scholarly journals Electrophysiological correlates of the flexible allocation of visual working memory resources

2019 ◽  
Author(s):  
Christine Salahub ◽  
Holly A. Lockhart ◽  
Blaire Dube ◽  
Naseem Al-Aidroos ◽  
Stephen M. Emrich
Keyword(s):  
Working Memory ◽  
Resource Allocation ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Load ◽  
Continuous Model ◽  
Attentional Selection ◽  
Distribution Of Resources ◽  
Flexible Resource ◽  
Memory Resources

AbstractVisual working memory is a brief, capacity-limited store of visual information that is involved in a large number of cognitive functions. To guide one’s behavior effectively, one must efficiently allocate these limited memory resources across memory items. Previous research has suggested that items are either stored in memory or completely blocked from memory access. However, recent behavioral work proposes that memory resources can be flexibly split across items based on their level of task importance. Here, we investigated the electrophysiological correlates of flexible resource allocation by manipulating the distribution of resources amongst systematically lateralized memory items. We examined the contralateral delay activity (CDA), a waveform typically associated with the number of items held in memory. Across three experiments, we found that, in addition to memory load, the CDA flexibly tracks memory resource allocation. This allocation occurred as early as attentional selection, as indicated by the N2pc. Additionally, CDA amplitude was better-described when fit with a continuous model predicted by load and resources together than when fit with either alone. Our findings show that electrophysiological markers of attentional selection and memory maintenance not only track memory load, but also the proportion of memory resources those items receive.

scholarly journals Electrophysiological correlates of the flexible allocation of visual working memory resources

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christine Salahub ◽  
Holly A. Lockhart ◽  
Blaire Dube ◽  
Naseem Al-Aidroos ◽  
Stephen M. Emrich
Keyword(s):  
Working Memory ◽  
Resource Allocation ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Load ◽  
Continuous Model ◽  
Attentional Selection ◽  
Distribution Of Resources ◽  
Flexible Resource ◽  
Memory Resources

AbstractVisual working memory is a brief, capacity-limited store of visual information that is involved in a large number of cognitive functions. To guide one’s behavior effectively, one must efficiently allocate these limited memory resources across memory items. Previous research has suggested that items are either stored in memory or completely blocked from memory access. However, recent behavioral work proposes that memory resources can be flexibly split across items based on their level of task importance. Here, we investigated the electrophysiological correlates of flexible resource allocation by manipulating the distribution of resources amongst systematically lateralized memory items. We examined the contralateral delay activity (CDA), a waveform typically associated with the number of items held in memory. Across three experiments, we found that, in addition to memory load, the CDA flexibly tracks memory resource allocation. This allocation occurred as early as attentional selection, as indicated by the N2pc. Additionally, CDA amplitude was better-described when fit with a continuous model predicted by load and resources together than when fit with either alone. Our findings show that electrophysiological markers of attentional selection and memory maintenance not only track memory load, but also the proportion of memory resources those items receive.

scholarly journals Reprioritization of Features of Multidimensional Objects Stored in Visual Working Memory

2017 ◽  
Vol 28 (12) ◽  
pp. 1773-1785 ◽  
Author(s):  
Young Eun Park ◽  
Jocelyn L. Sy ◽  
Sang Wook Hong ◽  
Frank Tong
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Complete Loss ◽  
Object Representations ◽  
Maintenance Period ◽  
Object Based ◽  
Multidimensional Objects ◽  
The Cost ◽  
Memory Resources

A prevalent view of visual working memory (VWM) is that visual information is actively maintained in the form of perceptually integrated objects. Such reliance on object-based representations would predict that after an object is fully encoded into VWM, all features of that object would need to be maintained as a coherent unit. Here, we evaluated this idea by testing whether memory resources can be redeployed to a specific feature of an object already stored in VWM. We found that observers can utilize a retrospective cue presented during the maintenance period to attenuate both the gradual deterioration and complete loss of memory for a cued feature over time, but at the cost of accelerated loss of information regarding the uncued feature. Our findings demonstrate that object representations held within VWM can be decomposed into individual features and that having to retain additional features imposes greater demands on active maintenance processes.

scholarly journals Working memory resources can be efficiently deallocated from items that become obsolete

2021 ◽  
Author(s):  
Robert Taylor ◽  
Ivan Tomic ◽  
David Aagten-Murphy ◽  
Paul Bays
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Small Proportion ◽  
Visual Information ◽  
Visually Guided ◽  
Active Process ◽  
Current Task ◽  
Stored Information ◽  
Task Goals ◽  
Memory Resources

