To identify the sleep wave marked in the EEG during the sleep-wake cycle, it is essential to understand the characteristics of each sleep stage: Stage 1, Stage 2, Stage 3, and REM sleep.
1. Stage 1 Sleep: This is the lightest stage of sleep. EEG registers low-amplitude, mixed-frequency brain waves. It is a transition between wakefulness and sleep.
2. Stage 2 Sleep: Here, the EEG shows sleep spindles and K-complexes which indicate periodic bursts of brain activity. This stage forms about 50% of our total sleep.
3. Stage 3 Sleep: Known as deep or slow-wave sleep (SWS), the EEG displays delta waves, which are high-amplitude and low-frequency.
4. REM Sleep: EEG shows low-amplitude, mixed-frequency waves resembling the wake stage. Despite its paradoxical EEG patterns (resembles waking state), this stage is crucial for dreaming and cognitive processes.
Based on the characteristics described and typical features seen in EEGs, the marked sleep wave is identified as REM sleep, which corresponds with mixed-frequency, low-amplitude waves.
