Visual Working Memory Capacity Load Does Not Modulate Distractor Processing

In the recent decade, researchers have explored the influence of visual working memory (WM) load on selective attention by focusing on the modulation of visual WM load on distractor processing. However, there are three distinct hypotheses (perceptual load hypothesis, resolution hypothesis, domain-specific hypothesis) with different predictions. The perceptual load hypothesis suggests that visual WM load serves as a type of perceptual load: Higher visual WM load leads to less distractor processing. The resolution hypothesis holds that the visual WM capacity load serves as a type of cognitive load, while visual WM resolution load functions as a type of perceptual load. However, the domain-specific hypothesis claims that visual WM load serves as a type of cognitive load, but only when there is a content overlap between the WM task and the perceptual task. We attempted to figure out the influence of visual WM load on distractor processing by adding a flanker task into the maintenance phase of a visual WM task. We manipulated the parameters of the task settings (including memory array and flanker task, Experiments 1–4), the perceptual load of flanker task (Experiment 5), the content overlap between WM task and flanker task (Experiment 6), and the exposure time of flanker task (Experiments 7–9). However, against all the three hypotheses, we consistently found that the visual WM load did not modulate the distractor processing in nine experiments. The implications of the current finding were discussed.