Brain Waves During Sleep
🧠 As you move through the stages of sleep, your brain activity shifts dramatically. Scientists can measure these changes with an EEG (electroencephalogram), which records brain waves. Each sleep stage is defined by its own pattern of brain waves.
Brain Waves Across Sleep Stages
- Stage 1 Sleep – dominated by theta waves as the brain slows down from wakeful alpha activity.
- Stage 2 Sleep – mostly theta waves with bursts of sleep spindles and K-complexes for memory and sensory processing.
- Stage 3 Sleep – deep sleep defined by delta waves, the slowest and largest-amplitude brain activity.
- REM Sleep – a unique stage where brain activity looks similar to wakefulness, with mixed-frequency waves and vivid dreaming.
Why Brain Waves Matter
Brain waves aren’t just patterns on a chart — they reflect the way your brain is functioning. From memory consolidation in Stage 2 to emotional processing in REM, each wave pattern serves a critical role in mental and physical health.
How Brain Waves Are Measured
EEG (electroencephalogram) technology uses electrodes on the scalp to measure brain activity. Researchers rely on EEG data to define sleep stages and understand conditions like insomnia, sleep apnea, and narcolepsy.
Explore the Sleep Stages
Now that you know how brain waves define sleep, explore the stages in detail: