RPSGT Core Concepts & Fundamentals 3 — Questions and Answers
Question 1: K-complexes are characteristic of which sleep stage?
- Stage W
- Stage N1
- Stage N2 (Correct answer)
- Stage N3
Correct answer: Stage N2
K-complexes are the defining EEG feature of Stage N2, appearing as sharp negative deflection followed by a positive component.
Question 2: What is the standard low-frequency filter (LFF) setting typically used for EEG channels in PSG?
- 0.1 Hz
- 0.3 Hz (Correct answer)
- 1.0 Hz
- 5.0 Hz
Correct answer: 0.3 Hz
A low-frequency filter of 0.3 Hz is the standard for EEG to preserve slow-wave components while removing DC drift.
Question 3: The international 10-20 electrode placement system gets its name from what?
- The year it was established (1920) and updated (1960)
- The 10% and 20% intervals measured between skull landmarks (Correct answer)
- The 10 and 20 microamp calibration signals used
- The 10 primary and 20 secondary electrode positions
Correct answer: The 10% and 20% intervals measured between skull landmarks
Electrode positions are placed at 10% and 20% intervals between four skull landmarks (nasion, inion, and preauricular points).
Question 4: During REM sleep, which of the following is NOT typically observed?
- Rapid eye movements
- Low-voltage mixed-frequency EEG
- Sleep spindles (Correct answer)
- Muscle atonia
Correct answer: Sleep spindles
Sleep spindles are a feature of NREM sleep (N2) and do not occur during REM sleep.
Question 5: What is the typical duration of a sleep spindle?
- 0.1–0.3 seconds
- 0.5–3 seconds (Correct answer)
- 5–10 seconds
- 10–20 seconds
Correct answer: 0.5–3 seconds
Sleep spindles last 0.5–3 seconds and appear as waxing-and-waning oscillations at 11–16 Hz.
Question 6: In PSG, the EOG channels are used primarily to detect which event?
- Electrode artifacts
- Eye movements associated with sleep stages (Correct answer)
- Eyelid muscle EMG activity
- Pupillary light response
Correct answer: Eye movements associated with sleep stages
Electro-oculography (EOG) records eye movements that help distinguish REM from NREM and wakefulness.
Question 7: Which brain region is considered the master circadian pacemaker in humans?
- Pineal gland
- Suprachiasmatic nucleus (SCN) (Correct answer)
- Raphe nuclei
- Locus coeruleus
Correct answer: Suprachiasmatic nucleus (SCN)
The suprachiasmatic nucleus in the hypothalamus is the primary circadian clock, synchronizing to light-dark cycles.
RPSGT Core Concepts & Fundamentals 3
K-complexes are characteristic of which sleep stage?