Object-based Encoding in Visual Working Memory: Evidence from Memory-driven Attentional Capture

Abstract

Visual working memory (VWM) adopts a specific manner of object-based encoding (OBE) to extract perceptual information: Whenever one feature-dimension is selected for entry into VWM, the others are also extracted. Currently most studies revealing OBE probed an ‘irrelevant-change distracting effect’, where changes of irrelevant-features dramatically affected the performance of the target feature. However, the existence of irrelevant-feature change may affect participants’ processing manner, leading to a false-positive result. The current study conducted a strict examination of OBE in VWM, by probing whether irrelevant-features guided the deployment of attention in visual search. The participants memorized an object’s colour yet ignored shape and concurrently performed a visual-search task. They searched for a target line among distractor lines, each embedded within a different object. One object in the search display could match the shape, colour, or both dimensions of the memory item, but this object never contained the target line. Relative to a neutral baseline, where there was no match between the memory and search displays, search time was significantly prolonged in all match conditions, regardless of whether the memory item was displayed for 100 or 1000 ms. These results suggest that task-irrelevant shape was extracted into VWM, supporting OBE in VWM.

Involuntary top-down control by search-irrelevant features: Visual working memory biases attention in an object-based manner

“…The reported results are related to a different line of research investigating attentional biasing effects of VWM contents in dual task studies (Gao et al, 2016;Olivers, Meijer, & Theeuwes, 2006;Sala & Courtney, 2009;Soto & Humphreys, 2009). In this line of research, a first task requires to store items in VWM for later use.…”

“…Fortunately, the dual-task line of research on VWM and attention can provide first insights into this question. Among these dual-task studies on VWM and attention, a few studies asked whether all or only relevant features of a VWM item bias attention (Gao et al, 2016;Olivers et al, 2006;Sala & Courtney, 2009;Soto & Humphreys, 2009). Participants in Gao et al (2016) were asked to memorize the color of a colored shape for later recall.…”

“…This finding strengthens our previous conclusions of involuntary object-based attentional biasing, assuming that similar mechanisms are responsible for the dual-task and the single-task biasing effects. In addition, instead of real-word objects, Gao et al (2016) as well as Soto and Humphreys (2009) used geometric forms like triangles, circles, and squares. In Soto and Humphreys (2009), the color of the to-be-remembered geometric forms was irrelevant for a later match-to-sample task and nevertheless biased attention during an interim search task, indicated by prolonged search times.…”

Oculomotor capture by search-irrelevant features in visual working memory: on the crucial role of target–distractor similarity

“…In most experimentally studied visual-search scenarios and many real-life situations, one specific feature of the VWM template is target defining, while other features are uninformative or even shared with distractors. Conflicting results have been reported for different visual-search paradigms (Foerster & Schneider, 2018;Gao et al, 2016;Olivers et al, 2006;Sala & Courtney, 2009;).…”

Agent identity drives adaptive encoding of biological motion into working memory

“…To address this question, we focused on a common phenomenon in our daily life: While memorizing the actions of distinct people on a street, will their clothing colors be extracted into WM involuntarily? A similar question has been extensively explored for static visual objects in WM (e.g., Gao, Li, Yin, & Shen, 2010;Gao et al, 2016;Shen, Tang, Wu, Shui, & Gao, 2013;Shin & Ma, 2016, 2017Swan, Collins, & Wyble, 2016;Zhao, Chen, Zhang, Shen, & Gao, 2018). A growing body of research has found that even if only one basic feature is required to be memorized, the other features will also be extracted into this cognitive unit, suggesting that an object-based encoding manner takes place for visual objects.…”