1. Light. 4-5%. Muscle activity slows. Twitching. Theta activity
2. Breathing & heart rate slow. 45-55%. Sleep spindles, K complexes.
3. Deep. 4-6%. Beginning of Delta waves.
4. Deepest. 12-15%. Delta waves >50%. Rhythmic breathing, limited muscle activity.
- 5. REM. 20 - 25%. Close to light (stage 1) sleep in brain, but muscles relaxed close to deep (stage 4). Occurs every 90 mins. Eyes dart around. REM increases in amount of time, the closer to waking up you get.
- Atonia = Lack of muscle control