Working memory and Stroop interference: An individual differences investigation

We investigated the claim that individual differences in working-memory capacity reflect limitations on the ability to inhibit task-irrelevant information and/or to maintain activation in the face of distracting or interfering events. Specifically, we investigated whether high- and low-capacity individuals differed in their susceptibility to interference on the Stroop task and whether high-capacity individuals employed a strategy for minimizing Stroop interference. In Experiment 1, we found that high-capacity participants showed substantial interference when conflict trials were infrequent, but almost no interference when conflict trials were frequent. In contrast, low-capacity participants showed substantial interference irrespective of the proportion of conflict trials. In Experiment 2, we found that high-capacity participants experienced substantial negative priming, slow responses when the to-be-named color was the irrelevant word on the previous trial. We discuss these results and their implications for high-capacity individuals' ability to reduce Stroop interference in light of both inhibitory and noninhibitory accounts of negative priming.