The Science of Sleep: What Happens During the 5 Stages of Your Sleep Cycle [Infographic]

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.

via HubSpot Marketing Blog http://bitly.com/1MMwhV3