Tore makes an important point, I believe. In my own response, I made
reference to derealization, and to temporal lobe epilepsy; others have
referred to "non-neurological" contexts for experiences of
derealization and/or depersonalization.
Given the confluence of limbic system and sensory systems in the
medial temporal lobe, there are rich opportunities for sensory
distortions with this sort of emotional flavor.
However, just as regards temporal lobe alone, we know from (e.g.) Mort
Mishkin's work (much of it with Leslie Ungerleider) something about the
different paths visual input takes to the hippocampus (they have
focused on the distinction between dorsal "where" and ventral "what"
visual streams). Accordingly, we should be alert to aberrations at
earlier points along these routes which might produce "pure" visual
anomalies without any social/emotional aspects, other than the natural
reactions one might have to odd visual experiences.
Two examples that come to mind: palinopsia; formed visual
hallucinations (e.g. with some disturbances of posterior
cerebrovascular circulation).
F. Frank LeFever, Ph.D.
New York Neuropsychology Group
In <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.
>>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.
>>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.
>--
>Tore Lund <tl001 at online.no>
>
