Abstract
There have been a considerable number of studies supporting the assertion that top-down knowledge of a distractors’ basic visual features (e.g., color, orientation) can elicit distractor suppression (e.g., Gaspelin et al., 2015; Woodman & Luck, 2007). Recently, we demonstrated that category-level knowledge of distractors can also elicit distractor suppression effects (Goetz & Neider, 2021). In that study, we only presented two possible categories. In the current study, we tested whether the effects of categorical distractor suppression remained robust when three categories were presented. We expected faster RTs on trials presenting the suppressed category—indicative of distractor suppression—regardless of the number of categories presented. This prediction parallels the findings of the current distractor suppression studies examining basic visual features: varied stimuli sets do not affect distractor suppression (e.g., Arita et al., 2012; Gaspelin & Luck, 2018). Using three stimulus sets developed from our prior studies (teddy bears, butterflies, and fish silhouettes that preserved form information), 47 participants were instructed to actively suppress a specific object category while the two not-suppressed categories were considered neutral and could be used as either targets or neutral distractors. Participants had to indicate the location of a target circle on each trial appearing at one of the cardinal positions adjacent to a target object. Three trial types were presented: isolated (one object from neutral categories), neutral (two objects from neutral categories), and suppress (1 object from neutral categories and 1 object from the category to be suppressed). As expected, RTs were fastest on isolated trials (all ps < .001). Critically, participants were significantly (~24 ms) faster to respond on suppress trials than neutral trials (p = .04). This finding provides evidence that top-down knowledge of categorical information can elicit distractor suppression despite increased variance in target categories.