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Reviewed 5/10/2022

The human brain: True or false?

Your brain is the most complex part of your body—controlling thought, movement and behavior. Scientists have learned more about it in the last few decades than in all of the previous centuries. So how much do you know about the human brain?

True or false: The brain weighs about 3 pounds.

True. Your brain could weigh a little more or a little less. But that wouldn't necessarily mean you were any more or less intelligent than most people.

True or false: The main intellectual part of the brain is toward the back of the head.

False. The part of the brain that holds your memories and allows you to think, plan and read books is the cerebrum. It's found in the forebrain—the biggest and most highly developed part of the brain.

True or false: The right side of your brain controls the left side of your body.

True. In addition, the left side of your brains controls the right side of your body. If one side of the brain is damaged—such as from a stroke—a person may lose functionality in the opposite side of the body.

True or false: The part of the brain that's responsible for pleasure can be damaged by drugs.

True. The brain's reward center releases a chemical know as dopamine, which causes a person to feel pleasure, like when they eat something tasty. However, illicit substances can overload the brain with dopamine—and, in time, make it difficult for a person to feel pleasure without drugs.

True or false: The brain is called "gray matter" because it's mostly a dark gray color.

False. The insulation around nerves in the brain actually makes most of it appear white. The term "gray matter" comes from the thin rind of tissue that coats the surface of much of the brain. This gray-colored rind of tissue is called the cortex.

Curious for more? There's a lot more to learn about.

Visit the Brain health topic center

Sources: National Institute of Neurological Disorders and Stroke; National Institute on Drug Abuse

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