Some states of consciousness don’t occur naturally and must be induced in some way. These include hypnotic states, meditative states, and drug-induced states.
Hypnosis is a procedure that opens people to the power of suggestion. A hypnotist puts a subject in an altered state by encouraging relaxation and sleepiness and often describing the sorts of physical sensations a subject should be feeling. Once a subject is in the altered state, he or she may act, perceive, think, or feel according to the hypnotist’s suggestions. Not everyone can be hypnotized, and some people are more hypnotizable than others. The following chart shows what hypnosis can and can’t do.
|Hypnosis can:||Hypnosis can’t:|
|Cause people to be relaxed, have a narrowed focus of attention, and be highly engaged in fantasies||Work equally effectively for everyone|
|Produce anesthesia and treat a range of psychological and medical problems||Force people to do things against their will|
|Cause hallucinations and distortions in sensory perception||Make people act in ways that would normally be beyond their physical or mental abilities|
|Reduce inhibitions||Reliably increase the accuracy of memories|
|Cause changes in behavior after the hypnosis has ended||Allow people to actually reexperience past events or lives|
If hypnotized people are instructed to forget what happened during hypnosis, they later claim to have no memory of it. This phenomenon is called posthypnotic amnesia.
A hypnotic state isn’t sleep—brain waves, for example, do not reliably change during hypnosis as they do during sleep. Researchers don’t even agree that hypnosis is an altered state of consciousness. Researchers propose two main theories about hypnosis:
Meditation is the practice of focusing attention. People meditate to enhance awareness and gain more control of physical and mental processes. Techniques used in meditation vary and include activities such as repetitive chanting and breathing exercises.
Meditative states are associated with an increase in alpha and theta brain waves, and physical indicators of relaxation such as slowed pulse and breathing. Some researchers have found that meditation has long-term effects such as improving physical and mental health and reducing stress. However, researchers disagree about whether meditative states are unique states of consciousness. Some researchers believe relaxation techniques can produce the same kind of state produced by meditation.