Brain Rules

John Medina is a scientist specializing in molecular biology and the founder of two brain research institutes. He has deeply studied the subject and created the Brain Rules so we can get the most out of this super sophisticated equipment we carry around with us.

Medina explains that everything we know about how the brain works comes from biologists who study tissues, experimental psychologists who study behaviors, and cognitive neuroscientists who study how tissues relate to behaviors, plus studies from evolutionary biologists. The results of all this research suggest that the brain seems to have been developed to:

• solve problems

• related to survival

• in an open and unstable environment, and

• does this while constantly moving.

I'll summarize the 12 rules explained in his book of the same name, but I should mention that each one deserves a separate review.

RULE #1: THE HUMAN BRAIN EVOLVES

Medina explains that we're human precisely because we can fantasize, meaning we can imagine attributes or meanings for things that don't have them, or even invent these things.

We combine symbols and derive layers of meaning; that's why we're capable of writing and reading a language, reasoning through mathematical questions, and producing art like painting, sculpture, music, literature, and poetry.

In other words, we're able to create cultures, collaborate, infer motivations and intentions to, ultimately, dominate the world. But this is only possible because of the neocortex, which is relatively recent in our evolutionary history. And we continue to change and adapt.

RULE #2: EXERCISE BOOSTS BRAIN POWER

Of everything that's been studied about human evolution, one thing is certain: we've always moved.

Research indicates that, for much of our evolutionary time, we walked about 20 km every day.

Only in the last century have people started spending most of their time sitting, a completely unnatural position. Sure, the brain will adapt to this too, but we don't have thousands of years to wait until it performs well under these conditions.

We knew this was bad for the spine, circulation, and the body in general, but the fact is that a sedentary lifestyle also impairs the cognitive performance of the brain.

Walking a few kilometers a day is good, but doing 30 minutes of aerobic exercise (that is: sweating!) two or three times a week reduces by more than 60% the risk of developing degenerative diseases like dementia and Alzheimer's.

Why? Exercise increases blood flow in the body and, consequently, increases access to oxygen. And the brain is an oxygen sponge. This is very serious.

RULE #3: SLEEP WELL, THINK WELL

Actually, when we sleep, the brain doesn't stop working and continues to consume the same amount of energy as when we're awake.

The exception is the period known as non-REM, but it corresponds to only 20% of the cycle time, with the number of hours needed and the period varying according to each person's circadian cycle.

Studies show that naps during the day bring enormous benefits to cognitive ability and concentration. Scholars believe that some type of offline processing happens during the night, reproducing and remembering what was experienced during the day, among other activities.

In short, sleeping well is essential for brain health.

RULE #4: STRESSED BRAINS DON'T LEARN THE SAME WAY

There are several known types of stress; some increase learning and others really hinder the process.

For example: skydiving can be a nightmare for some and a dream for others. Each organism will determine how to process each type, but there are always physiological changes involved (acceleration of heartbeats, increased blood pressure, sensation of massive energy release; in some cases, loss of emotional control).

In any case, it's known that stress deeply affects the immune system and memory; in extreme cases, it can even kill hippocampus cells. There's also a relationship between stress and depression, also impairing language, reason, fluid intelligence, and spatial perception.

And it's not possible to separate domestic stress from the work environment; one affects the other and both enhance each other.

RULE #5: EVERY BRAIN IS WIRED DIFFERENTLY

Did you know that identical twins, who go through the same experiences, don't have identical brains?

Every time we learn something, our brain physically changes its configuration.

This means that the brain doesn't stop changing its internal configurations; they're altered all the time and are never the same for two people.

The brain behaves like a muscle; the more you learn, the more complex and strong it becomes.

RULE #6: WE DON'T PAY ATTENTION TO BORING THINGS

Paying attention essentially depends on our interest in the thing and how we're emotionally connected to it.

And, very importantly, our brain IS NOT MULTITASKING!

