title: Disentangling the effects of spatial inconsistency of targets and distractors when searching in realistic scenes.
abstract: Previous research has suggested that correctly placed objects facilitate eye guidance, but also that objects violating spatial associations within scenes may be prioritized for selection and subsequent inspection. We analyzed the respective eye guidance of spatial expectations and target template (precise picture or verbal label) in visual search, while taking into account any impact of object spatial inconsistency on extrafoveal or foveal processing. Moreover, we isolated search disruption due to misleading spatial expectations about the target from the influence of spatial inconsistency within the scene upon search behavior. Reliable spatial expectations and precise target template improved oculomotor efficiency across all search phases. Spatial inconsistency resulted in preferential saccadic selection when guidance by template was insufficient to ensure effective search from the outset and the misplaced object was bigger than the objects consistently placed in the same scene region. This prioritization emerged principally during early inspection of the region, but the inconsistent object also tended to be preferentially fixated overall across region viewing. These results suggest that objects are first selected covertly on the basis of their relative size and that subsequent overt selection is made considering object-context associations processed in extrafoveal vision. Once the object was fixated, inconsistency resulted in longer first fixation duration and longer total dwell time. As a whole, our findings indicate that observed impairment of oculomotor behavior when searching for an implausibly placed target is the combined product of disruption due to unreliable spatial expectations and prioritization of inconsistent objects before and during object fixation.
authors.affiliation: School of Psychology, University of Dundee, Park Place, Dundee, Scotland, UK Institut de Neurosciences de la Timone (INT), CNRS & Aix-Marseille University, Marseille, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Spotorno
authors.affiliation: Department of Psychology, The George Washington University, Washington DC, USA.
authors.forename: George L
authors.initials: GL
authors.lastname: Malcolm
authors.affiliation: School of Psychology, University of Dundee, Park Place, Dundee, Scotland, UK.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Tatler
mesh_terms: D000293:Adolescent; D000328:Adult; D003463:Cues; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D055815:Young Adult
keywords: context information; eye movements; spatial consistency; target template; visual search