In article <3791BFDC.3784 at online.no>, Tore Lund <tl001 at online.no> writes
>In article <3790408A.2ED6 at online.no>, Tore Lund <tl001 at online.no> writes
>>In the book "Complexity" by Roger Lewin (1993) [snip]
>>>> ...Chris felt he was living in the middle of a cube, the sides of
>> which were cinema screens with pictures projected on them.
>> (Beginning of chapter 8, page 151 in Phoenix ed.)
>>Nick Medford wrote:
>>>> I haven't read the book, but the quote above sounds like he could be
>> describing the depersonalisation/derealisation syndrome. [snip]
>>>> These phenomena are currently the subject of research at the Institute
>> of Psychiatry in London. You can get more info and references at our
>> website: http://www.iop.kcl.ac.uk/home/dpu/index.htm>>Thanks for the pointer, Nick. There are quite a few references to
>visual disturbances at this site. Let's look at some of them:
>>Anonymous:
>> "Get telescopic vision ... The people I was talking to began to turn
> into paper cutouts."
>>Jennifer:
>> "My vision even feels like a 2-dimensional movie screen all of the
> time."
>>Kerry:
>> "Suddenly, that surreal, dream-like quality returned, complete with
> altered depth perception..."
>>The mini-FAQ:
>> "I really don't have any 3-D vision it seems. Everything appears
> flat."
>>You and C_Thomas seem to doubt that Chris was actually seeing the world
>as a cube with the world projected on its sides. Taken together with
>the quotes above, however, it seems to me that these people actually
>have *visual* disturbances.
>
Well, you've moved from the specific to the general. If you're saying
that sensory illusions and misperceptions can occur in depersonalisation
states, then of course I agree. That's very well documented. I just
wasn't sure from the quote you posted that this was the case in the
particular instance you cite.
Other phenomena that may occur in such states include a distorted sense
of time, or a feeling that the body is so light it might float away. The
frequency with which particular phenomena occur must in part depend on
the underlying cause. As I mentioned a wide range of conditions can give
rise to such states- they also occur in "normals" under conducive
conditions eg sleep deprivation, also when faced with life-threatening
danger (check the 1977 paper by Netti and Kloyes, referenced on the
website). Also under the influence of certain psychotropics eg LSD.
>Presumably, what happens is that patients of this sort come to a
>specialist who is not interested in vision - and the vision specialists
>never see these patients. Hence these disturbances are never properly
>studied and described.
>Well, "patients of this sort" covers a multitude of different underlying
problems (see above). Of course there may be similarities in the
neurophysiological mechanisms, whatever the underlying medical
condition.
I'm trying to picture the reaction of your average ophthalmologist being
asked to see such a patient. (Is this what you mean by "vision
specialist"?) They deal with problems affecting the organ and apparatus
of vision ie problems affecting the eyes and optic nerves. They don't
deal with neuropsychiatric problems.
The types of visual distortions you mention are highly unlikely to have
anything to do with problems in the eye itself. Rather they point to a
subtle disturbance of the brain's ability to process and make sense of
sensory information. Thus it seems apropriate to me that such patients
are seen by neurologists and psychiatrists...particularly those
interested in clinical neuroscience. Semir Zeki's book "A Vision of the
Brain" gives a first-hand account of discoveries in the neuroscience of
vision, if this is an area that interests anyone out there.
I'd accept that this whole area is poorly understood in many ways. Study
of depersonalisation states opens up some real cans of worms. Like, if
someone says they feel unreal, how do they (or you) define what feels
real and what doesn't? And from there it's a short jump to all those
arguments about self-constructs, zombies, consciousness etc etc. So it's
thorny stuff.
>I repeat that I think these phenomena could tell us something about our
>stereoscopic vision - because the distortions that can arise in a system
>can tell us a lot about the nature of that system and rule out models
>that don't allow for such distortions.
>>Just a thought.
--
Nick Medford
