Is Working Memory Load Irrelevant to Inhibitory Cognitive Control in Negative Priming?
Two issues were addressed in this study. First, it addresses the viability of the assertion that working memory is crucial for reducing distraction by maintaining the prioritization of relevant over irrelevant information in visual selective attention tasks. The authors tested this hypothesis in an experiment involving a modified n-back task with attentional displays consisting of a distractor word superimposed on a target picture. Working memory load is deemed to be low in a 1-back task and relatively higher in a 2-back task. Here we report surprising results from 1- and 2-back versions of an n-back task with negative priming measures to assess the extent of distractor word processing. The second issue addressed a controversy in the negative priming literature involving whether it is possible to obtain negative priming effects with a large pool of stimuli, since it is generally thought that obtaining negative priming with words requires that words are encountered repeatedly as targets before becoming ignored distractors in the prime display of a prime-probe couplet. Thus, negative priming is ostensibly only produced when a relatively small pool of words is used, and these words exchange roles, acting as targets on some trials and distractors on others in the course of the task. Here, significant negative priming effects were observed despite using a large pool of stimuli and without ever having the distractor word appear as a target stimulus prior to the target probe on an ignored repetition trial. Possible resolutions to the opposing findings are provided.