In 2003, Chiara Cirelli from the University of Wisconsin-Madison theorized that this mass downscaling happens specifically while we sleep. In fact, she argued, it might be one of the reasons that sleep exists at all—to provide a quiet time when our brains can effectively renormalize our synapses, ready for another day of learning. That may partly explain why sleep is so universal among animals, and why our mental abilities take a hit after a sleepless night. Sleep is the price we pay for the ability to learn, and it’s non-negotiable.
Office of Strategic Communication