This is why we sleep
Despite literally trillions of hours earth's creatures have spent sleeping since the dawn of life, scientists still don't fully know what purpose sleep serves. New research gives us an idea, though.
According to paper published in the journal Science, sleep gives our brains the opportunity to hit the reset button on its synapses, or memory-storing connections that send signals between neurons. In waking hours, synapses grow to allow more information gathered through the day's experiences to travel around the brain. During sleep, the researchers found, the synapses of mice shrank by 18 percent on average. Without the sleep time, they hypothesized, the brain might get bogged down with extraneous information and memories, which certainly wouldn't help our brains function.
Larger synapses remained unaltered in the mice, which led the researchers to believe they held more important memories. "During sleep, we are much less preoccupied by the external world … and the brain can sample [or assess] all our synapses, and renormalize them in a smart way," study co-author Dr. Chiara Cirelli told Live Science.
This shrinking-to-forget process may just be one function of sleep, and it may not be be the direct reason humans and animals do it. But it does present an argument for what the brain does when it's conked out.