Bryan R. Burnham James H. Neely Peter B. Walker W. Trammell Neill Department of Psychology

1. Interference from irrelevant color-singletons during serial search depends on visual attention being spatially diffuse Bryan R. Burnham James H. Neely Peter B. Walker W. Trammell Neill Department of Psychology University at Albany, State University of New York

2. Distractor-Absent Distractor-Present Visual Search • Salient, irrelevant stimuli can disrupt visual search • Theeuwes (1992) • Slower RTs with distractor present • Distractor ‘captured’ attention

3. Reasons for Search Disruption • Distractor-Target Feature Association • Bacon & Egeth (1994); Folk, Remington & Johnston (1992) • Distractor related to Target by “singletoness” • Stimulus-Driven Capture of Attention • Salience “naturally” captures attention ‘Singleton’ Search ‘Feature’ Search

4. No Capture with Feature Search? • Theeuwes (2004) • Absence of capture not due to feature dissimilarity • Feature search displays lower a singleton’s salience Visually “Noisy” Visually “Quieter”

5. If display is visually ‘noisy’ • Distractor not perceived as a singleton • Serial search adopted • Theeuwes (2004) • Attentional Window narrows with serial search • Focus on one item at a time • Distractor cannot be perceived as a singleton • No attentional capture during serial search • Theeuwes & Burger (1998) • No attentional capture during serial search • ONLY with strong attentional control • Capture found during serial search when attentional control was incomplete

6. Present Study • Research shows no attentional capture during serial search when attentional control is strong • But, items always in a circular pattern • Item-locations repeated and predictable • Observers could pre-focus attention • With serial search, distractor neverperceived as a singleton • Will a color singleton capture attention when: • Serial search is used • Strong attentional control is exerted • Target is not a singleton • Attention is diffuse when display appears

7. R R B H B K E H K E N S N S U Z Z U Method • Two groups searched for ‘A’ vs. ‘R’ • Target among 4, 6 or 8 different letters • Color singleton on random ½ of trials • Relevant and irrelevant colors fixed • Groups differed by display configuration: Circle Configuration Random Configuration

8. Results • No speed-accuracy tradeoff • Compared RTs in Distractor Present vs. Absent conditions for each Set Size between groups • Configuration x Distractor Presence interaction: • Interference: • Random Group: 13.7 ± 12.7 ms* • Circle Group: - 4.3 ± 12.0 ms • RT/Item Slopes • Circle Absent 36.5 ms/item* • Circle Preset 37.5 ms/item* • Random Absent 35.2 ms/item* • Random Present 33.2 ms/item*

9. Discussion • Conclusion: Attentional capture is possible during serial search when attentional control is strong • Depends on visual attention being spatially diffuse when display appears • Absence of capture in circular display group • Replicates Theeuwes & Burger (1998) • Capture in random display group • Occurred when serial search was evident • Initially diffuse attention • Diffuse attention needed to determine item-locations • Distractor perceived as a singleton • Overrode strong attentional control • “Stimulus-driven” attentional capture? • No target-distractor association • Capture overrode attentional control

10. The End Contact: bb7090@albany.edu