7 myths about your brain

November 7, 2011 by Chris in Science

1. The brain is grey

Your brain is not just grey, it’s also black, white and red! While the bulk of the brain is grey matter, there are also white matter, black substantia nigra and red blood vessels. The reason preserved brains we see are grey is because of the formaldehyde.

2. We only use 10% of our brain

Everyone’s heard this one before. The idea is that most people are only using 10% of your potential brain power. If you can unlock the other 90%, you could do great things. It’s often a plot device in pop culture, most recently in the film Limitless, where taking a drug can unlock the other 90%. A possible origin of this myth is from Harvard psychologists James and Sidis, who said that people were only meeting a fraction of their mental potential.

Actually, MRIs show that 100% of the brain is being used all the time–even when you’re asleep. If 90% of the brain wasn’t used, then brain damage wouldn’t be nearly as severe.

3. Subliminal messages affect the brain

Subliminal messages are sensory stimuli that are below the absolute threshold for conscious perception, that is, you don’t know you’re experiencing it. It could be anything from an imperceptible flash of images to an inaudible sound. The idea is that these messages can subliminally influence your behavior, making you buy products.

The origins of this belief stem from research done by James Vicary. Vicary said he inserted subliminal messages advocating popcorn into a movie, and that sales went up almost 60% in that theater. In reality, Vicary had lied. More modern research shows no evidence that subliminal messages can affect the brain.

4. Alcohol kills brain cells

Alchol never actually results in brain cell death. Instead, it damages dendrites (the end of neurons), which impairs brain cells’ ability to communicate with each other. Most research indicates that this damage is reversible. Don’t take this as an excuse to binge, however!

Alcohol is still bad for you. Excessive consumption can lead to a neurological disorder called Wernicke-Korsakoff syndrome, which kills neurons, leading to amnesia, confusion, paralysis and even death. Of course, there are also dozens of other organs alcohol can hurt–just not the brain so much.

5. Adults have more brain cells than children

The logic behind this one seems to make sense. An adult is smarter, his brain is bigger, so he must have more brain cells. Not so!

The number of brain cells you have remain essentially constant for your life: around 100 billion. This is the same for adults and children alike. The reason adults have a bigger brain (or head) than children is because of other cells in the brain that grow, such as the area between neurons.

6. You are either left-brained, or right-brained

The idea is that everyone is either left-brained or right-brained. If you’re left-brained, you tend to be more logical and rational, while right-brainers are more creative and emotional. If you’re right-handed, you’re left-brained and if you’re left-handed, you’re right-brained.

This isn’t true! While the brain is split into the right and left hemisphere, the brain almost always acts as whole. No action can be done by an independent hemisphere. Sometimes a side of the brain is dominant, but never alone.

7. Your brain still works after decapitation

The idea is that even if your head is removed from your body, your brain will remain active–even for a while seconds. Anecdotal evidence goes all the way back to the French Revolution, where victims of the guillotine were able to blink up to 30 seconds after their decapitation.

Today, doctors believe any actions resulting from decapitation are muscle reflexes, and not conscious movements. Without oxygen, consciousness is lost within seconds and the brain instantly goes into a coma.