In article <7n0s0j$bbc at dfw-ixnews6.ix.netcom.com>, F. Frank LeFever
<flefever at ix.netcom.com> writes
>Just to point out that there are "neuro-ophthalmologists" who might be
>a little more attuned to this sort of visual oddity.
Maybe. I would guess there a lot more of these in the US than here in
the UK, where it's a tiny sub-specialty (but a fascinating one.)
>>ALSO, do not forget neuropsychologists
Frank, rest assured I will never do that.
>--many of whom are quite
>knowledgeable about (and may have more intellectual curiosity about)
>such things than the vast majority of neurologists (and perhaps more
>than most neuropsychiatrists, who may tend to focus more on phenomena
>of more immediate "psychiatric" relevance).
I think that's probably a fair criticism. A striking thing about the
literature on depersonalisation is that older (say, pre-WWII) accounts
tend to have much richer descriptions of the sensory phenomena, while
more recent writings tend to focus on the "unreality" aspect and perhaps
fail to capture the full story.
>>F. Frank LeFever, Ph.D.
>New York Neuropsychology Group
>>>>In <dDqmHCATIhk3EwWI at hermit0.demon.co.uk> Nick Medford
><nick at hermit0.demon.co.uk> writes:
>>>>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
>
--
Nick Medford
