Brain waves or brain waves are electrical oscillations in the brain. They can also be measured in the various states of consciousness, such as in hypnosis, and above all also influenced. They represent, so to speak, the communication between nerve cells and nerve plexuses and can be described in certain frequencies. They come about through voltage fluctuations within individual brain cells, which then generate waves through the electrical change of state. Brain waves differ in frequency and thus perform different tasks. Thus, there are the delta waves, theta waves (divided into theta 1 and theta 2), alpha waves, lambda waves, beta waves, gamma waves and my waves. In hypnosis, brain waves tend to be in the theta range. Similar frequency ranges can also be observed in meditation or daydreaming.Theta waves are associated with creativity, dreaming, insights, and reduced consciousness, also light sleep. In a light to moderate trance, theta 2 waves are more likely to be observed, which can be measured by electroencephalography or neurofeedback. Here, the hypnotized person is more consciously present, and consciousness is more easily restricted. Theta 1 involves a deeper dissociated hypnosis or trance. The hypnotized person's consciousness is more restricted in hypnosis. This may increase the likelihood that mild amnesia may occur after hypnosis.