Visual Working Memory Research Articles

Not all objects are created equal: The object benefit in visual working memory is supported by greater recollection-like memory, but only for memorable objects

Not all objects are created equal: The object benefit in visual working memory is supported by greater recollection-like memory, but only for memorable objects

Enhancing visual working memory in schizophrenia: effects of frontoparietal theta tACS in low-performing patients

Schizophrenia is a complex neuro-psychiatric disorder including positive symptoms, negative symptoms, and cognitive deficits. A key cognitive dysfunction in schizophrenia is a deficit in visual working memory (VWM). VWM involves three distinct stages: encoding, maintenance, and retrieval. The deficit in any one stage would produce the same symptom (i.e., poor VWM), although their causes are not the same. In this study, we used a retro-cue VWM task that provides helpful cues at different stages: early in maintenance (early cue), late in maintenance (late cue), or during retrieval (retrieval cue). This modification would help “tag” or identify the cognitive stage(s) most responsible for impaired VWM performance in schizophrenia. Additionally, we took advantage of this tagging feature and applied 6 Hz transcranial alternating current stimulation (tACS) over the right dorsolateral prefrontal cortex (DLPFC) and right posterior parietal cortex (PPC)—which has previously been shown to enhance VWM in low-performing healthy individuals—to examine whether tACS would improve a specific stage or all stages of VWM processing in schizophrenia. We observed that cues significantly enhanced performance in low-performing patients, who benefited equally from early and late maintenance cues, but not from retrieval cues. These low-performers also responded well to theta tACS in their overall VWM performance as opposed to a specific VWM stage. No improvement effect was observed in high-performing patients for both retro cue and tACS. Together, our data suggest that 1) low-performing patients’ VWM deficits likely stem from poor memory consolidation rather than retrieval, 2) right frontoparietal theta tACS can improve low-performing patients’ VWM performance, and 3) such facilitatory tACS effect is not selective of a specific VWM stage and thus is likely driven by an improvement in overall visual attention.

The Effects of the Complexity of 3D Virtual Objects on Visual Working Memory Capacity in AR Interface for Mobile Phones

The current study aims to investigate the effects of 3D virtual object complexity on visual working memory capacity in mobile augmented reality (MAR) interfaces. With the popularity of augmented reality technology in mobile applications, 3D virtual elements play a key role in interaction. However, prior studies ignored the correlation between virtual object presentation and visual working memory (VWM). Given that visual working memory capacity is closely related to overall cognitive ability, the current study explored the relationship between the complexity of 3D virtual objects and VWM capacity in AR interfaces. Sixty volunteers participated in a 5-point Likert scale rating to eliminate the interference factors of familiarity, concreteness and similarity in 3D virtual material objects. Then, we further conducted an MAR change detection paradigm experiment and successfully manipulated the complexity of 3D virtual objects and the set size. Thirty-one subjects completed the formal experiment. Three measurements (reaction time, proportion correct, and Cowan’s K) were analyzed for nine experimental conditions (three object complexity levels and three object set sizes). The results confirmed that the visual working memory capacity in mobile AR interfaces is modulated by the complexity of the 3D virtual objects and set size, which decreases with the increase in complexity and set size of the displayed 3D virtual objects. As the complexity of the 3D virtual objects increases, the amount of resources allocated to each item decreases, resulting in a decrease in memory capacity and memory accuracy. This study highlights the effectiveness of VWM capacity in MAR interface design research and provides valuable insights into determining the best way to present 3D virtual objects.

Supplemental Material for Verbal and Visual Short-Term Memory Predict Performance in a Multiplication Production Task: Evidence From a Malaysian Sample

Supplemental Material for Verbal and Visual Short-Term Memory Predict Performance in a Multiplication Production Task: Evidence From a Malaysian Sample

Holding the product of visual working memory integration: The role of attention.

