Why is deep sleep so important to memory? It's about time.

It's no hidden health secret that sleep is really good for us. It helps our immune systems and supports almost every organ system in the body. We've also known for almost two decades that the slow, synchronous electrical waves in the brain during deep sleep supports memory formation. However, we did not know exactly how the brain does this until now. These slow waves make the neocortex–where long-term memory is stored in the brain–particularly receptive to new information.