scholarly journals When “capacity” changes with set size: Ensemble representations support the detection of across-category changes in visual working memory

2018 ◽  
Author(s):  
Mark Schurgin ◽  
Timothy F. Brady
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Limited Resource ◽  
Fixed Number ◽  
Stimulus Similarity ◽  
Set Size ◽  
Complex Stimuli ◽  
Potential Use ◽  
Ensemble Representations

Is there a fixed limit on how many objects we can hold actively in mind? Generally, researchers have found participants are able to remember fewer objects if they are more complex, suggesting a limited resource rather than a fixed number of objects best explains working memory performance. However, some evidence has suggested that stimulus similarity better accounts for these effects, and that after accounting for such similarity, the data support a slot-based fixed- item limit for working memory. Much of the evidence used to support the latter claim relies on working memory displays containing different categories of items. It has been found that for large, across-category changes, performance does not differ for different kinds of complex stimuli. However, many of these studies fail to adequately control for the potential use of ensemble information in discriminating such large, across-category changes. Here, we sought to identify how much ensemble representations may explain performance across these tasks. In Experiment 1, we observed that as set size increased from 4 to 12 items, capacity estimates for across-category changes increased linearly as well, providing evidence against the claim of a fixed capacity. In Experiment 2, we controlled for stimulus complexity and similarity but varied the utility of ensemble representations for the change detection task. We observed significantly greater capacity when ensemble information could be used. Altogether, these results are contrary to a slot-like, fixed-object constraint on working memory capacity, and consistent with object complexity and ensemble representations strongly affecting working memory performance.

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.

Visuospatial Working Memory Capacity in the Brain After Working Memory Training in College Students With ADHD: A Randomized Controlled Trial

2019 ◽  
pp. 108705471987948 ◽  
Author(s):  
Steven Woltering ◽  
Chao Gu ◽  
Zhong-Xu Liu ◽  
Rosemary Tannock
Keyword(s):  
College Students ◽  
Working Memory ◽  
Controlled Trial ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Memory Training ◽  
Treatment Groups ◽  
Before And After ◽  
Students With Adhd ◽  
The Brain

Objective: ADHD has been associated with persistent problems of working memory. This study investigated the efficacy of an intensive and adaptive computerized working memory treatment (CWMT) at behavioral and neural levels. Method: College students ( n = 89; 40 females) with ADHD were randomized into a standard-length CWMT (45 min/session, 25 sessions, n = 29), shortened-length CWMT (15 min/session, 25 sessions, n = 32), and a waitlist group ( n = 28). Both CWMT groups received treatment for 5 days a week for 5 weeks. Lab sessions before and after CWMT assessed electroencephalography (EEG) indicators of working memory, behavioral indicators of working memory performance, and ADHD symptomatology. Results: No evidence was found for neural or any other behavioral transfer effects of improvement for the CWMT treatment groups over the active control or waitlist group. Conclusion: Our study does not provide evidence for the benefits of CWMT at neural or behavioral levels.

A Comparison of Computation Span and Reading Span Working Memory Measures’ Relations With Problem-Solving Criteria

2017 ◽  
Vol 121 (3) ◽  
pp. 430-444
Author(s):  
Richard Perlow ◽  
Mia Jattuso
Keyword(s):  
Working Memory ◽  
Problem Solving ◽  
Cognitive Abilities ◽  
Practical Implication ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Theory Development ◽  
Performance Outcomes ◽  
Phonological Loop ◽  
Working Memory Models

Researchers have operationalized working memory in different ways and although working memory–performance relationships are well documented, there has been relatively less attention devoted to determining whether seemingly similar measures yield comparable relations with performance outcomes. Our objective is to assess whether two working memory measures deploying the same processes but different item content yield different relations with two problem-solving criteria. Participants completed a computation-based working memory measure and a reading-based measure prior to performing a computerized simulation. Results reveal differential relations with one of the two criteria and support the notion that the two working memory measures tap working memory capacity and other cognitive abilities. One implication for theory development is that researchers should consider incorporating other cognitive abilities in their working memory models and that the selection of those abilities should correspond to the criterion of interest. One practical implication is that researchers and practitioners shouldn’t automatically assume that different phonological loop-based working memory scales are interchangeable.

scholarly journals Reviewing the Role of Cognitive Load, Expertise Level, Motivation, and Unconscious Processing in Working Memory Performance

2015 ◽  
Vol 4 (2) ◽  
pp. 142 ◽  
Author(s):  
Seffetullah Kuldas ◽  
Shahabuddin Hashim ◽  
Hairul Nizam Ismail ◽  
Zainudin Abu Bakar
Keyword(s):  
Working Memory ◽  
Emotional Processing ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Cognitive Learning ◽  
Learning Task ◽  
Cognitive Capacity ◽  
Unconscious Processing ◽  
Expertise Level

<p class="p1">Human cognitive capacity is unavailable for conscious processing of every amount of instructional messages. Aligning an instructional design with learner expertise level would allow better use of available working memory capacity in a cognitive learning task. Motivating students to learn consciously is also an essential determinant of the capacity usage. However, motivational factors are often subject to unconscious rather than conscious emotional processing. This review sets out the need for further studies to elucidate the role of motivation and unconscious processing in the use of cognitive capacity<span class="s1">. </span></p>

scholarly journals Frontoparietal connectivity correlates with working memory performance in multiple sclerosis

2019 ◽  
Author(s):  
Alejandra Figueroa-Vargas ◽  
Claudia Cárcamo ◽  
Rodrigo Henríquez-Ch ◽  
Francisco Zamorano ◽  
Ethel Ciampi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Working Memory ◽  
Cognitive Deficit ◽  
Memory Load ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Theta Activity ◽  
Therapeutic Interventions ◽  
Oscillatory Dynamics ◽  
Phase Amplitude