The involuntary integration of discrete fragments into meaningful units (e.g., Gestalt) within visual working memory (VWM) is a crucial process in mind. However, the mechanisms governing the maintenance of these integrated products within VWM have remained largely unexplored. The current study sought to address this gap by investigating whether maintaining such VWM integration products places a greater demand on attention resources compared to discrete representations. We hypothesized that maintenance may be costless or require additional attention, which may be domain-specific or domain-general. To examine these hypotheses, we tested whether the emerged Gestalts by VWM integration can be abolished by an attention consumption task. Participants were required to memorize a sequence of oriented disks with or without Gestalt cues, alongside a secondary task during maintenance, consuming a specific type of attention. We found that a task consuming spatial attention impaired the VWM Gestalts of bar contours (Experiments 1 and 3), but not the Gestalts of square contours (Experiment 2). Moreover, a task consuming domain-general attention did not affect the VWM Gestalts of bar contours (Experiment 4). These findings provide evidence suggesting that maintaining VWM integration products requires more attention than discrete representations and that the type of attention required is domain-specific.

Visual short-term memory for crossed and uncrossed binocular disparities.

Previous work on visual short-term memory (VSTM) has encompassed various stimulus attributes including spatial frequency, color, and contrast, revealing specific time courses and a dependence on stimulus parameters. This study investigates visual short-term memory for binocular depth, using dynamic random dot stereograms (DRDS) featuring disparity planes in front of or behind the plane of fixation. In a delayed match-to-sample paradigm, we employed four distinct reference disparities (17.5', 28.8' either crossed or uncrossed) at two contrast levels (20%, 80%), spanning interstimulus intervals (ISI) of up to 4 s. Test stimuli represented a range of equally spaced values centered around the reference disparity of the ongoing trial. In addition, the impact of a memory masking stimulus was also tested in a separate experiment. Accuracy and point of subjective equality (PSE) served as performance markers. The performance, indicated by the accuracy of responses, was better for smaller reference disparities (±17.5') compared to larger ones (±28'), but both deteriorated as a function of ISI. The PSE demonstrated a consistent shift with increasing ISIs, irrespective of the magnitude of the initial disparity, converging gradually toward the range of 20-22' and deviating from the reference disparity. Notably, the influence of masking stimuli on the PSE was more marked when the mask disparity diverged from the reference value. The findings from our study indicate that the retention of absolute disparity in memory is imprecise, it deteriorates with retention time or due to perturbation by dissimilar masking stimuli. As a result, the memory trace is gradually replaced by a default depth value. This value could potentially signify an optimal point within low-level perceptual memory, however, our results are better explained by perceptual averaging whereby the visual system computationally derives a statistical summary of the presented disparities over time. The latter mechanism would aid in the computation of relative disparity in a dynamically changing environment.

The Suppression Mechanisms of Passive Memory in Visual Working Memory: The Evidence from Electrophysiology.

Recent studies of visual working memory (VWM) underscore a structured hierarchy of storage states. Memories that are not immediately relevant to the task at hand but are essential for later use are transferred to a passive state, which operates independently of actively maintaining and manipulating current memories. Note that stimulating passive memory forcefully can reactivate it into an active state, resulting in a competition with active memory. Thus, to remain stable representations for both states within VWM, passive memory might involve sustained suppression during activity-silent maintenance to prevent reactivation from disrupting the current active storage. To investigate this, we analyzed lateralized electrophysiology signals while human participants (both women and men) were engaged in a sequential presentation memory task across two experiments. The results revealed positive contralateral delayed activity components and lateralized alpha enhancement for passive memory, neural indicative of suppression on passive storage. In addition, the suppression effect was independent of the memory load in both the active and the passive states. These findings support the notion of sustained suppression during activity-silent maintenance of passive memory, facilitating the stable maintenance of distinct storage states and advancing our understanding of the dynamic coding framework in VWM.

Susceptibility to Attentional Capture by Target-Matching Distractors Predicts High Visual Working Memory Capacity.

