Until the 1950s, most people thought sleep was an entirely passive activity. Nowadays, we know that our brains are actually very active when we're sleeping. In fact, neurons in our brain fire nearly as often when we’re asleep as when we're awake -- and they consume almost as much energy.
Why? Some scientists say it’s because neural circuits replay important memories when we sleep. This strengthens the connections among cells in those circuits, helping us form new memories, consolidate older ones, and link more recent memories to earlier ones.
Not only does sleep help us create and consolidate memories, but it also helps us maintain a healthy immune system, regulate hormones that affect our appetites, and stay energetic when we're awake.
But what's really happening in our brains and bodies while we're snoozing away? And how much sleep do we really need?
探花精选 teamed up with to create the infographic below. It answers these questions, and more, about the science of sleep. Check it out.