RPSGT Core Concepts & Fundamentals 5

Question 1

In a healthy young adult, approximately what percentage of total sleep time is spent in REM sleep?

Accepted Answer

20–25%

Answer

REM sleep constitutes approximately 20–25% of total sleep time in healthy young adults.

Question 2

What artifact in PSG is most commonly caused by 60 Hz electrical interference from nearby equipment?

Accepted Answer

60 Hz (AC) artifact

Answer

60 Hz AC artifact appears as a regular, high-frequency hum on the tracing caused by alternating current electrical interference.

Question 3

The process by which the circadian clock is reset by external cues such as light is called:

Accepted Answer

Entrainment

Answer

Entrainment is the synchronization of the internal biological clock to external zeitgebers (time cues) such as light.

Question 4

Which of the following EEG waveforms is characterized by a frequency of 0.5–2 Hz and amplitude greater than 75 µV?

Accepted Answer

Delta waves

Answer

Delta waves are defined by frequencies of 0.5–2 Hz and amplitudes exceeding 75 µV, and they define slow-wave sleep.

Question 5

What is the function of the chin (submental) EMG channel in a standard PSG recording?

Accepted Answer

Evaluate muscle tone to help identify REM sleep

Answer

Submental EMG monitors chin muscle tone; reduced or absent tone during REM helps confirm REM sleep staging.

RPSGT Exam Practice Test