Figure 2.13 | Sleep Stages and the Brain Waves Associated with Each Stage | The various stages of sleep are indicated by changes in the brain waves in the EEG recordings. As you pass from awake to deep sleep (Stages 3 and 4), the brain waves get larger and slow down. After deep sleep, you ascend back through Stages 3 and 2 into REM sleep, for which the waves are more rapid and resemble those of Stage 1.