Visual working memory (VWM) resources are limited, placing constraints on how much visual information can be simultaneously retained. During visually-guided activity, stored information can quickly become outdated, so updating mechanisms are needed to ensure the contents of memory remain relevant to current task goals. In particular, successful deallocation of resources from items that become obsolete is likely to be critical for maintaining the precision of those representations still in memory. The experiments in this study involved presenting two memory arrays of coloured disks in sequence. The appearance of the second array was a cue to replace either one, or all, of the colours in memory from the first array. When compared to conditions that were matched in the total number of items presented, we predicted that successful updating would result in fewer actively maintained items, owing to the removal of pre-replacement features. Comparison of recall precision between these two conditions should therefore provide a test of successful updating. We identified a very small proportion (~5%) of trials in which participants incorrectly reported a feature from the first array in place of its replacement in the second, which we interpreted as a failure to incorporate the information from the second display into memory. Once these trials were discounted, precision estimates were consistent with complete deallocation of resources from pre-replacement features. We conclude that working memory can be efficiently updated when previous information becomes obsolete, but that this is a demanding active process that occasionally fails.

scholarly journals Planning the potential future during multi-item visual working memory

2021 ◽  
Author(s):  
Rose Nasrawi ◽  
Freek van Ede
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Load ◽  
Memory Task ◽  
Action Planning ◽  
Beta Activity ◽  
Response Hand ◽  
Manual Responses ◽  
Human Participants

Working memory allows us to retain visual information to guide upcoming future behavior. In line with this future-oriented purpose of working memory, recent studies have shown that action planning occurs during encoding and retention of a single visual item, for which the upcoming action is certain. We asked whether and how this extends to multi-item visual working memory, when visual representations serve the potential future. Human participants performed a visual working memory task with a memory-load manipulation (one/two/four items), and a delayed orientation-reproduction report (of one item). We measured EEG to track 15-25 Hz beta activity in electrodes contralateral to the required response hand - a canonical marker of action planning. We show an attenuation of beta activity, not only in load one (with one certain future action), but also in load two (with two potential future actions), compared to load four (with low prospective-action certainty). Moreover, in load two, potential action planning occurs regardless whether both visual items afford similar or dissimilar manual responses; and it predicts the speed of ensuing memory-guided behavior. This shows that potential action planning occurs during multi- item visual working memory, and brings the perspective that working memory helps us prepare for the potential future.

Visual Search Facilitation in Repeated Displays Depends on Visuospatial Working Memory

2012 ◽  
Vol 59 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Angela A. Manginelli ◽  
Franziska Geringswald ◽  
Stefan Pollmann
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Control Experiment ◽  
Memory Load ◽  
Contextual Cueing ◽  
Long Term Memory ◽  
Visuospatial Working Memory ◽  
Working Memory Load ◽  
Memory Resources

When distractor configurations are repeated over time, visual search becomes more efficient, even if participants are unaware of the repetition. This contextual cueing is a form of incidental, implicit learning. One might therefore expect that contextual cueing does not (or only minimally) rely on working memory resources. This, however, is debated in the literature. We investigated contextual cueing under either a visuospatial or a nonspatial (color) visual working memory load. We found that contextual cueing was disrupted by the concurrent visuospatial, but not by the color working memory load. A control experiment ruled out that unspecific attentional factors of the dual-task situation disrupted contextual cueing. Visuospatial working memory may be needed to match current display items with long-term memory traces of previously learned displays.

scholarly journals Does perceptual grouping improve visuospatial working memory? Optimized processing or encoding bias

2021 ◽  
Author(s):  
Antonio Prieto ◽  
Vanesa Peinado ◽  
Julia Mayas
Keyword(s):  
Working Memory ◽  
Change Detection ◽  
Visual Working Memory ◽  
Visual Information ◽  
Detection Accuracy ◽  
Visuospatial Working Memory ◽  
Gestalt Grouping ◽  
Color Similarity ◽  
Automatic Encoding ◽  
Change Detection Performance

AbstractVisual working memory has been defined as a system of limited capacity that enables the maintenance and manipulation of visual information. However, some perceptual features like Gestalt grouping could improve visual working memory effectiveness. In two different experiments, we aimed to explore how the presence of elements grouped by color similarity affects the change detection performance of both, grouped and non-grouped items. We combined a change detection task with a retrocue paradigm in which a six item array had to be remembered. An always valid, variable-delay retrocue appeared in some trials during the retention interval, either after 100 ms (iconic-trace period) or 1400 ms (working memory period), signaling the location of the probe. The results indicated that similarity grouping biased the information entered into the visual working memory, improving change detection accuracy only for previously grouped probes, but hindering change detection for non-grouped probes in certain conditions (Exp. 1). However, this bottom-up automatic encoding bias was overridden when participants were explicitly instructed to ignore grouped items as they were irrelevant for the task (Exp. 2).

Greater Visual Working Memory Capacity for Visually Matched Stimuli When They Are Perceived as Meaningful

2021 ◽  
Vol 33 (5) ◽  
pp. 902-918 ◽  
Author(s):  
Isabel E. Asp ◽  
Viola S. Störmer ◽  
Timothy F. Brady
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Visual Complexity ◽  
Memory Capacity ◽  
Subjective Perception ◽  
Neural Delay ◽  
Meaningful Stimuli

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.

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