P131 Comparing the impact of various transcranial electrical stimulation setups on the performance during a visual working memory task

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

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The Impact of Object Complexity on Visual Working Memory Capacity

Psychology ◽

10.4236/psych.2017.86060 ◽

2017 ◽

Vol 08 (06) ◽

pp. 929-937 ◽

Cited By ~ 2

Author(s):

Xiaoxi Chen ◽

Bin Li ◽

Yaozhong Liu

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Working Memory Capacity ◽

Memory Capacity ◽

The Impact

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Working Memory Training and Transcranial Direct Current Stimulation

Cognitive and Working Memory Training ◽

10.1093/oso/9780199974467.003.0006 ◽

2019 ◽

pp. 105-130

Author(s):

Jacky Au ◽

Martin Buschkuehl ◽

Susanne M. Jaeggi

Keyword(s):

Working Memory ◽

Electrical Stimulation ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Working Memory Training ◽

Memory Training ◽

Transcranial Electrical Stimulation ◽

Direct Current Stimulation ◽

Underlying Mechanisms ◽

The Brain

The aim of this chapter is to contribute to the discussion of the cognitive neuroscience of brain stimulation. In doing so, the authors emphasize work from their own laboratory that focuses both on working memory training and transcranial direct current stimulation. Transcranial direct current stimulation is one of the most commonly used and extensively researched methods of transcranial electrical stimulation. The chapter focuses on implementation of transcranial direct current stimulation to enhance and inform research on working memory training, and not on the underlying mechanisms of transcranial direct current stimulation. Thus, while respecting the intricacies and unknowns of the inner workings of electrical stimulation on the brain, the chapter relies on the premise that transcranial direct current stimulation is able to directly affect the electrophysiological profile of the brain and provides evidence that this in turn can influence behavior given the right parameters.

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The influence of visual working memory representations on attention bias to threat in individuals with high trait anxiety

Journal of Experimental Psychopathology ◽

10.1177/2043808719876149 ◽

2019 ◽

Vol 10 (4) ◽

pp. 204380871987614

Author(s):

Nisha Yao ◽

Marcus A. Rodriguez ◽

Mengyao He ◽

Mingyi Qian

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Experimental Studies ◽

Memory Task ◽

Attention Bias ◽

Control Group ◽

Negative Valence ◽

Memory Representations ◽

High Trait Anxiety ◽

The Relationship

Experimental studies have yielded discrepant results regarding the relationship between anxiety and attention bias to threat. Cognitive factors modulating the presence of threat-related attention bias in anxiety have drawn growing attention. Previous research demonstrated that visual working memory (WM) representations can guide attention allocation in a top-down manner. Whether threat-related WM representations affected the presence of attention bias in anxiety awaits examination. Combining a memory task and a dot-probe task, this study investigated how WM representations of faces with neutral or negative expressions modulated the attention bias to threat among highly anxious individuals versus controls. Results showed that highly anxious individuals developed more pronounced attention bias to threat when maintaining WM representations of negative faces as compared to the control group. There were no significant between-group effects when the WM representations were neutral. These results suggested that highly anxious individuals were more susceptible to the influence of mental representations with negative valence on attention deployment.

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Auditory and Visual Working Memory Are Differentially Related to Carotenoid Status in Preadolescent Children

Current Developments in Nutrition ◽

10.1093/cdn/nzaa041_002 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 98-98

Author(s):

Corinne Cannavale ◽

Caitlyn Edwards ◽

Ruyu Liu ◽

Samantha Iwinski ◽

Anne Walk ◽

...

