scholarly journals Spatial and feature-based suppression in working memory

2020 ◽  
Author(s):  
Liam Matthews ◽  
Tobias Feldmann-Wüstefeld

Working memory (WM) can guide attention towards items similar to its content, both based on features and locations maintained in WM. So far, however, this has only been demonstrated with memory items that are relevant and thus maintained with a positive weight. The finding that negative attention templates can support the suppression of upcoming distractors raises the question whether items can also be stored with a negative priority in WM. We let participants memorize the exact hue of a memory target that was presented among not-to-be-encoded memory distractors. Before their WM was probed, they performed a visual search task in which they had to find a target among distractors. When the search target was presented in the same color as an item suppressed from WM, response times (RTs) were longer than for a target presented in the same color as the memory target. Similarly, when the search target was presented at the same location as an items suppressed from WM, RTs were longer than for a target presented at the same location as the memory target. Our results suggest that items can be maintained in WM with a negative priority and then support the suppression of subsequent similar stimuli. Such items with negative priority in WM may be what constitutes negative attentional templates.

2019 ◽  
Author(s):  
Cherie Zhou ◽  
Monicque M. Lorist ◽  
Sebastiaan Mathôt

AbstractDuring visual search, task-relevant representations in visual working memory (VWM), known as attentional templates, are assumed to guide attention. A current debate concerns whether only one (Single-Item-Template hypothesis, or SIT) or multiple (Multiple-Item-Template hypothesis, or MIT) items can serve as attentional templates simultaneously. The current study was designed to test these two hypotheses. Participants memorized two colors, prior to a visual-search task in which the target and the distractor could match or not match the colors held in VWM. Robust attentional guidance was observed when one of the memory colors was presented as the target (reduced response times [RTs] on target-match trials) or the distractor (increased RTs on distractor-match trials). We constructed two drift-diffusion models that implemented the MIT and SIT hypotheses, which are similar in their predictions about overall RTs, but differ in their predictions about RTs on individual trials. Critically, simulated RT distributions and error rates revealed a better match of the MIT hypothesis to the observed data than the SIT hypothesis. Taken together, our findings provide behavioral and computational evidence for the concurrent guidance of attention by multiple items in VWM.Significance statementTheories differ in how many items within visual working memory can guide attention at the same time. This question is difficult to address, because multiple- and single-item-template theories make very similar predictions about average response times. Here we use drift-diffusion modeling in addition to behavioral data, to model response times at an individual level. Crucially, we find that our model of the multiple-item-template theory predicts human behavior much better than our model of the single-item-template theory; that is, modeling of behavioral data provides compelling evidence for multiple attentional templates that are simultaneously active.


Author(s):  
Hanshu Zhang ◽  
Joseph W. Houpt

The prevalence of items in visual search may have substantial performance consequences. In laboratory visual search tasks in which the target is rare, viewers are likely to miss the target. A dual-threshold model proposed by Wolfe and Van Wert (2010) assumes that in the low prevalence condition, viewers shift their criteria resulting in more miss errors. However, from the prospective of prospect theory (Kahneman & Tversky, 1979), decision makers tend to overweight small probability. To explore how viewers subjectively weight the probability in the low prevalence visual search task, we compared viewers’ criteria with the optimal criteria by presenting different probability descriptions for a fixed prevalence rate. The data from this experiment indicated that target presence had an effect on viewers’ accuracy and response times but not probability descriptions. Viewers’ criteria under different probability descriptions were higher than optimal. These results are in accordance with the dual-threshold model assumption that viewers respond “target absent” more frequently than optimal, leading to more miss errors in the low prevalence condition.


2020 ◽  
pp. 174702182096626
Author(s):  
Lingxia Fan ◽  
Lin Zhang ◽  
Liuting Diao ◽  
Mengsi Xu ◽  
Ruiyang Chen ◽  
...  

