Final answer:
Alpha waves are the type of brain waves produced by normal adults while, resting with eyes closed. This type of wave is characterized by a frequency of 8-12 Hz and is found during the early stage of a relaxed, wakeful state transitioning into sleep. Progressing into deeper stages of sleep, the brain produces lower frequency theta waves.
Step-by-step explanation:
The brain waves produced by normal adults while they are resting with their eyes closed are known as alpha waves. Alpha waves are characterized by a frequency of 8-12 Hz and are primarily found during the early stage of NREM (Non-Rapid Eye Movement) sleep, which resembles the state of a person who is relaxed but awake. As one moves deeper into sleep, the brain starts producing theta waves.
The alpha wave patterns have less variability (are more synchronized) and are relatively lower in frequency and higher in amplitude than beta waves. Beta waves, with a frequency between 13-30 Hz, are primarily associated with wakefulness, showing high frequency and low amplitude. However, as we begin to fall asleep, this beta wave activity transitions into alpha wave activity.
The human brain doesn't produce a uniform type of wave. While awake, the brain wave activity is dominated by beta waves. As we begin to fall asleep, this activity changes, first to alpha waves as we go into a relaxed, almost awake-like state, then proceeding to lower frequency theta waves as we enter deeper stages of sleep.
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