Mike,
The critical thing in the Brown-Peterson paradigm is to get the subjects
counting backwards accurately at a very quick rate. If that's not enforced,
they'll slow down in order to slip in some covert rehearsal - similar to
Baddeley & Hitch (1974) where subjects could maintain six digits while
simultaneously doing a sentence verification task.
There may be individual differences in math abitlity that allow high
ability folks to perform the subtraction quickly enough to have time left
over for rehearsal. I've run into this in my own work on individual
differences in working memory capacity (see Lovett, Daily & Reder at
http://www.elsevier.nl/locate/cogsys ). One possible way to deal with that
would be to administer a test of math ability before the B-P task and use
it as a covariate or screening device. Just a quick thought.
Larry
--On Sunday, March 05, 2000 4:39 PM +0100 Michael Ofsowitz <[EMAIL PROTECTED]>
wrote:
> For a class project I had students look for release from proactive
> interference in STM. They used the Brown-Peterson-Peterson distraction
> technique of counting backwards by 3's starting with 3-digit numbers like
> 482 to prevent rehearsal. One student reported the following:
>
>> Some subjects reported that when the numbers that started off as
>> easy calculations ie multiples of 3 or the number 0 they had less
>> trouble remembering the words than when the starting number was not
>> an easy calculation ie the numbers 1, 2, 4, 5, etc.
>
> Another student said that at debriefing one of her subjects said he was
> trying extra hard to remember the words while counting backwards.
>
> Is this common? Does B-P not distract rehearsal sufficiently in some
> instances (e.g., where the initial subtractions are more easily
> calculated)?
>
> --> Mike O.
> --
> _______________________________________________
>
> Michael S. Ofsowitz
> University of Maryland - European Division
> http://faculty.ed.umuc.edu/~mofsowit
> _______________________________________________
*********************************************************
Larry Z. Daily
Post-doctoral Research Associate
Department of Psychology
Carnegie Mellon University
phone: (412) 268-4194
email: [EMAIL PROTECTED]
Web: http://www.andrew.cmu.edu/user/ldaily/index.html
