Final answer:
While awake, the brain emits beta waves with high frequency and low amplitude. This brain wave activity changes as we transition into different sleep stages.
Step-by-step explanation:
When we are awake, our brain emits beta waves which are characterized by a high frequency of 13-30 Hz and a very low amplitude. These waves display more variability compared to when we are asleep. As we transition from wakefulness to sleep, the brain wave patterns change, shifting to alpha and theta waves in the initial stages of non-REM (NREM) sleep, and eventually to delta waves in the deeper stages of sleep.