Working memory span and the role of proactive interference

The authors investigated the possibility that working memory span tasks are influenced by interference and that interference contributes to the correl ation between span and other measures. Younger and older adults received th e span task either in the standard format or one designed to reduce the imp act of interference with no impact on capacity demands. Participants then r ead and recalled a short prose passage. Reducing the amount of interference in the span task raised span scores, replicating previous results (C. P. M ay, L. Hasher, & M. J. Kane, 1999). The same interference-reducing manipula tions that raised span substantially altered the relation between span and prose recall. These results suggest that span is influenced by interference , that age differences in span may be due to differences in the ability to overcome interference rather than to differences in capacity, and that inte rference plays an important: role in the relation between span and other ta sks.