Delta waves are associated with which sleep stage?

Delta waves are associated with which sleep stage?

• A. Delta waves
• B. Alpha waves
• C. Theta waves
• D. Hypnic jerk

Answer: (A)

Delta waves indicate deep slow-wave sleep, the deepest stage of non-REM sleep. They are high-amplitude, low-frequency brain waves (about 0.5–4 Hz) that dominate during slow‑wave sleep, often called N3. This stage is associated with restorative processes, reduced responsiveness to the environment, and the highest arousal threshold. The other options point to different phenomena: alpha activity appears when you’re awake and relaxed with eyes closed; theta waves show up in lighter sleep and drowsiness; a hypnic jerk is a sudden muscle contraction at sleep onset, not a brain-wave pattern tied to a sleep stage.

Delta waves indicate deep slow-wave sleep, the deepest stage of non-REM sleep. They are high-amplitude, low-frequency brain waves (about 0.5–4 Hz) that dominate during slow‑wave sleep, often called N3. This stage is associated with restorative processes, reduced responsiveness to the environment, and the highest arousal threshold. The other options point to different phenomena: alpha activity appears when you’re awake and relaxed with eyes closed; theta waves show up in lighter sleep and drowsiness; a hypnic jerk is a sudden muscle contraction at sleep onset, not a brain-wave pattern tied to a sleep stage.