Sleep Spindles: Brief bursts of brain activity that occur during stage 2 of non-REM sleep and are believed to play a role in memory consolidation.
Rapid Eye Movement (REM) Sleep: A stage of sleep characterized by rapid eye movements, vivid dreaming, and muscle paralysis.
Activation-Synthesis Theory: The theory that dreams result from random neural activity during REM sleep and the brain's attempt to make sense of it by creating narratives.