Recent studies have demonstrated that in visual working memory (VWM), only items in an active state can guide attention. Further evidence has revealed that items with higher perceptual salience or items prioritised by a valid retro-cue in VWM tend to be in an active state. However, it is unclear which factor (perceptual salience or retro-cues) is more important for influencing the item state in VWM or whether the factors can act concurrently. Experiment 1 examined the role of perceptual salience by asking participants to hold two features with relatively different perceptual salience (colour vs. shape) in VWM while completing a visual search task. Guidance effects were found when either colour or both colour and shape in VWM matched one of the search distractors but not when shape matched. This demonstrated that the more salient feature in VWM can actively guide attention, while the less salient feature cannot. However, when shape in VWM was cued to be more relevant (prioritised) in Experiment 2, we found guidance effects in both colour-match and shape-match conditions. That is, both more salient but non-cued colour and less salient but cued shape could be active in VWM, such that attentional selection was affected by the matching colour or shape in the visual search task. This suggests that bottom-up perceptual salience and top-down retro-cues can jointly determine the active state in VWM.


2018 ◽  
Author(s):  
Marcella Frătescu ◽  
Dirk Van Moorselaar ◽  
Sebastiaan Mathôt

AbstractStimuli that resemble the content of visual working memory (VWM) capture attention. However, theories disagree on how many VWM items can bias attention simultaneously. The multiple-state account posits a distinction between template and accessory VWM items, such that only a single template item biases attention. In contrast, homogenous-state accounts posit that all VWM items bias attention. Recently, Van Moorselaar et al. (2014) and Hollingworth and Beck (2016) tested these accounts, but obtained seemingly contradictory results. Van Moorselaar et al. (2014) found that a distractor in a visual-search task captured attention more when it matched the content of VWM (memory-driven capture). Crucially, memory-driven capture disappeared when more than one item was held in VWM, in line with the multiple-state account. In contrast, Hollingworth and Beck (2016) found memory-driven capture even when multiple items were kept in VWM, in line with a homogenous-state account. Considering these mixed results, we replicated both studies with a larger sample, and found that all key results are reliable. It is unclear to what extent these divergent results are due to paradigm differences between the studies. We conclude that is crucial to our understanding of VWM to determine the boundary conditions under which memory-driven capture occurs.


2018 ◽  
Vol 71 (10) ◽  
pp. 2235-2248 ◽  
Author(s):  
Alexandra Trani ◽  
Paul Verhaeghen

We investigated pupil dilation in 96 subjects during task preparation and during a post-trial interval in a visual search task and an auditory working memory task. Completely informative difficulty cues (easy, medium, or hard) were presented right before task preparation to examine whether pupil dilation indicated advance mobilisation of attentional resources; functional magnetic resonance imaging (fMRI) studies have argued for the existence of such task preparation, and the literature shows that pupil dilation tracks attentional effort during task performance. We found, however, little evidence for such task preparation. In the working memory task, pupil size was identical across cues, and although pupil dilation in the visual search task tracked the cue, pupil dilation predicted subsequent performance in neither task. Pupil dilation patterns in the post-trial interval were more consistent with an effect of emotional reactivity. Our findings suggest that the mobilisation of attentional resources in the service of the task does not occur during the preparatory interval, but is delayed until the task itself is initiated.


Author(s):  
Michael F. Gorman ◽  
Donald L. Fisher

The fact that response times increase as one ages has long been established. Previously, a model of general slowing in the nonlexical domains has done a really good job of explaining the differences between older and younger adults. However, an alternative process-specific model has not been conclusively ruled out. This experiment tested general and process-specific models of slowing in the nonlexical domain using older and younger adults performing a visual search task. The task manipulated the presence of the target, the number of search items, and the structure of the display of the search items. It was found that a process-specific model explained significantly more of the variability than a general model of slowing. It was also discovered that the process most greatly affected was that of deciding to terminate a search when no target was present in the display.


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