Hypnosis is a state of human consciousness involving focused attention and reduced peripheral awareness and an enhanced capacity for response to suggestion. The term may also refer to an art, skill, or act of inducing hypnosis.
The ability to be hypnotized has been described as heritable as shown in twin studies.
Theories explaining what occurs during hypnosis fall into two groups. Altered state theories see hypnosis as an altered state of mind or trance, marked by a level of awareness different from the ordinary conscious state. In contrast, Non-state theories see hypnosis as a form of imaginative role-enactment.
During hypnosis, a person is said to have heightened focus and concentration. The person can concentrate intensely on a specific thought or memory, while blocking out sources of distraction. Hypnotised subjects are said to show an increased response to suggestions. Hypnosis is usually induced by a procedure known as a hypnotic induction involving a series of preliminary instructions and suggestion. The use of hypnotism for therapeutic purposes is referred to as “hypnotherapy?, while its use as a form of entertainment for an audience is known as “stage hypnosis?. Stage hypnosis is often performed by Mentalists practicing the art form of Mentalism.
Hypnosis may be done either audibly or with the help of inaudible subliminal messages below the threshold of conscious hearing, often embedded in music files.
A binaural beat is an auditory illusion perceived when two different pure-tone sine waves, both with frequencies lower than 1500 Hz, with less than a 40 Hz difference between them, are presented to a listener dichotically, that is one through each ear. For example, if a 530 Hz pure tone is presented to a subject’s right ear, while a 520 Hz pure tone is presented to the subject’s left ear, the listener will perceive the auditory illusion of a third tone, in addition to the two pure-tones presented to each ear. The third sound is called a binaural beat, and in this example would have a perceived pitch correlating to a frequency of 10 Hz, that being the difference between the 530 Hz and 520 Hz pure tones presented to each ear.
Isochronic tones are regular beats of a single tone that are used alongside monaural beats and binaural beats in the process called brainwave entrainment. At its simplest level, an isochronic tone is a tone that is being turned on and off rapidly. They create sharp, distinctive pulses of sound.
Duration of effects
Brainwave entrainment does not have a long-term effect on the patterns of neural impulses. That is, very soon after the external stimulus stops, the brainwaves return to their normal state.
In 2008, clinical neurologist Steven Novella published an article on brainwave entrainment, claiming ‘A number of companies and individuals have then extrapolated from the phenomenon of entrainment to claim that altering the brain waves changes the actual functioning of the brain. There is no theoretical or empirical basis for this.’ However, Novella is a renowned skeptic who founded The Skeptics’ Guide to the Universe in 2005, along with numerous other professional ventures to promote scientific skepticism.
In direct contradiction to Novella’s claim, more than twenty-one independent peer-reviewed, placebo-controlled studies have been conducted between 1979 and 2012 which show a range of cognitive-behavioral benefits achieved through the practice of temporarily altering brain waves, including: cognitive enhancement after 6 weeks of gamma wave stimulation; improvement in academic achievement after beta brain wave stimulation; increase in alpha wave strength measured by EEG during meditation; substantial reduction in anxiety and corresponding increase in relaxation after theta wave stimulation; and reduc