The frequency of electrical activity in the brain can be measured, in cycles per second/hertz, using an electroencephalogram. Changes in mental state and activity produce changes in the frequency of our “brain waves”, with four distinct states being relevant to hypnotherapy.
The beta state, between 14-30 Hz, is the normal awake & conscious state of the brain. This is the normal state for the brain when it is alert, analysing, and computing.
The alpha state, between 8-13 Hz, signals the surfacing of the subconscious mind. Alpha state may be reached simply through relaxing but can also occur when you are engaged in creative or imaginative activities. It is the “daydream” state – a light hypnotic state where the conscious mind is less dominant but not inactive and is still able to process input.
The Theta state, between 4-7 Hz, occurs when we are dreaming, meditating, or in a deeper hypnotic trance. The theta frequency can be reached through repetitive physical activity and is the state that people refer to as “being in the zone” when exercising. Repetitive auditory stimulus can also help to induce the theta brainwave state.
In Theta state the subconscious mind is dominant. Past emotions and experiences that may be inaccessible to the conscious mind can be accessed. The Theta state is required to achieve effects such as hypnoanaesthesia.
The Delta state occurs when we are asleep or unconscious. If a client falls asleep during the hypnosis session, they will enter the Delta state. In the Delta state neither suggestions cannot be made to the subconscious mind.
The brain will naturally change state based on activity and stimulus. During a hypnotherapy session our aim is to move the client from the Beta state, through Alpha, and into Theta. Once in the Theta state, suggestions can be made that will deeply embed into the subconscious mind. The client can then be gently brought back through from Theta into Alpha, the fully conscious and wide awake again in Beta state.