#01: What is Sleep?

Episode 01: Highlights Human sleep has been separated into two main types: Non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleepNREM sleep is further divided into four stages, with each stage increasing in their depth of sleepREM sleep is named this way because of the bizarre, horizontal, shuttling eye movements that occur underneath your eyelids during this stage of sleepREM sleep is the principal stage in which we dream, although it can occur in the other stages as we...