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#askMIT: Why Don't We Use All of Our Brain Cells?

3 minutes

Hi, my name is Veneta. I live in Acton, Massachusetts, and I am in grade five. My question is, why don't we use all our brain cells? What do we do with the brain cells we are not using? I'm Hannah Iaccarino at the Picower Institute for Learning and Memory at MIT. I'm here to answer a question: "Why don't we use all our brain cells?" We actually do, just not all at the same time. There are three main reasons. The first are neurons. These are the ones we think of in the brain. They communicate with each other and help us perform the tasks we perform during the day, like talking, learning, listening. There's another brain cell we don't think about as often. Those cells are called glia. Glia help the neurons do their daily tasks. When neurons are talking to each other and doing their normal activities to help us do our activities, they'll sometimes create waste. Glia clean up that waste. Another function of glia is that when neurons are injured-- say you get a concussion-- glia activate and help fix the neurons so your brain can function. We use all our cells, but not all at the same time. Repair cells aren't used unless there was something to repair. To help us walk, we need our motor cortex. It controls our feet and legs and helps us walk properly and control our muscles. To learn and form a memory, you need a brain area called the hippocampus. That brain area takes in outside information and packages it into a pretty package so we can remember that memory now until forever. When we're walking, we wouldn't use our memory cells to control our legs. Even though we'll use memory cells and motor cells, we'll use them at different times for different activities. If a computer has bytes to store memory, imagine using all your bytes by turning on your computer and saving one file. That would be a very inefficient computer. You'd need a new computer for every document you produced. Now think about your brain. If you used every cell for a memory, you'd need a brain for every memory. That is just not possible. It's a rumor that we don't use all our brain cells. We use them all, just not all at the same time. Accessibility provided by the U.S. Department of Education.

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Hannah Laccarino, a graduate student in Brain and Cognitive Sciences at MIT, answers questions about the importance of brain cells. She also discusses what happens to the brain cells not used. Part of the "#askMIT" series.

Media Details

Runtime: 3 minutes

#askMIT
Episode 1
3 minutes
Grade Level: 8 - 12
#askMIT
Episode 2
3 minutes
Grade Level: 9 - 12
#askMIT
Episode 3
2 minutes
Grade Level: 10 - 12