The longer you're awake, the faster your brain revs

Ever felt like you brain had a mind of its own? Your sense that your sleep-deprived brain is racing -- albeit unproductively -- is accurate. Dr. Marcello Massimini, a neurophysiologist at the University of Milan, says he's found that when you "poke" a sleepy brain it reacts with stronger, faster spikes in activity than a well-rested brain. Unfortunately, as we already know, faster isn't always better in the brainscape, so while this discovery won't help us pull all-nighters, it does explain why depressed people with very low brain activity show mood improvement when they skip sleep. "You keep them awake for one night, and, incredibly, they get better," Massimi tells Scientific American.