Your Brain on Hypnosis

In a previous blog entry I gave some definitions of hypnosis as an altered state, a dissociation of awareness, focused attention, etc. Here I’d like to define hypnosis by describing what takes place in the brain under hypnosis.

Humans have four basic states of awareness corresponding to four identifiable brain-wave patterns:

• Beta state (alertness, active thinking, and concentration)
• Alpha state (relaxed alertness and light hypnosis)
• Theta state (day dreaming, deep hypnosis, drowsiness, and light sleep)
• Delta state (deep sleep).

The brain passes through each of these four states as the electrical activity decreases on the way to sleep (theta and delta states) and increases on the way to wakefulness (beta state). In other words, we necessarily pass through the hypnotic states every time we go into and awaken from sleep.

We spend most of our waking hours in the beta state of alert awareness. In the beta state the mind analyzes, evaluates, judges, and makes decisions. This is the state in which we attempt to overcome problems with “will power,” often unsuccessfully.

In hypnosis the brain enters the alpha (light hypnosis) and theta (deep hypnosis) states, and one is highly focused on hypnotic suggestions and imagery while suspending the ordinary thinking processes of the beta state. In the alpha and theta states, hypnotic suggestions are integrated into the mind more easily, and memories become more accessible.

There are many techniques for inducing hypnosis, and most of them bring about the alpha and theta hypnotic states with the same basic method that you use to put yourself to sleep at night: you close your eyes, control the sound, and lie still. When you limit sensory stimulation in these ways, your neural activity slows down, taking you from the waking state (beta) into the states of hypnosis (alpha and theta). In these states the brain’s centers of awareness and imagining shift from cortex (where conscious, analytical thinking takes place) to the sub-cortical structures involved in unconscious and emotional processes, the stress response, and long-term memory. In simple terms, by limiting sensory input the brain slows down, and the unconscious mind is made accessible.