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Interference from irrelevant color-singletons Interference from irrelevant color-singletons during serial search depends on visual during serial search depends on visual

attention being spatially diffuseattention being spatially diffuse

Bryan R. BurnhamBryan R. BurnhamJames H. NeelyJames H. NeelyPeter B. WalkerPeter B. Walker

W. Trammell NeillW. Trammell Neill

Department of PsychologyDepartment of PsychologyUniversity at Albany, State University of New YorkUniversity at Albany, State University of New York

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Visual SearchVisual Search Salient, irrelevant stimuli can disrupt visual searchSalient, irrelevant stimuli can disrupt visual search Theeuwes (1992)Theeuwes (1992)

Distractor-AbsentDistractor-Absent Distractor-PresentDistractor-Present

Slower RTs with distractor presentSlower RTs with distractor present

Distractor ‘captured’ attentionDistractor ‘captured’ attention

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Reasons for Search DisruptionReasons for Search Disruption Stimulus-Driven Capture of AttentionStimulus-Driven Capture of Attention

Salience “naturally” captures attentionSalience “naturally” captures attention Distractor-Target Feature AssociationDistractor-Target Feature Association

Bacon & Egeth (1994); Folk, Remington & Johnston (1992)Bacon & Egeth (1994); Folk, Remington & Johnston (1992) Distractor related to Target by “singletoness”Distractor related to Target by “singletoness”

‘‘Singleton’ SearchSingleton’ Search ‘‘Feature’ SearchFeature’ Search

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No Capture with Feature Search?No Capture with Feature Search? Theeuwes (2004) Theeuwes (2004)

Absence of capture not due to feature dissimilarityAbsence of capture not due to feature dissimilarity Feature search displays lower a singleton’s salienceFeature search displays lower a singleton’s salience

Visually “Noisy”Visually “Noisy”Visually “Quieter”Visually “Quieter”

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If display is visually ‘noisy’If display is visually ‘noisy’ Distractor not perceived as a singletonDistractor not perceived as a singleton Serial search adoptedSerial search adopted

Theeuwes (2004)Theeuwes (2004) Attentional WindowAttentional Window narrows with serial search narrows with serial search

Focus on one item at a timeFocus on one item at a time Distractor cannot be Distractor cannot be perceivedperceived as a singleton as a singleton No attentional capture during serial searchNo attentional capture during serial search

Theeuwes & Burger (1998)Theeuwes & Burger (1998) No attentional capture during serial searchNo attentional capture during serial search

ONLYONLY with strong attentional control with strong attentional control

Capture found during serial search when Capture found during serial search when attentional control was incompleteattentional control was incomplete

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Present StudyPresent Study Research shows no attentional capture during Research shows no attentional capture during

serial search when attentional control is strongserial search when attentional control is strong But, items But, items alwaysalways in a circular pattern in a circular pattern

Item-locations repeated and predictableItem-locations repeated and predictable Observers could Observers could pre-focuspre-focus attention attention

With serial search, distractor With serial search, distractor nevernever perceivedperceived as a as a singletonsingleton

Will a color singleton capture attention when:Will a color singleton capture attention when:A)A) Serial search is usedSerial search is used

B)B) Strong attentional control is exertedStrong attentional control is exerted

C)C) Target is not a singletonTarget is not a singleton

D)D) Attention is diffuse when display appearsAttention is diffuse when display appears

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MethodMethod Two groups searched for ‘A’ vs. ‘R’Two groups searched for ‘A’ vs. ‘R’

Target among 4, 6 or 8 different lettersTarget among 4, 6 or 8 different letters Color singleton on random ½ of trialsColor singleton on random ½ of trials Relevant and irrelevant colors fixedRelevant and irrelevant colors fixed Groups differed by display configuration:Groups differed by display configuration:

Circle Configuration Random Configuration

RB

E

SN

H

K

ZU

R

E

B

U

H

S

Z

N

K

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ResultsResults No speed-accuracy tradeoffNo speed-accuracy tradeoff Compared RTs in Distractor Present vs. Absent Compared RTs in Distractor Present vs. Absent

conditions for each Set Size between groupsconditions for each Set Size between groups Configuration x Distractor Presence interaction:Configuration x Distractor Presence interaction:

675

700

725750

775

800

825850

875

900

5 7 9

Set Size (Number of Items)

RT

(mse

c)

Circle-Absent

Circle Present

Random-Absent

Random-Present

Interference:Interference: Random Group:Random Group:

13.7 13.7 ± 12.7 ms± 12.7 ms** Circle Group:Circle Group:

- 4.3 - 4.3 ± 12.0 ms± 12.0 ms

RT/Item SlopesRT/Item Slopes Circle AbsentCircle Absent

36.536.5 ms/item* ms/item* Circle PresetCircle Preset

37.5 ms/item*37.5 ms/item* Random AbsentRandom Absent

35.2 35.2 ms/item*ms/item* Random PresentRandom Present

33.2 ms/item*33.2 ms/item*

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DiscussionDiscussion Absence of capture in circular display groupAbsence of capture in circular display group

Replicates Theeuwes & Burger (1998)Replicates Theeuwes & Burger (1998)

Capture in random display groupCapture in random display group Occurred when serial search was evidentOccurred when serial search was evident

Initially diffuse attentionInitially diffuse attention Diffuse attention needed to determine item-locationsDiffuse attention needed to determine item-locations Distractor perceived as a singletonDistractor perceived as a singleton

Overrode strong attentional controlOverrode strong attentional control

““Stimulus-driven” attentional capture?Stimulus-driven” attentional capture? No target-distractor associationNo target-distractor association Capture overrode attentional controlCapture overrode attentional control

ConclusionConclusion: Attentional capture is possible : Attentional capture is possible during serial search when attentional control during serial search when attentional control is strongis strong Depends on visual attention being spatially Depends on visual attention being spatially

diffuse when display appearsdiffuse when display appears

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The EndThe End

Contact:

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