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Cognitive Abilities ◽

Memory Function ◽

Memory Task ◽

Whole Body ◽

Set Size ◽

Preadolescent Children ◽

Central Illinois ◽

The Relationship

Abstract Objectives Carotenoids are plant pigments known to deposit in neural tissues including the hippocampus, a brain substrate that supports several memory forms. However, there is a dearth of knowledge regarding carotenoid status and working memory function in children. Accordingly, this study aimed to understand the relationship between macular and skin carotenoids to visual and auditory working memory (WM) function. Methods Seventy preadolescent children (7–12 years, 32 males) were recruited from the East-Central Illinois area. Auditory working memory was assessed using the story recall subtest of the Woodcock-Johnson IV Test of Cognitive Abilities. A subsample (N = 61, 27 males) completed a visual working memory task and reaction time was quantified to determine speed of memory processing at set sizes of 1 to 4 items. Macular pigment optical density (MPOD) was assessed using customized heterochromatic flicker photometry. Skin carotenoids were assessed using reflection spectroscopy (Veggie Meter). Hierarchical linear regressions were conducted to assess the relationship between carotenoid status and WM function, while controlling for age, sex, income, and whole-body % fat (DXA). Results Auditory WM was positively associated with skin carotenoids (b = 0.263, P = 0.039) but not MPOD (b = −0.044, P = 0.380). In contrast, MPOD was significantly associated with faster visual WM speed at set size 3 (b = −0.253, P = 0.039) and trending at set sizes of 1 (b = −0.225, P = 0.051), 2 (b = −0.171, P = 0.121), and 4 (b = −0.230, P = 0.055). Interestingly, skin carotenoids were not related to visual WM performance at either set size (all P’s > 0.300). Conclusions These results indicate that auditory and visual WM may be differentially related to carotenoids. While skin carotenoids encompass all carotenoids consumed in diet, lutein and zeaxanthin are the only carotenoids which deposit in the macula. Given that MPOD was only related to visual WM, this suggests lutein plays a larger role in these neural functions relative to auditory WM. Interestingly, MPOD's relationship with visual WM increased in strength with the more difficult trial type (i.e., increasing set size), indicating MPOD is related at higher levels of WM capacity. Funding Sources This study was funded by the Egg Nutrition Center.

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Tracking stimulus representation across a 2-back visual working memory task

Royal Society Open Science ◽

10.1098/rsos.190228 ◽

2020 ◽

Vol 7 (8) ◽

pp. 190228 ◽

Cited By ~ 2

Author(s):

Quan Wan ◽

Ying Cai ◽

Jason Samaha ◽

Bradley R. Postle

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Memory Task ◽

Memory Item ◽

Neural Representation ◽

Stimulus Representation ◽

Representational Format ◽

The Status ◽

Memory Content ◽

Default Assumption

How does the neural representation of visual working memory content vary with behavioural priority? To address this, we recorded electroencephalography (EEG) while subjects performed a continuous-performance 2-back working memory task with oriented-grating stimuli. We tracked the transition of the neural representation of an item ( n ) from its initial encoding, to the status of ‘unprioritized memory item' (UMI), and back to ‘prioritized memory item', with multivariate inverted encoding modelling. Results showed that the representational format was remapped from its initially encoded format into a distinctive ‘opposite' representational format when it became a UMI and then mapped back into its initial format when subsequently prioritized in anticipation of its comparison with item n + 2. Thus, contrary to the default assumption that the activity representing an item in working memory might simply get weaker when it is deprioritized, it may be that a process of priority-based remapping helps to protect remembered information when it is not in the focus of attention.

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Perturbing Neural Representations of Working Memory with Task-irrelevant Interruption

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01481 ◽

2020 ◽

Vol 32 (3) ◽

pp. 558-569 ◽

Cited By ~ 3

Author(s):

Nicole Hakim ◽

Tobias Feldmann-Wüstefeld ◽

Edward Awh ◽

Edward K. Vogel

Keyword(s):

Working Memory ◽

Memory Task ◽

Relevant Information ◽

Alpha Power ◽

Neural Signals ◽

Neural Representations ◽

Contralateral Delay Activity ◽

The Face ◽

Task Irrelevant ◽

The Impact

Working memory maintains information so that it can be used in complex cognitive tasks. A key challenge for this system is to maintain relevant information in the face of task-irrelevant perturbations. Across two experiments, we investigated the impact of task-irrelevant interruptions on neural representations of working memory. We recorded EEG activity in humans while they performed a working memory task. On a subset of trials, we interrupted participants with salient but task-irrelevant objects. To track the impact of these task-irrelevant interruptions on neural representations of working memory, we measured two well-characterized, temporally sensitive EEG markers that reflect active, prioritized working memory representations: the contralateral delay activity and lateralized alpha power (8–12 Hz). After interruption, we found that contralateral delay activity amplitude momentarily sustained but was gone by the end of the trial. Lateralized alpha power was immediately influenced by the interrupters but recovered by the end of the trial. This suggests that dissociable neural processes contribute to the maintenance of working memory information and that brief irrelevant onsets disrupt two distinct online aspects of working memory. In addition, we found that task expectancy modulated the timing and magnitude of how these two neural signals responded to task-irrelevant interruptions, suggesting that the brain's response to task-irrelevant interruption is shaped by task context.

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