Just to clarify some terminology: "semantic "memory" is often used to
refer to "knowedge of facts" and that sort of thing, dissociated from
any "episodic" memory, i.e. without any conscious recollection of where
or when one learned these "facts". It is easiest to think of verbal or
at least verbally-expressed examples, and probably this is easiest to
test, but one should not over-interpret this as referring to "semantic"
in the more traditional sense, i.e. specifying words to designate
particular objects.
For example, I think I would be fair to include (for example) knowledge
that monkeys are smaller than elephants among "semantic" memories.
Within this realm, there can be dissociations, however, such as
inability to say what a monkey or an elephant is, or to name them
either one when seen (or described; yet another possible dissociation,
i.e "visual confrontation" anomia vs. inability to name to verbal
description)--and yet ability to show some "semantic" knowledge of them
by saying which is larger when shown drawings of them with both drawn
to the same size (e.g. 4" X 6"). (I believe this is one of the
procedures Elizabeth and her group routinely use in exploring intact
and defective areas in her patients' semantic memories).
Your friend is an example of someone with very good episodic memory (I
assume he recalls the context in which he met these people, etc.) for a
paticular category: i.e., people. Others may have good episodic memory
of particular places (e.g. can describe very well at which point they
looked out over the city from Pont Neuf, what they saw, etc.).
I heartily concur that memory studies have been very narrow. Not only
have they over-emphasized verbal memory (both in the semantic and in
the episodic realm), but in general studies of "nonverbal" memory have
been been constricted and rather atheoretical. A perennial complaint
of mine: my "overly-clinical" (i.e. focused on immediate needs of
clinical assessment) colleagues tend not only to equate "nonverbal"
with "visual", but to be shocked and confused when various "visual"
memory tests disagree in the case of a given patient (assuming they do
not simply give just one "visual memory" test, whatever is easiest or
most familiar to them).
(NOT making this up; much consternation, discussion, and complaints
about new "visual memory" subtests in the recently released WMS III, in
a neuropsych listserver I subscribe to--along with some of he b est in
the business...)
My own small effort along these lines has been construction of FIST
(Face In Space Test) which Dr. Elena Kumkova and I presented at the INS
meeting in Seattle a few years ago--an effort to measure "what"
(ventral stream) and "where" (dorsal stream) visual memoruy separately
but concurrently (apparently successful, judging by follow up study by
others using left vs. right temporal lobe epilepsy patients).
Many years before, I had presented data from a "shape vs. (visual)
texture" test, which suggested what men used the left hemisphere for in
this test women used the right hemisphere, and vice versa (INS, San
Diego, 1985; also a followup at APA and at INS aa year or soo later).
An example of "visual memory" I did some preliminary work on but put
aside (may take it up again?): memory for color, BUT NOT COLOR WHICH
CAN BE USEFULLY LABELED VERBALLY. (Psych Corp blew that one!)
And then there is "nonverbal NONVISUAL memory": sounds (not those which
can be verbally labeled), odors (ditto), etc. A FEW laboratory
studies, but nothing in clinical use (Well, partial exception:
olfactory SEMANTIC memory, e.g. Bill Cain's low-tech approach, or the
more expensive UPSIT; no olfactory EPISODIC memory tests that I know of
(pace Proust!).
F. Frank LeFever, Ph.D.
New York Neuropsychology Group
In <932719197.47102 at server.australia.net.au> "John"
<johnhkm at netsprintXXXX.net.au> writes:
>>>flefever wrote in message <7n8qps$s7i at dfw-ixnews17.ix.netcom.com>...
>>>Elizabeth Warrington (my speaker last November at the NY Academy of
>>Science joint meeting with NYNG) has for many years used patients
with
>>odd dissociations (e.g. inability to name inanimate objects
preseented
>>visually, vs. inability to name animate ones presented auditorally)
to
>>develop a model of brain organization involving modalityXcategory
>>interactions. People have, indeed tried to explain some of these odd
>>cases in terms of relationships with broad modes of experience (e.g.
>>inanimate objects small enough to be manipulated vs. those too large
>>for this), and this makes plausible an involvement of areas related
to
>>actions involving objects represented in "semantic" memory (this is
the
>>current term for this type oof memory).
>>>I remember the idea that some types of temporal lobe damage cause
memory
>loss for spectific things and came across an extension of this once
where
>one researcher said that it could be that one way of categorising
>information is by reference to the "self" for the relevant individual,
hence
>my blathering about memory and self. I wonder if memory studies are
too
>semantically oriented, if perhaps we might learn more about memory and
the
>categories we create by understanding memory as part of the self
mechanism
>or serving it or whatever and I freely confess I don't know what
"self" is I
>beg do not ask for a definition. So you see how easily swayed my
thinking is
>by what I currently remember.
>>A crude eg. A few years ago I ran into an old school chum (from age 8,
now
>40) who was dyslexic, dropped out at 15, but has done quite well for
>himself; now basically in semi-retirement. He was not too bright at
school
>but shows excellent street sense so I don't think he's dense even
though he
>occasionally says the same of himself. But what amazes me about him is
his
>constant references, "Johnny, do you remember so and so ... ." I never
>remember these people but he speaks as if he's known them since way
back
>when. I have virtually no recollection of those past people and find
that
>after about 5 years it's all just about gone. But when it comes to
>remembering semantic information of certain types ... I can be
airtight. So
>who has the better memory here?
>>Somewhere I have a reference for a study done on memory for expert
chess
>players and while they found that the chess players were excellent for
>logical piece positions when placed randomly they did little better
than
>norms. So memory is something very specific in its effectiveness,
perhaps
>not so global at all.
>>>>HOWEVER, I don't know if such memory deficits are "OFTEN" correlated
>>with plausibly specific "motor/sensory" sites. If you can give a
>>reference for the example you use, it wouod be helpful; one could
>>trace backwards (via the article's references) and forwards (via
>>Science Citation Abstracts) to see how oftern similar findings have
>>been reported.
>>>I have never heard such memory deficits.
>>John
>Remove XXXX in reply address
>>>>
