Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School

by John Medina

people don’t pay attention to boring things (Brain Rule #6). You’ve got seconds to grab someone’s attention and only 10 minutes to keep it. At 9 minutes and 59 seconds, you must do something to regain attention and restart the clock—something emotional and relevant. Also, the brain needs a break.

In one study, a 26-minute nap improved NASA pilots’ performance by 34 percent.

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. I call this the brain’s performance envelope.

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.

There are two ways to beat the cruelty of a harsh environment: You can become stronger or you can become smarter.

Our brains can behold a symbolic object as real by itself and yet, simultaneously, also representing something else.

Dual Representational Theory.

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. We went on to conquer other ecological niches in Africa. Then we took over the world.

Walking on two legs instead of four both freed up our hands and used fewer calories. It was energy-efficient. Our ancestral bodies used the energy surplus not to pump up our muscles but to pump up our minds.

Phineas Gage,

Gage’s case was the first real evidence that the prefrontal cortex governs several uniquely human cognitive talents, called “executive functions”: solving problems, maintaining attention, and inhibiting emotional impulses. In short, this region controls many of the behaviors that separate us from other animals (and from teenagers).

Your most ancient neural structure is the brain stem, or “lizard brain.” This rather insulting label reflects the fact that the brain stem functions the same way in you as in a Gila monster. The brain stem

controls most of your body’s housekeeping chores: breathing, heart rate, sleeping, waking. Lively as Las Vegas, these neurons are always active, keeping your brain buzzing along whether you’re napping or wide awake.

Sitting atop your brain stem is your “mam...

The amygdala allows you to feel rage. Or fear. Or pleasure. Or memories of past experiences of rage, fear, or pleasure. The amygdala is responsible for both the creation of emotions and the memories they generate.

The hippocampus converts your short-term memories into longer-term forms.

The thalamus is one of the most active, well-connected parts of the brain—a control tower for the senses.

Then World War I happened. It was the first major conflict where medical advances allowed large numbers of combatants to survive shrapnel injuries.