And when you look at this structure in those people who had a full night of sleep, we saw lots of healthy learning-related activity. Yet in those people who were sleep deprived, we actually couldn't find any significant signal whatsoever. So it's almost as though sleep deprivation had shut down your memory inbox and any new incoming files, they were just being bounced. You couldn't effectively commit new experiences to memory. There are big, powerful brainwaves that happen during the very deepest stages of sleep that have riding on top of them the spectacular burst of electrical activity that we call sleep spindles. And it's the combined quality of these deep sleep brainwaves that acts like a file transfer mechanism at night. Shifting memories from a short-term vulnerable reservoir to a more permanent long-term storage site within the brain.