Working memory capacity as a determinant of proactive interference and auditory distraction

Individual differences in working memory capacity are related to performance on a range of elemental and higher order cognitive tasks. The current experiment tests the assumptions of two theoretical approaches to working memory capacity: working memory as executive attention and working memory as temporary binding. These approaches are examined using a short-term updating task where proactive interference is manipulated, such that old responses have to be suppressed in favour of new responses. A second source of distraction is introduced by way of irrelevant, to-be-ignored background speech that accompanies presentation of the list items. This speech reinforces either the to-be-remembered item on the current list, or the to-be-suppressed item. Working memory capacity was significantly related to overall level of correct performance on the short-term task, and to the degree of proactive interference experienced. However, there was no evidence for individual differences in the ability to suppress the interfering foil, nor in priming effects associated with the irrelevant speech. The results provided little support for the working memory capacity as executive attention perspective, some evidence for the binding perspective, but also evidence supporting the fact that some effects of distraction are not under voluntary control.