Final answer:
Stage 1 or light sleep is characterized by small irregular waves with some alpha waves.
Step-by-step explanation:
Stage 1 or light sleep is characterized by small irregular waves with some alpha waves. These waves can be observed using an electroencephalogram (EEG), which measures the electrical activity of the brain. Alpha waves have a frequency of around 8-12 Hz and are present when a person is awake but in a relaxed state. In Stage 1 sleep, the alpha waves are mixed with other types of waves, leading to the small irregular pattern.
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