title: Attention searches nonuniformly in space and in time.
abstract: Difficult search tasks are known to involve attentional resources, but the spatiotemporal behavior of attention remains unknown. Are multiple search targets processed in sequence or in parallel? We developed an innovative methodology to solve this notoriously difficult problem. Observers performed a difficult search task during which two probes were flashed at varying delays. Performance in reporting probes at each location was considered a measure of attentional deployment. By solving a second-degree equation, we determined the probability of probe report at the most and least attended probe locations on each trial. Because these values differed significantly, we conclude that attention was focused on one stimulus or subgroup of stimuli at a time, and not divided uniformly among all search stimuli. Furthermore, this deployment was modulated periodically over time at ∼ 7 Hz. These results provide evidence for a nonuniform spatiotemporal deployment of attention during difficult search.
authors.affiliation: CNRS, UMR5549, Centre de Recherche Cerveau et Cognition, Faculté de Médecine de Purpan, 31052 Toulouse, France; Université Paul Sabatier, 31062 Toulouse, France laura.dugue@nyu.edu.
authors.forename: Laura
authors.initials: L
authors.lastname: Dugué
authors.affiliation: CNRS, UMR5549, Centre de Recherche Cerveau et Cognition, Faculté de Médecine de Purpan, 31052 Toulouse, France; Université Paul Sabatier, 31062 Toulouse, France.
authors.forename: Douglas
authors.identifier: http://orcid.org/0000-0002-5892-9854
authors.initials: D
authors.lastname: McLelland
authors.affiliation: Université Paul Sabatier, 31062 Toulouse, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Lajous
authors.affiliation: CNRS, UMR5549, Centre de Recherche Cerveau et Cognition, Faculté de Médecine de Purpan, 31052 Toulouse, France; Université Paul Sabatier, 31062 Toulouse, France.
authors.forename: Rufin
authors.identifier: http://orcid.org/0000-0002-3611-7716
authors.initials: R
authors.lastname: VanRullen
mesh_terms: D001288:Attention; D006801:Humans; D010775:Photic Stimulation; D013647:Task Performance and Analysis
keywords: attention; nonuniform; periodic; sequential; visual search