11 Fascinating Facts You Never Knew About Your Brain

It only weighs 3 pounds. It runs on about 20 watts of electricity. It’s what sets us apart from other animals.

Figure it out yet? We’re talking about the human brain.

While it’s undoubtedly the most important organ, we tend to forget about it while it’s quietly keeping the body breathing, walking, and talking. The brain does so much, in fact, that scientists still don’t understand exactly why and how it carries out all its complex functions. What we do know about the brain, however, is seriously awe-inspiring. Case in point: these 11 facts.

1. THE HUMAN BRAIN IS SHRINKING

For the first 2 million years of human evolution, the brain grew. And grew and grew, until the time of the Cro-Magnons, a brawny incarnation of humans with huge jaws and enormous chests. That was 20,000 years ago—and since then, our brains have shrunk in size, losing a chunk about the size of a tennis ball.

Though scientists don’t believe this change is anything to be concerned about, they also don’t know exactly why it’s happening.

2. THE BRAIN IN YOUR SKULL ISN’T YOUR ONLY BRAIN

Guilty of blowing your budget at the grocery store when you shop hungry? There’s a reason for that: each of us has a so-called “second brain” in the intestines.

All kidding aside, recent research has shed more light on what experts call the gut-brain connection. Sure, the mass of 100 million neurons in the intestines deals mainly with digestion, but that’s not all. The enteric nervous system also produces serotonin (the neurotransmitter that balances our moods) and may have an impact on depression. 

3. YOUR BRAIN IS BETTER AT SOME THINGS AT 70 THAN IT WAS AT 22

As you age, you get better at some things and worse at others. Contrary to popular belief, cognitive function doesn’t just drop off after middle age.

Though your brain processes information most quickly at age 18 or 19, its ability to understand complex emotions improves until your 50s, and your grasp of vocabulary will likely be its best in your 70s.

4. YOUR SUBCONSCIOUS REALLY RUNS THE SHOW

Think you’re in control of your life? Think again. Researchers believe that 95 percent of decision-making occurs in the subconscious mind. You’re not consciously deciding whether or not to stop at a red light or continue breathing in or out—the subconscious is taking over.

Don’t worry, this isn’t a bad thing—experts say the subconscious mind is much more rational than the conscious mind.

5. A BAD ATTITUDE COULD PERMANENTLY ALTER YOUR BRAIN

Every time you have a thought, the brain shoots neurotransmitters across its synapses to pass the message from cell to cell. The more you think a certain way, the easier it becomes for those synapses to connect—and the more likely you are to have those thoughts in the future.

Yes, that means negativity actually rewires the brain. Complaining more often actually makes you more unhappy—so keep that in mind the next time the barista gives you whole milk instead of skim.

6. THERE’S NO SUCH THING AS A “PHOTOGRAPHIC” MEMORY

Just imagine it: During a test, you could conjure up an image of your notes to give you the answers. There’s no need to add phone numbers to your address book—you’d know them all by heart. Having a photographic memory sure would be nice.

Convenient as seems, scientists say there’s no such thing. The closest thing? Eidetic imagery. People with this rare ability can vividly remember an image with near-perfect accuracy after having seen it for only a few seconds. It’s most common in children, but often fades as their brains grow and learn to process information more efficiently.

7. YOUR BRAIN CAN PREDICT THE FUTURE—SORT OF

A 2012 study revealed that the frontopolar cortex draws on past experiences to predict future events. In the experiment, researchers gave their subjects four slot machines to play. What the patients didn’t know is that the probability of winning on one of the machines changed unexpectedly throughout the experiment. Researchers were surprised to see that their subjects were able to devise a strategy to win the most money by observing the trends in winning—using the frontopolar cortex. Pretty impressive. (No word on why you always lose money in Vegas, though.)

8. NO, YOU’RE NOT PSYCHIC—BUT SCIENTISTS DON’T REALLY KNOW WHAT CAUSES DÉJÀ VU

Hate to break it to you, but that feeling of already having been here you sometimes get when walking into a room doesn’t make you clairvoyant. At least 30 percent of us will experience déjà vu—French for “already seen”—in our lifetime, and it’s most common in people under 25. Some even experience this unsettling feeling for the first time by age 6!

Scientists still don’t know exactly what causes this condition, since it’s extremely difficult to research, and no one really knows how to trigger it in a lab. Methods to induce déjà vu in clinical settings (like squirting warm water in a patient’s ear) have rarely worked. The operating theory is that misfiring neurons produce this feeling of having “already seen” something. And, since we do know that people with epilepsy or dementia experience the condition more often, the theory makes sense.

9. SOME PEOPLE REALLY DO EXPERIENCE STIMULI MORE VIVIDLY

Ever watched a Kanye West interview? He speaks so ardently about his music. This is the guy who said, “I am Warhol. I am the No. 1 most impactful artist of our generation. I am Shakespeare in the flesh.”

Maybe there’s a reason for that. Like Duke Ellington, Pharrell Williams, and Stevie Wonder, Yeezy has synesthesia, a condition in which one sense is perceived as another. Specifically, West sees music as brilliant colors. Only one in 2,000 people experience this condition, and it takes many forms—you might feel voices brush against your skin, or taste food as explosions of colors and texture.

10. UNDER THE RIGHT CONDITIONS, YOU CAN CONTROL YOUR DREAMS

It sounds like something right out of “Inception,” but lucid dreaming—or the ability to interact with and control your dreams—is real.

Though scientists used to be pretty skeptical, they now believe lucid dreaming happens during REM sleep, when you realize you’re dreaming and consciously decide to enter the dream. Never had one? It’s not too late—the average person has three to five dreams every night, and you might be able to hack into one of them by following these tips.

11. WHILE YOU SLEEP, THE BRAIN PARALYZES THE BODY

When your dreams feel real, it’s a wonder you aren’t sleepwalking, running, and jumping all over the place in the middle of the night. Guess what—the brain’s responsible for keeping you safe from harm while your mental self is off in dreamland, too.

During REM sleep, specialized neurotransmitters switch off the cells that allow your muscles to move. (We shudder to imagine what would happen if this wasn’t the case!)

And not just during sleep—when you think about it, your noggin protects you from harm all day long. That’s reason enough to treat it to some brain food, if you ask us.