Object-based target templates guide attention during visual search.

Abstract

During visual search, attention is believed to be controlled in a strictly feature-based fashion, without any guidance by object-based target representations. To challenge this received view, we measured electrophysiological markers of attentional selection (N2pc component) and working memory (sustained posterior contralateral negativity; SPCN) in search tasks where two possible targets were defined by feature conjunctions (e.g., blue circles and green squares). Critically, some search displays also contained nontargets with two target features (incorrect conjunction objects, e.g., blue squares). Because feature-based guidance cannot distinguish these objects from targets, any selective bias for targets will reflect object-based attentional control. In Experiment 1, where search displays always contained only one object with target-matching features, targets and incorrect conjunction objects elicited identical N2pc and SPCN components, demonstrating that attentional guidance was entirely feature-based. In Experiment 2, where targets and incorrect conjunction objects could appear in the same display, clear evidence for object-based attentional control was found. The target N2pc became larger than the N2pc to incorrect conjunction objects from 250 ms poststimulus, and only targets elicited SPCN components. This demonstrates that after an initial feature-based guidance phase, object-based templates are activated when they are required to distinguish target and nontarget objects. These templates modulate visual processing and control access to working memory, and their activation may coincide with the start of feature integration processes. Results also suggest that while multiple feature templates can be activated concurrently, only a single object-based target template can guide attention at any given time. (PsycINFO Database Record

Task-Irrelevant Features in Visual Working Memory Influence Covert Attention: Evidence from a Partial Report Task

“…Note, however, that we do not make any claims about whether guidance by feature conjunctions is beneficial above what would be expected from the sum of their higher-weighted features. This is also an interesting question and has been investigated elsewhere [58,59,60]. It seems that guidance differs if the target is defined by a conjunction of features rather than identifiable on the basis of a single feature [60].…”

The guidance of attention by templates for rejection during visual search

“…Templates are activated during the preparation for search (Grubert & Eimer, 2018), and elicit rapid biases in attention towards stimuli with template-matching features (e.g., Eimer & Kiss, 2008;Folk et al, 1992). Search templates can specify basic target features such as color or size (e.g., Eimer & Kiss, 2008), but can also represent feature combinations in an object-based fashion (e.g., Berggren & Eimer, 2018). There is also evidence that multiple feature templates can be activated simultaneously (e.g., Irons, Folk, & Remington, 2012).…”

Not looking for any trouble? Purely affective attentional settings do not induce goal-driven attentional capture

“…An alternative possibility, however, could lie in suggestions that involuntary capture can only result from prioritization of a single perceptual feature (e.g., colour or shape; van Mooreselaar, Theeuwes, & Olivers, 2014), or only for multiple features related to a single object file (e.g., Berggren & Eimer, 2018). It might be argued that affective categories are, therefore, too perceptually heterogeneous to induce goal-driven attentional capture.…”