Effects of verbal and nonverbal interference on spatial and object visual working memory.

PubMed

Postle, Bradley R; Desposito, Mark; Corkin, Suzanne

2005-03-01

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the "what/where" organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function.

Effects of verbal and nonverbal interference on spatial and object visual working memory

PubMed Central

POSTLE, BRADLEY R.; D’ESPOSITO, MARK; CORKIN, SUZANNE

2005-01-01

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the “what/where” organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function. PMID:16028575

Control of interference during working memory updating.

PubMed

Szmalec, Arnaud; Verbruggen, Frederick; Vandierendonck, André; Kemps, Eva

2011-02-01

The current study examined the nature of the processes underlying working memory updating. In 4 experiments using the n-back paradigm, the authors demonstrate that continuous updating of items in working memory prevents strong binding of those items to their contexts in working memory, and hence leads to an increased susceptibility to proactive interference. Results of Experiments 1 and 2 show that this interference reflects a competition between a process that reveals the degree of familiarity of an item and a context-sensitive recollection process that depends on the strength of bindings in working memory. Experiment 3 further clarifies the origins of interference during updating by demonstrating that even items that are semantically related to the updated working memory contents but that have not been maintained in working memory before cause proactive interference. Finally, the results of Experiment 4 indicate that the occurrence of interference leads to top-down behavioral adjustments that prioritize recollection over familiarity assessment. The implications of these findings for the construct validity of the n-back task, for the control processes involved in working memory updating, and for the concept of executive control more generally are discussed. (c) 2010 APA, all rights reserved.

Transfer after Working Memory Updating Training

PubMed Central

Waris, Otto; Soveri, Anna; Laine, Matti

2015-01-01

During the past decade, working memory training has attracted much interest. However, the training outcomes have varied between studies and methodological problems have hampered the interpretation of results. The current study examined transfer after working memory updating training by employing an extensive battery of pre-post cognitive measures with a focus on near transfer. Thirty-one healthy Finnish young adults were randomized into either a working memory training group or an active control group. The working memory training group practiced with three working memory tasks, while the control group trained with three commercial computer games with a low working memory load. The participants trained thrice a week for five weeks, with one training session lasting about 45 minutes. Compared to the control group, the working memory training group showed strongest transfer to an n-back task, followed by working memory updating, which in turn was followed by active working memory capacity. Our results support the view that working memory training produces near transfer effects, and that the degree of transfer depends on the cognitive overlap between the training and transfer measures. PMID:26406319

Transfer after Working Memory Updating Training.

PubMed

Waris, Otto; Soveri, Anna; Laine, Matti

2015-01-01

During the past decade, working memory training has attracted much interest. However, the training outcomes have varied between studies and methodological problems have hampered the interpretation of results. The current study examined transfer after working memory updating training by employing an extensive battery of pre-post cognitive measures with a focus on near transfer. Thirty-one healthy Finnish young adults were randomized into either a working memory training group or an active control group. The working memory training group practiced with three working memory tasks, while the control group trained with three commercial computer games with a low working memory load. The participants trained thrice a week for five weeks, with one training session lasting about 45 minutes. Compared to the control group, the working memory training group showed strongest transfer to an n-back task, followed by working memory updating, which in turn was followed by active working memory capacity. Our results support the view that working memory training produces near transfer effects, and that the degree of transfer depends on the cognitive overlap between the training and transfer measures.

Individual differences in media multitasking and performance on the n-back.

PubMed

Ralph, Brandon C W; Smilek, Daniel

2017-02-01

A number of studies have recently examined the link between individual differences in media multitasking (using the MMI) and performance on working memory paradigms. However, these studies have yielded mixed results. Here we examine the relation between media multitasking and one particular working memory paradigm-the n-back (2- and 3-back)-improving upon previous research by (a) treating media multitasking as a continuous variable and adopting a correlational approach as well as (b) using a large sample of participants. First, we found that higher scores on the MMI were associated with a greater proportion of omitted trials on both the 2-back and 3-back, indicating that heavier media multitaskers were more disengaged during the n-back. In line with such a claim, heavier media multitaskers were also more likely to confess to responding randomly during various portions of the experiment, and to report media multitasking during the experiment itself. Importantly, when controlling for the relation between MMI scores and omissions, higher scores on the MMI were associated with an increase in false alarms, but not with a change in hits. These findings refine the extant literature on media multitasking and working memory performance (specifically, performance on the n-back), and suggest that media multitasking may be related to the propensity to disengage from ongoing tasks.

78. Augmenting NMDA Receptor Signaling Enhances Working Memory and Alters Gamma Oscillations in Patients With Schizophrenia

PubMed Central

Forsyth, Jennifer; Bachman, Peter; Asarnow, Robert

2017-01-01

Abstract Background: Gamma band oscillations (30–80 Hz) are associated with numerous sensory and higher cognitive functions and are abnormal in patients with schizophrenia. Glutamate signaling at the N-methyl-D-aspartate receptor (NMDAR) is theorized to play a key role in the pathophysiology of schizophrenia and NMDAR antagonists disrupt working memory and gamma oscillations in healthy individuals. It has therefore been suggested that NMDAR dysfunction may contribute to abnormalities in gamma oscillations and working memory in schizophrenia. In the current study, we examined the effects of acutely augmenting NMDAR signaling using the NMDAR agonist, d-cycloserine (DCS), on working memory and gamma power in patients with schizophrenia. Methods: In a double-blind design, patients with schizophrenia were randomized to receive a single dose of 100 mg DCS (SZ-DCS; n = 24) or Placebo (SZ-PLC; n = 21). Patients completed a spatial n-back task involving a 0-back control condition and 1-back and 2-back working memory loads while undergoing EEG recording. Gamma power (30–80 Hz) during the 0-back condition assessed gamma power associated with basic perceptual, motor, and attentive processes. Change in gamma power for correct working memory trials relative to the 0-back condition assessed gamma power associated with working memory function. Results: Among patients who performed above chance (SZ-DCS = 17, SZ-PLC = 16), patients who received DCS showed superior working memory performance compared to patients who received Placebo. Gamma power during the 0-back control condition was similar between SZ-DCS and SZ-PLC who performed above chance. However, gamma power associated with working memory function was significantly suppressed in SZ-DCS compared to SZ-PLC, particularly over frontal right channels. In addition, whereas higher working memory gamma power over frontal right channels was associated with better working memory performance in SZ-PLC, this relationship

A simultaneous examination of two forms of working memory training: Evidence for near transfer only.

PubMed

Minear, Meredith; Brasher, Faith; Guerrero, Claudia Brandt; Brasher, Mandy; Moore, Andrew; Sukeena, Joshua

2016-10-01

The efficacy of working-memory training is a topic of considerable debate, with some studies showing transfer to measures such as fluid intelligence while others have not. We report the results of a study designed to examine two forms of working-memory training, one using a spatial n-back and the other a verbal complex span. Thirty-one undergraduates completed 4 weeks of n-back training and 32 completed 4 weeks of verbal complex span training. We also included two active control groups. One group trained on a non-adaptive version of n-back and the other trained on a real-time strategy video game. All participants completed pre- and post-training measures of a large battery of transfer tasks used to create composite measures of short-term and working memory in both verbal and visuo-spatial domains as well as verbal reasoning and fluid intelligence. We only found clear evidence for near transfer from the spatial n-back training to new forms of n-back, and this was the case for both adaptive and non-adaptive n-back.

A randomised controlled trial investigating the benefits of adaptive working memory training for working memory capacity and attentional control in high worriers.

PubMed

Hotton, Matthew; Derakshan, Nazanin; Fox, Elaine

2018-01-01

The process of worry has been associated with reductions in working memory capacity and availability of resources necessary for efficient attentional control. This, in turn, can lead to escalating worry. Recent investigations into working memory training have shown improvements in attentional control and cognitive performance in high trait-anxious individuals and individuals with sub-clinical depression. The current randomised controlled trial investigated the effects of 15 days of adaptive n-back working memory training, or an active control task, on working memory capacity, attentional control and worry in a sample of high worriers. Pre-training, post-training and one-month follow-up measures of working memory capacity were assessed using a Change Detection task, while a Flanker task was used to assess attentional control. A breathing focus task was used as a behavioural measure of worry in addition to a number of self-report assessments of worry and anxiety. Overall there was no difference between the active training and the active control condition with both groups demonstrating similar improvements in working memory capacity and worry, post-training and at follow-up. However, training-related improvements on the n-back task were associated with gains in working memory capacity and reductions in worry symptoms in the active training condition. These results highlight the need for further research investigating the role of individual differences in working memory training. Copyright © 2017. Published by Elsevier Ltd.

Working Memory Training Does Not Improve Intelligence in Healthy Young Adults

ERIC Educational Resources Information Center

Chooi, Weng-Tink; Thompson, Lee A.

2012-01-01

Jaeggi and her colleagues claimed that they were able to improve fluid intelligence by training working memory. Subjects who trained their working memory on a dual n-back task for a period of time showed significant improvements in working memory span tasks and fluid intelligence tests such as the Raven's Progressive Matrices and the Bochumer…

FMRI of visual working memory in high school football players.

PubMed

Shenk, Trey E; Robinson, Meghan E; Svaldi, Diana O; Abbas, Kausar; Breedlove, Katherine M; Leverenz, Larry J; Nauman, Eric A; Talavage, Thomas M

2015-01-01

Visual working memory deficits have been observed in at-risk athletes. This study uses a visual N-back working memory functional magnetic resonance imaging task to longitudinally assess asymptomatic football athletes for abnormal activity. Athletes were increasingly "flagged" as the season progressed. Flagging may provide early detection of injury.

Angular default mode network connectivity across working memory load.

PubMed

Vatansever, D; Manktelow, A E; Sahakian, B J; Menon, D K; Stamatakis, E A

2017-01-01

Initially identified during no-task, baseline conditions, it has now been suggested that the default mode network (DMN) engages during a variety of working memory paradigms through its flexible interactions with other large-scale brain networks. Nevertheless, its contribution to whole-brain connectivity dynamics across increasing working memory load has not been explicitly assessed. The aim of our study was to determine which DMN hubs relate to working memory task performance during an fMRI-based n-back paradigm with parametric increases in difficulty. Using a voxel-wise metric, termed the intrinsic connectivity contrast (ICC), we found that the bilateral angular gyri (core DMN hubs) displayed the greatest change in global connectivity across three levels of n-back task load. Subsequent seed-based functional connectivity analysis revealed that the angular DMN regions robustly interact with other large-scale brain networks, suggesting a potential involvement in the global integration of information. Further support for this hypothesis comes from the significant correlations we found between angular gyri connectivity and reaction times to correct responses. The implication from our study is that the DMN is actively involved during the n-back task and thus plays an important role related to working memory, with its core angular regions contributing to the changes in global brain connectivity in response to increasing environmental demands. Hum Brain Mapp 38:41-52, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Measuring Working Memory Deficits in Aphasia

ERIC Educational Resources Information Center

Mayer, Jamie F.; Murray, Laura L.

2012-01-01

Purpose: Many adults with aphasia demonstrate concomitant deficits in working memory (WM), but such deficits are difficult to quantify because of a lack of validated measures as well as the complex interdependence between language and WM. We examined the feasibility, reliability, and internal consistency of an "n"-back task for…

Working Memory in Early-School-Age Children with Asperger's Syndrome

ERIC Educational Resources Information Center

Cui, Jifang; Gao, Dingguo; Chen, Yinghe; Zou, Xiaobing; Wang, Ya

2010-01-01

Using a battery of working memory span tasks and n-back tasks, this study aimed to explore working memory functions in early-school-age children with Asperger's syndrome (AS). Twelve children with AS and 29 healthy children matched on age and IQ were recruited. Results showed: (a) children with AS performed better in digit and word recall tasks,…

Working memory at work: how the updating process alters the nature of working memory transfer.

PubMed

Zhang, Yanmin; Verhaeghen, Paul; Cerella, John

2012-01-01

In three N-Back experiments, we investigated components of the process of working memory (WM) updating, more specifically access to items stored outside the focus of attention and transfer from the focus to the region of WM outside the focus. We used stimulus complexity as a marker. We found that when WM transfer occurred under full attention, it was slow and highly sensitive to stimulus complexity, much more so than WM access. When transfer occurred in conjunction with access, however, it was fast and no longer sensitive to stimulus complexity. Thus the updating context altered the nature of WM processing: The dual-task situation (transfer in conjunction with access) drove memory transfer into a more efficient mode, indifferent to stimulus complexity. In contrast, access times consistently increased with complexity, unaffected by the processing context. This study reinforces recent reports that retrieval is a (perhaps the) key component of working memory functioning. Copyright © 2011 Elsevier B.V. All rights reserved.

Working Memory at Work: How the Updating Process Alters the Nature of Working Memory Transfer

PubMed Central

Zhang, Yanmin; Verhaeghen, Paul; Cerella, John

2011-01-01

In three N-Back experiments, we investigated components of the process of working memory (WM) updating, more specifically access to items stored outside the focus of attention and transfer from the focus to the region of WM outside the focus. We used stimulus complexity as a marker. We found that when WM transfer occurred under full attention, it was slow and highly sensitive to stimulus complexity, much more so than WM access. When transfer occurred in conjunction with access, however, it was fast and no longer sensitive to stimulus complexity. Thus the updating context altered the nature of WM processing: The dual-task situation (transfer in conjunction with access) drove memory transfer into a more efficient mode, indifferent to stimulus complexity. In contrast, access times consistently increased with complexity, unaffected by the processing context. This study reinforces recent reports that retrieval is a (perhaps the) key component of working memory functioning. PMID:22105718

Working memory plasticity and aging.

PubMed

Rhodes, Rebecca E; Katz, Benjamin

2017-02-01

The present research explores how the trajectory of learning on a working memory task changes throughout the life span, and whether gains in working memory performance are exclusively a question of initial working memory capacity (WMC) or whether age exerts an independent effect. In a large, cross-sectional study of younger, middle-aged, and older adults, we examined learning on a widely used working memory task-the dual n-back task-over 20 sessions of practice. We found that, while all age groups improved on the task, older adults demonstrated less improvement on the task, and also reached a lower asymptotic maximum performance than younger adults. After controlling for initial WMC, we found that age exerted independent effects on training gains and asymptotic performance; older adults tended to improve less and reached lower levels of performance than younger adults. The difference between younger and older adults' rates of learning depended in part on initial WMC. These results suggest that age-related effects on working memory include not only effects on capacity, but also plasticity and the ability to improve on a task. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

MEG Working Memory N-Back Task Reveals Functional Deficits in Combat-Related Mild Traumatic Brain Injury.

PubMed

Huang, Ming-Xiong; Nichols, Sharon; Robb-Swan, Ashley; Angeles-Quinto, Annemarie; Harrington, Deborah L; Drake, Angela; Huang, Charles W; Song, Tao; Diwakar, Mithun; Risbrough, Victoria B; Matthews, Scott; Clifford, Royce; Cheng, Chung-Kuan; Huang, Jeffrey W; Sinha, Anusha; Yurgil, Kate A; Ji, Zhengwei; Lerman, Imanuel; Lee, Roland R; Baker, Dewleen G

2018-04-13

Combat-related mild traumatic brain injury (mTBI) is a leading cause of sustained cognitive impairment in military service members and Veterans. However, the mechanism of persistent cognitive deficits including working memory (WM) dysfunction is not fully understood in mTBI. Few studies of WM deficits in mTBI have taken advantage of the temporal and frequency resolution afforded by electromagnetic measurements. Using magnetoencephalography (MEG) and an N-back WM task, we investigated functional abnormalities in combat-related mTBI. Study participants included 25 symptomatic active-duty service members or Veterans with combat-related mTBI and 20 healthy controls with similar combat experiences. MEG source-magnitude images were obtained for alpha (8-12 Hz), beta (15-30 Hz), gamma (30-90 Hz), and low-frequency (1-7 Hz) bands. Compared with healthy combat controls, mTBI participants showed increased MEG signals across frequency bands in frontal pole (FP), ventromedial prefrontal cortex, orbitofrontal cortex (OFC), and anterior dorsolateral prefrontal cortex (dlPFC), but decreased MEG signals in anterior cingulate cortex. Hyperactivations in FP, OFC, and anterior dlPFC were associated with slower reaction times. MEG activations in lateral FP also negatively correlated with performance on tests of letter sequencing, verbal fluency, and digit symbol coding. The profound hyperactivations from FP suggest that FP is particularly vulnerable to combat-related mTBI.

Effect of a single dose of dextromethorphan on psychomotor performance and working memory capacity.

PubMed

Al-Kuraishy, Hayder M; Al-Gareeb, Ali I; Ashor, Ammar Waham

2012-04-01

Previous studies show that the prolonged use of dextromethorphan produces cognitive deterioration in humans. The aim of this study was to investigate the effect of a single dose of dextroemthrophan on psychomotor performance and working memory capacity. This is a randomized, double-blind, controlled, and prospective study. Thirty-six (17 women, 19 men) medical students enrolled in the study; half of them (7 women, 11 men) were given placebo, while the other half (10 women, 8 men) received dextromethorphan. The choice reaction time, critical flicker fusion threshold, and N-back working memory task were measured before and after 2 h of taking the drugs. Dextromethorphan showed a significant deterioration in the 3-back working memory task (P<0.05). No significant changes were seen as regards the choice reaction time components (total, recognition, motor) and critical flicker fusion threshold (P>0.05). On the other hand, placebo showed no significant changes as regards the choice reaction time, critical flicker fusion threshold, and N-back working memory task (P>0.05). A single dose of dextromethorphan has no effect on attention and arousal but may significantly impair the working memory capacity.

Gaming is related to enhanced working memory performance and task-related cortical activity.

PubMed

Moisala, M; Salmela, V; Hietajärvi, L; Carlson, S; Vuontela, V; Lonka, K; Hakkarainen, K; Salmela-Aro, K; Alho, K

2017-01-15

Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13-24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured using functional magnetic resonance imaging (fMRI). The results revealed that the extent of daily gaming activity was related to enhancements in both performance accuracy and speed during the most demanding (2-back) level of the working memory task. This improved working memory performance was accompanied by enhanced recruitment of a fronto-parietal cortical network, especially the dorsolateral prefrontal cortex. In contrast, during the less demanding (1-back) level of the task, gaming was associated with decreased activity in the same cortical regions. Our results suggest that a greater degree of daily gaming experience is associated with better working memory functioning and task difficulty-dependent modulation in fronto-parietal brain activity already in adolescence and even when non-expert gamers are studied. The direction of causality within this association cannot be inferred with certainty due to the correlational nature of the current study. Copyright © 2016 Elsevier B.V. All rights reserved.

Working memory training shows immediate and long-term effects on cognitive performance in children

PubMed Central

Pugin, Fiona; Metz, Andreas J.; Stauffer, Madlaina; Wolf, Martin; Jenni, Oskar G.; Huber, Reto

2014-01-01

Working memory is important for mental reasoning and learning processes. Several studies in adults and school-age children have shown performance improvement in cognitive tests after working memory training. Our aim was to examine not only immediate but also long-term effects of intensive working memory training on cognitive performance tests in children. Fourteen healthy male subjects between 10 and 16 years trained a visuospatial n-back task over 3 weeks (30 min daily), while 15 individuals of the same age range served as a passive control group. Significant differences in immediate (after 3 weeks of training) and long-term effects (after 2-6 months) in an auditory n-back task were observed compared to controls (2.5 fold immediate and 4.7 fold long-term increase in the training group compared to the controls). The improvement was more pronounced in subjects who improved their performance during the training. Other cognitive functions (matrices test and Stroop task) did not change when comparing the training group to the control group. We conclude that visuospatial working memory training in children boosts performance in similar memory tasks such as the auditory n-back task. The sustained performance improvement several months after the training supports the effectiveness of the training. PMID:25671082

The ERP research about the influence of the music of Chopin on working memory

NASA Astrophysics Data System (ADS)

Sun, C. A.; Wei, Hong-tao; Yue, Li-juan

2011-10-01

This study is to examine the effect of the music of Chopin on working memory and the electrical activity of the brain in different conditions by using event-related potentials (ERPs), adopting n-back experimental paradigm and to study the neuromechanism. Thirty adults performed behavioral experiments with three conditions of music and two levels of n-back task. Fourteen normal adults performed ERP experiments with the same program as the behavioral experiment and the EEG were recorded. Chopin music improved people's working memory and pilot music improved most effectively.P3 peak amplitude decreased as working memory load increased. Especially in high load task, P3 peak amplitude decreased gradually in pilot music, background music and free music condition.

Working memory plasticity in old age: practice gain, transfer, and maintenance.

PubMed

Li, Shu-Chen; Schmiedek, Florian; Huxhold, Oliver; Röcke, Christina; Smith, Jacqui; Lindenberger, Ulman

2008-12-01

Adult age differences in cognitive plasticity have been studied less often in working memory than in episodic memory. The authors investigated the effects of extensive working memory practice on performance improvement, transfer, and short-term maintenance of practice gains and transfer effects. Adults age 20-30 years and 70-80 years practiced a spatial working memory task with 2 levels of processing demands across 45 days for about 15 min per day. In both age groups and relative to age-matched, no-contact control groups, we found (a) substantial performance gains on the practiced task, (b) near transfer to a more demanding spatial n-back task and to numerical n-back tasks, and (c) 3-month maintenance of practice gains and near transfer effects, with decrements relative to postpractice performance among older but not younger adults. No evidence was found for far transfer to complex span tasks. The authors discuss neuronal mechanisms underlying adult age differences and similarities in patterns of plasticity and conclude that the potential of deliberate working memory practice as a tool for improving cognition in old age merits further exploration. Copyright (c) 2009 APA, all rights reserved.

