A Flash in the Pan? Distractor Suppression Cannot Be Inferred from the Early Lateralized Positivity

Humans excel at avoiding distraction in visual environments, successfully filtering out repeated salient distractors that could otherwise capture attention. A recent theoretical perspective posits a mechanism whereby such distractors can be proactively suppressed, reducing their impact on attentional deployment. Electrophysiological evidence for this view comes from the distractor positivity (PD), a neural component associated with distractor handling. The PD has been observed at early latencies (< 200 msec) following distractor appearance, a timing interpreted as reflecting distractor suppression before attentional capture. However, the relationship between this "early PD" and distractor suppression remains fundamentally correlational. This raises critical questions about the extent to which this neural marker exclusively indexes mechanisms of suppression, as opposed to being driven by other factors confounded with distractor presence, such as stimulus salience. We tested the specificity of this early positivity to distractor handling across three experiments employing visual search tasks. Participants were presented with unique color singletons serving as distractors, targets, or task-irrelevant items. The early lateralized positivity was elicited by salient color distractors, but also appeared in response to all other salient singletons, including those that could not be proactively suppressed. Our findings indicate that the early positivity is not unique to suppressed distractors-instead, it likely reflects sensory imbalance between visual hemifields or salience tagging in response to lateralized stimuli. Consequently, we argue that the "early PD" does not provide definitive evidence for proactive distractor suppression, as its association with distractor presence appears to be incidental rather than causal.