Abstract
Working memory (WM) capacity and conflict resolution (CR) are often regarded as overlapping functions. By one prominent account (e.g., Engle, 2002), working memory is necessary to maintain the current task goals, which in turn provide top-down control over conflicting response tendencies. Consistent with this account, some individual differences research has indicated WM and CR are correlated. Yet, the extent to which WM and CR share common cognitive resources within individuals is unknown. To study how overcoming conflict influences the maintenance of visual WM representations and vice versa, we ran three dual-task experiments in which both CR demand and WM load were manipulated. Participants performed an auditory Stroop task (“High” or “Low” spoken in high/low pitch), during a visual change detection task. The inter-stimulus interval (ISI) between WM array and auditory Stroop onset was either 0ms (stimuli for both tasks presented simultaneously), or 500ms (auditory onset during the WM delay period). In the first experiment, both Stroop task congruency and ISI varied trial-wise. In the second experiment, congruency varied trial-wise, but ISI was manipulated across blocks (varied by block). In the third experiment, both congruency and ISI were manipulated across block. Across the three experiments, we found no significant interaction between CR demand and WM load on performance in either task. Bayes factor analyses indicate strong confidence in favor of accepting the null hypothesis that there is no relationship between CR demand and WM load. Combined with recent individual differences research indicating difficulties with identifying a robust conflict resolution factor (e.g., Unsworth, 2015), these findings suggest that the relationship between working memory functioning and conflict regulation during response selection needs to be reconsidered.