Changes in Brain Network Efficiency and Working Memory Performance in Aging

PubMed Central

Stanley, Matthew L.; Simpson, Sean L.; Dagenbach, Dale; Lyday, Robert G.; Burdette, Jonathan H.; Laurienti, Paul J.

2015-01-01

Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency). Decreases in local efficiency during the working memory task were associated with better working memory performance in both age cohorts. In contrast, increases in global efficiency were associated with much better working performance for young participants; however, increases in global efficiency were associated with a slight decrease in working memory performance for older participants. Individual differences in local and global efficiency during resting-state sessions were not significant predictors of working memory performance. Significant group whole-brain functional network decreases in local efficiency also were observed during the working memory task compared to rest, whereas no significant differences were observed in network global efficiency. These results are discussed in relation to recently developed models of age-related differences in working memory. PMID:25875001

Changes in brain network efficiency and working memory performance in aging.

PubMed

Stanley, Matthew L; Simpson, Sean L; Dagenbach, Dale; Lyday, Robert G; Burdette, Jonathan H; Laurienti, Paul J

2015-01-01

Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency). Decreases in local efficiency during the working memory task were associated with better working memory performance in both age cohorts. In contrast, increases in global efficiency were associated with much better working performance for young participants; however, increases in global efficiency were associated with a slight decrease in working memory performance for older participants. Individual differences in local and global efficiency during resting-state sessions were not significant predictors of working memory performance. Significant group whole-brain functional network decreases in local efficiency also were observed during the working memory task compared to rest, whereas no significant differences were observed in network global efficiency. These results are discussed in relation to recently developed models of age-related differences in working memory.

Making working memory work: The effects of extended practice on focus capacity and the processes of updating, forward access, and random access

PubMed Central

Price, John M.; Colflesh, Gregory J. H.; Cerella, John; Verhaeghen, Paul

2014-01-01

We investigated the effects of 10 hours of practice on variations of the N-Back task to investigate the processes underlying possible expansion of the focus of attention within working memory. Using subtractive logic, we showed that random access (i.e., Sternberg-like search) yielded a modest effect (a 50% increase in speed) whereas the processes of forward access (i.e., retrieval in order, as in a standard N-Back task) and updating (i.e., changing the contents of working memory) were executed about 5 times faster after extended practice. We additionally found that extended practice increased working memory capacity as measured by the size of the focus of attention for the forward-access task, but not for variations where probing was in random order. This suggests that working memory capacity may depend on the type of search process engaged, and that certain working-memory-related cognitive processes are more amenable to practice than others. PMID:24486803

Making working memory work: the effects of extended practice on focus capacity and the processes of updating, forward access, and random access.

PubMed

Price, John M; Colflesh, Gregory J H; Cerella, John; Verhaeghen, Paul

2014-05-01

We investigated the effects of 10h of practice on variations of the N-Back task to investigate the processes underlying possible expansion of the focus of attention within working memory. Using subtractive logic, we showed that random access (i.e., Sternberg-like search) yielded a modest effect (a 50% increase in speed) whereas the processes of forward access (i.e., retrieval in order, as in a standard N-Back task) and updating (i.e., changing the contents of working memory) were executed about 5 times faster after extended practice. We additionally found that extended practice increased working memory capacity as measured by the size of the focus of attention for the forward-access task, but not for variations where probing was in random order. This suggests that working memory capacity may depend on the type of search process engaged, and that certain working-memory-related cognitive processes are more amenable to practice than others. Copyright © 2014 Elsevier B.V. All rights reserved.

Oscillatory lower body negative pressure impairs working memory task-related functional hyperemia in healthy volunteers.

PubMed

Merchant, Sana; Medow, Marvin S; Visintainer, Paul; Terilli, Courtney; Stewart, Julian M

2017-04-01

Neurovascular coupling (NVC) describes the link between an increase in task-related neural activity and increased cerebral blood flow denoted "functional hyperemia." We previously showed induced cerebral blood flow oscillations suppressed functional hyperemia; conversely functional hyperemia also suppressed cerebral blood flow oscillations. We used lower body negative pressure (OLBNP) oscillations to force oscillations in middle cerebral artery cerebral blood flow velocity (CBFv). Here, we used N-back testing, an intellectual memory challenge as a neural activation task, to test the hypothesis that OLBNP-induced oscillatory cerebral blood flow can reduce functional hyperemia and NVC produced by a working memory task and can interfere with working memory. We used OLBNP (-30 mmHg) at 0.03, 0.05, and 0.10 Hz and measured spectral power of CBFv at all frequencies. Neither OLBNP nor N-back, alone or combined, affected hemodynamic parameters. 2-Back power and OLBNP individually were compared with 2-back power during OLBNP. 2-Back alone produced a narrow band increase in oscillatory arterial pressure (OAP) and oscillatory cerebral blood flow power centered at 0.0083 Hz. Functional hyperemia in response to 2-back was reduced to near baseline and 2-back memory performance was decreased by 0.03-, 0.05-, and 0.10-Hz OLBNP. OLBNP alone produced increased oscillatory power at frequencies of oscillation not suppressed by added 2-back. However, 2-back preceding OLBNP suppressed OLBNP power. OLBNP-driven oscillatory CBFv blunts NVC and memory performance, while memory task reciprocally interfered with forced CBFv oscillations. This shows that induced cerebral blood flow oscillations suppress functional hyperemia and functional hyperemia suppresses cerebral blood flow oscillations. NEW & NOTEWORTHY We show that induced cerebral blood flow oscillations suppress functional hyperemia produced by a working memory task as well as memory task performance. We conclude that oscillatory

Complex Span versus Updating Tasks of Working Memory: The Gap Is Not that Deep

ERIC Educational Resources Information Center

Schmiedek, Florian; Hildebrandt, Andrea; Lovden, Martin; Wilhelm, Oliver; Lindenberger, Ulman

2009-01-01

How to best measure working memory capacity is an issue of ongoing debate. Besides established complex span tasks, which combine short-term memory demands with generally unrelated secondary tasks, there exists a set of paradigms characterized by continuous and simultaneous updating of several items in working memory, such as the n-back, memory…

Working memory maintenance is sufficient to reduce state anxiety.

PubMed

Balderston, Nicholas L; Quispe-Escudero, David; Hale, Elizabeth; Davis, Andrew; O'Connell, Katherine; Ernst, Monique; Grillon, Christian

2016-11-01

According to the attentional control theory (ACT) proposed by Eysenck and colleagues, anxiety interferes with cognitive processing by prioritizing bottom-up attentional processes over top-down attentional processes, leading to competition for access to limited resources in working memory, particularly the central executive (Eysenck, Derakshan, Santos, & Calvo, ). However, previous research using the n-back working memory task suggests that working memory load also reduces state anxiety. Assuming that similar mechanisms underlie the effect of anxiety on cognition, and the effect of cognition on anxiety, one possible implication of the ACT would suggest that the reduction of state anxiety with increasing working memory load is driven by activation of central executive attentional control processes. We tested this hypothesis using the Sternberg working memory paradigm, where maintenance processes can be isolated from central executive processes (Altamura et al., ; Sternberg, ). Consistent with the n-back results, subjects showed decreased state anxiety during the maintenance period of high-load trials relative to low-load trials, suggesting that maintenance processes alone are sufficient to achieve this state anxiety reduction. Given that the Sternberg task does not require central executive engagement, these results are not consistent with an implication of the ACT where the cognition/anxiety relationship and anxiety/cognition relationship are mediated by similar central executive mechanisms. Instead, we propose an extension of the ACT such that engaging working memory maintenance suppresses state anxiety in a load-dependent manner. Furthermore, we hypothesize that the efficacy of this effect may moderate the effect of trait anxiety on cognition. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Architecture of fluid intelligence and working memory revealed by lesion mapping.

PubMed

Barbey, Aron K; Colom, Roberto; Paul, Erick J; Grafman, Jordan

2014-03-01

Although cognitive neuroscience has made valuable progress in understanding the role of the prefrontal cortex in human intelligence, the functional networks that support adaptive behavior and novel problem solving remain to be well characterized. Here, we studied 158 human brain lesion patients to investigate the cognitive and neural foundations of key competencies for fluid intelligence and working memory. We administered a battery of neuropsychological tests, including the Wechsler Adult Intelligence Scale (WAIS) and the N-Back task. Latent variable modeling was applied to obtain error-free scores of fluid intelligence and working memory, followed by voxel-based lesion-symptom mapping to elucidate their neural substrates. The observed latent variable modeling and lesion results support an integrative framework for understanding the architecture of fluid intelligence and working memory and make specific recommendations for the interpretation and application of the WAIS and N-Back task to the study of fluid intelligence in health and disease.

Shielding cognition from nociception with working memory.

PubMed

Legrain, Valéry; Crombez, Geert; Plaghki, Léon; Mouraux, André

2013-01-01

Because pain often signals the occurrence of potential tissue damage, nociceptive stimuli have the capacity to capture attention and interfere with ongoing cognitive activities. Working memory is known to guide the orientation of attention by maintaining goal priorities active during the achievement of a task. This study investigated whether the cortical processing of nociceptive stimuli and their ability to capture attention are under the control of working memory. Event-related brain potentials (ERPs) were recorded while participants performed primary tasks on visual targets that required or did not require rehearsal in working memory (1-back vs 0-back conditions). The visual targets were shortly preceded by task-irrelevant tactile stimuli. Occasionally, in order to distract the participants, the tactile stimuli were replaced by novel nociceptive stimuli. In the 0-back conditions, task performance was disrupted by the occurrence of the nociceptive distracters, as reflected by the increased reaction times in trials with novel nociceptive distracters as compared to trials with standard tactile distracters. In the 1-back conditions, such a difference disappeared suggesting that attentional capture and task disruption induced by nociceptive distracters were suppressed by working memory, regardless of task demands. Most importantly, in the conditions involving working memory, the magnitude of nociceptive ERPs, including ERP components at early latency, were significantly reduced. This indicates that working memory is able to modulate the cortical processing of nociceptive input already at its earliest stages, and could explain why working memory reduces consequently ability of nociceptive stimuli to capture attention and disrupt performance of the primary task. It is concluded that protecting cognitive processing against pain interference is best guaranteed by keeping out of working memory pain-related information. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effect of binaural beats on verbal working memory and cortical connectivity.

PubMed

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

2017-04-01

Synchronization in activated regions of cortical networks affect the brain's frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain's response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant's accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

Reduced prefrontal efficiency for visuospatial working memory in attention-deficit/hyperactivity disorder.

PubMed

Bédard, Anne-Claude V; Newcorn, Jeffrey H; Clerkin, Suzanne M; Krone, Beth; Fan, Jin; Halperin, Jeffrey M; Schulz, Kurt P

2014-09-01

Visuospatial working memory impairments have been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). However, most ADHD research has focused on the neural correlates of nonspatial mnemonic processes. This study examined brain activation and functional connectivity for visuospatial working memory in youth with and without ADHD. Twenty-four youth with ADHD and 21 age- and sex-matched healthy controls were scanned with functional magnetic resonance imaging while performing an N-back test of working memory for spatial position. Block-design analyses contrasted activation and functional connectivity separately for high (2-back) and low (1-back) working memory load conditions versus the control condition (0-back). The effect of working memory load was modeled with linear contrasts. The 2 groups performed comparably on the task and demonstrated similar patterns of frontoparietal activation, with no differences in linear gains in activation as working memory load increased. However, youth with ADHD showed greater activation in the left dorsolateral prefrontal cortex (DLPFC) and left posterior cingulate cortex (PCC), greater functional connectivity between the left DLPFC and left intraparietal sulcus, and reduced left DLPFC connectivity with left midcingulate cortex and PCC for the high load contrast compared to controls (p < .01; k > 100 voxels). Reanalysis using a more conservative statistical approach (p < .001; k > 100 voxels) yielded group differences in PCC activation and DLPFC-midcingulate connectivity. Youth with ADHD show decreased efficiency of DLPFC for high-load visuospatial working memory and greater reliance on posterior spatial attention circuits to store and update spatial position than healthy control youth. Findings should be replicated in larger samples. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Enhanced emotional interference on working memory performance in adults with ADHD.

PubMed

Marx, Ivo; Domes, Gregor; Havenstein, Carolin; Berger, Christoph; Schulze, Lars; Herpertz, Sabine C

2011-09-01

Subjects with attention-deficit/hyperactivity disorder (ADHD) suffer from both executive dysfunction and deficits in emotion regulation. However, up to now, there has been no research demonstrating a clear impact of emotional dysregulation on cognitive performance in subjects with ADHD. Male and female adults with ADHD (n=39) and gender- and IQ-matched control subjects (n=40) performed an emotional working memory task (n-back task). In the background of the task, we presented neutral and negative stimuli varied in emotional saliency (negative pictures with low saliency, negative pictures with high saliency), but subjects were instructed to ignore these pictures and to process the working memory task as quickly and as accurately as possible. Compared to control subjects, ADHD patients showed both a general working memory deficit and enhanced distractability by emotionally salient stimuli in terms of lower n-back performance accuracy. In particular, while controls showed impaired WM performance when presented with highly arousing negative background pictures, a comparable decrement was observed in the ADHD group already with lowly arousing pictures. Our results suggest that difficulties in suppressing attention towards emotionally laden stimuli might result from deficient executive control in ADHD.

Dynamic working memory performance in individuals with single-domain amnestic mild cognitive impairment.

PubMed

Guild, Emma B; Vasquez, Brandon P; Maione, Andrea M; Mah, Linda; Ween, Jon; Anderson, Nicole D

2014-01-01

Previous studies have observed poorer working memory performance in individuals with amnestic mild cognitive impairment than in healthy older adults. It is unclear, however, whether these difficulties are true only of the multiple-domain clinical subtype in whom poorer executive functioning is common. The current study examined working memory, as measured by the self-ordered pointing task (SOPT) and an n-back task, in healthy older adults and adults with single-domain amnestic mild cognitive impairment (aMCI). Individuals with single-domain aMCI committed more errors and required longer to develop an organizational strategy on the SOPT. The single-domain aMCI group did not differ from healthy older adults on the 1-back or 2-back, but had poorer discrimination on the 3-back task. This is, to our knowledge, the first characterization of dynamic working memory performance in a single-domain aMCI group. These results lend support for the idea that clinical amnestic MCI subtypes may reflect different stages on a continuum of progression to dementia and question whether standardized measures of working memory (span tasks) are sensitive enough to capture subtle changes in performance.

Genetic predictor of working memory and prefrontal function in women with HIV.

PubMed

Sundermann, Erin E; Bishop, Jeffrey R; Rubin, Leah H; Little, Deborah M; Meyer, Vanessa J; Martin, Eileen; Weber, Kathleen; Cohen, Mardge; Maki, Pauline M

2015-02-01

The Val158Met (rs4680) single-nucleotide polymorphism (SNP) of the catechol-O-methyltransferase gene (COMT) influences executive function and prefrontal function through its effect on dopamine (DA) metabolism. Both HIV and the Val allele of the Val158Met SNP are associated with compromised executive function and inefficient prefrontal function. The present study used behavioral and neuroimaging techniques to determine independent and interactive associations between HIV serostatus and COMT genotype on working memory and prefrontal function in women. For the behavioral study, 54 HIV-infected and 33 HIV-uninfected women completed the 0-, 1-, and 2-back conditions of the verbal N-back, a working memory test. For the imaging study, 36 women (23 HIV-infected, 13 HIV-uninfected) underwent functional magnetic resonance imaging (fMRI) assessments while completing the N-back task. HIV-infected women demonstrated significantly worse N-back performance compared with HIV-uninfected women (p < 0.05). A significant serostatus by genotype interaction (p < 0.01) revealed that, among Val/Val, but not Met allele carriers, HIV-infected women performed significantly worse than HIV-uninfected controls across N-back conditions (p < 0.01). Analogous to behavioral findings, a serostatus by genotype interaction revealed that HIV-infected Val/Val carriers showed significantly greater prefrontal activation compared with HIV-uninfected Val/Val carriers (p < 0.01). Conversely, HIV-uninfected Met allele carriers demonstrated significantly greater prefrontal activation compared with HIV-infected Met allele carriers. Findings suggest that the combination of HIV infection and the Val/Val COMT genotype leads to working memory deficits and altered prefrontal function in HIV-infected individuals.

Muscular and Aerobic Fitness, Working Memory, and Academic Achievement in Children.

PubMed

Kao, Shih-Chun; Westfall, Daniel R; Parks, Andrew C; Pontifex, Matthew B; Hillman, Charles H

2017-03-01

This study investigated the relationship between aerobic and muscular fitness with working memory and academic achievement in preadolescent children. Seventy-nine 9- to 11-yr-old children completed an aerobic fitness assessment using a graded exercise test; a muscular fitness assessment consisting of upper body, lower body, and core exercises; a serial n-back task to assess working memory; and an academic achievement test of mathematics and reading. Hierarchical regression analyses indicated that after controlling for demographic variables (age, sex, grade, IQ, socioeconomic status), aerobic fitness was associated with greater response accuracy and d' in the 2-back condition and increased mathematic performance in algebraic functions. Muscular fitness was associated with increased response accuracy and d', and longer reaction time in the 2-back condition. Further, the associations of muscular fitness with response accuracy and d' in the 2-back condition were independent of aerobic fitness. The current findings suggest the differential relationships between the aerobic and the muscular aspects of physical fitness with working memory and academic achievement. With the majority of research focusing on childhood health benefits of aerobic fitness, this study suggests the importance of muscular fitness to cognitive health during preadolescence.

The effect of binaural beats on verbal working memory and cortical connectivity

NASA Astrophysics Data System (ADS)

Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

2017-04-01

Objective. Synchronization in activated regions of cortical networks affect the brain’s frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain’s response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. Approach. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. Main results. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant’s accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Significance. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

Noradrenaline transporter blockade increases fronto-parietal functional connectivity relevant for working memory.

PubMed

Hernaus, Dennis; Casales Santa, Marta Ma; Offermann, Jan Stefan; Van Amelsvoort, Thérèse

2017-04-01

Experimental animal work has demonstrated that dopamine and noradrenaline play an essential role in modulating prefrontal cortex-mediated networks underlying working memory performance. Studies of functional connectivity have been instrumental in extending such notions to humans but, so far, have almost exclusively focussed on pharmacological agents with a predominant dopaminergic mechanism of action. Here, we investigate the effect of a single dose of atomoxetine 60mg, a noradrenaline transporter inhibitor, on working memory performance and associated functional connectivity during an n-back task in 19 healthy male volunteers. Atomoxetine increased functional connectivity between right anterior insula and dorsolateral prefrontal cortex, precentral gyrus, posterior parietal cortex and precuneus during the high-working memory load condition of the n-back task. Increased atomoxetine-induced insula-dorsolateral prefrontal cortex functional connectivity during this condition correlated with decreased reaction time variability and was furthermore predicted by working memory capacity. These results show for the first time that noradrenaline transporter blockade-induced increases in cortical catecholamines accentuate fronto-parietal working memory-related network integrity. The observation of significant inter-subject variability in response to atomoxetine has implications for inverted-U frameworks of dopamine and noradrenaline function, which could be useful to predict drug effects in clinical disorders with variable treatment response. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

Working memory training improves visual short-term memory capacity.

PubMed

Schwarb, Hillary; Nail, Jayde; Schumacher, Eric H

2016-01-01

Since antiquity, philosophers, theologians, and scientists have been interested in human memory. However, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, J Exp Psychol 113:1-2, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, Behav Brain Sci 24:87-185, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle What is working-memory capacity? 297-314, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison and Chein, Psychol Bull Rev 18:46-60 2011). However, initial investigations across a wide variety of cognitive functions have produced mixed results regarding the transferability of training-related improvements. Across two experiments, the present research focuses on the benefit of working memory training on visual short-term memory capacity-a cognitive process that has received little attention in the training literature. Data reveal training-related improvement of global measures of visual short-term memory as well as of measures of the independent sub-processes that contribute to capacity (Awh et al., Psychol Sci 18(7):622-628, 2007). These results suggest that the ability to inhibit irrelevant information within and between trials is enhanced via n-back training allowing for selective improvement on untrained tasks. Additionally, we highlight a potential limitation of the standard adaptive training procedure and propose a modified design to ensure variability in the training environment.

Reduced but broader prefrontal activity in patients with schizophrenia during n-back working memory tasks: a multi-channel near-infrared spectroscopy study.

