Definition reprinted with permission from Culebras, Antonio, Clinical Handbook of Sleep Disorders, Butterworth-Heinemann
An EEG rhythm in the range of 13-35 Hz, when the predominant frequency, beta rhythm, is usually associated with alert wakefulness or vigilance and is accompanied by a high tonic EMG. The amplitude of beta rhythm is variable but usually is below 30 uV. This rhythm may be drug induced.
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