Addressing the differences in speed of processing of the intervening calculation task on the modified Brown-Peterson task.

The Modified Brown-Peterson task (MBPT) is a task of divided attention and working memory that requires central executive functioning. It is a variant of the Brown-Peterson technique and is useful for studying short-term retention of information. It involves the recall of auditory information under conditions of interference (i.e., counting backwards). Previous research has not addressed the effect of individual differences in processing speed for the intervening calculations. In a sample of 81 young participants, we determined whether the number of correct calculations performed is related to recall performance on the MBPT. Results indicated that the number of calculations performed was not significantly related to the recall performance on the MBPT. Rather, the number of correct calculations performed during the interference task of the MBPT was associated with arithmetic ability as measured by the arithmetic subtest of the Adult Intelligence Scale-III (Wechsler, 1997). These results suggest that the subtractions in the MBPT create interference regardless of mathematical ability or speed at which the subtractions are performed during the interference condition of the MBPT task. This observation suggests that the results on this test are independent of mathematical ability and represent a useful measure of working memory.