PubMed

Koike, Shinsuke; Takizawa, Ryu; Nishimura, Yukika; Kinou, Masaru; Kawasaki, Shingo; Kasai, Kiyoto

2013-09-01

Caudal regions of the prefrontal cortex, including the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortex, are involved in essential cognitive functions such as working memory. In contrast, more rostral regions, such as the frontopolar cortex (FpC), have integrative functions among cognitive functions and thereby contribute crucially to real-world social activity. Previous functional magnetic resonance imaging studies have shown patients with schizophrenia had different DLPFC activity pattern in response to cognitive load changes compared to healthy controls; however, the spatial relationship between the caudal and rostral prefrontal activation has not been evaluated under less-constrained conditions. Twenty-six patients with schizophrenia and 26 age-, sex-, and premorbid-intelligence-matched healthy controls participated in this study. Hemodynamic changes during n-back working memory tasks with different cognitive loads were measured using multi-channel near-infrared spectroscopy (NIRS). Healthy controls showed significant task-related activity in the bilateral VLPFC and significant task-related decreased activity in the DLPFC, with greater signal changes when the task required more cognitive load. In contrast, patients with schizophrenia showed activation in the more rostral regions, including bilateral DLPFC and FpC. Neither decreased activity nor greater activation in proportion to elevated cognitive load occurred. This multi-channel NIRS study demonstrated that activation intensity did not increase in patients with schizophrenia associated with cognitive load changes, suggesting hypo-frontality as cognitive impairment in schizophrenia. On the other hand, patients had broader prefrontal activity in areas such as the bilateral DLPFC and FpC regions, thus suggesting a hyper-frontality compensatory response. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impaired theta-gamma coupling during working memory performance in schizophrenia.

PubMed

Barr, Mera S; Rajji, Tarek K; Zomorrodi, Reza; Radhu, Natasha; George, Tony P; Blumberger, Daniel M; Daskalakis, Zafiris J

2017-11-01

Working memory deficits represent a core feature of schizophrenia. These deficits have been associated with dysfunctional dorsolateral prefrontal cortex (DLPFC) cortical oscillations. Theta-gamma coupling describes the modulation of gamma oscillations by theta phasic activity that has been directly associated with the ordering of information during working memory performance. Evaluating theta-gamma coupling may provide greater insight into the neural mechanisms mediating working memory deficits in this disorder. Thirty-eight patients diagnosed with schizophrenia or schizoaffective disorder and 38 healthy controls performed the verbal N-Back task administered at 4 levels, while EEG was recorded. Theta (4-7Hz)-gamma (30-50Hz) coupling was calculated for target and non-target correct trials for each working memory load. The relationship between theta-gamma coupling and accuracy was determined. Theta-gamma coupling was significantly and selectively impaired during correct responses to target letters among schizophrenia patients compared to healthy controls. A significant and positive relationship was found between theta-gamma coupling and 3-Back accuracy in controls, while this relationship was not observed in patients. These findings suggest that impaired theta-gamma coupling contribute to working memory dysfunction in schizophrenia. Future work is needed to evaluate the predictive utility of theta-gamma coupling as a neurophysiological marker for functional outcomes in this disorder. Copyright © 2017. Published by Elsevier B.V.

Neurophysiological capacity in a working memory task differentiates dependent from nondependent heavy drinkers and controls.

PubMed

Wesley, Michael J; Lile, Joshua A; Fillmore, Mark T; Porrino, Linda J

2017-06-01

Determining the neurobehavioral profiles that differentiate heavy drinkers who are and are not alcohol dependent will inform treatment efforts. Working memory is linked to substance use disorders and can serve as a representation of the demand placed on the neurophysiology associated with cognitive control. Behavior and brain activity (via fMRI) were recorded during an N-Back working memory task in controls (CTRL), nondependent heavy drinkers (A-ND) and dependent heavy drinkers (A-D). Typical and novel step-wise analyses examined profiles of working memory load and increasing task demand, respectively. Performance was significantly decreased in A-D during high working memory load (2-Back), compared to CTRL and A-ND. Analysis of brain activity during high load (0-Back vs. 2- Back) showed greater responses in the dorsal lateral and medial prefrontal cortices of A-D than CTRL, suggesting increased but failed compensation. The step-wise analysis revealed that the transition to Low Demand (0-Back to 1-Back) was associated with robust increases and decreases in cognitive control and default-mode brain regions, respectively, in A-D and A-ND but not CTRL. The transition to High Demand (1-Back to 2-Back) resulted in additional engagement of these networks in A-ND and CTRL, but not A-D. Heavy drinkers engaged working memory neural networks at lower demand than controls. As demand increased, nondependent heavy drinkers maintained control performance but relied on additional neurophysiological resources, and dependent heavy drinkers did not display further resource engagement and had poorer performance. These results support targeting these brain areas for treatment interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

Visual working memory buffers information retrieved from visual long-term memory.

PubMed

Fukuda, Keisuke; Woodman, Geoffrey F

2017-05-16

Human memory is thought to consist of long-term storage and short-term storage mechanisms, the latter known as working memory. Although it has long been assumed that information retrieved from long-term memory is represented in working memory, we lack neural evidence for this and need neural measures that allow us to watch this retrieval into working memory unfold with high temporal resolution. Here, we show that human electrophysiology can be used to track information as it is brought back into working memory during retrieval from long-term memory. Specifically, we found that the retrieval of information from long-term memory was limited to just a few simple objects' worth of information at once, and elicited a pattern of neurophysiological activity similar to that observed when people encode new information into working memory. Our findings suggest that working memory is where information is buffered when being retrieved from long-term memory and reconcile current theories of memory retrieval with classic notions about the memory mechanisms involved.

Normative data on the n-back task for children and young adolescents

PubMed Central

Pelegrina, Santiago; Lechuga, M. Teresa; García-Madruga, Juan A.; Elosúa, M. Rosa; Macizo, Pedro; Carreiras, Manuel; Fuentes, Luis J.; Bajo, M. Teresa

2015-01-01

The n-back task is a frequently used measure of working memory (WM) in cognitive neuroscience research contexts, and it has become widely adopted in other areas over the last decade. This study aimed to obtain normative data for the n-back task from a large sample of children and adolescents. To this end, a computerized verbal n-back task with three levels of WM load (1-back, 2-back, and 3-back) was administered to 3722 Spanish school children aged 7–13 years. Results showed an overall age-related increase in performance for the different levels of difficulty. This trend was less pronounced at 1-back than at 2-back when hits were considered. Gender differences were also observed, with girls outperforming boys although taking more time to respond. The theoretical implications of these results are discussed. Normative data stratified by age and gender for the three WM load levels are provided. PMID:26500594

Normative data on the n-back task for children and young adolescents.

PubMed

Pelegrina, Santiago; Lechuga, M Teresa; García-Madruga, Juan A; Elosúa, M Rosa; Macizo, Pedro; Carreiras, Manuel; Fuentes, Luis J; Bajo, M Teresa

2015-01-01

The n-back task is a frequently used measure of working memory (WM) in cognitive neuroscience research contexts, and it has become widely adopted in other areas over the last decade. This study aimed to obtain normative data for the n-back task from a large sample of children and adolescents. To this end, a computerized verbal n-back task with three levels of WM load (1-back, 2-back, and 3-back) was administered to 3722 Spanish school children aged 7-13 years. Results showed an overall age-related increase in performance for the different levels of difficulty. This trend was less pronounced at 1-back than at 2-back when hits were considered. Gender differences were also observed, with girls outperforming boys although taking more time to respond. The theoretical implications of these results are discussed. Normative data stratified by age and gender for the three WM load levels are provided.

Neural Basis of Working Memory Enhancement after Acute Aerobic Exercise: fMRI Study of Preadolescent Children.

PubMed

Chen, Ai-Guo; Zhu, Li-Na; Yan, Jun; Yin, Heng-Chan

2016-01-01

Working memory lies at the core of cognitive function and plays a crucial role in children's learning, reasoning, problem solving, and intellectual activity. Behavioral findings have suggested that acute aerobic exercise improves children's working memory; however, there is still very little knowledge about whether a single session of aerobic exercise can alter working memory's brain activation patterns, as assessed by functional magnetic resonance imaging (fMRI). Therefore, we investigated the effect of acute moderate-intensity aerobic exercise on working memory and its brain activation patterns in preadolescent children, and further explored the neural basis of acute aerobic exercise on working memory in these children. We used a within-subjects design with a counterbalanced order. Nine healthy, right-handed children were scanned with a Siemens MAGNETOM Trio 3.0 Tesla magnetic resonance imaging scanner while they performed a working memory task (N-back task), following a baseline session and a 30-min, moderate-intensity exercise session. Compared with the baseline session, acute moderate-intensity aerobic exercise benefitted performance in the N-back task, increasing brain activities of bilateral parietal cortices, left hippocampus, and the bilateral cerebellum. These data extend the current knowledge by indicating that acute aerobic exercise enhances children's working memory, and the neural basis may be related to changes in the working memory's brain activation patterns elicited by acute aerobic exercise.

Enhanced dimension-specific visual working memory in grapheme–color synesthesia☆

PubMed Central

Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-01-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme–color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. PMID:23892185

Catastrophe models for cognitive workload and fatigue in N-back tasks.

PubMed

Guastello, Stephen J; Reiter, Katherine; Malon, Matthew; Timm, Paul; Shircel, Anton; Shaline, James

2015-04-01

N-back tasks place a heavy load on working memory, and thus make good candidates for studying cognitive workload and fatigue (CWLF). This study extended previous work on CWLF which separated the two phenomena with two cusp catastrophe models. Participants were 113 undergraduates who completed 2-back and 3-back tasks with both auditory and visual stimuli simultaneously. Task data were complemented by several measures hypothesized to be related to cognitive elasticity and compensatory abilities and the NASA TLX ratings of subjective workload. The adjusted R2 was .980 for the workload model, which indicated a highly accurate prediction with six bifurcation (elasticity versus rigidity) effects: algebra flexibility, TLX performance, effort, and frustration; and psychosocial measures of inflexibility and monitoring. There were also two cognitive load effects (asymmetry): 2 vs. 3-back and TLX temporal demands. The adjusted R2 was .454 for the fatigue model, which contained two bifurcation variables indicating the amount of work done, and algebra flexibility as the compensatory ability variable. Both cusp models were stronger than the next best linear alternative model. The study makes an important step forward by uncovering an apparently complete model for workload, finding the role of subjective workload in the context of performance dynamics, and finding CWLF dynamics in yet another type of memory-intensive task. The results were also consistent with the developing notion that performance deficits induced by workload and deficits induced by fatigue result from the impact of the task on the workspace and executive functions of working memory respectively.

Working memory is differentially affected by stress in men and women.

PubMed

Schoofs, Daniela; Pabst, Stephan; Brand, Matthias; Wolf, Oliver T

2013-03-15

Stress has been shown to influence working memory. However, sex differences and the potential impact of stimulus emotionality have not received much attention. In a first experiment the effects of stress on a neutral working memory (WM) paradigm were tested in male and female participants (Experiment 1). Experiment 2 employed the same paradigm but used emotional stimuli. For this purpose, healthy participants were exposed either to a stressful (Trierer Social Stress Test (TSST)) or to a non-stressful control condition. Subsequently, WM performance in an n-back task was assessed. In Experiment 1, single digits were used as stimuli, while in Experiment 2 neutral and negative pictures were additionally employed. Salivary cortisol and Alpha-Amylase (sAA) were measured before and three times after the treatment as a marker of hypothalamus-pituitary-adrenal (HPA) axis- and sympathetic nervous system (SNS) activity. In both experiments, stress caused a substantial cortisol and sAA increase. For WM performance (response time) a stress by sex interaction was apparent. Stress enhanced performance in men, while impairing it in women. In both experiments stress had no effect on response accuracy. No modulating effect of the emotional quality of stimuli on n-back performance was observed (study 2). The results indicate that the effect of acute stress on n-back performance differs between the sexes. In contrast to long-term memory, the influence of stress on WM appears not to be modulated by the emotionality of the employed stimuli if stimuli are potential targets as it is the case in the n-back task. Copyright © 2013 Elsevier B.V. All rights reserved.

Enhancing Mobile Working Memory Training by Using Affective Feedback

ERIC Educational Resources Information Center

Schaaff, Kristina

2013-01-01

The objective of this paper is to propose a novel approach to enhance working memory (WM) training for mobile devices by using information about the arousal level of a person. By the example of an adaptive n-back task, we combine methodologies from different disciplines to tackle this challenge: mobile learning, affective computing and cognitive…

The polarity-dependent effects of the bilateral brain stimulation on working memory.

PubMed

Keshvari, Fatemeh; Pouretemad, Hamid-Reza; Ekhtiari, Hamed

2013-01-01

Working memory plays a critical role in cognitive processes which are central to our daily life. Neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (DLFPC). This study was aimed to assess whether bilateral modulation of the DLPFC using a noninvasive brain stimulation, namely transcranial direct current stimulation (tDCS), modifies the working memory function in healthy adults. In a randomized sham-controlled cross-over study, 60 subjects (30 Males) received sham and active tDCS in two subgroups (anode left/cathode right and anode right/cathode left) of the DLPFC. Subjects were presented working memory n-back task while the reaction time and accuracy were recorded. A repeated measures, mixed design ANOVA indicated a significant difference between the type of stimulation (sham vs. active) in anodal stimulation of the left DLPFC with cathodal stimulation of the right DLPFC [F(1,55)= 5.29, P=0.019], but not the inverse polarity worsened accuracy in the 2-back working memory task. There were also no statistically significant changes in speed of working memory [F(1,55)= 0.458,P=0.502] related to type or order of stimulation. The results would imply to a polarity dependence of bilateral tDCS of working memory. Left anodal/ right cathodal stimulation of DLPFC could impair working memory, while the reverser stimulation had no effect. Meaning that bilateral stimulation of DLFC would not be a useful procedure to improve working memory. Further studies are required to understand subtle effects of different tDCS stimulation/inhibition electrode positioning on the working memory.

Visual working memory buffers information retrieved from visual long-term memory

PubMed Central

Fukuda, Keisuke; Woodman, Geoffrey F.

2017-01-01

Human memory is thought to consist of long-term storage and short-term storage mechanisms, the latter known as working memory. Although it has long been assumed that information retrieved from long-term memory is represented in working memory, we lack neural evidence for this and need neural measures that allow us to watch this retrieval into working memory unfold with high temporal resolution. Here, we show that human electrophysiology can be used to track information as it is brought back into working memory during retrieval from long-term memory. Specifically, we found that the retrieval of information from long-term memory was limited to just a few simple objects’ worth of information at once, and elicited a pattern of neurophysiological activity similar to that observed when people encode new information into working memory. Our findings suggest that working memory is where information is buffered when being retrieved from long-term memory and reconcile current theories of memory retrieval with classic notions about the memory mechanisms involved. PMID:28461479

History of concussion impacts electrophysiological correlates of working memory.

PubMed

Hudac, Caitlin M; Cortesa, Cathryn S; Ledwidge, Patrick S; Molfese, Dennis L

2017-10-10

Sports-related concussions occur in approximately 21% of college athletes with implications for long-term cognitive impairments in working memory. Working memory involves the capacity to maintain short-term information and integrate with higher-order cognitive processing for planning and behavior execution, critical skills for optimal cognitive and athletic performance. This study quantified working memory impairments in 36 American football college athletes (18-23years old) using event-related potentials (ERPs). Despite performing similarly in a standard 2-back working memory task, athletes with history of concussion exhibited larger P1 and P3 amplitudes compared to Controls. Concussion History group latencies were slower for the P1 and faster for the N2. Source estimation analyses indicated that previously concussed athletes engaged different brain regions compared to athletes with no concussion history. These findings suggest that ERPs may be a sensitive and objective measure to detect long-term cognitive consequences of concussion. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced dimension-specific visual working memory in grapheme-color synesthesia.

PubMed

Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-10-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme-color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

[Formula: see text]Working memory and attention in pediatric brain tumor patients treated with and without radiation therapy.

PubMed

Raghubar, Kimberly P; Mahone, E Mark; Yeates, Keith Owen; Cecil, Kim M; Makola, Monwabisi; Ris, M Douglas

2017-08-01

Children are at risk for cognitive difficulties following the diagnosis and treatment of a brain tumor. Longitudinal studies have consistently demonstrated declines on measures of intellectual functioning, and recently it has been proposed that specific neurocognitive processes underlie these changes, including working memory, processing speed, and attention. However, a fine-grained examination of the affected neurocognitive processes is required to inform intervention efforts. Radiation therapy (RT) impacts white matter integrity, likely affecting those cognitive processes supported by distributed neural networks. This study examined working memory and attention in children during the early delayed stages of recovery following surgical resection and RT. The participants included 27 children diagnosed with pediatric brain tumor, treated with (n = 12) or without (n = 15) RT, who completed experimental and standardized measures of working memory and attention (n-back and digit span tasks). Children treated with radiation performed less well than those who did not receive radiation on the n-back measure, though performance at the 0-back level was considerably poorer than would be expected for both groups, perhaps suggesting difficulties with more basic processes such as vigilance. Along these lines, marginal differences were noted on digit span forward. The findings are discussed with respect to models of attention and working memory, and the interplay between the two.

Preliminary findings of the effects of rivastigmine, an acetylcholinesterase inhibitor, on working memory in cocaine-dependent volunteers

PubMed Central

Mahoney, James J.; Kalechstein, Ari D.; Verrico, Christopher D.; Arnoudse, Nicholas M.; Shapiro, Benjamin A.; De La Garza, Richard

2015-01-01

Long-term cocaine use is a risk factor for the onset of neurocognitive impairment. This study sought to determine whether the cholinesterase inhibitor rivastigmine could improve neurocognitive performance in cocaine-dependent individuals. Cocaine-dependent individuals who were not seeking treatment at the time of enrollment in the study were randomly assigned to receive placebo (n = 16), rivastigmine 3 mg (n = 13), or rivastigmine 6 mg (n = 12). The baseline neurocognitive assessment, which included measures of attention/information processing (as measured by the Continuous Performance Task-II (CPT-II)), verbal learning/episodic memory (as measured by the Hopkins Verbal Learning Test-Revised (HVLT-R)), and working memory (as measured by the Dual N-Back Task), was conducted prior to the administration of study medication (Day 0). The follow-up assessment was conducted on Day 8 after the participants had received rivastigmine or placebo for 7 days (Day 2–8). Rivastigmine administration significantly improved performance on one measure of working memory span (mean n-back span). This study provides additional data showing that cocaine-associated neurocognitive impairment, specifically working memory deficits, can be remediated, at least to some degree. PMID:24239594

Preliminary findings of the effects of rivastigmine, an acetylcholinesterase inhibitor, on working memory in cocaine-dependent volunteers.

PubMed

Mahoney, James J; Kalechstein, Ari D; Verrico, Christopher D; Arnoudse, Nicholas M; Shapiro, Benjamin A; De La Garza, Richard

2014-04-03

Long-term cocaine use is a risk factor for the onset of neurocognitive impairment. This study sought to determine whether the cholinesterase inhibitor rivastigmine could improve neurocognitive performance in cocaine-dependent individuals. Cocaine-dependent individuals who were not seeking treatment at the time of enrollment in the study were randomly assigned to receive placebo (n=16), rivastigmine 3mg (n=13), or rivastigmine 6mg (n=12). The baseline neurocognitive assessment, which included measures of attention/information processing (as measured by the Continuous Performance Task-II (CPT-II)), verbal learning/episodic memory (as measured by the Hopkins Verbal Learning Test-Revised (HVLT-R)), and working memory (as measured by the Dual N-Back Task), was conducted prior to the administration of study medication (Day 0). The follow-up assessment was conducted on Day 8 after the participants had received rivastigmine or placebo for 7days (Day 2-8). Rivastigmine administration significantly improved performance on one measure of working memory span (mean n-back span). This study provides additional data showing that cocaine-associated neurocognitive impairment, specifically working memory deficits, can be remediated, at least to some degree. Copyright © 2013. Published by Elsevier Inc.

Task positive and default mode networks during a working memory in children with primary monosymptomatic nocturnal enuresis and healthy controls.

PubMed

Zhang, Kaihua; Ma, Jun; Lei, Du; Wang, Mengxing; Zhang, Jilei; Du, Xiaoxia

2015-10-01

Nocturnal enuresis is a common developmental disorder in children, and primary monosymptomatic nocturnal enuresis (PMNE) is the dominant subtype. This study investigated brain functional abnormalities that are specifically related to working memory in children with PMNE using function magnetic resonance imaging (fMRI) in combination with an n-back task. Twenty children with PMNE and 20 healthy children, group-matched for age and sex, participated in this experiment. Several brain regions exhibited reduced activation during the n-back task in children with PMNE, including the right precentral gyrus and the right inferior parietal lobule extending to the postcentral gyrus. Children with PMNE exhibited decreased cerebral activation in the task-positive network, increased task-related cerebral deactivation during a working memory task, and longer response times. Patients exhibited different brain response patterns to different levels of working memory and tended to compensate by greater default mode network deactivation to sustain normal working memory function. Our results suggest that children with PMNE have potential working memory dysfunction.

Liar, liar, working memory on fire: Investigating the role of working memory in childhood verbal deception.

PubMed

Alloway, Tracy Packiam; McCallum, Fiona; Alloway, Ross G; Hoicka, Elena

2015-09-01

The aim of the current study was to investigate the role of working memory in verbal deception in children. We presented 6- and 7-year-olds with a temptation resistance paradigm; they played a trivia game and were then given an opportunity to peek at the final answers on the back of a card. Measures of both verbal and visuospatial working memory were included. The good liars performed better on the verbal working memory test in both processing and recall compared with the bad liars. However, there was no difference in visuospatial working scores between good liars and bad liars. This pattern suggests that verbal working memory plays a role in processing and manipulating the multiple pieces of information involved in lie-telling. Copyright © 2015 Elsevier Inc. All rights reserved.

Histamine H3 receptor density is negatively correlated with neural activity related to working memory in humans.

