title: Object-based selection modulates top-down attentional shifts.
abstract: A large body of evidence supports that visual attention - the cognitive process of selectively concentrating on a salient or task-relevant subset of visual information - often works on object-based representation. Recent studies have postulated two possible accounts for the object-specific attentional advantage: attentional spreading and attentional prioritization, each of which modulates a bottom-up signal for sensory processing and a top-down signal for attentional allocation, respectively. It is still unclear which account can explain the object-specific attentional advantage. To address this issue, we examined the influence of object-specific advantage on two types of visual search: parallel search, invoked when a bottom-up signal is fully available at a target location, and serial search, invoked when a bottom-up signal is not enough to guide target selection and a top-down control for shifting of focused attention is required. Our results revealed that the object-specific advantage is given to the serial search but not to the parallel search, suggesting that object-based attention facilitates stimulus processing by affecting the priority of attentional shifts rather than by enhancing sensory signals. Thus, our findings support the notion that the object-specific attentional advantage can be explained by attentional prioritization but not attentional spreading.
authors.affiliation: Department of Integrative Brain Science, Graduate School of Medicine, Kyoto University Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishida
authors.affiliation: Graduate School of Information Science, Nara Institute of Science and Technology Ikoma, Japan ; Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology Kitakyushu, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Graduate School of Information Science, Nara Institute of Science and Technology Ikoma, Japan.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Ikeda
keywords: attentional prioritization; attentional spreading; object-based attention; object-specific advantage; parallel and serial search; psychophysics; visual attention; visual search