Why sleep? -- How do we know sleep is important for the brain? -- Building blocks of the brain -- How the brain controls sleep -- Mental spring cleaning while you sleep -- How and why memories are replayed in sleep -- What is dreaming and what does it tell us memory? -- Sleep, semantics, and the mind -- Emotional memories and sleep -- Does sleep disarm dangerous emotions? -- Good sleepers and bad sleepers -- Getting the most out of your sleep -- Brief notes on how to get the sleep you need

Neuroscientist Penny Lewis explores the latest research into the nighttime brain to understand the real benefits of sleep, showing how, while our body rests, the brain practices tasks it learned during the day, replays traumatic events to mollify them, and forges connections between distant concepts