PubMed

Ito, Takehito; Kimura, Yasuyuki; Seki, Chie; Ichise, Masanori; Yokokawa, Keita; Kawamura, Kazunori; Takahashi, Hidehiko; Higuchi, Makoto; Zhang, Ming-Rong; Suhara, Tetsuya; Yamada, Makiko

2018-06-14

The histamine H 3 receptor is regarded as a drug target for cognitive impairments in psychiatric disorders. H 3 receptors are expressed in neocortical areas, including the prefrontal cortex, the key region of cognitive functions such as working memory. However, the role of prefrontal H 3 receptors in working memory has not yet been clarified. Therefore, using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) techniques, we aimed to investigate the association between the neural activity of working memory and the density of H 3 receptors in the prefrontal cortex. Ten healthy volunteers underwent both fMRI and PET scans. The N-back task was used to assess the neural activities related to working memory. H 3 receptor density was measured with the selective PET radioligand [ 11 C] TASP457. The neural activity of the right dorsolateral prefrontal cortex during the performance of the N-back task was negatively correlated with the density of H 3 receptors in this region. Higher neural activity of working memory was associated with lower H 3 receptor density in the right dorsolateral prefrontal cortex. This finding elucidates the role of H 3 receptors in working memory and indicates the potential of H 3 receptors as a therapeutic target for the cognitive impairments associated with neuropsychiatric disorders.

The catechol-O-methyltransferase (COMT) Val158Met genotype modulates working memory-related dorsolateral prefrontal response and performance in bipolar disorder.

PubMed

Miskowiak, K W; Kjaerstad, H L; Støttrup, M M; Svendsen, A M; Demant, K M; Hoeffding, L K; Werge, T M; Burdick, K E; Domschke, K; Carvalho, A F; Vieta, E; Vinberg, M; Kessing, L V; Siebner, H R; Macoveanu, J

2017-05-01

Cognitive dysfunction affects a substantial proportion of patients with bipolar disorder (BD), and genetic-imaging paradigms may aid in the elucidation of mechanisms implicated in this symptomatic domain. The Val allele of the functional Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene is associated with reduced prefrontal cortex dopamine and exaggerated working memory-related prefrontal activity. This functional magnetic resonance imaging (fMRI) study investigated for the first time whether the COMT Val158Met genotype modulates prefrontal activity during spatial working memory in BD. Sixty-four outpatients with BD in full or partial remission were stratified according to COMT Val158Met genotype (ValVal [n=13], ValMet [n=34], and MetMet [n=17]). The patients completed a spatial n-back working memory task during fMRI and the Cambridge Neuropsychological Test Automated Battery (CANTAB) Spatial Working Memory test outside the scanner. During high working memory load (2-back vs 1-back), Val homozygotes displayed decreased activity relative to ValMet individuals, with Met homozygotes displaying intermediate levels of activity in the right dorsolateral prefrontal cortex (dlPFC) (P=.016). Exploratory whole-brain analysis revealed a bilateral decrease in working memory-related dlPFC activity in the ValVal group vs the ValMet group which was not associated with differences in working memory performance during fMRI. Outside the MRI scanner, Val carriers performed worse in the CANTAB Spatial Working Memory task than Met homozygotes (P≤.006), with deficits being most pronounced in Val homozygotes. The association between Val allelic load, dlPFC activity and WM impairment points to a putative role of aberrant PFC dopamine tonus in the cognitive impairments in BD. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Effects of Theta and Gamma tACS on Working Memory and Electrophysiology

PubMed Central

Pahor, Anja; Jaušovec, Norbert

2018-01-01

A single blind sham-controlled study was conducted to explore the effects of theta and gamma transcranial alternating current stimulation (tACS) on offline performance on working memory tasks. In order to systematically investigate how specific parameters of tACS affect working memory, we manipulated the frequency of stimulation (theta frequency vs. gamma frequency), the type of task (n-back vs. change detection task) and the content of the tasks (verbal vs. figural stimuli). A repeated measures design was used that consisted of three sessions: theta tACS, gamma tACS and sham tACS. In total, four experiments were conducted which differed only with respect to placement of tACS electrodes (bilateral frontal, bilateral parietal, left fronto-parietal and right-fronto parietal). Healthy female students (N = 72) were randomly assigned to one of these groups, hence we were able to assess the efficacy of theta and gamma tACS applied over different brain areas, contrasted against sham stimulation. The pre-post/sham resting electroencephalogram (EEG) analysis showed that theta tACS significantly affected theta amplitude, whereas gamma tACS had no significant effect on EEG amplitude in any of the frequency bands of interest. Gamma tACS did not significantly affect working memory performance compared to sham, and theta tACS led to inconsistent changes in performance on the n-back tasks. Active theta tACS significantly affected P3 amplitude and latency during performance on the n-back tasks in the bilateral parietal and right-fronto parietal protocols. PMID:29375347

Brain Activation and Deactivation during Location and Color Working Memory Tasks in 11-13-Year-Old Children

ERIC Educational Resources Information Center

Vuontela, Virve; Steenari, Maija-Riikka; Aronen, Eeva T.; Korvenoja, Antti; Aronen, Hannu J.; Carlson, Synnove

2009-01-01

Using functional magnetic resonance imaging (fMRI) and n-back tasks we investigated whether, in 11-13-year-old children, spatial (location) and nonspatial (color) information is differentially processed during visual attention (0-back) and working memory (WM) (2-back) tasks and whether such cognitive task performance, compared to a resting state,…

Monitoring of prefrontal cortex activation during verbal n-back task with 24-channel functional NIRS imager

NASA Astrophysics Data System (ADS)

Li, Chengjun; Gong, Hui; Gan, Zhuo; Luo, Qingming

2005-01-01

Human prefrontal cortex (PFC) helps mediate working memory (WM), a system that is used for temporary storage and manipulation of information and is involved with many higher-level cognitive functions. Here, we report a functional near-infrared spectroscopy (NIRS) study on the PFC activation caused by verbal WM task. For investigating the effect of memory load on brain activation, we adopted the "n-back" task in which subjects must decide for each present letter whether it matches the letter presented n items back in sequence. 27 subjects (ages 18-24, 13 females) participated in the work. Concentration changes in oxy-Hb (HbO2), deoxy-Hb (Hb), and total-Hb (HbT) in the subjects" prefrontal cortex were monitored by a 24-channel functional NIRS imager. The cortical activations and deactivations were found in left ventrolateral PFC and bilateral dorsolateral PFC. As memory load increased, subjects showed poorer behavioral performance as well as monotonically increasing magnitudes of the activations and deactivations in PFC.

Looking inward and back: Real-time monitoring of visual working memories.

PubMed

Suchow, Jordan W; Fougnie, Daryl; Alvarez, George A

2017-04-01

Confidence in our memories is influenced by many factors, including beliefs about the perceptibility or memorability of certain kinds of objects and events, as well as knowledge about our skill sets, habits, and experiences. Notoriously, our knowledge and beliefs about memory can lead us astray, causing us to be overly confident in eyewitness testimony or to overestimate the frequency of recent experiences. Here, using visual working memory as a case study, we stripped away all these potentially misleading cues, requiring observers to make confidence judgments by directly assessing the quality of their memory representations. We show that individuals can monitor the status of information in working memory as it degrades over time. Our findings suggest that people have access to information reflecting the existence and quality of their working memories, and furthermore, that they can use this information to guide their behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Working Memory Load and Reminder Effect on Event-Based Prospective Memory of High- and Low-Achieving Students in Math.

PubMed

Chen, Youzhen; Lian, Rong; Yang, Lixian; Liu, Jianrong; Meng, Yingfang

The effects of working memory (WM) demand and reminders on an event-based prospective memory (PM) task were compared between students with low and high achievement in math. WM load (1- and 2-back tasks) was manipulated as a within-subject factor and reminder (with or without reminder) as a between-subject factor. Results showed that high-achieving students outperformed low-achieving students on all PM and n-back tasks. Use of a reminder improved PM performance and thus reduced prospective interference; the performance of ongoing tasks also improved for all students. Both PM and n-back performances in low WM load were better than in high WM load. High WM load had more influence on low-achieving students than on high-achieving students. Results suggest that low-achieving students in math were weak at PM and influenced more by high WM load. Thus, it is important to train these students to set up an obvious reminder for their PM and improve their WM.

Effects of Cogmed working memory training on cognitive performance.

PubMed

Etherton, Joseph L; Oberle, Crystal D; Rhoton, Jayson; Ney, Ashley

2018-04-16

Research on the cognitive benefits of working memory training programs has produced inconsistent results. Such research has frequently used laboratory-specific training tasks, or dual-task n-back training. The current study used the commercial Cogmed Working Memory (WM) Training program, involving several different training tasks involving visual and auditory input. Healthy college undergraduates were assigned to either the full Cogmed training program of 25, 40-min training sessions; an abbreviated Cogmed program of 25, 20-min training sessions; or a no-contact control group. Pretest and posttest measures included multiple measures of attention, working memory, fluid intelligence, and executive functions. Although improvement was observed for the full training group for a digit span task, no training-related improvement was observed for any of the other measures. Results of the study suggest that WM training does not improve performance on unrelated tasks or enhance other cognitive abilities.

Dual n-back training increases the capacity of the focus of attention.

PubMed

Lilienthal, Lindsey; Tamez, Elaine; Shelton, Jill Talley; Myerson, Joel; Hale, Sandra

2013-02-01

Working memory (WM) training has been reported to benefit abilities as diverse as fluid intelligence (Jaeggi et al., Proceedings of the National Academy of Sciences of the United States of America, 105:6829-6833, 2008) and reading comprehension (Chein & Morrison, Psychonomic Bulletin & Review, 17:193-199, 2010), but transfer is not always observed (for reviews, see Morrison & Chein, Psychonomics Bulletin & Review, 18:46-60, 2011; Shipstead et al., Psychological Bulletin, 138:628-654, 2012). In contrast, recent WM training studies have consistently reported improvement on the trained tasks. The basis for these training benefits has received little attention, however, and it is not known which WM components and/or processes are being improved. Therefore, the goal of the present study was to investigate five possible mechanisms underlying the effects of adaptive dual n-back training on working memory (i.e., improvements in executive attention, updating, and focus switching, as well as increases in the capacity of the focus of attention and short-term memory). In addition to a no-contact control group, the present study also included an active control group whose members received nonadaptive training on the same task. All three groups showed significant improvements on the n-back task from pretest to posttest, but adaptive training produced larger improvements than did nonadaptive training, which in turn produced larger improvements than simply retesting. Adaptive, but not nonadaptive, training also resulted in improvements on an untrained running span task that measured the capacity of the focus of attention. No other differential improvements were observed, suggesting that increases in the capacity of the focus of attention underlie the benefits of adaptive dual n-back training.

Psychotic Experiences, Working Memory, and the Developing Brain: A Multimodal Neuroimaging Study

PubMed Central

Fonville, Leon; Cohen Kadosh, Kathrin; Drakesmith, Mark; Dutt, Anirban; Zammit, Stanley; Mollon, Josephine; Reichenberg, Abraham; Lewis, Glyn; Jones, Derek K.; David, Anthony S.

2015-01-01

Psychotic experiences (PEs) occur in the general population, especially in children and adolescents, and are associated with poor psychosocial outcomes, impaired cognition, and increased risk of transition to psychosis. It is unknown how the presence and persistence of PEs during early adulthood affects cognition and brain function. The current study assessed working memory as well as brain function and structure in 149 individuals, with and without PEs, drawn from a population cohort. Observer-rated PEs were classified as persistent or transient on the basis of longitudinal assessments. Working memory was assessed using the n-back task during fMRI. Dynamic causal modeling (DCM) was used to characterize frontoparietal network configuration and voxel-based morphometry was utilized to examine gray matter. Those with persistent, but not transient, PEs performed worse on the n-back task, compared with controls, yet showed no significant differences in regional brain activation or brain structure. DCM analyses revealed greater emphasis on frontal connectivity within a frontoparietal network in those with PEs compared with controls. We propose that these findings portray an altered configuration of working memory function in the brain, potentially indicative of an adaptive response to atypical development associated with the manifestation of PEs. PMID:26286920

Dissociation of working memory impairments and attention-deficit/hyperactivity disorder in the brain.

PubMed

Mattfeld, Aaron T; Whitfield-Gabrieli, Susan; Biederman, Joseph; Spencer, Thomas; Brown, Ariel; Fried, Ronna; Gabrieli, John D E

2016-01-01

Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working memory, but accumulating clinical evidence suggests a dissociation between ADHD and executive dysfunctions. This study examined whether ADHD and working memory capacity are behaviorally and neurobiologically separable using functional magnetic resonance imaging (fMRI). Participants diagnosed with ADHD in childhood who subsequently remitted or persisted in their diagnosis as adults were characterized at follow-up in adulthood as either impaired or unimpaired in spatial working memory relative to controls who never had ADHD. ADHD participants with impaired spatial working memory performed worse than controls and ADHD participants with unimpaired working memory during an n-back working memory task while being scanned. Both controls and ADHD participants with unimpaired working memory exhibited significant linearly increasing activation in the inferior frontal junction, precuneus, lingual gyrus, and cerebellum as a function of working-memory load, and these activations did not differ significantly between these groups. ADHD participants with impaired working memory exhibited significant hypoactivation in the same regions, which was significantly different than both control participants and ADHD participants with unimpaired working memory. These findings support both a behavioral and neurobiological dissociation between ADHD and working memory capacity.

Dissociation of working memory impairments and attention-deficit/hyperactivity disorder in the brain

PubMed Central

Mattfeld, Aaron T.; Whitfield-Gabrieli, Susan; Biederman, Joseph; Spencer, Thomas; Brown, Ariel; Fried, Ronna; Gabrieli, John D.E.

2015-01-01

Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working memory, but accumulating clinical evidence suggests a dissociation between ADHD and executive dysfunctions. This study examined whether ADHD and working memory capacity are behaviorally and neurobiologically separable using functional magnetic resonance imaging (fMRI). Participants diagnosed with ADHD in childhood who subsequently remitted or persisted in their diagnosis as adults were characterized at follow-up in adulthood as either impaired or unimpaired in spatial working memory relative to controls who never had ADHD. ADHD participants with impaired spatial working memory performed worse than controls and ADHD participants with unimpaired working memory during an n-back working memory task while being scanned. Both controls and ADHD participants with unimpaired working memory exhibited significant linearly increasing activation in the inferior frontal junction, precuneus, lingual gyrus, and cerebellum as a function of working-memory load, and these activations did not differ significantly between these groups. ADHD participants with impaired working memory exhibited significant hypoactivation in the same regions, which was significantly different than both control participants and ADHD participants with unimpaired working memory. These findings support both a behavioral and neurobiological dissociation between ADHD and working memory capacity. PMID:26900567

What is working memory capacity, and how can we measure it?

PubMed Central

Wilhelm, Oliver; Hildebrandt, Andrea; Oberauer, Klaus

2013-01-01

A latent variable study examined whether different classes of working-memory tasks measure the same general construct of working-memory capacity (WMC). Data from 270 subjects were used to examine the relationship between Binding, Updating, Recall-N-back, and Complex Span tasks, and the relations of WMC with secondary memory measures, indicators of cognitive control from two response-conflict paradigms (Simon task and Eriksen flanker task), and fluid intelligence. Confirmatory factor analyses support the concept of a general WMC factor. Results from structural-equation modeling show negligible relations of WMC with response-conflict resolution, and very strong relations of WMC with secondary memory and fluid intelligence. The findings support the hypothesis that individual differences in WMC reflect the ability to build, maintain and update arbitrary bindings. PMID:23898309

Neural correlates of working memory performance in primary insomnia.

PubMed

Drummond, Sean P A; Walker, Matthew; Almklov, Erin; Campos, Manuel; Anderson, Dane E; Straus, Laura D

2013-09-01

To examine neural correlates of working memory performance in patients with primary insomnia (PIs) compared with well-matched good sleepers (GSs). Twenty-five PIs and 25 GSs underwent functional MRI while performing an N-back working memory task. VA hospital sleep laboratory and University-based functional imaging center. 25 PIs, 25 GSs. N/A. Although PIs did not differ from GSs in cognitive performance, PIs showed the expected differences from GSs in both self-reported and objective sleep measures. PIs, relative to GSs, showed reduced activation of task-related working memory regions. This manifested both as an overall reduction in activation of task-related regions and specifically as reduced modulation of right dorsolateral prefrontal cortex with increasing task difficulty. Similarly, PIs showed reduced modulation (i.e., reduced deactivation) of default mode regions with increasing task difficulty, relative to GSs. However, PIs showed intact performance. These data establish a profile of abnormal neural function in primary insomnia, reflected both in reduced engagement of task-appropriate brain regions and an inability to modulate task-irrelevant (i.e., default mode) brain areas during working memory performance. These data have implications for better understanding the neuropathophysiology of the well established, yet little understood, discrepancy between ubiquitous subjective cognitive complaints in primary insomnia and the rarely found objective deficits during testing.

Regulation of Cognitive Resources During an N-Back Task in Youth-Onset Psychosis and Attention-Deficit/Hyperactivity Disorder (ADHD)

PubMed Central

Karatekin, Canan; Bingham, Christopher; White, Tonya

2009-01-01

The goals of the current study were to use behavioral and pupillary measures to examine working memory on a spatial n-back task in 8-20-year-olds with youth-onset psychosis or ADHD (Combined subtype) and healthy controls to determine the contribution of different attentional factors to spatial working memory impairments, and to examine if age-related changes in performance differed across groups. Although both clinical groups had lower perceptual sensitivity on both 0- and 1-back, there was no evidence of an impairment in spatial working memory or differential order effects on the 0-back. Instead, results suggest that both clinical groups had difficulty encoding the stimuli. They also appeared to have difficulty maintaining attention and/or readiness to respond, and, to a lesser extent, recruiting resources on a trial-to-trial basis. It is likely that these attentional problems prevented the clinical groups from encoding the stimuli effectively and contributed to their general performance deficits. PMID:19427339

Functional Connectivity of Cognitive Brain Networks in Schizophrenia during a Working Memory Task

PubMed Central

Godwin, Douglass; Ji, Andrew; Kandala, Sridhar; Mamah, Daniel

2017-01-01

Task-based connectivity studies facilitate the understanding of how the brain functions during cognition, which is commonly impaired in schizophrenia (SZ). Our aim was to investigate functional connectivity during a working memory task in SZ. We hypothesized that the task-negative (default mode) network and the cognitive control (frontoparietal) network would show dysconnectivity. Twenty-five SZ patient and 31 healthy control scans were collected using the customized 3T Siemens Skyra MRI scanner, previously used to collect data for the Human Connectome Project. Blood oxygen level dependent signal during the 0-back and 2-back conditions were extracted within a network-based parcelation scheme. Average functional connectivity was assessed within five brain networks: frontoparietal (FPN), default mode (DMN), cingulo-opercular (CON), dorsal attention (DAN), and ventral attention network; as well as between the DMN or FPN and other networks. For within-FPN connectivity, there was a significant interaction between n-back condition and group (p = 0.015), with decreased connectivity at 0-back in SZ subjects compared to controls. FPN-to-DMN connectivity also showed a significant condition × group effect (p = 0.003), with decreased connectivity at 0-back in SZ. Across groups, connectivity within the CON and DAN were increased during the 2-back condition, while DMN connectivity with either CON or DAN were decreased during the 2-back condition. Our findings support the role of the FPN, CON, and DAN in working memory and indicate that the pattern of FPN functional connectivity differs between SZ patients and control subjects during the course of a working memory task. PMID:29312020

Functional Connectivity of Cognitive Brain Networks in Schizophrenia during a Working Memory Task.

PubMed

Godwin, Douglass; Ji, Andrew; Kandala, Sridhar; Mamah, Daniel

2017-01-01

Task-based connectivity studies facilitate the understanding of how the brain functions during cognition, which is commonly impaired in schizophrenia (SZ). Our aim was to investigate functional connectivity during a working memory task in SZ. We hypothesized that the task-negative (default mode) network and the cognitive control (frontoparietal) network would show dysconnectivity. Twenty-five SZ patient and 31 healthy control scans were collected using the customized 3T Siemens Skyra MRI scanner, previously used to collect data for the Human Connectome Project. Blood oxygen level dependent signal during the 0-back and 2-back conditions were extracted within a network-based parcelation scheme. Average functional connectivity was assessed within five brain networks: frontoparietal (FPN), default mode (DMN), cingulo-opercular (CON), dorsal attention (DAN), and ventral attention network; as well as between the DMN or FPN and other networks. For within-FPN connectivity, there was a significant interaction between n -back condition and group ( p  = 0.015), with decreased connectivity at 0-back in SZ subjects compared to controls. FPN-to-DMN connectivity also showed a significant condition × group effect ( p  = 0.003), with decreased connectivity at 0-back in SZ. Across groups, connectivity within the CON and DAN were increased during the 2-back condition, while DMN connectivity with either CON or DAN were decreased during the 2-back condition. Our findings support the role of the FPN, CON, and DAN in working memory and indicate that the pattern of FPN functional connectivity differs between SZ patients and control subjects during the course of a working memory task.

