4.0318 Short-Term Memory (1/56)
Elaine Brennan & Allen Renear (EDITORS@BROWNVM.BITNET)
Wed, 25 Jul 90 17:41:53 EDT
Humanist Discussion Group, Vol. 4, No. 0318. Wednesday, 25 Jul 1990.
Date: Mon, 23 Jul 90 23:52:29 EDT
From: Frank Dane <FDANE@UGA>
Mary Dee Harris asked for experts on memory. While I cannot claim that
label, I submitted her query and those of others to another forum that
includes such experts (PSYCOLOQUY: the psychological equivalent of
Apparently, the colleague to whom Harris referred could not have
actually lost her short-term memory. Instead, her short-term memory
capacity was severely limited in terms of space or temporal stability.
Short-term memory (STM) survives only about 30 seconds in the absence of
continued refreshment (continued perception of the "stuff" to be held in
STM. And, STM has a capacity of 7 (+/- 2) "things." If the information
(and here I'm sure it's information, not knowledge) is "chunked," more
material can be held in STM, but the limit remains 7+/-2. Thus, a phone
number (with area code) might be pushing the limits of most people's
STM, but chunking (area code + exchange + four digits) compresses the
material to 6 "things."
True loss of STM (although I imagine it's true enough to Harris's
colleague) would prohibit one from learning anything new. All
information that eventually is stored on long-term memory (LTM) must
pass through STM first, and must be held in STM for some (currently
unknown) amount of time for the brain cells to have whatever magic
occurs to them happen during the conversion to LTM.
Visual and auditory memory may or may not be two different processes;
the researchers are currently fighting it out with various experiments.
There is sufficient evidence to conclude that auditory and visual
material are stored in different memory bins, but it's not clear that
the processes by which they are stored and/or retrieved are different.
The notion of memory bins also is used to explain the phenomenon of
"knowing you know something but being unable to recall it." Current
theory and research is based on an analog of computer storage processes,
and proposes that there may be "bins" for what has been stored--much
like the FAT for a disk--and separate bins for the actual information/
knowledge. Presumably, human FATs are not as reliable as computer FATs,
and the analogous explanation is similar to the notion of having the
file names stored in the FAT but with incorrect or incomplete
information about the path under which the file (actual information) can
be found. Thus, you know you know something (the file name is in the
FAT), but you don't know which where it's stored (faulty path
Also, it appears that humans are constantly in dual process mode. After
having given up on intentionally recovering the path information, the
brain continues to search various pathways until it finds the "hidden"
file. That is the explanation offered for suddenly remembering the
information minutes/hours/days after you have given up trying to
remember it. Point of etiquette: current memory types shudder at the
mention of "unconscious" processes because it smacks too much of
Freudian notions; they (and I) prefer the term "unintentional."
That's probably more than anyone (including Harris) wanted to know, so
I'll stop now.
Frank Dane, Psychology, Mercer University