Recent event-related potential (ERP) studies showed that individuals with low visual working memory (VWM) capacity are more susceptible to salience-driven attentional capture than high-capacity individuals are, with the latter being able to proactively suppress salient but irrelevant distractors. However, it remains unclear whether and how contingent attentional capture by distractors that possess a task-relevant (target) feature is related to VWM capacity. Here, we adopted a central focused-attention task that contained peripheral target-matching distractors to investigate this issue (N = 51 adults). Surprisingly, we revealed that target-matching distractors elicited both a larger N2-posterior-contralateral (N2pc) and a larger post-N2pc distractor positivity (PD) component in high-capacity individuals than in low-capacity ones, meaning that high-capacity individuals are less able to ignore such distractors initially, though they could call on a stronger reactive suppression mechanism afterward. These findings illustrate that high-capacity individuals are more (rather than less or equally) susceptible to contingent attention capture compared with low-capacity ones.

Neuropsychological outcomes following endovascular clot retrieval and intravenous thrombolysis in ischemic stroke.

Cognitive impairment, anxiety, depression, fatigue, and dependence in instrumental activities of daily living (ADL) are common after stroke; however, little is known about how these outcomes may differ following treatment with endovascular clot retrieval (ECR), intravenous tissue plasminogen activator (t-PA), or conservative management. Patients were recruited after acute treatment and invited to participate in an outcome assessment 90-120 days post-stroke. The assessment included a cognitive test battery and several questionnaires. The COVID-19 pandemic led to significant disruptions in recruitment and data collection, and the t-PA and conservative management groups were combined into a standard medical care (SMC) group. Sixty-two participants were included in the study (ECR = 31, SMC = 31). Mean age was 66.5 (20-86) years, and 35 (56.5%) participants were male. Participants treated with ECR had significantly higher National Institutes of Health Stroke Scale scores at presentation and significantly lower education. After adjusting for stroke severity, premorbid intellectual ability, and age, treatment with ECR was associated with significantly better performances on measures of cognitive screening, visual working memory, and verbal learning and memory. Participants treated with ECR also experienced less fatigue and were more likely to achieve independence in basic and instrumental ADLs. Despite this, cognitive impairment and fatigue were still common among participants treated with ECR and anxiety and depression symptoms were experienced similarly by both groups. Cognitive impairment and fatigue were less common but still prevalent following treatment with ECR. This has important practical implications for stroke rehabilitation, and routine assessment of cognition, emotion, and fatigue is recommended for all stroke survivors regardless of stroke treatment and functional outcome.

Integrated encoding of relations and objects in visual working memory.

Comprehensive understanding of visual scenes necessitates grasping the relations among visual objects. Given the potentially pivotal role of visual working memory (VWM) in processing visual relations, it is important to investigate the representation of relations in VWM. In our previous study, we proposed the integrated storage hypothesis, postulating that relations and objects are stored together as an integrated structured representation in VWM. The present study aimed to test this hypothesis against the alternative separate encoding hypothesis by probing the irrelevant-distracting effect. Across three experiments, where participants memorized object shapes/colors while disregarding relations, an irrelevant-distracting effect was consistently observed across varying types of changes in relation and set sizes. Critically, recombining the probe with irrelevant relation from another memory item (Experiment 2) or reversing the relational roles of probed objects relative to the memory item (Experiment 3) were perceived as inconsistency with stored representations and impaired change detection. These findings supported the integrated storage hypothesis, indicating that the dynamic relations between the objects are automatically encoded alongside object identities to form an integrated structured representation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Sensory-memory interactions via modular structure explain errors in visual working memory

Sensory-memory interactions via modular structure explain errors in visual working memory

Sensory-memory interactions via modular structure explain errors in visual working memory.

Errors in stimulus estimation reveal how stimulus representation changes during cognitive processes. Repulsive bias and minimum variance observed near cardinal axes are well-known error patterns typically associated with visual orientation perception. Recent experiments suggest that these errors continuously evolve during working memory, posing a challenge that neither static sensory models nor traditional memory models can address. Here, we demonstrate that these evolving errors, maintaining characteristic shapes, require network interaction between two distinct modules. Each module fulfills efficient sensory encoding and memory maintenance, which cannot be achieved simultaneously in a single-module network. The sensory module exhibits heterogeneous tuning with strong inhibitory modulation reflecting natural orientation statistics. While the memory module, operating alone, supports homogeneous representation via continuous attractor dynamics, the fully connected network forms discrete attractors with moderate drift speed and nonuniform diffusion processes. Together, our work underscores the significance of sensory-memory interaction in continuously shaping stimulus representation during working memory.