Neural Effects of Short-Term Training on Working Memory

PubMed Central

Buschkuehl, Martin; Garcia, Luis Hernandez; Jaeggi, Susanne M.; Bernard, Jessica A.; Jonides, John

2014-01-01

Working memory training has been the focus of intense research interest. Despite accumulating behavioral work, knowledge about the neural mechanisms underlying training effects is scarce. Here we show that seven days of training on an n back task lead to substantial performance improvements in the trained task; furthermore, the experimental group shows cross modal transfer as compared to an active control group. In addition, there are two neural effects that emerged as a function of training: first, increased perfusion during task performance in selected regions, reflecting a neural response to cope with high task demand; second, increased blood flow at rest in regions where training effects were apparent. We also found that perfusion at rest was correlated with task proficiency, probably reflecting an improved neural readiness to perform. Our findings are discussed within the context of the available neuroimaging literature on n back training. PMID:24496717

DRD2/CHRNA5 Interaction on Prefrontal Biology and Physiology during Working Memory

PubMed Central

Fazio, Leonardo; D'Ambrosio, Enrico; Gelao, Barbara; Tomasicchio, Aldo; Selvaggi, Pierluigi; Taurisano, Paolo; Quarto, Tiziana; Masellis, Rita; Rampino, Antonio; Caforio, Grazia; Popolizio, Teresa; Blasi, Giuseppe; Sadee, Wolfgang; Bertolino, Alessandro

2014-01-01

Background Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560) and in the nicotinic receptor α5 gene (CHRNA5, rs16969968) on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. Methods A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T) and CHNRA5 rs16969968 (G>A) on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. Results We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. Conclusions The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5. PMID:24819610

DRD2/CHRNA5 interaction on prefrontal biology and physiology during working memory.

PubMed

Di Giorgio, Annabella; Smith, Ryan M; Fazio, Leonardo; D'Ambrosio, Enrico; Gelao, Barbara; Tomasicchio, Aldo; Selvaggi, Pierluigi; Taurisano, Paolo; Quarto, Tiziana; Masellis, Rita; Rampino, Antonio; Caforio, Grazia; Popolizio, Teresa; Blasi, Giuseppe; Sadee, Wolfgang; Bertolino, Alessandro

2014-01-01

Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560) and in the nicotinic receptor α5 gene (CHRNA5, rs16969968) on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T) and CHNRA5 rs16969968 (G>A) on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5.

Anxiety and working memory capacity: A meta-analysis and narrative review.

PubMed

Moran, Tim P

2016-08-01

Cognitive deficits are now widely recognized to be an important component of anxiety. In particular, anxiety is thought to restrict the capacity of working memory by competing with task-relevant processes. The evidence for this claim, however, has been mixed. Although some studies have found restricted working memory in anxiety, others have not. Within studies that have found impairments, there is little agreement regarding the boundary conditions of the anxiety/WMC association. The aim of this review is to critically evaluate the evidence for anxiety-related deficits in working memory capacity. First, a meta-analysis of 177 samples (N = 22,061 individuals) demonstrated that self-reported measures of anxiety are reliably related to poorer performance on measures of working memory capacity (g = -.334, p < 10-29). This finding was consistent across complex span (e.g., OSPAN; g = -.342, k = 30, N = 3,196, p = .000001), simple span (e.g., digit span; g = -.318, k = 127, N = 17,547, p < 10-17), and dynamic span tasks (e.g., N-Back; g = -.437, k = 20, N = 1,318, p = .000003). Second, a narrative review of the literature revealed that anxiety, whether self-reported or experimentally induced, is related to poorer performance across a wide variety of tasks. Finally, the review identified a number of methodological limitations common in the literature as well as avenues for future research. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls

PubMed Central

Mackenzie, Michael J.; Zuniga, Krystle E.; Raine, Lauren B.; Awick, Elizabeth A.; Hillman, Charles H.; Kramer, Arthur F.

2016-01-01

Abstract Background: This study examined the effects of cardiorespiratory fitness, heart rate recovery, and physical activity on working memory in breast cancer survivors and age-matched controls. Method: Using a case-control design, 32 women who had received a breast cancer diagnosis and completed primary treatment within the past 36-months (11 radiation only; 21 chemotherapy) and 30 age-matched women with no previous cancer diagnosis completed a n-back continuous performance task commonly used as an assessment of working memory. In addition, cardiorespiratory fitness and heart rate recovery were measured during a submaximal graded exercise test and physical activity was measured using 7-days of accelerometer monitoring. Results: Breast cancer survivors who had received chemotherapy had poorer heart rate recovery (p = .010) and engaged in less physical activity than women who had received radiation only (p = .004) or non-cancer controls (p = .029). Cancer treatment (radiation; chemotherapy) predicted differences in reaction times on the 1-back working memory task (p = .029). However, more rapid heart rate recovery predicted shorter reaction times on the 1-back task in the age-matched control group (p = .002). All participants with greater cardiorespiratory fitness displayed greater accuracy independent of disease status on the 1-back task (p = .017). No significant group differences in reaction times were observed for 2-back target trials between breast cancer survivors and controls. However, greater total physical activity predicted shorter reaction times in breast cancer survivors (radiation, chemotherapy) on the 2-back task (p = .014). In addition, all participants who exhibited more rapid heart rate recovery demonstrated better greater accuracy regardless of disease status (p = .013). Conclusion: These findings support differences in physical activty participation, heart rate recovery, and 1- and 2-back working memory reaction

Paging memory from random access memory to backing storage in a parallel computer

DOEpatents

Archer, Charles J; Blocksome, Michael A; Inglett, Todd A; Ratterman, Joseph D; Smith, Brian E

2013-05-21

Paging memory from random access memory (`RAM`) to backing storage in a parallel computer that includes a plurality of compute nodes, including: executing a data processing application on a virtual machine operating system in a virtual machine on a first compute node; providing, by a second compute node, backing storage for the contents of RAM on the first compute node; and swapping, by the virtual machine operating system in the virtual machine on the first compute node, a page of memory from RAM on the first compute node to the backing storage on the second compute node.

The ties to unbind: age-related differences in feature (un)binding in working memory for emotional faces

PubMed Central

Pehlivanoglu, Didem; Jain, Shivangi; Ariel, Robert; Verhaeghen, Paul

2014-01-01

In the present study, we investigated age-related differences in the processing of emotional stimuli. Specifically, we were interested in whether older adults would show deficits in unbinding emotional expression (i.e., either no emotion, happiness, anger, or disgust) from bound stimuli (i.e., photographs of faces expressing these emotions), as a hyper-binding account of age-related differences in working memory would predict. Younger and older adults completed different N-Back tasks (side-by-side 0-Back, 1-Back, 2-Back) under three conditions: match/mismatch judgments based on either the identity of the face (identity condition), the face’s emotional expression (expression condition), or both identity and expression of the face (both condition). The two age groups performed more slowly and with lower accuracy in the expression condition than in the both condition, indicating the presence of an unbinding process. This unbinding effect was more pronounced in older adults than in younger adults, but only in the 2-Back task. Thus, older adults seemed to have a specific deficit in unbinding in working memory. Additionally, no age-related differences were found in accuracy in the 0-Back task, but such differences emerged in the 1-Back task, and were further magnified in the 2-Back task, indicating independent age-related differences in attention/STM and working memory. Pupil dilation data confirmed that the attention/STM version of the task (1-Back) is more effortful for older adults than younger adults. PMID:24795660

The ties to unbind: age-related differences in feature (un)binding in working memory for emotional faces.

PubMed

Pehlivanoglu, Didem; Jain, Shivangi; Ariel, Robert; Verhaeghen, Paul

2014-01-01

In the present study, we investigated age-related differences in the processing of emotional stimuli. Specifically, we were interested in whether older adults would show deficits in unbinding emotional expression (i.e., either no emotion, happiness, anger, or disgust) from bound stimuli (i.e., photographs of faces expressing these emotions), as a hyper-binding account of age-related differences in working memory would predict. Younger and older adults completed different N-Back tasks (side-by-side 0-Back, 1-Back, 2-Back) under three conditions: match/mismatch judgments based on either the identity of the face (identity condition), the face's emotional expression (expression condition), or both identity and expression of the face (both condition). The two age groups performed more slowly and with lower accuracy in the expression condition than in the both condition, indicating the presence of an unbinding process. This unbinding effect was more pronounced in older adults than in younger adults, but only in the 2-Back task. Thus, older adults seemed to have a specific deficit in unbinding in working memory. Additionally, no age-related differences were found in accuracy in the 0-Back task, but such differences emerged in the 1-Back task, and were further magnified in the 2-Back task, indicating independent age-related differences in attention/STM and working memory. Pupil dilation data confirmed that the attention/STM version of the task (1-Back) is more effortful for older adults than younger adults.

The effects of working memory resource depletion and training on sensorimotor adaptation

PubMed Central

Anguera, Joaquin A.; Bernard, Jessica A.; Jaeggi, Susanne M.; Buschkuehl, Martin; Benson, Bryan L.; Jennett, Sarah; Humfleet, Jennifer; Reuter-Lorenz, Patricia; Jonides, John; Seidler, Rachael D.

2011-01-01

We have recently demonstrated that visuospatial working memory performance predicts the rate of motor skill learning, particularly during the early phase of visuomotor adaptation. Here, we follow up these correlational findings with direct manipulations of working memory resources to determine the impact on visuomotor adaptation, a form of motor learning. We conducted two separate experiments. In the first one, we used a resource depletion strategy to investigate whether the rate of early visuomotor adaptation would be negatively affected by fatigue of spatial working memory resources. In the second study, we employed a dual n-back task training paradigm that has been shown to result in transfer effects [1] over five weeks to determine whether training-related improvements would boost the rate of early visuomotor adaptation. The depletion of spatial working memory resources negatively affected the rate of early visuomotor adaptation. However, enhancing working memory capacity via training did not lead to improved rates of visuomotor adaptation, suggesting that working memory capacity may not be the factor limiting maximal rate of visuomotor adaptation in young adults. These findings are discussed from a resource limitation / capacity framework with respect to current views of motor learning. PMID:22155489

Association Between Sluggish Cognitive Tempo Symptoms and Attentional Network and Working Memory in Primary Schoolchildren.

PubMed

Camprodon-Rosanas, E; Ribas-Fitó, N; Batlle, S; Persavento, C; Alvarez-Pedrerol, M; Sunyer, J; Forns, J

2017-04-01

Few consistent data are available in relation to the cognitive and neuropsychological processes involved in sluggish cognitive tempo (SCT) symptoms. The objective of this study was to determine the association of working memory and attentional networks with SCT symptoms in primary schoolchildren. The participants were schoolchildren aged 7 to 10 years ( n = 183) from primary schools in Catalonia (Spain). All the participants completed a working memory task (n-back) and an attentional network task (ANT). Their parents completed an SCT-Child Behavior Checklist self-report and a questionnaire concerning sociodemographic variables. Teachers of the participants provided information on ADHD symptoms and learning determinants. SCT symptoms were correlated with lower scores in both the n-back and ANT. In multivariate regression analysis, SCT symptoms were associated with slower hit reaction times from the ANT. Our results suggest that SCT symptoms are associated with a neuropsychological profile that is different from the classical ADHD profile and characterized by slower reaction times.

The relationship between sustained inattentional blindness and working memory capacity.

PubMed

Beanland, Vanessa; Chan, Esther Hiu Chung

2016-04-01

Inattentional blindness, whereby observers fail to detect unexpected stimuli, has been robustly demonstrated in a range of situations. Originally research focused primarily on how stimulus characteristics and task demands affect inattentional blindness, but increasingly studies are exploring the influence of observer characteristics on the detection of unexpected stimuli. It has been proposed that individual differences in working memory capacity predict inattentional blindness, on the assumption that higher working memory capacity confers greater attentional capacity for processing unexpected stimuli. Unfortunately, empirical investigations of the association between inattentional blindness and working memory capacity have produced conflicting findings. To help clarify this relationship, we examined the relationship between inattentional blindness and working memory capacity in two samples (Ns = 195, 147) of young adults. We used three common variants of sustained inattentional blindness tasks, systematically manipulating the salience of the unexpected stimulus and primary task practice. Working memory capacity, measured by automated operation span (both Experiments 1 & 2) and N-back (Experiment 1 only) tasks, did not predict detection of the unexpected stimulus in any of the inattentional blindness tasks tested. Together with previous research, this undermines claims that there is a robust relationship between inattentional blindness and working memory capacity. Rather, it appears that any relationship between inattentional blindness and working memory is either too small to have practical significance or is moderated by other factors and consequently varies with attributes such as the sample characteristics within a given study.

Is the Focus of Attention in Working Memory Expanded Through Practice?

ERIC Educational Resources Information Center

Oberauer, Klaus

2006-01-01

This article reinvestigates the claim by P. Verhaeghen, J. Cerella, and C. Basak (2004) that the focus of attention in working memory can be expanded from 1 to 4 items through practice. Using a modified version of Verhaeghen et al.'s n-back paradigm, Experiments 1 and 3 show that a signature of a one-item focus, the time cost for switching between…

Dopaminergic contributions to working memory-related brain activation in postmenopausal women

PubMed Central

Dumas, Julie A.; Filippi, Christopher G.; Newhouse, Paul A.; Naylor, Magdalena R.

2016-01-01

Objective The current study examined the effects of pharmacologic dopaminergic manipulations on working memory-related brain activation in postmenopausal women to further understand the neurochemistry underlying cognition after menopause. Method Eighteen healthy postmenopausal women, mean age 55.21 years, completed three study days with dopaminergic drug challenges during which they performed an fMRI visual verbal N-back test of working memory. Acute stimulation with 1.25 mg oral D2 agonist bromocriptine, acute blockade with 1.5 mg oral haloperidol, and matching placebo were administered randomly and blindly on three study days. Results We found that dopaminergic stimulation increased activation primarily in the posterior regions of the working memory network compared to dopaminergic blockade using a whole brain cluster-level corrected analysis. The dopaminergic medications did not affect working memory performance. Conclusions Patterns of increased BOLD signal activation after dopaminergic stimulation were found in this study in posterior brain regions with no effect on working memory performance. Further studies should examine specific dopaminergic contributions to brain functioning in healthy postmenopausal women in order to determine the effects of the increased brain activation on cognition and behavior. PMID:27676634

Dopaminergic contributions to working memory-related brain activation in postmenopausal women.

PubMed

Dumas, Julie A; Filippi, Christopher G; Newhouse, Paul A; Naylor, Magdalena R

2017-02-01

The current study examined the effects of pharmacologic dopaminergic manipulations on working memory-related brain activation in postmenopausal women to further understand the neurochemistry underlying cognition after menopause. Eighteen healthy postmenopausal women, mean age 55.21 years, completed three study days with dopaminergic drug challenges during which they performed a functional magnetic resonance imaging visual verbal N-back test of working memory. Acute stimulation with 1.25 mg oral D2 agonist bromocriptine, acute blockade with 1.5 mg oral haloperidol, and matching placebo were administered randomly and blindly on three study days. We found that dopaminergic stimulation increased activation primarily in the posterior regions of the working memory network compared with dopaminergic blockade using a whole brain cluster-level corrected analysis. The dopaminergic medications did not affect working memory performance. Patterns of increased blood-oxygen-level dependent signal activation after dopaminergic stimulation were found in this study in posterior brain regions with no effect on working memory performance. Further studies should examine specific dopaminergic contributions to brain functioning in healthy postmenopausal women to determine the effects of the increased brain activation on cognition and behavior.

Subtle persistent working memory and selective attention deficits in women with premenstrual syndrome.

PubMed

Slyepchenko, Anastasiya; Lokuge, Sonali; Nicholls, Brianne; Steiner, Meir; Hall, Geoffrey B C; Soares, Claudio N; Frey, Benicio N

2017-03-01

As a recurrent, cyclical phenomenon, premenstrual syndrome (PMS) affects a significant proportion of women of the reproductive age, and leads to regular monthly days of functional impairment. Symptoms of PMS include somatic and psychological symptoms, such as headaches, sleep disturbances, social withdrawal and mood changes, during the late luteal phase of the menstrual cycle, which alleviate during the follicular phase. This study investigated neurocognitive functioning in women with moderate to severe PMS symptoms (n=13) compared to women with mild/no PMS (n=27) through administration of a battery of neuropsychological tests during the asymptomatic follicular phase of the menstrual cycle. Relative to women with mild/no PMS symptoms, women with moderate to severe PMS showed significantly poorer accuracy and more errors of omission on the N-0-back, as well as more errors of omission on the N-2-back task, indicating the presence of impairment in selective attention and working memory. This study provides evidence of persistent, subtle working memory and selective attention difficulties in those with moderate to severe PMS during the follicular phase of the menstrual cycle. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Failure of Working Memory Training to Enhance Cognition or Intelligence

PubMed Central

Thompson, Todd W.; Waskom, Michael L.; Garel, Keri-Lee A.; Cardenas-Iniguez, Carlos; Reynolds, Gretchen O.; Winter, Rebecca; Chang, Patricia; Pollard, Kiersten; Lala, Nupur; Alvarez, George A.; Gabrieli, John D. E.

2013-01-01

Fluid intelligence is important for successful functioning in the modern world, but much evidence suggests that fluid intelligence is largely immutable after childhood. Recently, however, researchers have reported gains in fluid intelligence after multiple sessions of adaptive working memory training in adults. The current study attempted to replicate and expand those results by administering a broad assessment of cognitive abilities and personality traits to young adults who underwent 20 sessions of an adaptive dual n-back working memory training program and comparing their post-training performance on those tests to a matched set of young adults who underwent 20 sessions of an adaptive attentional tracking program. Pre- and post-training measurements of fluid intelligence, standardized intelligence tests, speed of processing, reading skills, and other tests of working memory were assessed. Both training groups exhibited substantial and specific improvements on the trained tasks that persisted for at least 6 months post-training, but no transfer of improvement was observed to any of the non-trained measurements when compared to a third untrained group serving as a passive control. These findings fail to support the idea that adaptive working memory training in healthy young adults enhances working memory capacity in non-trained tasks, fluid intelligence, or other measures of cognitive abilities. PMID:23717453

Structural correlates of impaired working memory in hippocampal sclerosis.

PubMed

Winston, Gavin P; Stretton, Jason; Sidhu, Meneka K; Symms, Mark R; Thompson, Pamela J; Duncan, John S

2013-07-01

Temporal lobe epilepsy (TLE) has been considered to impair long-term memory, whilst not affecting working memory, but recent evidence suggests that working memory is compromised. Functional MRI (fMRI) studies demonstrate that working memory involves a bilateral frontoparietal network the activation of which is disrupted in hippocampal sclerosis (HS). A specific role of the hippocampus to deactivate during working memory has been proposed with this mechanism faulty in patients with HS. Structural correlates of disrupted working memory in HS have not been explored. We studied 54 individuals with medically refractory TLE and unilateral HS (29 left) and 28 healthy controls. Subjects underwent 3T structural MRI, a visuospatial n-back fMRI paradigm and diffusion tensor imaging (DTI). Working memory capacity assessed by three span tasks (digit span backwards, gesture span, motor sequences) was combined with performance in the visuospatial paradigm to give a global working memory measure. Gray and white matter changes were investigated using voxel-based morphometry and voxel-based analysis of DTI, respectively. Individuals with left or right HS performed less well than healthy controls on all measures of working memory. fMRI demonstrated a bilateral frontoparietal network during the working memory task with reduced activation of the right parietal lobe in both patient groups. In left HS, gray matter loss was seen in the ipsilateral hippocampus and parietal lobe, with maintenance of the gray matter volume of the contralateral parietal lobe associated with better performance. White matter integrity within the frontoparietal network, in particular the superior longitudinal fasciculus and cingulum, and the contralateral temporal lobe, was associated with working memory performance. In right HS, gray matter loss was also seen in the ipsilateral hippocampus and parietal lobe. Working memory performance correlated with the gray matter volume of both frontal lobes and white matter

Structural correlates of impaired working memory in hippocampal sclerosis

PubMed Central

Winston, Gavin P; Stretton, Jason; Sidhu, Meneka K; Symms, Mark R; Thompson, Pamela J; Duncan, John S

2013-01-01

Purpose: Temporal lobe epilepsy (TLE) has been considered to impair long-term memory, whilst not affecting working memory, but recent evidence suggests that working memory is compromised. Functional MRI (fMRI) studies demonstrate that working memory involves a bilateral frontoparietal network the activation of which is disrupted in hippocampal sclerosis (HS). A specific role of the hippocampus to deactivate during working memory has been proposed with this mechanism faulty in patients with HS. Structural correlates of disrupted working memory in HS have not been explored. Methods: We studied 54 individuals with medically refractory TLE and unilateral HS (29 left) and 28 healthy controls. Subjects underwent 3T structural MRI, a visuospatial n-back fMRI paradigm and diffusion tensor imaging (DTI). Working memory capacity assessed by three span tasks (digit span backwards, gesture span, motor sequences) was combined with performance in the visuospatial paradigm to give a global working memory measure. Gray and white matter changes were investigated using voxel-based morphometry and voxel-based analysis of DTI, respectively. Key Findings: Individuals with left or right HS performed less well than healthy controls on all measures of working memory. fMRI demonstrated a bilateral frontoparietal network during the working memory task with reduced activation of the right parietal lobe in both patient groups. In left HS, gray matter loss was seen in the ipsilateral hippocampus and parietal lobe, with maintenance of the gray matter volume of the contralateral parietal lobe associated with better performance. White matter integrity within the frontoparietal network, in particular the superior longitudinal fasciculus and cingulum, and the contralateral temporal lobe, was associated with working memory performance. In right HS, gray matter loss was also seen in the ipsilateral hippocampus and parietal lobe. Working memory performance correlated with the gray matter volume of

Improving attention control in dysphoria through cognitive training: transfer effects on working memory capacity and filtering efficiency.

