Gamma (31-100 Hz): Gamma waves are the fastest group of brainwaves and the only frequency group to be found in all parts of the brain. For a long time, scientists and researchers dismissed gamma waves as ‘spare brain noise’ until it was discovered that they are highly prevalent in states of heightened perception and concentration, high level cognitive functions, memory recall, and advanced states of consciousness. Altered gamma activity has been observed in many mood and cognitive disorders such as Alzheimer's disease, epilepsy, and schizophrenia as well as certain learning disabilities.
Beta (16-30 Hz): Beta brainwaves dominate our normal waking state of consciousness when attention is directed towards cognitive tasks and the outside world. It is the predominant brain activity going on when we are alert, attentive, engaged in problem solving, focused on mental activity, and making decisions. Beta activity can be subdivided into three bandwidths.