A. Kane York¹, Han Zhang¹, Jacob Sellers¹, Taraz Lee¹, John Jonides¹; ¹University of Michigan

Visual attention is highly susceptible to interference, particularly from two common types of distractors: uniquely colored items (color singletons) and suddenly appearing items (abrupt onsets). How do individuals process and ultimately disregard such distractions? To explore this, we used an innovative forced-response paradigm to examine the temporal dynamics of attentional shifts during a feature-search task. Three types of distractors were investigated: color singletons, abrupt onsets, and a combined distractor featuring both attributes (color onset singletons). In the forced-response paradigm, participants were trained to make a saccade in response to a fixed "go" signal, while the duration of the stimulus display was systematically varied. This method revealed the full temporal landscape of visual processing, showing that abrupt onset distractors elicited a stronger and more sustained attentional bias compared to the other two distractors. However, this bias diminished as saccade initiation was delayed. Separately, a novel salience measurement method was used with a different group of participants to evaluate distractor salience. Interestingly, this measure indicated that abrupt onsets were the least salient among the three distractor types. In a follow-up experiment, participants completed both the salience measure and the forced-response task with the same stimuli. This allowed for direct comparison within the same group, and the results replicated the findings from the separate populations: abrupt onsets produced a distinct temporal attentional bias in the forced-response task, while being less salient. These findings, combined with insights from a computational model that detailed differences in distractor suppression across conditions, highlight the dynamic and evolving mechanisms of attentional control in the presence of distractors.

Acknowledgements: National Science Foundation