Is Hypnosis a Distinct Form of Consciousness?
Featured in Scientific American Mind Magazine
Scott Lilienfeld and Hal Arkowitz (2009) summarises research on hypnosis. Lilienfeld is a psychology professor at Emory University, and Arkowitz is a psychology professor at the University of Arizona.
'... investigators have sought to uncover distinct physiological markers of hypnosis. Under hypnosis, EEGs, especially those of highly suggestible participants, sometimes display a shift toward heightened activity in the theta band (four to seven cycles per second). In addition, hypnotized participants frequently exhibit increased activity in their brain's anterior cingulate cortex (ACC).
Yet neither finding is surprising. Theta activity is typically associated with states of quiet concentration, which frequently accompany hypnosis. The ACC is linked to the perception of contradictions, which many hypnotized participants experience as they imagine things-such as childhood experiences in the present-that seem to conflict with reality. [...]
Fueling the perception of hypnosis as a distinct trancelike state is the widespread assumption that it leads to marked increases in suggestibility, even complete compliance to the therapist's suggestions. Nowhere is this zombielike stereotype portrayed more vividly than in stage hypnosis shows, in which people are seemingly induced to bark like dogs, sing karaoke and engage in other comical behaviors in full view of hundreds of amused audience members [...]
Before beginning their shtick, they prescreen audience members for high suggestibility by providing those people with a string of suggestions. They then handpick their participants from among the minority who comply.
We agree with Lynn and psychologist Irving Kirsch of the University of Hull in England, who wrote in 1995 that "having failed to find reliable markers of trance after 50 years of careful research, most researchers have concluded that this hypothesis [that hypnosis is a unique state of consciousness] has outlived its usefulness." Increasingly, evidence is suggesting that the effects of hypnosis result largely from people's expectations about what hypnosis entails rather than from the hypnotic state itself [...] Although hypnosis poses fascinating mysteries that will keep scientists busy for decades, it seems clear that it has far more in common with everyday wakefulness than with the watch-induced trance of Hollywood crime thrillers'. (Scott Lilienfeld and Hal Arkowitz, 2009 bold added for emphasis)