Beta wave, or beta rhythm, is the term used to designate the frequency range of brain activity above 12 Hz (12 transitions or cycles per second). Beta states are the states associated with normal waking consciousness. Low amplitude beta waves with multiple and varying frequencies are often associated with active, busy, or anxious thinking and active concentration. Rhythmic beta with a dominant set of frequencies is associated with various pathologies and drug effects. For instance, beta activity can be accentuated by sedative-hypnotic drugs such as benzodiazepines or barbiturates. It can also be absent or reduced if the patient underwent cortical damage.
Beta Waves are also split into three sections: High Beta Waves (19Hz+); Beta Waves (15-18Hz); and Low Beta Waves (12-15Hz).