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
1
Visual Search
 Salient, irrelevant stimuli can disrupt visual search
 Theeuwes (1992)
Distractor-Absent
Distractor-Present
 Slower RTs with distractor present
 Distractor ‘captured’ attention
2
Reasons for Search Disruption
 Stimulus-Driven Capture of Attention
 Salience “naturally” captures attention
 Distractor-Target Feature Association
 Bacon & Egeth (1994); Folk, Remington & Johnston
(1992)
 Distractor related to Target by “singletoness”
‘Singleton’ Search
‘Feature’ Search
3
No Capture with Feature Search?
 Theeuwes (2004)
 Absence of capture not due to feature dissimilarity
 Feature search displays lower a singleton’s salience
Visually
Visually “Quieter”
“Noisy”
4
 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
5
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 never perceived as a
singleton

Will a color singleton capture attention when:
A)
B)
C)
D)
Serial search is used
Strong attentional control is exerted
Target is not a singleton
Attention is diffuse when display appears
6
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
R
H
Random Configuration
R
B
K
E
N
H K
Z
E
N
S
U
B
U
S
Z
7
Results
 No speed-accuracy tradeoff
 Compared RTs in Distractor Present vs. Absent
conditions for each Set Size between groups
 Configuration x Distractor Presence interaction:
36.5 ms/item*
13.7
± 12.7 ms*
 Circle Preset
Group:
- 4.3 ms/item*
37.5
± 12.0 ms
 Random Absent
35.2 ms/item*
 Random Present
33.2 ms/item*
RT (msec)
 Interference:
RT/Item Slopes
 Circle
Random
Absent
Group:
900
875
850
825
800
775
750
725
700
675
Circle-Absent
Circle Present
Random-Absent
Random-Present
5
7
9
Set Size (Number of Items)
8
Discussion
 Absence of capture in circular display group
 Replicates Theeuwes & Burger (1998)
 Conclusion:
Attentional
capture
Capture in random
display
groupis possible
during
serial
search
 Occurred
when
serialwhen
searchattentional
was evident
control
is diffuse
strongattention
 Initially
 Depends
on visual
attention
being spatially
 Diffuse attention
needed
to determine
item-locations
diffuse
when
displayasappears
 Distractor
perceived
a singleton
 Overrode strong attentional control
 “Stimulus-driven” attentional capture?
 No target-distractor association
 Capture overrode attentional control
9
The End
Contact:
10
bb7090@albany.edu