PubMed

Owens, Max; Koster, Ernst H W; Derakshan, Nazanin

2013-03-01

Impaired filtering of irrelevant information from working memory is thought to underlie reduced working memory capacity for relevant information in dysphoria. The current study investigated whether training-related gains in working memory performance on the adaptive dual n-back task could result in improved inhibitory function. Efficacy of training was monitored in a change detection paradigm allowing measurement of a sustained event-related potential asymmetry sensitive to working memory capacity and the efficient filtering of irrelevant information. Dysphoric participants in the training group showed training-related gains in working memory that were accompanied by gains in working memory capacity and filtering efficiency compared to an active control group. Results provide important initial evidence that behavioral performance and neural function in dysphoria can be improved by facilitating greater attentional control. Copyright © 2013 Society for Psychophysiological Research.

The Auditory-Visual Speech Benefit on Working Memory in Older Adults with Hearing Impairment

PubMed Central

Frtusova, Jana B.; Phillips, Natalie A.

2016-01-01

This study examined the effect of auditory-visual (AV) speech stimuli on working memory in older adults with poorer-hearing (PH) in comparison to age- and education-matched older adults with better hearing (BH). Participants completed a working memory n-back task (0- to 2-back) in which sequences of digits were presented in visual-only (i.e., speech-reading), auditory-only (A-only), and AV conditions. Auditory event-related potentials (ERP) were collected to assess the relationship between perceptual and working memory processing. The behavioral results showed that both groups were faster in the AV condition in comparison to the unisensory conditions. The ERP data showed perceptual facilitation in the AV condition, in the form of reduced amplitudes and latencies of the auditory N1 and/or P1 components, in the PH group. Furthermore, a working memory ERP component, the P3, peaked earlier for both groups in the AV condition compared to the A-only condition. In general, the PH group showed a more robust AV benefit; however, the BH group showed a dose-response relationship between perceptual facilitation and working memory improvement, especially for facilitation of processing speed. Two measures, reaction time and P3 amplitude, suggested that the presence of visual speech cues may have helped the PH group to counteract the demanding auditory processing, to the level that no group differences were evident during the AV modality despite lower performance during the A-only condition. Overall, this study provides support for the theory of an integrated perceptual-cognitive system. The practical significance of these findings is also discussed. PMID:27148106

Working Memory for Linguistic and Non-linguistic Manual Gestures: Evidence, Theory, and Application.

PubMed

Rudner, Mary

2018-01-01

Linguistic manual gestures are the basis of sign languages used by deaf individuals. Working memory and language processing are intimately connected and thus when language is gesture-based, it is important to understand related working memory mechanisms. This article reviews work on working memory for linguistic and non-linguistic manual gestures and discusses theoretical and applied implications. Empirical evidence shows that there are effects of load and stimulus degradation on working memory for manual gestures. These effects are similar to those found for working memory for speech-based language. Further, there are effects of pre-existing linguistic representation that are partially similar across language modalities. But above all, deaf signers score higher than hearing non-signers on an n-back task with sign-based stimuli, irrespective of their semantic and phonological content, but not with non-linguistic manual actions. This pattern may be partially explained by recent findings relating to cross-modal plasticity in deaf individuals. It suggests that in linguistic gesture-based working memory, semantic aspects may outweigh phonological aspects when processing takes place under challenging conditions. The close association between working memory and language development should be taken into account in understanding and alleviating the challenges faced by deaf children growing up with cochlear implants as well as other clinical populations.

Working Memory for Linguistic and Non-linguistic Manual Gestures: Evidence, Theory, and Application

PubMed Central

Rudner, Mary

2018-01-01

Linguistic manual gestures are the basis of sign languages used by deaf individuals. Working memory and language processing are intimately connected and thus when language is gesture-based, it is important to understand related working memory mechanisms. This article reviews work on working memory for linguistic and non-linguistic manual gestures and discusses theoretical and applied implications. Empirical evidence shows that there are effects of load and stimulus degradation on working memory for manual gestures. These effects are similar to those found for working memory for speech-based language. Further, there are effects of pre-existing linguistic representation that are partially similar across language modalities. But above all, deaf signers score higher than hearing non-signers on an n-back task with sign-based stimuli, irrespective of their semantic and phonological content, but not with non-linguistic manual actions. This pattern may be partially explained by recent findings relating to cross-modal plasticity in deaf individuals. It suggests that in linguistic gesture-based working memory, semantic aspects may outweigh phonological aspects when processing takes place under challenging conditions. The close association between working memory and language development should be taken into account in understanding and alleviating the challenges faced by deaf children growing up with cochlear implants as well as other clinical populations. PMID:29867655

Working and strategic memory deficits in schizophrenia

NASA Technical Reports Server (NTRS)

Stone, M.; Gabrieli, J. D.; Stebbins, G. T.; Sullivan, E. V.

1998-01-01

Working memory and its contribution to performance on strategic memory tests in schizophrenia were studied. Patients (n = 18) and control participants (n = 15), all men, received tests of immediate memory (forward digit span), working memory (listening, computation, and backward digit span), and long-term strategic (free recall, temporal order, and self-ordered pointing) and nonstrategic (recognition) memory. Schizophrenia patients performed worse on all tests. Education, verbal intelligence, and immediate memory capacity did not account for deficits in working memory in schizophrenia patients. Reduced working memory capacity accounted for group differences in strategic memory but not in recognition memory. Working memory impairment may be central to the profile of impaired cognitive performance in schizophrenia and is consistent with hypothesized frontal lobe dysfunction associated with this disease. Additional medial-temporal dysfunction may account for the recognition memory deficit.

The Effects of a Distracting N-Back Task on Recognition Memory Are Reduced by Negative Emotional Intensity

PubMed Central

Buratto, Luciano G.; Pottage, Claire L.; Brown, Charity; Morrison, Catriona M.; Schaefer, Alexandre

2014-01-01

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated. PMID:25330251

The effects of a distracting N-back task on recognition memory are reduced by negative emotional intensity.

PubMed

Buratto, Luciano G; Pottage, Claire L; Brown, Charity; Morrison, Catriona M; Schaefer, Alexandre

2014-01-01

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated.

The Effects of Green Tea Extract on Working Memory in Healthy Women.

PubMed

Liu, Y; Fly, A D; Wang, Z; Klaunig, J E

2018-01-01

This study aimed to examine the effects of green tea extract on working memory in healthy younger (21 - 29 y) and older (50 - 63 y) women. A single-blind, placebo-controlled, crossover design was used. A university laboratory. Twenty non-smoking Caucasian women were recruited in the younger (10) and older (10) age group. Subjects received 5.4 g green tea extract (at least 45% epigallocatechin-3-gallate) or placebo (cornstarch) within a 24-hour period. Working memory was measured by reading span and N-back task paradigm. Blood sample (20 mL) was collected and measured for plasma malondialdehyde (MDA) and total antioxidant capacity (TEAC) concentration. A 24-hour recall was conducted for each treatment period to ensure similar dietary patterns. Green tea extract significantly improved reading span performance in older women, indicated by higher absolute and partial scores of reading span. No significant changes were observed in the younger group. N-back latencies and accuracies were not significantly different after green tea treatment in either age group. Plasma concentration of MDA and TEAC were not different after green tea extract in either group. Acute supplementation of decaffeinated green tea extract may enhance working memory capacity of women between 50 to 63 years of age. This study provides preliminary evidence that consumption of green tea extract may enhance the cognitive performance in older adults and thus provide potential chemopreventive benefits in this group. The mechanism should be explored in future research.

Assessing the Driver's Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study.

PubMed

Unni, Anirudh; Ihme, Klas; Jipp, Meike; Rieger, Jochem W

2017-01-01

Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver's cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back) forcing the participants to continuously update, memorize, and recall the previous 'n' speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS) and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE) 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04), indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1). Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload-related processing.

Psychotic Experiences and Working Memory: A Population-Based Study Using Signal-Detection Analysis.

PubMed

Rossi, Rodolfo; Zammit, Stanley; Button, Katherine S; Munafò, Marcus R; Lewis, Glyn; David, Anthony S

2016-01-01

Psychotic Experiences (PEs) during adolescence index increased risk for psychotic disorders and schizophrenia in adult life. Working memory (WM) deficits are a core feature of these disorders. Our objective was to examine the relationship between PEs and WM in a general population sample of young people in a case control study. 4744 individuals of age 17-18 from Bristol and surrounding areas (UK) were analyzed in a cross-sectional study nested within the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort study. The dependent variable was PEs, assessed using the semi-structured Psychosis-Like Symptom Interview (PLIKSi). The independent variable was performance on a computerized numerical n-back working memory task. Signal-Detection Theory indices, including standardized hits rate, false alarms rate, discriminability index (d') and response bias (c) from 2-Back and 3-Back tasks were calculated. 3576 and 3527 individuals had complete data for 2-Back and 3-Back respectively. Suspected/definite PEs prevalence was 7.9% (N = 374). Strongest evidence of association was seen between PEs and false alarms on the 2-Back, (odds ratio (OR) = 1.17 [95% confidence intervals (CI) 1.01, 1.35]) and 3-back (OR = 1.35 [1.18, 1.54]) and with c (OR = 1.59 [1.09, 2.34]), and lower d' (OR = 0.76 [0.65, 0.89]), on the 3-Back. Adjustment for several potential confounders, including general IQ, drug exposure and different psycho-social factors, and subsequent multiple imputation of missing data did not materially alter the results. WM is impaired in young people with PEs in the general population. False alarms, rather than poor accuracy, are more closely related to PEs. Such impairment is consistent with different neuropsychological models of psychosis focusing on signal-to-noise discrimination, probabilistic reasoning and impaired reality monitoring as a basis of psychotic symptoms.

Transfer after Dual n-Back Training Depends on Striatal Activation Change.

PubMed

Salminen, Tiina; Kühn, Simone; Frensch, Peter A; Schubert, Torsten

2016-09-28

The dual n-back working memory (WM) training paradigm (comprising auditory and visual stimuli) has gained much attention since studies have shown widespread transfer effects. By including a multimodal dual-task component, the task is demanding to the human cognitive system. We investigated whether dual n-back training improves general cognitive resources or a task-specific WM updating process in participants. We expected: (1) widespread transfer effects and the recruitment of a common neuronal network by the training and the transfer tasks and (2) narrower transfer results and that a common activation network alone would not produce transfer, but instead an activation focus on the striatum, which is associated with WM updating processes. The training group showed transfer to an untrained dual-modality WM updating task, but not to single-task versions of the training or the transfer task. They also showed diminished neuronal overlap between the training and the transfer task from pretest to posttest and an increase in striatal activation in both tasks. Furthermore, we found an association between the striatal activation increase and behavioral improvement. The control groups showed no transfer and no change in the amount of activation overlap or in striatal activation from pretest to posttest. We conclude that, instead of improving general cognitive resources (which would have required a transfer effect to all transfer tasks and that a frontal activation overlap between the tasks produced transfer), dual n-back training improved a task-specific process: WM updating of stimuli from two modalities. The current study allows for a better understanding of the cognitive and neural effects of working memory (WM) training and transfer. It shows that dual n-back training mainly improves specific processes of WM updating, and this improvement leads to narrow transfer effects to tasks involving the same processes. On a neuronal level this is accompanied by increased neural

A Potential Spatial Working Memory Training Task to Improve Both Episodic Memory and Fluid Intelligence

PubMed Central

Rudebeck, Sarah R.; Bor, Daniel; Ormond, Angharad; O’Reilly, Jill X.; Lee, Andy C. H.

2012-01-01

One current challenge in cognitive training is to create a training regime that benefits multiple cognitive domains, including episodic memory, without relying on a large battery of tasks, which can be time-consuming and difficult to learn. By giving careful consideration to the neural correlates underlying episodic and working memory, we devised a computerized working memory training task in which neurologically healthy participants were required to monitor and detect repetitions in two streams of spatial information (spatial location and scene identity) presented simultaneously (i.e. a dual n-back paradigm). Participants’ episodic memory abilities were assessed before and after training using two object and scene recognition memory tasks incorporating memory confidence judgments. Furthermore, to determine the generalizability of the effects of training, we also assessed fluid intelligence using a matrix reasoning task. By examining the difference between pre- and post-training performance (i.e. gain scores), we found that the trainers, compared to non-trainers, exhibited a significant improvement in fluid intelligence after 20 days. Interestingly, pre-training fluid intelligence performance, but not training task improvement, was a significant predictor of post-training fluid intelligence improvement, with lower pre-training fluid intelligence associated with greater post-training gain. Crucially, trainers who improved the most on the training task also showed an improvement in recognition memory as captured by d-prime scores and estimates of recollection and familiarity memory. Training task improvement was a significant predictor of gains in recognition and familiarity memory performance, with greater training improvement leading to more marked gains. In contrast, lower pre-training recollection memory scores, and not training task improvement, led to greater recollection memory performance after training. Our findings demonstrate that practice on a single

A potential spatial working memory training task to improve both episodic memory and fluid intelligence.

PubMed

Rudebeck, Sarah R; Bor, Daniel; Ormond, Angharad; O'Reilly, Jill X; Lee, Andy C H

2012-01-01

One current challenge in cognitive training is to create a training regime that benefits multiple cognitive domains, including episodic memory, without relying on a large battery of tasks, which can be time-consuming and difficult to learn. By giving careful consideration to the neural correlates underlying episodic and working memory, we devised a computerized working memory training task in which neurologically healthy participants were required to monitor and detect repetitions in two streams of spatial information (spatial location and scene identity) presented simultaneously (i.e. a dual n-back paradigm). Participants' episodic memory abilities were assessed before and after training using two object and scene recognition memory tasks incorporating memory confidence judgments. Furthermore, to determine the generalizability of the effects of training, we also assessed fluid intelligence using a matrix reasoning task. By examining the difference between pre- and post-training performance (i.e. gain scores), we found that the trainers, compared to non-trainers, exhibited a significant improvement in fluid intelligence after 20 days. Interestingly, pre-training fluid intelligence performance, but not training task improvement, was a significant predictor of post-training fluid intelligence improvement, with lower pre-training fluid intelligence associated with greater post-training gain. Crucially, trainers who improved the most on the training task also showed an improvement in recognition memory as captured by d-prime scores and estimates of recollection and familiarity memory. Training task improvement was a significant predictor of gains in recognition and familiarity memory performance, with greater training improvement leading to more marked gains. In contrast, lower pre-training recollection memory scores, and not training task improvement, led to greater recollection memory performance after training. Our findings demonstrate that practice on a single

Because difficulty is not the same for everyone: the impact of complexity in working memory is associated with cannabinoid 1 receptor genetic variation in young adults.

PubMed

Ruiz-Contreras, Alejandra E; Román-López, Talía V; Caballero-Sánchez, Ulises; Rosas-Escobar, Cintia B; Ortega-Mora, E Ivett; Barrera-Tlapa, Miguel A; Romero-Hidalgo, Sandra; Carrillo-Sánchez, Karol; Hernández-Morales, Salvador; Vadillo-Ortega, Felipe; González-Barrios, Juan Antonio; Méndez-Díaz, Mónica; Prospéro-García, Oscar

2017-03-01

Individual differences in working memory ability are mainly revealed when a demanding challenge is imposed. Here, we have associated cannabinoid 1 (CB1) receptor genetic variation rs2180619 (AA, AG, GG), which is located in a potential CNR1 regulatory sequence, with performance in working memory. Two-hundred and nine Mexican-mestizo healthy young participants (89 women, 120 men, mean age: 23.26 years, SD = 2.85) were challenged to solve a medium (2-back) vs. a high (3-back) difficulty N-back tasks. All subjects responded as expected, performance was better with the medium than the high demand task version, but no differences were found among genotypes while performing each working memory (WM) task. However, the cost of the level of complexity in N-back paradigm was double for GG subjects than for AA subjects. It is noteworthy that an additive-dosage allele relation was found for G allele in terms of cost of level of complexity. These genetic variation results support that the endocannabinoid system, evaluated by rs2180619 polymorphism, is involved in WM ability in humans.

Exploring Possible Neural Mechanisms of Intelligence Differences Using Processing Speed and Working Memory Tasks: An fMRI Study

ERIC Educational Resources Information Center

Waiter, Gordon D.; Deary, Ian J.; Staff, Roger T.; Murray, Alison D.; Fox, Helen C.; Starr, John M.; Whalley, Lawrence J.

2009-01-01

To explore the possible neural foundations of individual differences in intelligence test scores, we examined the associations between Raven's Matrices scores and two tasks that were administered in a functional magnetic resonance imaging (fMRI) setting. The two tasks were an n-back working memory (N = 37) task and inspection time (N = 47). The…

Working memory involvement in stuttering: exploring the evidence and research implications.

PubMed

Bajaj, Amit

2007-01-01

Several studies of utterance planning and attention processes in stuttering have raised the prospect of working memory involvement in the disorder. In this paper, potential connections between stuttering and two elements of Baddeley's [Baddeley, A. D. (2003). Working memory: Looking back and looking forward. Neuroscience, 4, 829-839] working memory model, phonological memory and central executive, are posited. Empirical evidence is drawn from studies on phonological memory and dual-task performance among children and adults who stutter to examine support for the posited connections. Implications for research to examine working memory as one of the psycholinguistic bases of stuttering are presented. The reader will learn about and be able to: (1) appraise potential relationships between working memory and stuttering; (2) evaluate empirical evidence that suggests the possibility of working memory involvement in stuttering; and (3) identify research directions to explore the role of working memory in stuttering.

Effects of electromagnetic fields emitted by GSM phones on working memory: a meta-analysis.

PubMed

Zubko, O; Gould, R L; Gay, H C; Cox, H J; Coulson, M C; Howard, R J

2017-02-01

Current treatments for Alzheimer's Disease (AD) do not affect the course of the illness and brain stimulation techniques are increasingly promoted as potential therapeutic interventions for AD. This study reviews the effects of electromagnetic field (EMF) exposure versus sham exposure on working memory (WM) performance of healthy human participants. Online literature databases and previous systematic reviews were searched for studies of EMF and WM in participants without reported memory problems. Two thousand eight hundred and fifty seven studies were identified, and 10 studies met the inclusion criteria. An assessment of study quality was completed, and separate, random effects meta-analyses were conducted for each of the three WM tasks included: n-back, substitution and digit span forward. No differences were found between participants exposed to active EMF versus sham conditions in any of the three working memory tasks examined. Results indicate that EMF does not affect WM during the n-back, substitution and digit-span tasks. Future studies should focus on the possible effects of chronic exposure to EMF in older adults with AD using a battery of comparable WM and attention tasks, before EMF can be seriously considered as a potential modulator of WM in AD. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Interaction of threat and verbal working memory in adolescents.

PubMed

Patel, Nilam; Vytal, Katherine; Pavletic, Nevia; Stoodley, Catherine; Pine, Daniel S; Grillon, Christian; Ernst, Monique

2016-04-01

Threat induces a state of sustained anxiety that can disrupt cognitive processing, and, reciprocally, cognitive processing can modulate an anxiety response to threat. These effects depend on the level of cognitive engagement, which itself varies as a function of task difficulty. In adults, we recently showed that induced anxiety impaired working memory accuracy at low and medium but not high load. Conversely, increasing the task load reduced the physiological correlates of anxiety (anxiety-potentiated startle). The present work examines such threat-cognition interactions as a function of age. We expected threat to more strongly impact working memory in younger individuals by virtue of putatively restricted cognitive resources and weaker emotion regulation. This was tested by examining the influence of age on the interaction of anxiety and working memory in 25 adolescents (10 to 17 years) and 25 adults (22 to 46 years). Working memory load was manipulated using a verbal n-back task. Anxiety was induced using the threat of an aversive loud scream and measured via eyeblink startle. Findings revealed that, in both age groups, accuracy was lower during threat than safe conditions at low and medium but not high load, and reaction times were faster during threat than safe conditions at high load but did not differ at other loads. Additionally, anxiety-potentiated startle was greater during low and medium than high load. Thus, the interactions of anxiety with working memory appear similar in adolescents and adults. Whether these similarities reflect common neural mechanisms would need to be assessed using functional neuroimaging. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Neural Correlates Associated with Successful Working Memory Performance in Older Adults as Revealed by Spatial ICA

PubMed Central

Saliasi, Emi; Geerligs, Linda; Lorist, Monicque M.; Maurits, Natasha M.

2014-01-01

To investigate which neural correlates are associated with successful working memory performance, fMRI was recorded in healthy younger and older adults during performance on an n-back task with varying task demands. To identify functional networks supporting working memory processes, we used independent component analysis (ICA) decomposition of the fMRI data. Compared to younger adults, older adults showed a larger neural (BOLD) response in the more complex (2-back) than in the baseline (0-back) task condition, in the ventral lateral prefrontal cortex (VLPFC) and in the right fronto-parietal network (FPN). Our results indicated that a higher BOLD response in the VLPFC was associated with increased performance accuracy in older adults, in both the baseline and the more complex task condition. This ‘BOLD-performance’ relationship suggests that the neural correlates linked with successful performance in the older adults are not uniquely related to specific working memory processes present in the complex but not in the baseline task condition. Furthermore, the selective presence of this relationship in older but not in younger adults suggests that increased neural activity in the VLPFC serves a compensatory role in the aging brain which benefits task performance in the elderly. PMID:24911016

Reduced prefrontal activation during working and long-term memory tasks and impaired patient-reported cognition among cancer survivors postchemotherapy compared with healthy controls.

