Distractor interference stays constant despite variation in working memory load

Previous studies have shown that working memory (WM) plays an important role in selective attention, so that high WM load leads to inefficient distractor inhibition, in comparison with low WM load. In the present study, we examined the effect of WM on distractor processing while the extent of attentional focus was held constant. Our results show that WM load affected distractor processing only when it was positively correlated with the extent of attentional focus. When the latter was held constant, the effect of WM became negligible. Furthermore, when low WM load was paired with a wide attentional focus and high WM load was matched with a narrow attentional focus, greater distractor processing was found when the WM load was low than when it was high. These results suggest that efficient distractor inhibition may require only minimal WM resources and that the effect of WM on distractor processing is more complex than has previously been assumed.