Hypnosis is basically meditation with intent. A person is relaxed into an artificially induced altered state of consciousness. The state resembles sleep but the mind becomes highly focused and responsive to suggestion. Hypnotherapist can use suggestion to explore repressed memories, instill a desire for heathy habits and even reprogram themselves to be open to ideas. During hypnosis the brain's cognitive systems are still able to interpret communication. The cognitive systems allow people to process information, categorize information, and create associations.
Hypnosis has been proven to be helpful in dealing with pain and was used to relax patients before anesthesia. Records show that ancient India and China used a form of hypnosis to relieve pain during surgery. The first case of hypnosis being used in surgery in Europe was recorded in 1794, when Jacob Grimm, one of the Brothers Grimm, was hypnotized prior to having an operation for a tumor. Hypnosis was officially recognized by medicine for pain relief in the 1950s and is now recognized as an accepted treatment for anxiety, depression, trauma, irritable bowel syndrome and eating disorders.
So how is this possible? In the “X-Files” episodes “Jose Chung's From Outer Space,” the fictional author played by Charles Nelson Reilly says he is fascinated by hypnosis, as a writer, because so much can be done with mere words. What gives the words this power? What happens to the brain that allows these words to effect such change? Science has tools that map and measure brain functions. Researchers compared the physical "body signs" of hypnotic subjects with unhypnotized people and found no significant physical change associated with the state of hypnosis. Hypnotized people's heart rates and respiration slow down as it does in any relaxed state, not the hypnotic state itself.
Magnetic resonance imaging found that hypnosis is a natural state of the mind that produces measurable effects in the brain. Electroencephalographs (EEGs) measure the electrical activity of the brain. EEG research found that brains produce different brain waves, rhythms of electrical voltage, depending on their mental state. The brain produces consistent waves at all frequencies. According to the study “Plasticity Changes In The Brain In Hypnosis And Meditation,” by Ulrike Halsband, Susanne Mueller, Thilo Hinterberger and Simon Strickner, EEGs showed that the brains of hypnotized subjects showed a boost in lower frequency waves associated with the dream state of sleep. There is also a reported drop in higher frequency waves associated with the wake state, according to the Wikipedia page on the trance state.
According to Science Daily, the brain has four different brain wave states: beta, alpha, theta, and delta. The beta state is the normal waking state, which is measured at a frequency of 14-28 cycles per second. The alpha state is a relaxed state which is inductive to visualization and creativity. The alpha wave pattern occurs during a brainwave frequency from 9 to 14 cycles per second. Theta occurs during REM Sleep. The theta state is a deeper state of relaxation that also occurs during hypnosis and meditation. The brain shows a theta wave pattern from 4 to 8 cycles per second, reports Science Daily. Theta brain waves can be considered the subconscious. It is the first stage of the phase where people dream. The delta state is the sleep state. The brain shows a delta wave pattern from 1 to 4 cycles per second. Gamma occurs when a person is processing stimuli and grouping things into a coherent whole. It is not a state of mind. It occurs during beta.
Scientists found that the alpha and theta brain wave frequencies relieve stress; facilitate deep physical relaxation and mental clarity; increase verbal ability and performance IQ; synchronize the two hemispheres of the brain; recall mental images and creative thinking and can reduce pain, promote euphoria and stimulate the release of endorphins.
A 2006 study in Germany found that specialized MRI brain scans showed less activity in two areas of the brain during hypnosis, the area that processes visuals and the area that handles conflicts. Researchers found that changes occur in the brain's cerebral cortex during hypnosis. Evidence suggests activity in the right hemisphere of the brain, which neurologists believe controls imagination and creativity, increases in hypnotized subjects. They found activity in the left hemisphere of the cerebral cortex, which controls logic, decreases. This could also explain why people feel less inhibited while under hypnosis.
When the brain is relaxed it is open to new ideas and is capable of turning those ideas into habits, if they choose to be guided in that direction.