Yesterday, I attempted to answer a question about short-term memory. I feel
uncomfortable doing this because I am not a cognitive psychologist, and every
time I try to read a book in this area, my head begins to spin. I stated:
>I have become aware through reading a book by Alan Baddeley (1993; _Your
>memory: A user's guide_. London: Prion) that the common view that ST memory
>holds about 7 items of information is not correct. Research on the related
>concept of working memory suggests that it is the amount of information that
>one can repeat subvocally (when the info to be remembered is verbal) in about
>1.5 seconds that tends to be recalled from working memory. Often, the word
>lists that we have students memorize in class demonstrations have one-syllable
>words. In this case, they can recall about 7 items of info. If you use word
>lists of two-syllable or higher words, they will recall fewer items of info.
Apparently, we have no cognitive psychologists on the list!! Well, just in case
there are a few of you lurking nearby, let me describe the work discussed by
Baddely and see if I can induce any of you to give a more complete and correct
account (since I may be misinterpreting him or, at least, not seeing the full
picture).
Baddely discussed the work on the "phonological loop system" of working memory.
This is a part of working memory that is postulated to rehearse material
subvocally. In having people memorize word lists containing words of various
lengths, he and his colleagues found an association between word length and
the number of items recalled: lists containing shorter words were remembered
better than lists containing longer words: "We assumed that the reason why
long words were harder to remember was because our subjects said the words to
themselves under their breath" (p. 52). They prevented subjects from doing
this by having them repeat the word "the" out loud as they were rehearsing.
This removed the association: word length no longer was important. Baddely
concluded the following:
"The relationship between the time it took to speak words of particular lengths
and memory span for them was very orderly.... On the basis of this, memory
span can be redefined: it is the amount of time that is constant, not the
number of items. Our subjects could only remember as much as they could say
in just 1.5 seconds." (p. 54)
The 7 +/- 2 capacity of short-term memory, thus, seems to be a myth that we
often promote in our lower-level classes. Is this interpretation correct?
Jeff Ricker
Scottsdale Community College
Scottsdale AZ
[EMAIL PROTECTED]
