This protocol guides users into a deep, trancelike state where alpha waves and theta waves, which signify deep relaxation, are elevated; frequencies found to promote a healing state that could be used to treat many things, from alcoholism to drug addiction to depression and anxiety. Clients allow a therapist's voice and sounds from a neurofeedback instrument to guide them into a deeply relaxed "alpha-theta crossover" state in the alpha (8-12 hertz) and the theta (4-8 hertz) range, right on the edge of sleep. The active ingredient of the training, many believe, is the imagery of painful, repressed memories that the client has suffered with for years, which surface and are then resolved in this state. The name comes from the behavior of the brain waves being shown on the screen. Alpha waves are usually higher in amplitude, or more powerful, than theta.
When, during this therapy, the amplitude of the alpha waves drops and the theta amplitude rises to the point where it crosses over the alpha waves -which means it has become more powerful - it is called alpha-theta crossover. It is a specific state that is associated with the resolution of traumatic memories. They often initiate deep psychological experiences that can be powerful and transformative. This brain wave training allows the repressed events that have caused the PTSD to surface to consciousness and be processed out, ending the grip they once held on clients.