scholarly journals The role of meaning in visual working memory: Real-world objects, but not simple features, benefit from deeper processing

2020 ◽  
Author(s):  
Timothy F. Brady ◽  
Viola S. Störmer

Visual working memory is a capacity-limited cognitive system used to actively store and manipulate visual information. Visual working memory capacity is not fixed, but varies by stimulus type: stimuli that are more meaningful are better remembered. In the current work, we investigate what conditions lead to the strongest benefits for meaningful stimuli. We propose that in some situations, participants may be prone to try to encode the entire display holistically (i.e., in a quick ‘snapshot’), encouraging participants to treat objects simply as meaningless colored ‘blobs’, rather than processing them individually and in a high-level way, which could reduce benefits for meaningful stimuli. In a series of experiments we directly test whether real-world objects, colors, perceptually-matched less-meaningful objects, and fully scrambled objects benefit from deeper processing. We systematically vary the presentation format of stimuli at encoding to be either simultaneous — encouraging a parallel, ‘take-a-quick-snapshot’ strategy — or present the stimuli sequentially, promoting a serial, each-item-at-once strategy. We find large advantages for meaningful objects in all conditions, but find that real-world objects — and to a lesser degree lightly scrambled, still meaningful versions of the objects — benefit from the sequential encoding and thus deeper, focused-on-individual-items processing, while colors do not. Our results suggest single feature objects may be an outlier in their affordance of parallel, quick processing, and that in more realistic memory situations, visual working memory likely relies upon representations resulting from in-depth processing of objects (e.g., in higher-level visual areas) rather than solely being represented in terms of their low-level features.

2021 ◽  
Vol 33 (5) ◽  
pp. 902-918 ◽  
Author(s):  
Isabel E. Asp ◽  
Viola S. Störmer ◽  
Timothy F. Brady

Abstract Almost all models of visual working memory—the cognitive system that holds visual information in an active state—assume it has a fixed capacity: Some models propose a limit of three to four objects, where others propose there is a fixed pool of resources for each basic visual feature. Recent findings, however, suggest that memory performance is improved for real-world objects. What supports these increases in capacity? Here, we test whether the meaningfulness of a stimulus alone influences working memory capacity while controlling for visual complexity and directly assessing the active component of working memory using EEG. Participants remembered ambiguous stimuli that could either be perceived as a face or as meaningless shapes. Participants had higher performance and increased neural delay activity when the memory display consisted of more meaningful stimuli. Critically, by asking participants whether they perceived the stimuli as a face or not, we also show that these increases in visual working memory capacity and recruitment of additional neural resources are because of the subjective perception of the stimulus and thus cannot be driven by physical properties of the stimulus. Broadly, this suggests that the capacity for active storage in visual working memory is not fixed but that more meaningful stimuli recruit additional working memory resources, allowing them to be better remembered.


2020 ◽  
Author(s):  
Colin Quirk ◽  
Kirsten C. S. Adam ◽  
Edward K. Vogel

Visual working memory is the ability to hold visual information temporarily in mind. A key feature of working memory is its starkly limited capacity, such that only a few simple items can be remembered at once. Prior work has shown that this capacity limit cannot be circumvented by providing additional encoding time — whether providing just 200 ms or up to 1,300 ms, capacity is still limited to only 3-4 items. In contrast, Brady, Störmer, and Alvarez (2016) hypothesized that real-world objects, but not simple items used in prior research, benefit from additional encoding time and are not subject to traditional capacity limits. They supported this hypothesis with results from both behavior and the contralateral delay activity (CDA), an EEG marker of working memory storage, and concluded that familiar, complex stimuli are necessary in order to observe encoding time effects. Here, we conducted three replications of Brady et al.’s key manipulation with a larger number of participants and more trials per condition. We failed to replicate their primary behavioral result (objects benefit more than colors from additional encoding time) and failed to observe an object-specific increase in the CDA. Instead, we found that encoding time benefitted both simple color items and real-world objects, in contrast to both the findings by Brady et al. and some prior work on this topic. Overall, we observed no support for the hypothesis that real-world objects have a different capacity than colored squares. We discuss the implications of our findings for theories of visual working memory.