We can only pay attention to and process one thing at a time. Oh, okay, and how can we walk and talk at the same time? It's because the brain isn't paying attention to both things at once, you see? Walking is on autopilot.

When we try to do two tasks that require attention at the same time, what the brain does is switch attention between the two in small time intervals.

This "switching" between activities costs a huge effort with clear damage to your performance.

RULE #7: REPEAT TO REMEMBER

The brain has several types of memory systems. Declarative memory, for example, has 4 processing stages: encode, store, retrieve, and forget.

The more elaborate the encoding during the initial moments, the stronger the memory will be (and this involves emotions).

The chances of remembering something increase if the person can reproduce the environment in which the memory was built.

Working memory is a collection of spaces that allow us to temporarily retain newly acquired information; if we don't repeat them, they're erased. Long-term memory, in turn, is a two-way path between the hippocampus and the cortex, until the hippocampus cuts the connection and the memory is definitively fixed in the cortex.

This can take years. So, the best way to remember things is to incorporate new information gradually and repeat it at intervals.

RULE #8: STIMULATE MORE SENSES

We only perceive the world because of our senses. Our "sensors" (eyes, skin, tongue, nose, ears, etc.) capture information from the external world, transform it into electrical signals, and take it to the brain.

Inside, these signals are combined and the brain compares what it received with what it had previously recorded to interpret the experience.

So, each sense influences the other in the construction of our perception, just as our previous experiences explain why, faced with a certain event, different people perceive it in completely different ways (of course, because everything depends on what they already had inside the brain to use as a reference).

Smell is the only one that takes a shortcut and doesn't go through the thalamus; it directly accesses our memories, see how powerful that is!

Because of the integration between the senses, we learn and memorize many more events if they stimulate more than one sense. That is, we learn more when we receive information from different sensors (example: vision+hearing+touch works much better than just hearing).

RULE #9: VISION TRUMPS ALL OTHER SENSES

We don't see with our eyes, but with our brain. The visual process is extremely complex and occupies almost all of the processing capacity of our senses, partly because only a portion of what we're seeing is sent as an electrical signal; the brain is responsible for filling in all the missing gaps with its stored collection.

And vision can prevail not only over smell and taste, but over touch as well.

RULE #10: MUSIC INCREASES COGNITIVE ABILITY

Learning music increases math scores, reading ability, Intelligence Quotient, spatial-temporal reasoning, the ability to learn foreign languages, empathy, and social skills; that's what the studies say.

Music also changes a person's mood because of the neurotransmitters dopamine, cortisol, and oxytocin, released when we listen to a song we like.

RULE #11: MALE AND FEMALE BRAINS ARE DIFFERENT

We learned in school that women carry XX chromosomes and men, XY. What I didn't learn (or don't remember) is that the X carries more than 1500 genes, while the Y, just over a hundred.

This means that women have a kind of backup in case any gene has problems (she ignores it and takes the one from the other X). If any gene on the X has a problem in a man, he has nowhere to draw from.

That's why men are more prone to diseases related to genetic mutations such as mental retardation and schizophrenia.

On the other hand, women are more prone to depression. Women also have the two hemispheres more connected, tending to use both to do most tasks, while men, who have weaker connections, tend to use only one.

Regarding behaviors, the influence of the social context is so great that there's no way to determine what is more influenced by culture and what is the role of genetics.

What can be said is that:

1) Emotions are fundamental; they're what make the brain pay attention;

2) Men and women process some emotions differently;

3) These differences are the result of a very complex interaction between biology and culture.

But, in general, experiments show that these differences don't influence the intellectual capacity of genders.

RULE #12: WE ARE NATURAL EXPLORERS

Babies are an excellent model to show how we learn: not passively, but by actively exploring the world, testing limits, observing, experimenting, and concluding.

The most interesting thing is that some parts of the adult brain remain as malleable and plastic as they were in childhood; this ability allows us to create neurons and learn new things throughout life.

Isn't that fantastic?

The website www.brainrules.net has a video about the book and even a version for parents with babies to help their little one's brain develop better.