford University noticed the same thing about the undergraduates they were teaching, and they decided to study it.

"First, they noticed that while all the students seemed to use digital devices incessantly, not all students did. True to stereotype, some kids were zombified, hyperdigital users. But some kids used their devices in a low-key fashion: not all the time, and not with two dozen windows open simultaneously. The researchers call the first category of students Heavy Media Multitaskers. Their less frantic colleagues were called Light Media Multitaskers."

"If you asked heavy users to concentrate on a problem while simultaneously giving them lots of distractions, the researchers wondered, how good was their ability to maintain focus? The hypothesis: Compared to light users, the heavy users would be faster and more accurate at switching from one task to another, because they were already so used to switching between browser windows and projects and media inputs. The hypothesis was wrong."

"In every attentional test the researchers threw at these students, the heavy users did consistently worse than the light users. Sometimes dramatically worse." 

"They weren’t as good at filtering out irrelevant information. They couldn’t organize their memories as well. And they did worse on every task-switching experiment. Psychologist Eyal Ophir, an author of the study, said of the heavy users, ‘They couldn’t help thinking about the task they weren’t doing."

"The high multitaskers are always drawing from all the information in front of them. They can’t keep things separate in their minds.’ This is just the latest illustration of the fact that the brain cannot multitask. Even if you are a Stanford student in the heart of Silicon Valley.”

Attention Residue

Cal Newport talks about attention residue in his book Deep Work

  • Essentially attention residue is the attention that is left behind when you are switching tasks
  • Based on the complexity of the task your mind will stay thinking about that task..  

How many of us are multitasking?

  • Do you have multiple things on your mind at once?  
  • This could be social media, multiple projects or even just office interruptions..  
  • The research shows that this is killing your ability to think clearly and effectively because humans simply cannot multitask!

Single Tasking

  • The most effective way to manage time is to 'single task' all of your most important work.. 
  • That means to focus on one thing until it's completed without distraction!
  • Here are some tips to help you get this done!

• First use a Pomodoro timer

• Cut off all distractions by using physical blocks

• Use music to keep you focused on one task and less likely to get distracted


“If scientists want to know whether you are retrieving a vivid memory, they don’t have to ask you. They can simply look in their fMRI machine and see whether your left inferior prefrontal cortex is active."

"Scientist Anthony Wagner used this fact to study two groups of students given a list of words to memorize. The first group was shown the words via mass repetition, reminiscent of students cramming for an exam. The second group was shown the words in spaced intervals over a longer period of time. The second group recalled the list of words with much more accuracy, with more activity in the cortex showing up on the fMRI (that’s ‘functional magnetic resonance imaging) machine.

"Based on these results, Harvard psychology professor Dan Schacter wrote: ‘If you want to study for a test you will be taking in a week’s time, and are able to go through the material 10 times, it is better to space out the 10 repetitions during the week than to squeeze them all together.’"

"Scientists aren’t yet sure which time intervals supply all the magic. But taken together, the relationship between repetition and memory is clear. 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 re-expose yourself to the information more elaborately and in fixed, spaced intervals if you want the retrieval as vivid as possible.”

Desirable Difficulty

Benedict Cary talks about creating 'Desirable Difficulty' in his book How We Learn

  • It's the process of making it just hard enough that your brain has to strain a little bit to remember information..  
  • Spacing out the studying of information would be one way to create this desirable difficulty..  
  • Because the brain has to strain just a little bit to remember the information it has to myelinate the pathway to get there making a stronger connection..

Creating quizzes for yourself may be the most effective way to do this!

  • First you write out the information in point form
  • Next you save the document as an 'answer key'
  • Then you study the answer key
  • After that you erase parts of the answer key leaving it 'fill in the blanks' style
  • Finally you do that quiz over and over again until you remember every single answer without straining

Where would this be effective in your life?

  • Presentations
  • Learning a new skill
  • Mind Mapping Books?


“Babies are born with a deep desire to understand the world around them and an incessant curiosity that compels them to aggressively explore it."

"This need for exploration is so powerfully stitched into their experience that some scientists describe it as a drive, just as hunger and thirst and sex are drives."

"All babies gather information by actively testing their environment, much as a scientist would."

"They make a sensory observation, form a hypothesis about what is going on, design an experiment capable of testing the hypothesis, and then draw conclusions from the findings. They use a series of increasingly self-corrected ideas to figure out how the world works.”

The Explorer Instinct

All humans have an 'explorer instinct' inside of us right from the time we are born..

  • This is the way babies learn and we often lose it as we become adults..  
  • Which is to our own detriment because it's really an effective way to learn!

This for me is the number one insight from the book.. 

  • I've realized that this is how I have learned my entire life!
  • This is the 'learn by doing' learning style to me and it's been the most effective for me..  
  • But I didn't know why!  So this was a big revelation..

How can you use this in your life?

  • What's something you want to do or create?
  • What hypothesis do you have about the best way to achieve it?
  • What exploration can you do around that to learn?
  • How can you continue to explore and learn new ways of doing things?
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