Certified Polysomnographic Technician (CPSGT) Practice Exam 2026 - Free CPSGT Practice Questions and Study Guide

During REM (Rapid Eye Movement) sleep, the electroencephalogram (EEG) typically exhibits a unique pattern characterized by sawtooth waves and low-voltage mixed frequency waves. This specific waveform pattern reflects the brain's activity during this sleep stage, which resembles the waking state in terms of some brain activity, although muscle atonia (loss of muscle tone) occurs and is a defining feature of REM sleep.

Sawtooth waves are distinct triangular waveforms that were first identified during the REM phase, specifically within the theta frequency range, and they often appear in bursts. Meanwhile, low-voltage mixed frequency activity comprises a combination of different waveforms that can include theta waves and some faster frequencies, indicating heightened brain activity during this phase of sleep.

This combination is significant as it correlates with vivid dreaming and neurological processes that occur during REM sleep. Recognizing these waveforms is crucial for professionals in polysomnography, as it aids in differentiating REM sleep from other sleep stages and understanding the complexities of sleep architecture.