Unravelling the object-based nature of visual working memory: insight from pointers.

Visual working memory (VWM) plays a crucial role in temporarily storing and processing visual information, but the nature of stored representations and their interaction with new inputs has long been unclear. The pointer system refers to how VWM links new sensory inputs to stored information using specific cues. This study aimed to investigate whether the pointer system is based on spatial, feature-based, or object-based cues by employing the repetition benefit effect, where memory performance improves with repeated memory items. Across three experiments, we manipulated spatial positions, shapes, and colors as pointer cues to determine how these features affect VWM consolidation and updating. The results showed that while spatial location serves as a strong pointer cue, shape and color features can also effectively reestablish object correspondence in VWM. These findings support the view that the pointer system in VWM is flexible and object-based, utilizing various feature cues to maintain memory continuity. This study provides new insights into how VWM connects new inputs with stored information through the pointer system.

Modifiable dementia risk factors associated with objective and subjective cognition.

Early detection of both objective and subjective cognitive impairment is important. Subjective complaints in healthy individuals can precede objective deficits. However, the differential associations of objective and subjective cognition with modifiable dementia risk factors are unclear. We gathered a large cross-sectional sample (N=3327, age 18 to 84) via a smartphone app and quantified the associations of 13 risk factors with subjective memory problems and three objective measures of executive function (visual working memory, cognitive flexibility, model-based planning). Depression, socioeconomic status, hearing handicap, loneliness, education, smoking, tinnitus, little exercise, small social network, stroke, diabetes, and hypertension were all associated with impairments in at least one cognitive measure. Subjective memory had the strongest link to most factors; these associations persisted after controlling for depression. Age mostly did not moderate these associations. Subjective cognition was more sensitive to self-report risk factors than objective cognition. Smartphones could facilitate detecting the earliest cognitive impairments. Smartphone assessments of cognition were sensitive to dementia risk factors. Subjective cognition had stronger links to most factors than did objective cognition. These associations were not fully explained by depression. These associations were largely consistent across the lifespan.

The Effects of Ageing on the Organisation of Visual Short-term Memory

Past research has reported a deterioration in the corpus callosum of older adults that causes less interhemispheric communication between the hemispheres. However, this study did not measure the corpus callosum; instead, it assumes that older people have smaller corpus callosum based on past research. Past research has also reported a considerable impairment in the elders' capacity to handle global statistics instead of local figures but a global preceding effect in younger adults. To study the ageing effects on the organisation of VSTM, 45 younger adults aged between 18-28 and 44 older adults aged between 62-80 (some exclusions were made later) participated in a change detection task. A memory display was presented to the participants. After a short delay, a test display was presented with one of the four conditions: single probe, whole probe, Half probe (across hemifield) or half probe (within hemifield). Participants had to choose if the colours were similar or distinct between the memory and the test display. Only the colours and probe conditions could change between memory and the test display, but the locations stayed the same. The study builds on the present knowledge of VSTM-related age decline in cognition. It was reported that overall, the older participants performed less accurately on the change detection task than the younger adults. The effects of the answer and the interaction between the probe condition and the answer were also reported. However, there was no significant interaction between the probe condition and the group. It was a complex online study which was a significant limitation of the study. Future research can investigate memory consolidation in older adults using a simpler design in a lab-based study. The present study is a follow-up study for Anonymous (2020).

