The delta rhythm will disappear, to be replaced by the activity pattern of brain waves.
δ节奏消失,并被脑电波的运动图形取代。
《分钟地球》趣味科普(精选双语)
In healthy brains, these waves are very consistent — for instance, during normal waking activity, your brain produces a pattern called the beta rhythm, and, in deepest sleep, it generates a slower delta rhythm.
Then about 40to 69 minutes after you lose consciousness you will have reached the deepest sleep of all. Your brain waves will show the large slow waves that are known as the delta rhythm.
A delta wave is a high amplitude brain wave with a frequency of oscillation between 0–4 hertz. Delta waves, like other brain waves, are recorded with an electroencephalogram (EEG) and are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and aid in characterizing the depth of sleep.