title: Previously seen and expected stimuli elicit surprise in the context of visual search.
abstract: In the context of visual search, surprise is the phenomenon by which a previously unseen and unexpected stimulus exogenously attracts spatial attention. Capture by such a stimulus occurs, by definition, independent of task goals and is thought to be dependent on the extent to which the stimulus deviates from expectations. However, the relative contributions of prior-exposure and explicit knowledge of an unexpected event to the surprise response have not yet been systematically investigated. Here observers searched for a specific color while ignoring irrelevant cues of different colors presented prior to the target display. After a brief familiarization period, we presented an irrelevant motion cue to elicit surprise. Across conditions we varied prior exposure to the motion stimulus - seen versus unseen - and top-down expectations of occurrence - expected versus unexpected - to assess the extent to which each of these factors contributes to surprise. We found no attenuation of the surprise response when observers were pre-exposed to the motion cue and or had explicit knowledge of its occurrence. Our results show that it is neither sufficient nor necessary that a stimulus be new and unannounced to elicit surprise and suggest that the expectations that determine the surprise response are highly context specific.
authors.affiliation: School of Psychology, McElwain Building, The University of Queensland, Brisbane, QLD, 4072, Australia. jdretell@gmail.com.
authors.forename: James D
authors.initials: JD
authors.lastname: Retell
authors.affiliation: School of Psychology, McElwain Building, The University of Queensland, Brisbane, QLD, 4072, Australia.
authors.forename: Stefanie I
authors.initials: SI
authors.lastname: Becker
authors.affiliation: School of Psychology, McElwain Building, The University of Queensland, Brisbane, QLD, 4072, Australia.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Remington
mesh_terms: D000328:Adult; D003118:Color Perception; D003463:Cues; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception; D010775:Photic Stimulation; D011336:Probability
keywords: Attentional capture; Surprise; Visual search