Attentional capture effects are modulated by the number of concurrently maintained search goals.

Introduction: In hybrid visual-memory search, multiple search goals are concurrently maintained in memory and searched for in a visual display. When there are few goals, maintenance can operate in visual working memory, whereas when there are many concurrent search goals, they may be maintained in activated long-term memory. A central question here is how multiple search goals are concurrently maintained in memory and selectively enhanced during search. Two attentional capture effects illustrate goal enhancement in the presence of distraction: contingent capture, when distractors resemble the current trial's target, and set-specific capture, when distractors resemble one of your search goals, but not the current trial's target. Methods: In the present study, participants memorized sets of 2, 4, or 16 objects, and searched for them in a continuous rapid serial visual presentation stream. On critical trials, a goal-related distractor appeared 1-2 frames before the target, matching either the Results: Contingent capture was greatest with 16-item sets, whereas set-specific capture was greatest with 2-item sets, and 4-item sets were in between. Discussion: These findings indicate that search goal enhancement flexibly adapts to memory load, with implications for models of goal maintenance and attentional control. They also provide the first evidence of set-specific capture with complex objects as search goals.