title: N2pc and attentional capture by colour and orientation-singletons in pure and mixed visual search tasks.
abstract: The capture of attention by singleton stimuli in visual search is a matter of contention. Some authors propose that singletons capture attention in a bottom-up fashion if they are salient. Others propose that capture is contingent upon whether or not the stimuli share task-relevant attributes with the target. This study assessed N2pc elicited by colour and orientation singletons in a mixed task (the singleton defined as target changed block-to-block), and a pure task (the target was the same across the whole task). Both singletons elicited N2pc when acting as targets; when acting as non-targets, orientation singletons elicited N2pc only in the mixed task. The results suggest that the singletons were not salient enough to engage attention in a purely bottom-up fashion. Elicitation of N2pc by non-targets in the mixed task should be attributed to top-down processes associated with the current task. Stimuli that act as targets in part of the blocks become not completely irrelevant when non-targets.
authors.affiliation: Department of Clinical Psychology and Psychobiology, University of Santiago de Compostela, Campus Universitario Sur s/n, Santiago de Compostela, E-15782 Galicia, Spain. rodriguez.holguin@usc.es
authors.forename: Socorro
authors.initials: S
authors.lastname: Rodríguez Holguín
authors.forename: Sonia
authors.initials: S
authors.lastname: Doallo
authors.forename: Carmen
authors.initials: C
authors.lastname: Vizoso
authors.forename: Fernando
authors.initials: F
authors.lastname: Cadaveira
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D003118:Color Perception / Q000502:physiology*; D004192:Discrimination, Psychological; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult