The relationship between working memory and the dual-target cost in visual search guidance.

Abstract

Searching for two targets produces a dual-target cost compared with single-target search, with reduced attentional guidance towards targets . We explore the effect of holding a color in working memory (WM) on guidance in single-target search. In Experiments 1 and 2, participants searched for a T of a specific color while holding one of the following in WM: a color patch, a letter, a dot pattern, or an oriented bar. Only when holding a color in WM was guidance in single-target search affected as strongly as it is in dual-target search. In Experiment 3, the target changed color from trial to trial. A color in WM reduced guidance, but not to the extent of dual-target search. However, search and WM error rates were high, suggesting interference and incomplete engagement with the combined task. We conclude that the guidance cost in dualtarget search is not solely due to attentional capture by the WM-color, because the WM-color can be effectively separated from search color, with little confusion between the two. However, WM load does cause substantial interference in guidance when both tasks involve color. These results illustrate the complex interactions between working memory and attentional guidance.When searching for two different target objects (e.g., guns and bombs in airport security screening), observers look at objects that are different from either target, which makes search much less efficient than search for a single target. The need to hold two items WORKING MEMORY AND DUAL-TARGET SEARCH 4 (rather than one) in working memory could contribute to this failure to keep irrrelevant objects from being attended. WORKING MEMORY AND DUAL-TARGET SEARCH

The Role of Working Memory in Dual-Target Visual Search

“…To this end, when two targets are dissimilar, they are apparently encoded as separate and discrete representations. In the latter experiments, participants searched for a target of a specific color while holding a color or a non-color item in WM (Menneer et al, 2019). Holding a color in WM caused the general disruption in attentional guidance to a color target, similar to that observed in dual-target search.…”

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

“…This cost emerges when searching for two targets, either of which can appear (disjunctive dual-target search). The attentional limitations demonstrated in this dual-target cost are providing useful new clues as to how search targets are stored in visual working memory and how those representations contribute to guidance of attention toward search targets (Menneer, Cave, Kaplan, Stroud, & Donnelly, n.d.).…”

Using Eye Movements to Understand how Security Screeners Search for Threats in X-Ray Baggage

“…Other experiments have demonstrated flexibility in search guidance that may be informative to understanding how to manage searching for multiple targets. In an eye-movement study by Beck, Hollingworth, and Luck [32], participants could either search for two target colors simultaneously, or search first for one color and then switch to the other, depending on the instructions. When left to choose their search method on their own, participants seem to do something in between purely simultaneous and purely successive search: they often switch between fixating one target color and fixating the other, but at a given moment during the search they seem to favour one target over the other [33].…”