Rapid parallel attentional target selection in single-color and multiple-color visual search.

Abstract

Previous work has demonstrated that when targets are defined by a constant feature, attention can be directed rapidly and in parallel to sequentially presented target objects at different locations. We assessed how fast attention is allocated to multiple objects when this process cannot be controlled by a unique color-specific attentional template. N2pc components were measured as temporal markers of the attentional selection of 2 color-defined targets that were presented in rapid succession. Both targets either had the same color (one color task) or differed in color (two color task). Although there were small but systematic delays of target selection in the two color task relative to the one color task, attention was allocated extremely rapidly to both target objects in the two color task, which is inconsistent with the hypothesis that their selection was based on a slow switch between different color templates. Two follow-up experiments demonstrated that these delays did not reflect template switch costs, but were the result of competitive interactions between simultaneously active attentional templates. These results show that the control of focal attention during multiple-feature search operates much faster and more flexibly than is usually assumed.

Rapid attentional selection processes operate independently and in parallel for multiple targets

“…Previous ERP studies have measured N2pc components as a marker of attentional target selection in tasks where two target/nontarget stimulus displays were presented in rapid succession, and found evidence for the rapid allocation of spatial attention to both target objects (Eimer & Grubert, 2014;Grubert & Eimer, 2015;Jenkins, Grubert, & Eimer, in press). These observations show that multiple attentional selection processes can be activated concurrently, but do not provide clear-cut evidence that these processes operate in a genuinely parallel and independent fashion.…”

Dual-target cost in visual search for multiple unfamiliar faces.

“…In some circumstances, such as when searching for colour targets, overall speed decreases and accuracy falls when searching for two targets compared with single-target search, but both targets can be found with accuracy levels above chance. Indeed, much of the previous research on searching for multiple targets suggests that separate mental representations of all targets can be maintained successfully (Barrett & Zobay, 2014;Beck, Hollingworth, & Luck, 2012;Grubert & Eimer, 2015, 2016Irons, Folk, & Remington, 2012;Wolfe, 2012).…”

The speed of voluntary and priority-driven shifts of visual attention.

“…This problem can be overcome by presenting one of these targets on the vertical meridian (above or below fixation). Because vertical targets do not elicit N2pc components, the N2pc will exclusively reflect the selection of the horizontal target, independently of any additional attentional processing of the vertical target object (e.g., Eimer & Grubert, 2014;Eimer, Kiss, & Nicholas, 2011;Hickey, Di Lollo, & McDonald, 2009;Hickey, McDonald, & Theeuwes, 2006;Woodman, & Luck, 1999;Eimer & Grubert, 2014;Grubert & Eimer, 2015, 2016aJenkins, Grubert, & Eimer, 2016).…”