AbstractWorking Memory (WM) impairment is the most common cognitive deficit of Multiple Sclerosis (MS) patients. However, evidence of its neurobiological mechanisms is scarce. Here we recorded electroencephalographic activity of twenty patients with relapsing-remitting MS and minimal cognitive deficit, and 20 healthy control (HC) subjects while they solved a WM task. In spite of similar performance, the HC group demonstrated both a correlation between temporoparietal theta activity and memory load, and a correlation between medial frontal theta activity and successful memory performances. MS patients did not show theses correlations leading significant differences between groups. Moreover, cortical connectivity analyses using granger causality and phase-amplitude coupling between theta and gamma revealed that HC group, but not MS group, presented a load-modulated progression of the frontal-to-parietal connectivity. This connectivity correlated with working memory capacity in MS groups. This early alterations in the oscillatory dynamics underlaying working memory could be useful for plan therapeutic interventions

scholarly journals Allocentric Spatial Memory Performance in a Virtual Reality-Based Task is Conditioned by Visuospatial Working Memory Capacity

2020 ◽  
Vol 10 (8) ◽  
pp. 552
Author(s):  
Joaquín Castillo Escamilla ◽  
José Javier Fernández Castro ◽  
Shishir Baliyan ◽  
Juan José Ortells-Pareja ◽  
Juan José Ortells Rodríguez ◽  
...  
Keyword(s):  
Working Memory ◽  
Virtual Reality ◽  
Spatial Memory ◽  
Medial Temporal Lobe ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Memory Task ◽  
Memory Capacity ◽  
Spatial Task ◽  
Analysis Of Covariance

Traditionally, the medial temporal lobe has been considered a key brain region for spatial memory. Nevertheless, executive functions, such as working memory, also play an important role in complex behaviors, such as spatial navigation. Thus, the main goal of this study is to clarify the relationship between working memory capacity and spatial memory performance. Spatial memory was assessed using a virtual reality-based procedure, the Boxes Room task, and the visual working memory with the computer-based Change Localization Task. One hundred and twenty-three (n = 123) participants took part in this study. Analysis of Covariance (ANCOVA) revealed a statistically significant relationship between working memory capacity and spatial abilities. Thereafter, two subgroups n = 60, were formed according to their performance in the working memory task (1st and 4th quartiles, n = 30 each). Results demonstrate that participants with high working memory capacity committed fewer mistakes in the spatial task compared to the low working memory capacity group. Both groups improved their performance through repeated trials of the spatial task, thus showing that they could learn spatial layouts independent of their working memory capacity. In conclusion, these findings support that spatial memory performance is directly related to working memory skills. This could be relevant for spatial memory assessment in brain lesioned patients.

Induced Social Power Improves Visual Working Memory

2019 ◽  
Vol 46 (2) ◽  
pp. 285-297 ◽  
Author(s):  
Britt Hadar ◽  
Roy Luria ◽  
Nira Liberman
Keyword(s):  
Working Memory ◽  
Low Power ◽  
Visual Working Memory ◽  
High Power ◽  
Social Power ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Filtering Efficiency ◽  
Sense Of Power

The possibility that social power improves working memory relative to conditions of powerlessness has been invoked to explain why manipulations of power improve performance in many cognitive tasks. Yet, whether power facilitates working memory performance has never been tested directly. In three studies, we induced high or low sense of power using the episodic recall task and tested participants’ visual working memory capacity. We found that working memory capacity estimates were higher in the high-power than in the low-power condition in the standard change-detection task (Study 1), in a variation of the task that introduced distractors alongside the targets (Study 2), and in a variation that used real-world objects (Study 3). Studies 2 and 3 also tested whether high power improved working memory relative to low power by enhancing filtering efficiency, but did not find support for this hypothesis. We discuss implications for theories of both power and working memory.

scholarly journals The Contribution of Attentional Lapses to Individual Differences in Visual Working Memory Capacity

2015 ◽  
Vol 27 (8) ◽  
pp. 1601-1616 ◽  
Author(s):  
Kirsten C. S. Adam ◽  
Irida Mance ◽  
Keisuke Fukuda ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Attentional Control ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Memory Task ◽  
Poor Performance ◽  
Memory Capacity ◽  
Attentional Engagement ◽  
Low Performance ◽  
Attentional Lapses

Attentional control and working memory capacity are important cognitive abilities that substantially vary between individuals. Although much is known about how attentional control and working memory capacity relate to each other and to constructs like fluid intelligence, little is known about how trial-by-trial fluctuations in attentional engagement impact trial-by-trial working memory performance. Here, we employ a novel whole-report memory task that allowed us to distinguish between varying levels of attentional engagement in humans performing a working memory task. By characterizing low-performance trials, we can distinguish between models in which working memory performance failures are caused by either (1) complete lapses of attention or (2) variations in attentional control. We found that performance failures increase with set-size and strongly predict working memory capacity. Performance variability was best modeled by an attentional control model of attention, not a lapse model. We examined neural signatures of performance failures by measuring EEG activity while participants performed the whole-report task. The number of items correctly recalled in the memory task was predicted by frontal theta power, with decreased frontal theta power associated with poor performance on the task. In addition, we found that poor performance was not explained by failures of sensory encoding; the P1/N1 response and ocular artifact rates were equivalent for high- and low-performance trials. In all, we propose that attentional lapses alone cannot explain individual differences in working memory performance. Instead, we find that graded fluctuations in attentional control better explain the trial-by-trial differences in working memory that we observe.

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