Dynamic causal brain circuits during working memory and their functional controllability

AbstractControl processes associated with working memory play a central role in human cognition, but their underlying dynamic brain circuit mechanisms are poorly understood. Here we use system identification, network science, stability analysis, and control theory to probe functional circuit dynamics during working memory task performance. Our results show that dynamic signaling between distributed brain areas encompassing the salience (SN), fronto-parietal (FPN), and default mode networks can distinguish between working memory load and predict performance. Network analysis of directed causal influences suggests the anterior insula node of the SN and dorsolateral prefrontal cortex node of the FPN are causal outflow and inflow hubs, respectively. Network controllability decreases with working memory load and SN nodes show the highest functional controllability. Our findings reveal dissociable roles of the SN and FPN in systems control and provide novel insights into dynamic circuit mechanisms by which cognitive control circuits operate asymmetrically during cognition.

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Abnormal prefrontal activity subserving attentional control of emotion in remitted depressed patients during a working memory task with emotional distracters

Psychological Medicine ◽

10.1017/s0033291711001097 ◽

2011 ◽

Vol 42 (1) ◽

pp. 29-40 ◽

Cited By ~ 60

Author(s):

R. Kerestes ◽

C. D. Ladouceur ◽

S. Meda ◽

P. J. Nathan ◽

H. P. Blumberg ◽

...

Keyword(s):

Working Memory ◽

Attentional Control ◽

Memory Load ◽

Memory Task ◽

Region Of Interest ◽

Blood Oxygen Level Dependent ◽

Emotional Information ◽

Working Memory Load ◽

Depressed Patients ◽

The Right

BackgroundPatients with major depressive disorder (MDD) show deficits in processing of facial emotions that persist beyond recovery and cessation of treatment. Abnormalities in neural areas supporting attentional control and emotion processing in remitted depressed (rMDD) patients suggests that there may be enduring, trait-like abnormalities in key neural circuits at the interface of cognition and emotion, but this issue has not been studied systematically.MethodNineteen euthymic, medication-free rMDD patients (mean age 33.6 years; mean duration of illness 34 months) and 20 age- and gender-matched healthy controls (HC; mean age 35.8 years) performed the Emotional Face N-Back (EFNBACK) task, a working memory task with emotional distracter stimuli. We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure neural activity in the dorsolateral (DLPFC) and ventrolateral prefrontal cortex (VLPFC), orbitofrontal cortex (OFC), ventral striatum and amygdala, using a region of interest (ROI) approach in SPM2.ResultsrMDD patients exhibited significantly greater activity relative to HC in the left DLPFC [Brodmann area (BA) 9/46] in response to negative emotional distracters during high working memory load. By contrast, rMDD patients exhibited significantly lower activity in the right DLPFC and left VLPFC compared to HC in response to positive emotional distracters during high working memory load. These effects occurred during accurate task performance.ConclusionsRemitted depressed patients may continue to exhibit attentional biases toward negative emotional information, reflected by greater recruitment of prefrontal regions implicated in attentional control in the context of negative emotional information.

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Contralateral Delay Activity Tracks Fluctuations in Working Memory Performance

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01233 ◽

2018 ◽

Vol 30 (9) ◽

pp. 1229-1240 ◽

Cited By ~ 32

Author(s):

Kirsten C. S. Adam ◽

Matthew K. Robison ◽

Edward K. Vogel

Keyword(s):

Working Memory ◽

Individual Differences ◽

Memory Load ◽

Memory Performance ◽

Memory Task ◽

Memory Storage ◽

Alpha Power ◽

Working Memory Load ◽

Contralateral Delay Activity ◽

Trial Performance

Neural measures of working memory storage, such as the contralateral delay activity (CDA), are powerful tools in working memory research. CDA amplitude is sensitive to working memory load, reaches an asymptote at known behavioral limits, and predicts individual differences in capacity. An open question, however, is whether neural measures of load also track trial-by-trial fluctuations in performance. Here, we used a whole-report working memory task to test the relationship between CDA amplitude and working memory performance. If working memory failures are due to decision-based errors and retrieval failures, CDA amplitude would not differentiate good and poor performance trials when load is held constant. If failures arise during storage, then CDA amplitude should track both working memory load and trial-by-trial performance. As expected, CDA amplitude tracked load (Experiment 1), reaching an asymptote at three items. In Experiment 2, we tracked fluctuations in trial-by-trial performance. CDA amplitude was larger (more negative) for high-performance trials compared with low-performance trials, suggesting that fluctuations in performance were related to the successful storage of items. During working memory failures, participants oriented their attention to the correct side of the screen (lateralized P1) and maintained covert attention to the correct side during the delay period (lateralized alpha power suppression). Despite the preservation of attentional orienting, we found impairments consistent with an executive attention theory of individual differences in working memory capacity; fluctuations in executive control (indexed by pretrial frontal theta power) may be to blame for storage failures.