7838 Improvement of Cognition and Memory Scores in Transgender Individuals Within One Year of Initiating Gender-Affirming Hormone Therapy

Abstract Disclosure: C.M. Godar: None. S.C. De La Torre: None. O. Bonsu: None. M.K. Shakir: None. T.D. Hoang: None. Introduction: The use of gender-affirming hormone therapy (GAHT) in transgender individuals is known to provide many beneficial health effects to reduce gender dysphoria, reduce depressive symptoms, and increase overall quality of life. Cognitive function and memory ability are known to be influenced by sex hormone levels in studies of hormone replacement therapy in post-menopausal women, but studies of GAHT’s effects on cognition and memory in transgender patients have been scarcely reported. We discuss a study of cognitive testing in transgender individuals before and after 12 months of gender-affirming feminizing or masculinizing hormone therapy using a validated cognitive assessment tool. Methods: A prospective study of 32 transgender patients aged 18-45 years was approved by IRB at an academic medical center. The Wechsler Memory Scale 4th edition (WMS®-IV, Pearson) was administered to 19 transgender females and 13 transgender males prior to initiation of GAHT and again after one year of GAHT use. Mean scores were analyzed and reported for five categories of cognitive and memory function: auditory memory (AMI), visual memory (VMI), visual working memory (VWMI), immediate memory (IMI), and delayed memory (DMI). Mean scores for baseline and 12-month data were analyzed for total population and male and female subgroups. Results: Baseline mean WMS-IV values for the total study population were: AMI 105 points, VMI 78 points, VWMI 107 points, IMI 88 points, DMI 91 points. Mean values after 12 months of GAHT were: AMI 120 points, VMI 81 points, VWMI 110 points, IMI 99 points, DMI 102 points. Mean percent change from baseline to 12 months was as follows: AMI 13.4%, VMI 8.9%, VWMI 2.6%, IMI 12.8%, DMI 13%. Similar patterns were noted for both gender subgroups. Discussion: It is well-known that transgender individuals are subject to higher rates of depression, anxiety, and suicidality compared to the general population. Decreased cognitive function and memory are known effects of untreated depression. Our study demonstrated that treatment of gender dysphoria with GAHT provided a tangible cognitive and memory benefit. The long-term impact of GAHT on cognition and memory is not known and deserves additional study. Limitations of this study included the absence of a cis-gender control group and inability to stratify data based on age, which may provide additional significance. Presentation: 6/2/2024

7838 Improvement of Cognition and Memory Scores in Transgender Individuals Within One Year of Initiating Gender-Affirming Hormone Therapy

Abstract Disclosure: C.M. Godar: None. S.C. De La Torre: None. O. Bonsu: None. M.K. Shakir: None. T.D. Hoang: None. Introduction: The use of gender-affirming hormone therapy (GAHT) in transgender individuals is known to provide many beneficial health effects to reduce gender dysphoria, reduce depressive symptoms, and increase overall quality of life. Cognitive function and memory ability are known to be influenced by sex hormone levels in studies of hormone replacement therapy in post-menopausal women, but studies of GAHT’s effects on cognition and memory in transgender patients have been scarcely reported. We discuss a study of cognitive testing in transgender individuals before and after 12 months of gender-affirming feminizing or masculinizing hormone therapy using a validated cognitive assessment tool. Methods: A prospective study of 32 transgender patients aged 18-45 years was approved by IRB at an academic medical center. The Wechsler Memory Scale 4th edition (WMS®-IV, Pearson) was administered to 19 transgender females and 13 transgender males prior to initiation of GAHT and again after one year of GAHT use. Mean scores were analyzed and reported for five categories of cognitive and memory function: auditory memory (AMI), visual memory (VMI), visual working memory (VWMI), immediate memory (IMI), and delayed memory (DMI). Mean scores for baseline and 12-month data were analyzed for total population and male and female subgroups. Results: Baseline mean WMS-IV values for the total study population were: AMI 105 points, VMI 78 points, VWMI 107 points, IMI 88 points, DMI 91 points. Mean values after 12 months of GAHT were: AMI 120 points, VMI 81 points, VWMI 110 points, IMI 99 points, DMI 102 points. Mean percent change from baseline to 12 months was as follows: AMI 13.4%, VMI 8.9%, VWMI 2.6%, IMI 12.8%, DMI 13%. Similar patterns were noted for both gender subgroups. Discussion: It is well-known that transgender individuals are subject to higher rates of depression, anxiety, and suicidality compared to the general population. Decreased cognitive function and memory are known effects of untreated depression. Our study demonstrated that treatment of gender dysphoria with GAHT provided a tangible cognitive and memory benefit. The long-term impact of GAHT on cognition and memory is not known and deserves additional study. Limitations of this study included the absence of a cis-gender control group and inability to stratify data based on age, which may provide additional significance. Presentation: 6/2/2024

Electrophysiological Correlates of Visual Memory Search.