PubMed

Wang, Lei; Apple, Alexandra C; Schroeder, Matthew P; Ryals, Anthony J; Voss, Joel L; Gitelman, Darren; Sweet, Jerry J; Butt, Zeeshan A; Cella, David; Wagner, Lynne I

2016-01-15

Patients who receive adjuvant chemotherapy have reported cognitive impairments that may last for years after the completion of treatment. Working memory-related and long-term memory-related changes in this population are not well understood. The objective of this study was to demonstrate that cancer-related cognitive impairments are associated with the under recruitment of brain regions involved in working and recognition memory compared with controls. Oncology patients (n = 15) who were receiving adjuvant chemotherapy and had evidence of cognitive impairment according to neuropsychological testing and self-report and a group of age-matched, education group-matched, cognitively normal control participants (n = 14) underwent functional magnetic resonance imaging. During functional magnetic resonance imaging, participants performed a nonverbal n-back working memory task and a visual recognition task. On the working memory task, when 1-back and 2-back data were averaged and contrasted with 0-back data, significantly reduced activation was observed in the right dorsolateral prefrontal cortex for oncology patients versus controls. On the recognition task, oncology patients displayed decreased activity of the left-middle hippocampus compared with controls. Neuroimaging results were not associated with patient-reported cognition. Decreased recruitment of brain regions associated with the encoding of working memory and recognition memory was observed in the oncology patients compared with the control group. These results suggest that there is a reduction in neural functioning postchemotherapy and corroborate patient-reported cognitive difficulties after cancer treatment, although a direct association was not observed. Cancer 2016;122:258-268. © 2015 American Cancer Society. © 2015 American Cancer Society.

Training working memory to improve attentional control in anxiety: A proof-of-principle study using behavioral and electrophysiological measures.

PubMed

Sari, Berna A; Koster, Ernst H W; Pourtois, Gilles; Derakshan, Nazanin

2016-12-01

Trait anxiety is associated with impairments in attentional control and processing efficiency (see Berggren & Derakshan, 2013, for a review). Working memory training using the adaptive dual n-back task has shown to improve attentional control in subclinical depression with transfer effects at the behavioral and neural level on a working memory task (Owens, Koster, & Derakshan, 2013). Here, we examined the beneficial effects of working memory training on attentional control in pre-selected high trait anxious individuals who underwent a three week daily training intervention using the adaptive dual n-back task. Pre and post outcome measures of attentional control were assessed using a Flanker task that included a stress induction and an emotional a Antisaccade task (with angry and neutral faces as target). Resting state EEG (theta/beta ratio) was recorded to as a neural marker of trait attentional control. Our results showed that adaptive working memory training improved attentional control with transfer effects on the Flanker task and resting state EEG, but effects of training on the Antisaccade task were less conclusive. Finally, training related gains were associated with lower levels of trait anxiety at post (vs pre) intervention. Our results demonstrate that adaptive working memory training in anxiety can have beneficial effects on attentional control and cognitive performance that may protect against emotional vulnerability in individuals at risk of developing clinical anxiety. Copyright © 2015 Elsevier B.V. All rights reserved.

Delineation of the working memory profile in female FMR1 premutation carriers: the effect of cognitive load on ocular motor responses.

PubMed

Shelton, Annie L; Cornish, Kim M; Godler, David E; Clough, Meaghan; Kraan, Claudine; Bui, Minh; Fielding, Joanne

2015-04-01

Fragile X mental retardation 1 (FMR1) premutation carriers (PM-carriers) are characterised as having mid-sized expansions of between 55 and 200 CGG repeats in the 5' untranslated region of the FMR1 gene. While there is evidence of executive dysfunction in PM-carriers, few studies have explicitly explored working memory capabilities in female PM-carriers. 14 female PM-carriers and 13 age- and IQ-matched healthy controls completed an ocular motor n-back working memory paradigm. This task examined working memory ability and the effect of measured increases in cognitive load. Female PM-carriers were found to have attenuated working memory capabilities. Increasing the cognitive load did not elicit the expected reciprocal increase in the task errors for female PM-carriers, as it did in controls. However female PM-carriers took longer to respond than controls, regardless of the cognitive load. Further, FMR1 mRNA levels were found to significantly predict PM-carrier response time. Although preliminary, these findings provide further evidence of executive dysfunction, specifically disruption to working memory processes, which were found to be associated with increases in FMR1 mRNA expression in female PM-carriers. With future validation, ocular motor paradigms such as the n-back paradigm will be critical to the development of behavioural biomarkers for identification of PM-carrier cognitive-affective phenotypes. Copyright © 2015 Elsevier B.V. All rights reserved.

Neural correlates of working memory in first episode and recurrent depression: An fMRI study.

PubMed

Yüksel, Dilara; Dietsche, Bruno; Konrad, Carsten; Dannlowski, Udo; Kircher, Tilo; Krug, Axel

2018-06-08

Patients suffering from major depressive disorder (MDD) show deficits in working memory (WM) performance accompanied by bilateral fronto-parietal BOLD signal changes. It is unclear whether patients with a first depressive episode (FDE) exhibit the same signal changes as patients with recurrent depressive episodes (RDE). We investigated seventy-four MDD inpatients (48 RDE, 26 FDE) and 74 healthy control (HC) subjects performing an n-back WM task (0-back, 2-back, 3-back condition) in a 3T-fMRI. FMRI analyses revealed deviating BOLD signal in MDD in the thalamus (0-back vs. 2-back), the angular gyrus (0-back vs. 3-back), and the superior frontal gyrus (2-back vs. 3-back). Further effects were observed between RDE vs. FDE. Thus, RDE displayed differing neural activation in the middle frontal gyrus (2-back vs. 3-back), the inferior frontal gyrus, and the precentral gyrus (0-back vs. 2-back). In addition, both HC and FDE indicated a linear activation trend depending on task complexity. Although we failed to find behavioral differences between the groups, results suggest differing BOLD signal in fronto-parietal brain regions in MDD vs. HC, and in RDE vs. FDE. Moreover, both HC and FDE show similar trends in activation shapes. This indicates a link between levels of complexity-dependent activation in fronto-parietal brain regions and the stage of MDD. We therefore assume that load-dependent BOLD signal during WM is impaired in MDD, and that it is particularly affected in RDE. We also suspect neurobiological compensatory mechanisms of the reported brain regions in (working) memory functioning. Copyright © 2018 Elsevier Inc. All rights reserved.

Emotion processing facilitates working memory performance.

PubMed

Lindström, Björn R; Bohlin, Gunilla

2011-11-01

The effect of emotional stimulus content on working memory performance has been investigated with conflicting results, as both emotion-dependent facilitation and impairments are reported in the literature. To clarify this issue, 52 adult participants performed a modified visual 2-back task with highly arousing positive stimuli (sexual scenes), highly arousing negative stimuli (violent death) and low-arousal neutral stimuli. Emotional stimulus processing was found to facilitate task performance relative to that of neutral stimuli, both in regards to response accuracy and reaction times. No emotion-dependent differences in false-alarm rates were found. These results indicate that emotional information can have a facilitating effect on working memory maintenance and processing of information.

DRD2 genotype predicts prefrontal activity during working memory after stimulation of D2 receptors with bromocriptine.

PubMed

Gelao, Barbara; Fazio, Leonardo; Selvaggi, Pierluigi; Di Giorgio, Annabella; Taurisano, Paolo; Quarto, Tiziana; Romano, Raffaella; Porcelli, Annamaria; Mancini, Marina; Masellis, Rita; Ursini, Gianluca; De Simeis, Giuseppe; Caforio, Grazia; Ferranti, Laura; Lo Bianco, Luciana; Rampino, Antonio; Todarello, Orlando; Popolizio, Teresa; Blasi, Giuseppe; Bertolino, Alessandro

2014-06-01

Pharmacological stimulation of D2 receptors modulates prefrontal neural activity associated with working memory (WM) processing. The T allele of a functional single-nucleotide polymorphism (SNP) within DRD2 (rs1076560 G > T) predicts reduced relative expression of the D2S receptor isoform and less efficient neural cortical responses during WM tasks. We used functional MRI to test the hypothesis that DRD2 rs1076560 genotype interacts with pharmacological stimulation of D2 receptors with bromocriptine on prefrontal responses during different loads of a spatial WM task (N-Back). Fifty-three healthy subjects (38 GG and 15 GT) underwent two 3-T functional MRI scans while performing the 1-, 2- and 3-Back versions of the N-Back WM task. Before the imaging sessions, either bromocriptine or placebo was administered to all subjects in a counterbalanced order. A factorial repeated-measures ANOVA within SPM8 (p < 0.05, family-wise error corrected) was used. On bromocriptine, GG subjects had reduced prefrontal activity at 3-Back together with a significant decrement in performance, compared with placebo. On the other hand, GT subjects had lower activity for the same level of performance at 1-Back but a trend for reduced behavioral performance in the face of unchanged activity at 2-Back. These results indicate that bromocriptine stimulation modulates prefrontal activity in terms of disengagement or of efficiency depending on DRD2 genotype and working memory load.

Atypical spatiotemporal signatures of working memory brain processes in autism.

PubMed

Urbain, C M; Pang, E W; Taylor, M J

2015-08-11

Working memory (WM) impairments may contribute to the profound behavioural manifestations in children with autism spectrum disorder (ASD). However, previous behavioural results are discrepant as are the few functional magnetic resonance imaging (fMRI) results collected in adults and adolescents with ASD. Here we investigate the precise temporal dynamics of WM-related brain activity using magnetoencephalography (MEG) in 20 children with ASD and matched controls during an n-back WM task across different load levels (1-back vs 2-back). Although behavioural results were similar between ASD and typically developing (TD) children, the between-group comparison performed on functional brain activity showed atypical WM-related brain processes in children with ASD compared with TD children. These atypical responses were observed in the ASD group from 200 to 600 ms post stimulus in both the low- (1-back) and high- (2-back) memory load conditions. During the 1-back condition, children with ASD showed reduced WM-related activations in the right hippocampus and the cingulate gyrus compared with TD children who showed more activation in the left dorso-lateral prefrontal cortex and the insulae. In the 2-back condition, children with ASD showed less activity in the left insula and midcingulate gyrus and more activity in the left precuneus than TD children. In addition, reduced activity in the anterior cingulate cortex was correlated with symptom severity in children with ASD. Thus, this MEG study identified the precise timing and sources of atypical WM-related activity in frontal, temporal and parietal regions in children with ASD. The potential impacts of such atypicalities on social deficits of autism are discussed.

Exposure to Blue Light Increases Subsequent Functional Activation of the Prefrontal Cortex During Performance of a Working Memory Task

PubMed Central

Alkozei, Anna; Smith, Ryan; Pisner, Derek A.; Vanuk, John R.; Berryhill, Sarah M.; Fridman, Andrew; Shane, Bradley R.; Knight, Sara A.; Killgore, William D.S.

2016-01-01

Study Objectives: Prolonged exposure to blue wavelength light has been shown to have an alerting effect, and enhances performance on cognitive tasks. A small number of studies have also shown that relatively short exposure to blue light leads to changes in functional brain responses during the period of exposure. The extent to which blue light continues to affect brain functioning during a cognitively challenging task after cessation of longer periods of exposure (i.e., roughly 30 minutes or longer), however, has not been fully investigated. Methods: A total of 35 healthy participants (18 female) were exposed to either blue (469 nm) (n = 17) or amber (578 nm) (n = 18) wavelength light for 30 minutes in a darkened room, followed immediately by functional magnetic resonance imaging (fMRI) while undergoing a working memory task (N-back task). Results: Participants in the blue light condition were faster in their responses on the N-back task and showed increased activation in the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortex compared to those in the amber control light condition. Furthermore, greater activation within the VLPFC was correlated with faster N-back response times. Conclusions: This is the first study to suggest that a relatively brief, single exposure to blue light has a subsequent beneficial effect on working memory performance, even after cessation of exposure, and leads to temporarily persisting functional brain changes within prefrontal brain regions associated with executive functions. These findings may have broader implication for using blue-enriched light in a variety of work settings where alertness and quick decision-making are important. Citation: Alkozei A, Smith R, Pisner DA, Vanuk JR, Berryhill SM, Fridman A, Shane BR, Knight SA, Killgore WD. Exposure to blue light increases subsequent functional activation of the prefrontal cortex during performance of a working memory task. SLEEP 2016;39(9):1671–1680. PMID:27253770

Cortical oscillations and entrainment in speech processing during working memory load.

PubMed

Hjortkjaer, Jens; Märcher-Rørsted, Jonatan; Fuglsang, Søren A; Dau, Torsten

2018-02-02

Neuronal oscillations are thought to play an important role in working memory (WM) and speech processing. Listening to speech in real-life situations is often cognitively demanding but it is unknown whether WM load influences how auditory cortical activity synchronizes to speech features. Here, we developed an auditory n-back paradigm to investigate cortical entrainment to speech envelope fluctuations under different degrees of WM load. We measured the electroencephalogram, pupil dilations and behavioural performance from 22 subjects listening to continuous speech with an embedded n-back task. The speech stimuli consisted of long spoken number sequences created to match natural speech in terms of sentence intonation, syllabic rate and phonetic content. To burden different WM functions during speech processing, listeners performed an n-back task on the speech sequences in different levels of background noise. Increasing WM load at higher n-back levels was associated with a decrease in posterior alpha power as well as increased pupil dilations. Frontal theta power increased at the start of the trial and increased additionally with higher n-back level. The observed alpha-theta power changes are consistent with visual n-back paradigms suggesting general oscillatory correlates of WM processing load. Speech entrainment was measured as a linear mapping between the envelope of the speech signal and low-frequency cortical activity (< 13 Hz). We found that increases in both types of WM load (background noise and n-back level) decreased cortical speech envelope entrainment. Although entrainment persisted under high load, our results suggest a top-down influence of WM processing on cortical speech entrainment. © 2018 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Modulation of steady state functional connectivity in the default mode and working memory networks by cognitive load.

PubMed

Newton, Allen T; Morgan, Victoria L; Rogers, Baxter P; Gore, John C

2011-10-01

Interregional correlations between blood oxygen level dependent (BOLD) magnetic resonance imaging (fMRI) signals in the resting state have been interpreted as measures of connectivity across the brain. Here we investigate whether such connectivity in the working memory and default mode networks is modulated by changes in cognitive load. Functional connectivity was measured in a steady-state verbal identity N-back task for three different conditions (N = 1, 2, and 3) as well as in the resting state. We found that as cognitive load increases, the functional connectivity within both the working memory the default mode network increases. To test whether functional connectivity between the working memory and the default mode networks changed, we constructed maps of functional connectivity to the working memory network as a whole and found that increasingly negative correlations emerged in a dorsal region of the posterior cingulate cortex. These results provide further evidence that low frequency fluctuations in BOLD signals reflect variations in neural activity and suggests interaction between the default mode network and other cognitive networks. Copyright © 2010 Wiley-Liss, Inc.

Levels of processing and language modality specificity in working memory.

PubMed

Rudner, Mary; Karlsson, Thomas; Gunnarsson, Johan; Rönnberg, Jerker

2013-03-01

Neural networks underpinning working memory demonstrate sign language specific components possibly related to differences in temporary storage mechanisms. A processing approach to memory systems suggests that the organisation of memory storage is related to type of memory processing as well. In the present study, we investigated for the first time semantic, phonological and orthographic processing in working memory for sign- and speech-based language. During fMRI we administered a picture-based 2-back working memory task with Semantic, Phonological, Orthographic and Baseline conditions to 11 deaf signers and 20 hearing non-signers. Behavioural data showed poorer and slower performance for both groups in Phonological and Orthographic conditions than in the Semantic condition, in line with depth-of-processing theory. An exclusive masking procedure revealed distinct sign-specific neural networks supporting working memory components at all three levels of processing. The overall pattern of sign-specific activations may reflect a relative intermodality difference in the relationship between phonology and semantics influencing working memory storage and processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Working memory training improves emotion regulation ability: Evidence from HRV.

PubMed

Xiu, Lichao; Zhou, Renlai; Jiang, Yihan

2016-03-01

Emotion regulation during social situations plays a pivotal role in health and interpersonal functioning. In this study, we propose a working memory training approach to improve emotion regulation ability. This training promotes an updating function that is a crucial modulated process for emotion regulation. In the present study, the participants in the training group completed a running memory task over 20 days of training. Their working memory capability and high-frequency heart rate variability (HF-HRV) data on pretest and posttest were assessed and analyzed. Compared with the control group, the training group's reaction time in the 2-back working memory task was reduced significantly. In addition, the HF-HRV in the emotion regulation condition was increased after the 20-day training, which indicates that the working memory training effect could transfer to emotion regulation. In other words, working memory training improved emotion regulation ability. Copyright © 2015 Elsevier Inc. All rights reserved.

The disruptive effects of pain on n-back task performance in a large general population sample

PubMed Central

Attridge, Nina; Noonan, Donna; Eccleston, Christopher; Keogh, Edmund

2015-01-01

Abstract Pain captures attention, displaces current concerns, and prioritises escape and repair. This attentional capture can be measured by its effects on general cognition. Studies on induced pain, naturally occurring acute pain, and chronic pain all demonstrate a detrimental effect on specific tasks of attention, especially those that involve working memory. However, studies to date have relied on relatively small samples and/or one type of pain, thus restricting our ability to generalise to wider populations. We investigated the effect of pain on an n-back task in a large heterogeneous sample of 1318 adults. Participants were recruited from the general population and tested through the internet. Despite the heterogeneity of pain conditions, participant characteristics, and testing environments, we found a performance decrement on the n-back task for those with pain, compared with those without pain; there were significantly more false alarms on nontarget trials. Furthermore, we also found an effect of pain intensity; performance was poorer in participants with higher intensity compared with that in those with lower intensity pain. We suggest that the effects of pain on attention found in the laboratory occur in more naturalistic settings. Pain is common in the general population, and such interruption may have important, as yet uninvestigated, consequences for tasks of everyday cognition that involve working memory, such as concentration, reasoning, motor planning, and prospective memory. PMID:26020226

Changes in brain activation during working memory and facial recognition tasks in patients with bipolar disorder with Lamotrigine monotherapy.

PubMed

Haldane, Morgan; Jogia, Jigar; Cobb, Annabel; Kozuch, Eliza; Kumari, Veena; Frangou, Sophia

2008-01-01

Verbal working memory and emotional self-regulation are impaired in Bipolar Disorder (BD). Our aim was to investigate the effect of Lamotrigine (LTG), which is effective in the clinical management of BD, on the neural circuits subserving working memory and emotional processing. Functional Magnetic Resonance Imaging data from 12 stable BD patients was used to detect LTG-induced changes as the differences in brain activity between drug-free and post-LTG monotherapy conditions during a verbal working memory (N-back sequential letter task) and an angry facial affect recognition task. For both tasks, LGT monotherapy compared to baseline was associated with increased activation mostly within the prefrontal cortex and cingulate gyrus, in regions normally engaged in verbal working memory and emotional processing. Therefore, LTG monotherapy in BD patients may enhance cortical function within neural circuits involved in memory and emotional self-regulation.

Functional Imaging of Working Memory and Peripheral Endothelial Function in Middle-Aged Adults

ERIC Educational Resources Information Center

Gonzales, Mitzi M.; Tarumi, Takashi; Tanaka, Hirofumi; Sugawara, Jun; Swann-Sternberg, Tali; Goudarzi, Katayoon; Haley, Andreana P.

2010-01-01

The current study examined the relationship between a prognostic indicator of vascular health, flow-mediated dilation (FMD), and working memory-related brain activation in healthy middle-aged adults. Forty-two participants underwent functional magnetic resonance imaging while completing a 2-Back working memory task. Brachial artery…

Working memory capacity and overgeneral autobiographical memory in young and older adults.

PubMed

Ros, Laura; Latorre, José Miguel; Serrano, Juan Pedro

2010-01-01

The objectives of this study are to compare the Autobiographical Memory Test (AMT) performance of two healthy samples of younger and older adults and to analyse the relationship between overgeneral memory (OGM) and working memory executive processes (WMEP) using a structural equation modelling with latent variables. The AMT and sustained attention, short-term memory and working memory tasks were administered to a group of young adults (N = 50) and a group of older adults (N = 46). On the AMT, the older adults recalled a greater number of categorical memories (p = .000) and fewer specific memories (p = .000) than the young adults, confirming that OGM occurs in the normal population and increases with age. WMEP was measured by reading span and a working memory with sustained attention load task. Structural equation modelling reflects that WMEP shows a strong relationship with OGM: lower scores on WMEP reflect an OGM phenomenon characterized by higher categorical and lower specific memories.

Attachment anxiety benefits from security priming: Evidence from working memory performance

PubMed Central

2018-01-01

The present study investigates the relationship between the attachment dimensions (anxious vs. avoidance) and the cognitive performance of individuals, specifically whether the attachment dimensions would predict the working memory (WM) performance. In the n-back task, reflecting the WM capacity, both attachment related and non-attachment related words were used. Participants were randomly assigned into two groups that received either the secure or the neutral subliminal priming. In the secure priming condition, the aim was to induce sense of security by presenting secure attachment words prior to the n-back task performance. In neutral priming condition, neutral words that did not elicit sense of security were presented. Structural equation modeling revealed divergent patterns for attachment anxiety and avoidance dimensions under the different priming conditions. In neutral priming condition, WM performance declined in terms of capacity in the n-back task for individuals who rated higher levels of attachment anxiety. However in the secure priming condition, WM performance was boosted in the n-back task for individuals who rated higher levels of attachment anxiety. In other words, the subliminal priming of the security led to increased WM capacity of individuals who rated higher levels of attachment anxiety. This effect, however, was not observed for higher levels of attachment avoidance. Results are discussed along the lines of hyperactivation and deactivation strategies of the attachment system. PMID:29522549

Dieting and Food Cue-Related Working Memory Performance.