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Effects of a secondary task and working memory load on multisensory hand position

Seeing and Perceiving ◽

10.1163/187847612x646794 ◽

2012 ◽

Vol 25 (0) ◽

pp. 58

Author(s):

Katrina Quinn ◽

Francia Acosta-Saltos ◽

Jan W. de Fockert ◽

Charles Spence ◽

Andrew J. Bremner

Keyword(s):

Working Memory ◽

Visual Information ◽

Secondary Task ◽

Memory Load ◽

Memory Task ◽

Hand Position ◽

Working Memory Load ◽

The Individual ◽

Task Conditions ◽

Relative Weighting

Information about where our hands are arises from different sensory modalities; chiefly proprioception and vision. These inputs differ in variability from situation to situation (or task to task). According to the idea of ‘optimal integration’, the information provided by different sources is combined in proportion to their relative reliabilities, thus maximizing the reliability of the combined estimate. It is uncertain whether optimal multisensory integration of multisensory contributions to limb position requires executive resources. If so, then it should be possible to observe effects of secondary task performance and/or working memory load (WML) on the relative weighting of the senses under conditions of crossmodal sensory conflict. Alternatively, an integrated signal may be affected by upstream influences of WML or a secondary task on the reliabilities of the individual sensory inputs. We examine these possibilities in two experiments which examine effects of WML on reaching tasks in which bisensory visual-proprioceptive (Exp. 1), and unisensory proprioceptive (Exp. 2) cues to hand position are provided. WML increased visual capture under conditions of visual-proprioceptive conflict, regardless of the direction of visual-proprioceptive conflict, and the degree of load imposed. This indicates that task-switching (rather than WML load) leads to an increased reliance on visual information regardless of its task-specific reliability (Exp. 1). This could not be explained due to an increase in the variability of proprioception under secondary working memory task conditions (Exp. 2). We conclude that executive resources are involved in the relative weighting of visual and proprioceptive cues to hand position.

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Working Memory and the Suppression of Reflexive Saccades

Journal of Cognitive Neuroscience ◽

10.1162/089892902317205357 ◽

2002 ◽

Vol 14 (1) ◽

pp. 95-103 ◽

Cited By ~ 80

Author(s):

Jason P. Mitchell ◽

C. Neil Macrae ◽

Iain D. Gilchrist

Keyword(s):

Working Memory ◽

Memory Load ◽

Critical Role ◽

Memory Task ◽

Behavioral Responses ◽

Error Rates ◽

Antisaccade Task ◽

Working Memory Load ◽

Reflexive Saccades ◽

Back Task

Conscious behavioral intentions can frequently fail under conditions of attentional depletion. In attempting to trace the cognitive origin of this effect, we hypothesized that failures of action control—specifically, oculomotor movement—can result from the imposition of fronto-executive load. To evaluate this prediction, participants performed an antisaccade task while simultaneously completing a working-memory task that is known to make variable demands on prefrontal processes (n-back task, see Jonides et al., 1997). The results of two experiments are reported. As expected, antisaccade error rates were increased in accordance with the fronto-executive demands of the n-back task (Experiment 1). In addition, the debilitating effects of working-memory load were restricted to the inhibitory component of the antisaccade task (Experiment 2). These findings corroborate the view that working memory operations play a critical role in the suppression of prepotent behavioral responses.

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Learning to suppress a distractor is not affected by working memory load

Psychonomic Bulletin & Review ◽

10.3758/s13423-019-01679-6 ◽

2019 ◽

Vol 27 (1) ◽

pp. 96-104 ◽

Cited By ~ 3

Author(s):

Ya Gao ◽

Jan Theeuwes

Keyword(s):

Working Memory ◽

High Probability ◽

Spatial Working Memory ◽

Memory Load ◽

Working Memory Capacity ◽

Memory Task ◽

Automatic Process ◽

Long Term Memory ◽

Working Memory Load ◽

Statistical Regularities

AbstractWhere and what we attend to is not only determined by our current goals but also by what we have encountered in the past. Recent studies have shown that people learn to extract statistical regularities in the environment resulting in attentional suppression of high-probability distractor locations, effectively reducing capture by a distractor. Here, we asked whether this statistical learning is dependent on working memory resources. The additional singleton task in which one location was more likely to contain a distractor was combined with a concurrent visual working memory task (Experiment 1) and a spatial working memory task (Experiment 2). The result showed that learning to suppress this high-probability location was not at all affected by working memory load. We conclude that learning to suppress a location is an implicit and automatic process that does not rely on visual or spatial working memory capacity, nor on executive control resources. We speculate that extracting regularities from the environment likely relies on long-term memory processes.

