alpha wave, one of several types of brain waves, characterized by a relatively high voltage or amplitude and a frequency of 8 to 13 Hz. Alpha waves are the “relaxed waves” of the brain and constitute the majority of waves recorded by electroencephalograms registering the activity of the parietal and the occipital lobes and the posterior parts of the temporal lobes when the individual is awake but nonattentive and relaxed, with the eyes closed. Opening and closing the eyes affect the patterns of the alpha waves and the beta waves. Also called alpha rhythm, Berger wave. Compare beta wave, delta wave, theta wave.
