Which pair of EEG derivations shows the highest amplitude of slow-wave sleep?

Which pair of EEG derivations shows the highest amplitude of slow-wave sleep?

• A. O1-A1 and O2-A2
• B. C3-A2 and C4-A1
• C. Cz-O2 and Pz-Oz
• D. F3-A2 and F4-A1

Answer: (D)

During slow-wave sleep, EEG shows high-amplitude delta waves (0.5–4 Hz). These delta waves are strongest in the frontal cortex, so frontal electrode sites tend to record the largest amplitudes. The pair with front-left and front-right placements (F3 and F4) using mastoid references (A2 and A1) best capture that maximal frontal delta activity, making it the best choice for high slow-wave amplitude. In contrast, posterior or central derivations (like those over occipital or central/prefontal areas) typically display lower delta amplitudes during deep sleep, so they don’t reach the same peak as frontal sites.

During slow-wave sleep, EEG shows high-amplitude delta waves (0.5–4 Hz). These delta waves are strongest in the frontal cortex, so frontal electrode sites tend to record the largest amplitudes. The pair with front-left and front-right placements (F3 and F4) using mastoid references (A2 and A1) best capture that maximal frontal delta activity, making it the best choice for high slow-wave amplitude. In contrast, posterior or central derivations (like those over occipital or central/prefontal areas) typically display lower delta amplitudes during deep sleep, so they don’t reach the same peak as frontal sites.