The interference condition of the Brown-Peterson task and the auditory consonant trigrams test was designed to evaluate working memory in that it required a division of attentional processes to complete two cognitive tasks. However, the specific cognitive functions contributing to the performance of this interference task have yet to be determined. The objective of this study was to determine what other tasks are comparable to the Brown-Peterson task and conduct an exploratory factor analysis that included the measures from the Brown-Peterson task and other neuropsychological measures. A neuropsychological battery was administered to younger participants (n=107, mean age=20.83) and older participants (n=93, mean age=70.14). Factor analysis yielded a two-factor solution. Performance after the intervening serial subtraction task loaded on an auditory/visual working memory and complex attention factor and had common loadings with working memory subtests of the WAIS-III and the spatial span subtest of the WMS-III. Results suggest that the performance after the intervening serial subtraction task evaluates dual information processing, complex attention, and working memory.