25 – 100 Hz
Gamma waves are important in higher cognitive functions and REM sleep. The fastest frequency, Gamma waves are associated with processing and consolidating of information from different locations of the brain. People with high IQ, cognitive function, and high level reasoning usually possess optimal levels of Gamma waves. Excess Gamma levels can lead to anxiety, high arousal, and stress. Deficient levels of Gamma waves can lead to ADHD, depression, and learning disabilities.
Gamma is the newest addition to this list and the least understood. We know Gamma waves disappear during anesthesia-induced sleep and that advanced Tibetan monks produce higher levels than those who do not practice meditation. Some hypothesize Gamma waves to be connected to spiritual experiences and relate to expanded consciousness.