Saturday, December 03, 2005

Hypnosis


This is a bit of a non-sequitur for KoH, but it does have something to do with spiritualism and a lot to do with science, and besides, I need to post again. Hypnosis has always been very interesting to me. Well, actually not just hypnosis but also the whole idea of meditation and all that mind-over-matter type stuff. But whenever I've asked about it, I've always just been given some spiritual explanation. I was reading something online (I seem to have lost the URL, sorry) about hypnosis and its scientific value, and becoming very intrigued. What follows is derived from a paper I wrote for school on the subject.

Hypnosis is not just a parlor trick. From its original use by German physician, Dr. Franz Mesmer in the 18th century to fool people into giving him money to its application in neuroscience today, it has always had an air of mystery about it. Now its mysteries are beginning to become unraveled by modern day science, and the results are truly revealing.

"The idea that perceptions can be manipulated by expectations" is fundamental to the study of cognition, said Michael I. Posner, an emeritus professor of neuroscience at the University of Oregon and expert on attention. "But now we're really getting at the mechanisms." Neuroscientists like Posner are speedily conducting tests on hypnotizables (people that can easily be hypnotized) and hypnosis resistants to look deeper into this world of discovery barely identified. Now, Dr. Posner and others said, new research on hypnosis and suggestion is providing a new view into the cogs and wheels of normal brain function.

One area that it may have illuminated is the processing of sensory data. Information from the eyes, ears and body is carried to primary sensory regions in the brain. From there, it is brought up to so-called higher regions where interpretation occurs. These higher regions are what we use to think, and it is here that hypnosis takes hold.

Allow me to illustrate: photons bouncing off a flower first reach the eye, where they are turned into a pattern that is sent to the primary visual cortex. There, the rough shape of the flower is recognized. The pattern is next sent to a higher region, where color is recognized, and then to an even higher region, where the flower's identity is encoded along with other knowledge about the particular bloom. Exciting, isn’t it?

This system of information traveling from lower to higher regions in the brain, which also works for all of your other senses, is what is call feedforward. But here’s the cool part: information travels the other way too. Surprisingly, there are ten times as many nerve fibers carrying information down as there are carrying it up. These feedback fibers mean that consciousness, what people see, hear, feel, etc., is based on what neuroscientists call “top down processing.” Here’s the point: what you see is not always what you get, because what you see depends on a framework built by experience that stands ready to interpret the raw information - as a flower or a hammer or a face. Your frame of reference can determine how you experience your life. Now that’s neat.

That’s where hypnosis comes in. A hypnotist can burden the higher functions of your brain so that they overload your lower regions, meaning that when your eyes see a pink flower, but your higher regions want it to be blue, it becomes blue. If the top is convinced, the bottom level of data will be overruled.

That is quite neat. I hope that y'all have learned something.


Thank you for your time.

3 Comments:

At 12/03/2005 11:03 AM, Blogger Francois Tremblay said...

Most magic, hypnosis and flummery is just about diverting your attention points, or for stage flummery, fulfilling expectations. Most people on stage fake being hypnotized because that's what they are expected to do. That's all there is to it.

 
At 12/03/2005 1:18 PM, Blogger Beowulf said...

Nice post. However, one always runs into the problem of qualia in these types of issues.

 
At 12/03/2005 9:27 PM, Anonymous Morgan said...

Most people on stage fake being hypnotized because that's what they are expected to do. That's all there is to it.

So what about the people not covered by 'most'? Are you saying that anyone who has ever been hypnotized is actually just faking because they think certain responses are expected of them? Or are you saying that anecdotal evidence based on stage performances is unhelpful in understanding the real phenomenon of hypnosis? The former seems unreasonably definite, unless you are an expert in the area. The latter just suggests we devise more rigorous means of investigating the matter.

 

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