In everyday life, we frequently engage in 'hybrid' visual and memory search, where we look for multiple items stored in memory (e.g., a mental shopping list) in our visual environment. Across three experiments, we used event-related potentials to better understand the contributions of visual working memory (VWM) and long-term memory (LTM) during the memory search component of hybrid search. Experiments 1 and 2 demonstrated that the FN400 - an index of LTM recognition - and the CDA -an index of VWM load - increased with memory set size (target load), suggesting that both VWM and LTM are involved in memory search, even when target load exceeds capacity limitations of VWM. In Experiment 3, we used these electrophysiological indices to test how categorical similarity of targets and distractors affects memory search. The CDA and FN400 were modulated by memory set size only if items resembled targets. This suggests that dissimilar distractor items can be rejected before eliciting a memory search. Together, our findings demonstrate the interplay of VWM and LTM processes during memory search for multiple targets.

Intrinsic functional networks for distinct sources of error in visual working memory.

Visual working memory (VWM) is a core cognitive function wherein visual information is stored and manipulated over short periods. Response errors in VWM tasks arise from the imprecise memory of target items, swaps between targets and nontargets, and random guesses. However, it remains unclear whether these types of errors are underpinned by distinct neural networks. To answer this question, we recruited 80 healthy adults to perform delayed estimation tasks and acquired their resting-state functional magnetic resonance imaging scans. The tasks required participants to reproduce the memorized visual feature along continuous scales, which, combined with mixture distribution modeling, allowed us to estimate the measures of memory precision, swap errors, and random guesses. Intrinsic functional connectivity within and between different networks, identified using a hierarchical clustering approach, was estimated for each participant. Our analyses revealed that higher memory precision was associated with increased connectivity within a frontal-opercular network, as well as between the dorsal attention network and an angular-gyrus-cerebellar network. We also found that coupling between the frontoparietal control network and the cingulo-opercular network contributes to both memory precision and random guesses. Our findings demonstrate that distinct sources of variability in VWM performance are underpinned by different yet partially overlapping intrinsic functional networks.

Action Planning Renders Objects in Working Memory More Attentionally Salient.

A rapidly growing body of work suggests that visual working memory (VWM) is fundamentally action oriented. Consistent with this, we recently showed that attention is more strongly biased by VWM representations of objects when we plan to act on those objects in the future. Using EEG and eye tracking, here, we investigated neurophysiological correlates of the interactions between VWM and action. Participants (n = 36) memorized a shape for a subsequent VWM test. At test, a probe was presented along with a secondary object. In the action condition, participants gripped the actual probe if it matched the memorized shape, whereas in the control condition, they gripped the secondary object. Crucially, during the VWM delay, participants engaged in a visual selection task, in which they located a target as fast as possible. The memorized shape could either encircle the target (congruent trials) or a distractor (incongruent trials). Replicating previous findings, we found that eye gaze was biased toward the VWM-matching shape and, importantly, more so when the shape was directly associated with an action plan. Moreover, the ERP results revealed that during the selection task, future action-relevant VWM-matching shapes elicited (1) a stronger Ppc (posterior positivity contralateral), signaling greater attentional saliency; (2) an earlier PD (distractor positivity) component, suggesting faster suppression; (3) a larger inverse (i.e., positive) sustained posterior contralateral negativity in incongruent trials, consistent with stronger suppression of action-associated distractors; and (4) an enhanced response-locked positivity over left motor regions, possibly indicating enhanced inhibition of the response associated with the memorized item during the interim task. Overall, these results suggest that action planning renders objects in VWM more attentionally salient, supporting the notion of selection-for-action in working memory.