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Performance Dissociation during Verbal and Spatial Working Memory Tasks

Perceptual and Motor Skills ◽

10.2466/pms.105.1.243-250 ◽

2007 ◽

Vol 105 (1) ◽

pp. 243-250 ◽

Cited By ~ 12

Author(s):

Bonnie J. Nagel ◽

Arthur Ohannessian ◽

Kevin Cummins

Keyword(s):

Working Memory ◽

Spatial Working Memory ◽

Memory Load ◽

Memory Task ◽

Past Research ◽

Neural Substrates ◽

Individual Performance ◽

Task Design ◽

Brain Response ◽

Working Memory Load

Past research has inconsistently distinguished the neural substrates of various types of working memory. Task design and individual performance differences are known to alter patterns of brain response during working-memory tasks. These task and individual differences may have produced discrepancies in imaging findings. This study of 50 healthy adults ( Mage = 19.6 yr., SD = .8) examined performance during various parametric manipulations of a verbal and spatial n-back working-memory task. Performance systematically dissociated on the basis of working-memory load, working memory type, and stimulus difficulty, with participants having greater accuracy but slower response time during conditions requiring verbal versus spatial working memory. These findings hold implications for cognitive and neuroimaging studies of verbal and spatial working memory and highlight the importance of considering both task design and individual behavior.

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The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000347 ◽

2017 ◽

Vol 64 (1) ◽

pp. 14-26 ◽

Cited By ~ 7

Author(s):

Saima Noreen ◽

Jan W. de Fockert

Keyword(s):

Working Memory ◽

Memory Load ◽

Memory Task ◽

Load Condition ◽

Cognitive Resources ◽

Working Memory Load ◽

Intentional Forgetting ◽

Probe Test ◽

Target Words

Abstract. We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants’ memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

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Working memory availability affects neural indices of distractor processing during visual search

10.1101/295378 ◽

2018 ◽

Cited By ~ 1

Author(s):

Dion T. Henare ◽

Jude Buckley ◽

Paul M. Corballis

Keyword(s):

Working Memory ◽

Visual Search ◽

Memory Load ◽

Individual Performance ◽

Event Related Potential ◽

Neural Mechanisms ◽

Human Cognition ◽

Working Memory Load ◽

Distractor Processing ◽

Selective Processing

AbstractWorking memory and selective attention are traditionally viewed as distinct processes in human cognition. However, increasing research demonstrates significant overlap between these constructs such that as working memory availability decreases, individuals perform worse on attention-based tasks. To date, the neural mechanisms involved in this interaction are unknown. We measured three candidate lateralized event-related potential components (N2pc, Ptc, and SPCN) to observe the effects of increased working memory load on selective processing of targets and distractors. We found that increased working memory load impaired the processing of distractors, but not targets, and this was reflected in attentuation of the Ptc to distractors. We also found that individual performance on the task is related to the neural response to both targets and distractors. This study suggests that working memory availability impacts individuals’ ability to disengage from irrelevant stimuli, and that individual differences in visual search ability under load are related to both target and distractor processing.

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Auditory cortex supports verbal working memory capacity

10.1101/2020.08.05.237727 ◽

2020 ◽

Author(s):

Gavin M. Bidelman ◽

Jane A. Brown ◽

Pouya Bashivan

Keyword(s):

Working Memory ◽

Individual Differences ◽

Auditory Cortex ◽

Memory Load ◽

Memory Task ◽

Verbal Working Memory ◽

Human Cognition ◽

Source Analysis ◽

Neural Basis

AbstractWorking memory (WM) is a fundamental construct of human cognition. The neural basis of auditory WM is thought to reflect a distributed brain network consisting of canonical memory and central executive brain regions including frontal lobe, prefrontal areas, and hippocampus. Yet, the role of auditory (sensory) cortex in supporting active memory representations remains controversial. Here, we recorded neuroelectric activity via EEG as listeners actively performed an auditory version of the Sternberg memory task. Memory load was taxed by parametrically manipulating the number of auditory tokens (letter sounds) held in memory. Source analysis of scalp potentials showed that sustained neural activity maintained in auditory cortex (AC) prior to memory retrieval closely scaled with behavioral performance. Brain-behavior correlations revealed lateralized modulations in left (but not right) AC predicted individual differences in auditory WM capacity. Our findings confirm a prominent role of auditory cortex, traditionally viewed as a sensory-perceptual processor, in actively maintaining memory traces and dictating individual differences in behavioral WM limits.

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