Dreaming, memory-making, problem-solving: A lot happens during the most active sleep phase.
Before scientists discovered REM sleep in the 1950s, it wasn’t clear that much of anything was happening in the brain at night. Researchers today, however, understand sleep as a highly active process composed of very different types of rest - including REM, which in some ways doesn’t seem like rest at all.
Lack of sleep in general is associated with death, but the research now suggests that not getting enough REM sleep is the single strongest factor.
REM also... (Read the full article here.)