title: Visual search performance is predicted by both prestimulus and poststimulus electrical brain activity.
abstract: An individual's performance on cognitive and perceptual tasks varies considerably across time and circumstances. We investigated neural mechanisms underlying such performance variability using regression-based analyses to examine trial-by-trial relationships between response times (RTs) and different facets of electrical brain activity. Thirteen participants trained five days on a color-popout visual-search task, with EEG recorded on days one and five. The task was to find a color-popout target ellipse in a briefly presented array of ellipses and discriminate its orientation. Later within a session, better preparatory attention (reflected by less prestimulus Alpha-band oscillatory activity) and better poststimulus early visual responses (reflected by larger sensory N1 waves) correlated with faster RTs. However, N1 amplitudes decreased by half throughout each session, suggesting adoption of a more efficient search strategy within a session. Additionally, fast RTs were preceded by earlier and larger lateralized N2pc waves, reflecting faster and stronger attentional orienting to the targets. Finally, SPCN waves associated with target-orientation discrimination were smaller for fast RTs in the first but not the fifth session, suggesting optimization with practice. Collectively, these results delineate variations in visual search processes that change over an experimental session, while also pointing to cortical mechanisms underlying performance in visual search.
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, United States.|University of Groningen, Univ Med Ctr Groningen, Department of Neuroscience, NL-9713 AW Groningen, The Netherlands.|Department of Experimental Psychology, Faculty of Behavioural and Social Sciences, University of Groningen, Groningen, The Netherlands.|BCN-NeuroImaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Berry
authors.initials: B
authors.lastname: van den Berg
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, United States.|Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, United States.
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Appelbaum
authors.affiliation: School of Psychology, Cardiff University, Cardiff, Wales, CF10 3AT, United Kingdom.
authors.forename: Kait
authors.initials: K
authors.lastname: Clark
authors.affiliation: University of Groningen, Univ Med Ctr Groningen, Department of Neuroscience, NL-9713 AW Groningen, The Netherlands.|Department of Experimental Psychology, Faculty of Behavioural and Social Sciences, University of Groningen, Groningen, The Netherlands.|BCN-NeuroImaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Monicque M
authors.initials: MM
authors.lastname: Lorist
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, United States.|Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, United States.
authors.forename: Marty G
authors.initials: MG
authors.lastname: Woldorff
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult