Stages of sleep!
Stage 1 - theta waves
Stage 2 - spindles, k-complexes
Stage 3 - delta waves appear
Stage 4 - mostly delta waves
Stage 5 - beta waves

Stages of sleep!
Stage 1 - theta waves
Stage 2 - spindles, k-complexes
Stage 3 - delta waves appear
Stage 4 - mostly delta waves
Stage 5 - beta waves
