http://teddysratlab.blogspot.com [Full link to blog for email clients.][FT:C44]
Some time back, I was asked a question about hypnosis, so I included it as a "mailbag" post. I apologize on behalf of the LabRats, they could not be here to see me trot this one back out in theme with the rest of the "Psychology" blogs in this section. Rest assured, the LabRats are well and visiting their new cousins in Texas! Perhaps we can get some pictures for future blogs!
Hypnosis, is it real?.
As I have stated a few times in recent blogs, to really cover hypnosis would require delving into psychology, which is not the primary subject of The Lab Rats' Guide to the Brain. However, experts agree that the hypnotic (or, more correctly: autohypnotic) trance is a state in which the conscious mind is less active, and one can interact with the subconscious. Most people are familiar with stage illusionists and hypnotists, and quite frequently doubt the truth of the results. We do know that a person cannot enter an autohypnotic state unless they *want* to (hence the "auto-" prefix), and they likewise would not act on a suggestion unless they were willing to do so. Thus the doubters claim that a hypnosis stage act is all about placebo and peer pressure, while the believers cite brainwave studies and cases in which hypnosis has real, lasting effects on behavior.
A true hypnotic trance or "state" looks very much like a dream (or daydream). The EEG (brain waves) show many characteristics of sleep - first the low power alpha rhythm of meditation and relaxation, then the very slow delta and theta rhythms of deep sleep, followed by the brief, fast rhythms of REM sleep. Psychologists consider the state to be akin to the "conscious mind" sleeping, while the "subconscious mind" is free to listen and interact with the hypnotist. We actually enter such a state many times during the day while doing tasks that are quiet, possibly boring, repetitive and automatic (driving!, mowing the lawn, reading, etc.).
The state is also characterized by a lack of the "executive" governance of conscience, inhibition, and anxiety - hence the child-like nature and willingness to act on suggestion. A major clinical/therapeutic benefit of autohypnotic trance is access to memory. To understand why this is so, we must look back at what we know of how memory is converted from short-term to long-term storage: If you want to remember something, you repeat it. First we repeat the phone number to ourselves, then we write it down, often repeating it again. Then we read it back. The brain does the same thing, shuffling short-term memories from prefrontal cortext to hippocampus and back again - many times! Then we have to let the remembered item sit idle, and come back and repeat it again at a later date. In our prior discussion of dreams, I mentioned that experiences are most likely repeated in the next sleep or dream period - in fact, interrupting sleep is a good way to interrupt long-term memory.
The long-term storage process is called "consolidation" (or "re-consolidation" as it affects existing patterns) and it helps to store memories by build *associations* with other memories. I discussed this in the blog on "flashbulb" and PTSD memory, but it is just as important to normal memory storage. Association is the key, or combination that allows us to retrieve memory when it is needed. What hypnosis does is allow access to the association and consolidation aspects of memory, much the same as during sleep and dreaming. Thus a "post-hypnotic suggestion," one which lasts or takes effect long after the end of the hypnotic trance, forms a new associational relationship to existing memory. This is useful in therapy for anxiety, weight loss, smoking cessation, or in setting up beneficial mental states for surgery or exercise.
Some therapists utilize hypnosis to access repressed memories. However, from an ethical psychological perspective, such use is not without dangers. Because the brain is in the "consolidation/association" state during a hypnotic trance, any memory accessed is also subject to creation of new associations, much the same as flashbulb memories are subject to conflation with other events. In fact, the use of hypnotic regression to uncover repressed memories in children and abuse cases is increasingly condemned. Essentially every time a memory with strong psychological components is recalled, it can be modified. In the case of PTSD, the emotional content produces physiological changes - rapid heartbeat, shortness of breath, sweat, anxiety. The resulting emotional state then re-consolidates with the original memory, strengthening the associated trauma and fear. Use of hypnosis to treat PTSD requires a careful manipulation to *reduce* emotional triggering as the memory reconsolidates.
Hypnosis and False Memory:
The greatest risk of memory manipulation in this state is that of false memory. A therapist, trusted by the patient, who consistently questions a patient about a repressed memory, can easily set up associations in the patient's subconscious such that they believe the *suggestion* strong enough to associate it with memory. Suggestion and reconsolidation do not require hypnosis, but they are certainly aided by the autohypnotic trance. In fact, all that is really needed for formation of a false memory is to repeatedly recall an existing memory under conditions that allow addition of false elements - such as constantly relating an incident with few original details, but strong emotional content (as with flashbulb memories) - the additions take on the seeming of the original memory.
A key sign of false memory is when the physiological reactions do not match the remembered events. A soldier remembering combat will react tot he sights, sounds and smells of combat; a young man remembering a fleeting encounter with a beautiful young lady will remember the warmth of her touch, the smell of her perfume; in each case, the brain and body areas involved with be active and involved in recall of the memory. Absent or inappropriate emotion will result when the associated sensory information is separated from memory - for the good, as in PTSD and abuse therapy - and for the bad as in implantation of false memory.
Memory is fragile. We can impair the mechanism for making new memory (amnesia) and for recalling existing ones (Alzheimer's disease), we can even alter the memories we think are solid with the addition of unrelated information. Hypnosis can work by adding beneficial suggestions, but can also irretrievably alter the real memory and obscure truth.
Truly memory is something to be tampered with only with extreme care and skill.