2020 ◽  
Vol 10 (8) ◽  
pp. 556
Author(s):  
Mariana R. Maniglia ◽  
Alessandra S. Souza

Healthy aging is associated with decline in the ability to maintain visual information in working memory (WM). We examined whether this decline can be explained by decreases in the ability to filter distraction during encoding or to ignore distraction during memory maintenance. Distraction consisted of irrelevant objects (Exp. 1) or irrelevant features of an object (Exp. 2). In Experiment 1, participants completed a spatial WM task requiring remembering locations on a grid. During encoding or during maintenance, irrelevant distractor positions were presented. In Experiment 2, participants encoded either single-feature (colors or orientations) or multifeature objects (colored triangles) and later reproduced one of these features using a continuous scale. In multifeature blocks, a precue appeared before encoding or a retrocue appeared during memory maintenance indicating with 100% certainty to the to-be-tested feature, thereby enabling filtering and ignoring of the irrelevant (not-cued) feature, respectively. There were no age-related deficits in the efficiency of filtering and ignoring distractor objects (Exp. 1) and of filtering irrelevant features (Exp. 2). Both younger and older adults could not ignore irrelevant features when cued with a retrocue. Overall, our results provide no evidence for an aging deficit in using attention to manage visual WM.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241110
Author(s):  
Ariel Starr ◽  
Mahesh Srinivasan ◽  
Silvia A. Bunge

We can retain only a portion of the visual information that we encounter within our visual working memory. Which factors influence how much information we can remember? Recent studies have demonstrated that the capacity of visual working memory is influenced by the type of information to be remembered and is greater for real-world objects than for abstract stimuli. One explanation for this effect is that the semantic knowledge associated with real-world objects makes them easier to maintain in working memory. Previous studies have indirectly tested this proposal and led to inconsistent conclusions. Here, we directly tested whether semantic knowledge confers a benefit for visual working memory by using familiar and unfamiliar real-world objects. We found a mnemonic benefit for familiar objects in adults and children between the ages of 4 and 9 years. Control conditions ruled out alternative explanations, namely the possibility that the familiar objects could be more easily labeled or that there were differences in low-level visual features between the two types of objects. Together, these findings demonstrate that semantic knowledge influences visual working memory, which suggests that the capacity of visual working memory is not fixed but instead fluctuates depending on what has to be remembered.


2016 ◽  
Author(s):  
◽  
Kimberly Bodner

Previous investigations of working memory performance in individuals with Autism Spectrum Disorder (ASD) have yielded mixed findings (e.g., Kenworthy, Yerys, Anthony, and Wallace, 2008; Geurts, de Vris, and van den Bergh, 2014). Research examining visual and spatial working memory abilities in older adolescents and adults with ASD specifically is limited. The current study assessed the contribution of working memory capacity, attention, and visual filtering abilities to visual working memory performance in adolescents and adults with and without ASD. Furthermore, the current study examined task performance related to real world report of working memory and attention abilities. Results revealed comparable estimates of visual working memory capacity overall between groups. However, visual working memory performance for individuals with ASD appeared to be more impacted by increases in attention and visual filtering demands. Individuals with ASD allocated their attention differently than non-ASD individuals, and spent less time looking at relevant information. The ASD group had more difficulty filtering distracting information in more challenging conditions. Difficulties on the task did not significantly relate to reported real world working memory or attention abilities. Findings suggest that visual working memory performance is similar between individuals with and without ASD when cognitive demands are low, but individuals with ASD are detrimentally effected when the cognitive load increases (increased attention and visual filtering demands), consistent with previous literature (Kenworthy et al., 2008). Given the complexity of our environments and need to filter visually distracting information, these findings may shed light on ASD-related difficulties in day-to-day functioning and provide a focus for intervention.


2020 ◽  
Author(s):  
Timothy F. Brady ◽  
Viola S. Störmer

The capacity of visual working and visual long-term memory play a critical role in theories of cognitive architecture and the relationship between memory and other cognitive systems. Here, we argue that before asking the question of how capacity varies across different stimuli or what the upper bound of capacity is for a given memory system, it is necessary to establish a methodology that allows a fair comparison between distinct stimulus sets and conditions. One of the most important factors determining performance in a memory task is target/foil dissimilarity. We argue that only by maximizing the dissimilarity of the target and foil in each stimulus set can we provide a fair basis for memory comparisons between stimuli. In the current work we introduce a new way to pick such foils objectively for complex, meaningful real-world objects by using deep convolutional neural networks, and we validate this using both memory tests and similarity metrics. Using this method, we then provide evidence that there is a greater capacity for real-world objects relative to simple colors in visual working memory; critically, we also show that this difference can be reduced or eliminated when non-comparable foils are used, potentially explaining why previous work has not always found such a difference. Our study thus demonstrates that working memory capacity is not fixed capacity but depends critically on the type of information that is remembered, and offers a solution of how to compare memory performance and other cognitive systems across different stimulus sets on common ground.


2018 ◽  
Vol 18 (10) ◽  
pp. 821
Author(s):  
Ariel Starr ◽  
Mahesh Srinivasan ◽  
Silvia Bunge

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