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Why Do We Sleep?

MINNEAPOLIS (WCCO) -- Many families with little children know that "falling back" an hour can be a nightmare. Just a one-hour change can make a difference in the strict sleep schedule of a 3-year-old. They may go to bed later, but wake up at the same time – far earlier than Mom or Dad might like.

It happened at Heather Brown's home this past weekend. So, she wondered: Why do we sleep? Good Question.

"We don't know is the short answer to that question," says Dr. Andrew Stiehm, a sleep specialist with Allina Health. "There are lots of thoughts behind why we might need to and I think the answer is broad."

Dr. Stiehm says, despite beliefs to the contrary, sleep is a productive time for all complex animals. Our brains are very busy when we sleep, but in a different way than when we are awake.

"It kind of diverts our attention, our bodies' attention to what task it's doing," he says.

During the day, people work, eat and provide through various physical tasks. At night, when we are in a state of altered consciousness, those tasks go away. The body can divert its attention to other important tasks like growing and healing. Dr. Stiehm says it's primarily during non-REM sleep that hormones to growing and healing surge.

Memories are also consolidated during the REM portion of our sleep cycle.

"That's our job in those 17 hours to take in that information," Dr. Stiehm says. "Then, at night, we have to change from taking in the information to preserving, storing, filing, processing that information."

Researching what happens when people stop sleeping is understandably difficult because the research subjects don't last long before falling apart.

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