PubMed

Meule, Adrian

2016-01-01

Executive functioning (e.g., working memory) is tightly intertwined with self-regulation. For example, food cue-elicited craving has been found to impair working memory performance. Furthermore, current dieters have been found to show lower working memory performance than non-dieters. Recent research, however, suggests that it is crucial to consider dieting success in addition to current dieting status or restrained eating in order to reveal cognitive mechanisms that are associated with successful eating-related self-regulation. The current study investigated food cue-related working memory performance as a function of dieting status and dieting success in female students. Participants performed an n -back task with pictures of food and neutral objects. Reaction time in response to food pictures was slower than in response to neutral pictures, whereas omission errors did not differ between picture types. Current food craving was increased after performing the food block, but not after the neutral block. There was an indirect effect of current dieting status on higher food craving after the food block, which was mediated by slower reaction time to food vs. neutral pictures. Furthermore, higher dieting success was associated with fewer omission errors in the food vs. neutral block in current dieters. There were no relationships of restrained eating with current food craving and task performance. Results further highlight the need to differentiate between successful and unsuccessful dieting in addition to current dieting status or restrained eating when examining possible mechanisms of overeating or successful restraint. Although palatable food cues induce food craving regardless of dieting success, they may boost executive functioning in successful dieters, which helps them to overcome these temptations.

Improving fluid intelligence with training on working memory: a meta-analysis.

PubMed

Au, Jacky; Sheehan, Ellen; Tsai, Nancy; Duncan, Greg J; Buschkuehl, Martin; Jaeggi, Susanne M

2015-04-01

Working memory (WM), the ability to store and manipulate information for short periods of time, is an important predictor of scholastic aptitude and a critical bottleneck underlying higher-order cognitive processes, including controlled attention and reasoning. Recent interventions targeting WM have suggested plasticity of the WM system by demonstrating improvements in both trained and untrained WM tasks. However, evidence on transfer of improved WM into more general cognitive domains such as fluid intelligence (Gf) has been more equivocal. Therefore, we conducted a meta-analysis focusing on one specific training program, n-back. We searched PubMed and Google Scholar for all n-back training studies with Gf outcome measures, a control group, and healthy participants between 18 and 50 years of age. In total, we included 20 studies in our analyses that met our criteria and found a small but significant positive effect of n-back training on improving Gf. Several factors that moderate this transfer are identified and discussed. We conclude that short-term cognitive training on the order of weeks can result in beneficial effects in important cognitive functions as measured by laboratory tests.

Increased working memory-related brain activity in middle-aged women with cognitive complaints.

PubMed

Dumas, Julie A; Kutz, Amanda M; McDonald, Brenna C; Naylor, Magdalena R; Pfaff, Ashley C; Saykin, Andrew J; Newhouse, Paul A

2013-04-01

Individuals who report subjective cognitive complaints but perform normally on neuropsychological tests might be at increased risk for pathological cognitive aging. The current study examined the effects of the presence of subjective cognitive complaints on functional brain activity during a working memory task in a sample of middle-aged postmenopausal women. Twenty-three postmenopausal women aged 50-60 completed a cognitive complaint battery of questionnaires. Using 20% of items endorsed as the threshold, 12 women were categorized as cognitive complainers (CC) and 11 were noncomplainers (NC). All subjects then took part in a functional magnetic resonance imaging scanning session during which they completed a visual-verbal N-back test of working memory. Results showed no difference in working memory performance between CC and NC groups. However, the CC group showed greater activation relative to the NC group in a broad network involved in working memory including the middle frontal gyrus (Brodmann area [BA] 9 and 10), the precuneus (BA 7), and the cingulate gyrus (BA 24 and 32). The CC group recruited additional regions of the working memory network compared with the NC group as the working memory load and difficulty of the task increased. This study showed brain activation differences during working memory performance in a middle-aged group of postmenopausal women with subjective cognitive complaints but without objective cognitive deficit. These findings suggest that subjective cognitive complaints in postmenopausal women might be associated with increased cortical activity during effort-demanding cognitive tasks. Copyright © 2013 Elsevier Inc. All rights reserved.

The effects of experimental pain and induced optimism on working memory task performance.

PubMed

Boselie, Jantine J L M; Vancleef, Linda M G; Peters, Madelon L

2016-07-01

Pain can interrupt and deteriorate executive task performance. We have previously shown that experimentally induced optimism can diminish the deteriorating effect of cold pressor pain on a subsequent working memory task (i.e., operation span task). In two successive experiments we sought further evidence for the protective role of optimism on pain-induced working memory impairments. We used another working memory task (i.e., 2-back task) that was performed either after or during pain induction. Study 1 employed a 2 (optimism vs. no-optimism)×2 (pain vs. no-pain)×2 (pre-score vs. post-score) mixed factorial design. In half of the participants optimism was induced by the Best Possible Self (BPS) manipulation, which required them to write and visualize about a life in the future where everything turned out for the best. In the control condition, participants wrote and visualized a typical day in their life (TD). Next, participants completed either the cold pressor task (CPT) or a warm water control task (WWCT). Before (baseline) and after the CPT or WWCT participants working memory performance was measured with the 2-back task. The 2-back task measures the ability to monitor and update working memory representation by asking participants to indicate whether the current stimulus corresponds to the stimulus that was presented 2 stimuli ago. Study 2 had a 2 (optimism vs. no-optimism)×2 (pain vs. no-pain) mixed factorial design. After receiving the BPS or control manipulation, participants completed the 2-back task twice: once with painful heat stimulation, and once without any stimulation (counter-balanced order). Continuous heat stimulation was used with temperatures oscillating around 1°C above and 1°C below the individual pain threshold. In study 1, the results did not show an effect of cold pressor pain on subsequent 2-back task performance. Results of study 2 indicated that heat pain impaired concurrent 2-back task performance. However, no evidence was found

Analyze the beta waves of electroencephalogram signals from young musicians and non-musicians in major scale working memory task.

PubMed

Hsu, Chien-Chang; Cheng, Ching-Wen; Chiu, Yi-Shiuan

2017-02-15

Electroencephalograms can record wave variations in any brain activity. Beta waves are produced when an external stimulus induces logical thinking, computation, and reasoning during consciousness. This work uses the beta wave of major scale working memory N-back tasks to analyze the differences between young musicians and non-musicians. After the feature analysis uses signal filtering, Hilbert-Huang transformation, and feature extraction methods to identify differences, k-means clustering algorithm are used to group them into different clusters. The results of feature analysis showed that beta waves significantly differ between young musicians and non-musicians from the low memory load of working memory task. Copyright © 2017 Elsevier B.V. All rights reserved.

Subvocal articulatory rehearsal during verbal working memory in multiple sclerosis.

PubMed

Sweet, Lawrence H; Vanderhill, Susan D; Jerskey, Beth A; Gordon, Norman M; Paul, Robert H; Cohen, Ronald A

2010-10-01

This study was designed to examine verbal working memory (VWM) components among multiple sclerosis (MS) patients and determine the influence of information processing speed. Of two frequently studied VWM sub-components, subvocal rehearsal was expected to be more affected by MS than short-term memory buffering. Furthermore, worse subvocal rehearsal was predicted to be specifically related to slower cognitive processing. Fifteen MS patients were administered a neuropsychological battery assessing VWM, processing speed, mood, fatigue, and disability. Participants performed a 2-Back VWM task with modified nested conditions designed to increase subvocal rehearsal (via inter-stimulus interval) and short-term memory buffering demands (via phonological similarity). Performance during these 2-Back conditions did not significantly differ and both exhibited strong positive correlations with disability. However, only scores on the subvocal rehearsal 2-Back were significantly related to performance on the remaining test battery, including processing speed and depressive symptoms. Findings suggest that performance during increased subvocal rehearsal demands is specifically influenced by cognitive processing speed and depressive symptoms.

Working Memory and Response Inhibition as One Integral Phenotype of Adult ADHD? A Behavioral and Imaging Correlational Investigation

ERIC Educational Resources Information Center

Schecklmann, Martin; Ehlis, Ann-Christine; Plichta, Michael M.; Dresler, Thomas; Heine, Monika; Boreatti-Hummer, Andrea; Romanos, Marcel; Jacob, Christian; Pauli, Paul; Fallgatter, Andreas J.

2013-01-01

Objective: It is an open question whether working memory (WM) and response inhibition (RI) constitute one integral phenotype in attention deficit hyperactivity disorder (ADHD). Method: The authors investigated 45 adult ADHD patients and 41 controls comparable for age, gender, intelligence, and education during a letter n-back and a stop-signal…

The effects of adaptive working memory training and mindfulness meditation training on processing efficiency and worry in high worriers.

PubMed

Course-Choi, Jenna; Saville, Harry; Derakshan, Nazanin

2017-02-01

Worry is the principle characteristic of generalised anxiety disorder, and has been linked to deficient attentional control, a main function of working memory (WM). Adaptive WM training and mindfulness meditation practice (MMP) have both shown potential to increase attentional control. The present study hence investigates the individual and combined effects of MMP and a dual adaptive n-back task on a non-clinical, randomised sample of high worriers. 60 participants were tested before and after seven days of training. Assessment included self-report questionnaires, as well as performance tasks measuring attentional control and working memory capacity. Combined training resulted in continued reduction in worry in the week after training, highlighting the potential of utilising n-back training as an adjunct to established clinical treatment. Engagement with WM training correlated with immediate improvements in attentional control and resilience, with worry decreasing over time. Implications of these findings and suggestions for future research are discussed. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Working Memory and Reasoning Benefit from Different Modes of Large-scale Brain Dynamics in Healthy Older Adults.

PubMed

Lebedev, Alexander V; Nilsson, Jonna; Lövdén, Martin

2018-07-01

Researchers have proposed that solving complex reasoning problems, a key indicator of fluid intelligence, involves the same cognitive processes as solving working memory tasks. This proposal is supported by an overlap of the functional brain activations associated with the two types of tasks and by high correlations between interindividual differences in performance. We replicated these findings in 53 older participants but also showed that solving reasoning and working memory problems benefits from different configurations of the functional connectome and that this dissimilarity increases with a higher difficulty load. Specifically, superior performance in a typical working memory paradigm ( n-back) was associated with upregulation of modularity (increased between-network segregation), whereas performance in the reasoning task was associated with effective downregulation of modularity. We also showed that working memory training promotes task-invariant increases in modularity. Because superior reasoning performance is associated with downregulation of modular dynamics, training may thus have fostered an inefficient way of solving the reasoning tasks. This could help explain why working memory training does little to promote complex reasoning performance. The study concludes that complex reasoning abilities cannot be reduced to working memory and suggests the need to reconsider the feasibility of using working memory training interventions to attempt to achieve effects that transfer to broader cognition.

Assessing the Driver’s Current Level of Working Memory Load with High Density Functional Near-infrared Spectroscopy: A Realistic Driving Simulator Study

PubMed Central

Unni, Anirudh; Ihme, Klas; Jipp, Meike; Rieger, Jochem W.

2017-01-01

Cognitive overload or underload results in a decrease in human performance which may result in fatal incidents while driving. We envision that driver assistive systems which adapt their functionality to the driver’s cognitive state could be a promising approach to reduce road accidents due to human errors. This research attempts to predict variations of cognitive working memory load levels in a natural driving scenario with multiple parallel tasks and to reveal predictive brain areas. We used a modified version of the n-back task to induce five different working memory load levels (from 0-back up to 4-back) forcing the participants to continuously update, memorize, and recall the previous ‘n’ speed sequences and adjust their speed accordingly while they drove for approximately 60 min on a highway with concurrent traffic in a virtual reality driving simulator. We measured brain activation using multichannel whole head, high density functional near-infrared spectroscopy (fNIRS) and predicted working memory load level from the fNIRS data by combining multivariate lasso regression and cross-validation. This allowed us to predict variations in working memory load in a continuous time-resolved manner with mean Pearson correlations between induced and predicted working memory load over 15 participants of 0.61 [standard error (SE) 0.04] and a maximum of 0.8. Restricting the analysis to prefrontal sensors placed over the forehead reduced the mean correlation to 0.38 (SE 0.04), indicating additional information gained through whole head coverage. Moreover, working memory load predictions derived from peripheral heart rate parameters achieved much lower correlations (mean 0.21, SE 0.1). Importantly, whole head fNIRS sampling revealed increasing brain activation in bilateral inferior frontal and bilateral temporo-occipital brain areas with increasing working memory load levels suggesting that these areas are specifically involved in workload-related processing. PMID

Direct comparison of prefrontal cortex regions engaged by working and long-term memory tasks.

PubMed

Braver, T S; Barch, D M; Kelley, W M; Buckner, R L; Cohen, N J; Miezin, F M; Snyder, A Z; Ollinger, J M; Akbudak, E; Conturo, T E; Petersen, S E

2001-07-01

Neuroimaging studies have suggested the involvement of ventrolateral, dorsolateral, and frontopolar prefrontal cortex (PFC) regions in both working (WM) and long-term memory (LTM). The current study used functional magnetic resonance imaging (fMRI) to directly compare whether these PFC regions show selective activation associated with one memory domain. In a within-subjects design, subjects performed the n-back WM task (two-back condition) as well as LTM encoding (intentional memorization) and retrieval (yes-no recognition) tasks. Additionally, each task was performed with two different types of stimulus materials (familiar words, unfamiliar faces) in order to determine the influence of material-type vs task-type. A bilateral region of dorsolateral PFC (DL-PFC; BA 46/9) was found to be selectively activated during the two-back condition, consistent with a hypothesized role for this region in active maintenance and/or manipulation of information in WM. Left frontopolar PFC (FP-PFC) was also found to be selectively engaged during the two-back. Although FP-PFC activity has been previously associated with retrieval from LTM, no frontopolar regions were found to be selectively engaged by retrieval. Finally, lateralized ventrolateral PFC (VL-PFC) regions were found to be selectively engaged by material-type, but uninfluenced by task-type. These results highlight the importance of examining PFC activity across multiple memory domains, both for functionally differentiating PFC regions (e.g., task-selectivity vs material-selectivity in DL-PFC and VL-PFC) and for testing the applicability of memory domain-specific theories (e.g., FP-PFC in LTM retrieval).

Activation of the occipital cortex and deactivation of the default mode network during working memory in the early blind.

PubMed

Park, Hae-Jeong; Chun, Ji-Won; Park, Bumhee; Park, Haeil; Kim, Joong Il; Lee, Jong Doo; Kim, Jae-Jin

2011-05-01

Although blind people heavily depend on working memory to manage daily life without visual information, it is not clear yet whether their working memory processing involves functional reorganization of the memory-related cortical network. To explore functional reorganization of the cortical network that supports various types of working memory processes in the early blind, we investigated activation differences between 2-back tasks and 0-back tasks using fMRI in 10 congenitally blind subjects and 10 sighted subjects. We used three types of stimulus sequences: words for a verbal task, pitches for a non-verbal task, and sound locations for a spatial task. When compared to the sighted, the blind showed additional activations in the occipital lobe for all types of stimulus sequences for working memory and more significant deactivation in the posterior cingulate cortex of the default mode network. The blind had increased effective connectivity from the default mode network to the left parieto-frontal network and from the occipital cortex to the right parieto-frontal network during the 2-back tasks than the 0-back tasks. These findings suggest not only cortical plasticity of the occipital cortex but also reorganization of the cortical network for the executive control of working memory.

Acute aerobic exercise increases cortical activity during working memory: a functional MRI study in female college students.

PubMed

Li, Lin; Men, Wei-Wei; Chang, Yu-Kai; Fan, Ming-Xia; Ji, Liu; Wei, Gao-Xia

2014-01-01

There is increasing evidence that acute aerobic exercise is associated with improved cognitive function. However, neural correlates of its cognitive plasticity remain largely unknown. The present study examined the effect of a session of acute aerobic exercise on working memory task-evoked brain activity as well as task performance. A within-subjects design with a counterbalanced order was employed. Fifteen young female participants (M = 19.56, SD = 0.81) were scanned using functional magnetic resonance imaging while performing a working memory task, the N-back task, both following an acute exercise session with 20 minutes of moderate intensity and a control rest session. Although an acute session of exercise did not improve behavioral performance, we observed that it had a significant impact on brain activity during the 2-back condition of the N-back task. Specifically, acute exercise induced increased brain activation in the right middle prefrontal gyrus, the right lingual gyrus, and the left fusiform gyrus as well as deactivations in the anterior cingulate cortexes, the left inferior frontal gyrus, and the right paracentral lobule. Despite the lack of an effect on behavioral measures, significant changes after acute exercise with activation of the prefrontal and occipital cortexes and deactivation of the anterior cingulate cortexes and left frontal hemisphere reflect the improvement of executive control processes, indicating that acute exercise could benefit working memory at a macro-neural level. In addition to its effects on reversing recent obesity and disease trends, our results provide substantial evidence highlighting the importance of promoting physical activity across the lifespan to prevent or reverse cognitive and neural decline.

Exposure to Blue Light Increases Subsequent Functional Activation of the Prefrontal Cortex During Performance of a Working Memory Task.

PubMed

Alkozei, Anna; Smith, Ryan; Pisner, Derek A; Vanuk, John R; Berryhill, Sarah M; Fridman, Andrew; Shane, Bradley R; Knight, Sara A; Killgore, William D S

2016-09-01

Prolonged exposure to blue wavelength light has been shown to have an alerting effect, and enhances performance on cognitive tasks. A small number of studies have also shown that relatively short exposure to blue light leads to changes in functional brain responses during the period of exposure. The extent to which blue light continues to affect brain functioning during a cognitively challenging task after cessation of longer periods of exposure (i.e., roughly 30 minutes or longer), however, has not been fully investigated. A total of 35 healthy participants (18 female) were exposed to either blue (469 nm) (n = 17) or amber (578 nm) (n = 18) wavelength light for 30 minutes in a darkened room, followed immediately by functional magnetic resonance imaging (fMRI) while undergoing a working memory task (N-back task). Participants in the blue light condition were faster in their responses on the N-back task and showed increased activation in the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortex compared to those in the amber control light condition. Furthermore, greater activation within the VLPFC was correlated with faster N-back response times. This is the first study to suggest that a relatively brief, single exposure to blue light has a subsequent beneficial effect on working memory performance, even after cessation of exposure, and leads to temporarily persisting functional brain changes within prefrontal brain regions associated with executive functions. These findings may have broader implication for using blue-enriched light in a variety of work settings where alertness and quick decision-making are important. © 2016 Associated Professional Sleep Societies, LLC.

Prediction of working memory performance in schizophrenia by plasma ratio of clozapine to N-desmethylclozapine.

PubMed

Rajji, Tarek K; Mulsant, Benoit H; Davies, Simon; Kalache, Sawsan M; Tsoutsoulas, Christopher; Pollock, Bruce G; Remington, Gary

2015-06-01

Clozapine's potent antagonism of muscarinic M1 receptors is thought to worsen working memory deficits associated with schizophrenia. In contrast, its major metabolite, N-desmethylclozapine (NDMC), is thought to enhance working memory via its M1 receptor agonist activity. The authors hypothesized that the ratio of serum clozapine and NDMC concentrations would be inversely associated with working memory performance in schizophrenia. Thirty patients with schizophrenia or schizoaffective disorder who were receiving clozapine monotherapy at bedtime completed the MATRICS Consensus Cognitive Battery (MCCB) on the day their blood was collected to assess concentrations of clozapine and NDMC as well as serum anticholinergic activity. The clozapine/NDMC ratio was significantly and negatively associated with working memory performance after controlling for age, gender, education, and symptom severity. No significant associations were found between individual clozapine and NDMC concentrations and working memory performance. Serum anticholinergic activity was significantly associated with clozapine concentration, but not with working memory performance or NDMC concentration. No significant associations were found between any pharmacological measure and performance on other MCCB cognitive domains. This hypothesis-driven study confirms that clozapine/NDMC ratio is a strong predictor of working memory performance in patients with schizophrenia. This finding suggests that manipulating the clozapine/NDMC ratio could enhance cognition in patients with schizophrenia treated with clozapine. It also supports the study of procholinergic agents, such as M1 receptor-positive allosteric modulators, to enhance cognition in schizophrenia.

Central load reduces peripheral processing: Evidence from incidental memory of background speech.

PubMed

Halin, Niklas; Marsh, John E; Sörqvist, Patrik

2015-12-01

Is there a trade-off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n-back task in one of two levels of central/cognitive load (i.e., 1-back or 2-back) in the presence of a to-be-ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n-back task was completed. Memory was poorer in the high central load (2-back) condition in comparison with the low central load (1-back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC) - with a superior ability for attentional engagement - remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing - as indexed by incidental memory of background speech - is constrained when task engagement is high. © 2015 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The Relationships of Working Memory, Secondary Memory, and General Fluid Intelligence: Working Memory is Special

PubMed Central

Shelton, Jill Talley; Elliott, Emily M.; Matthews, Russell A.; Hill, B. D.; Gouvier, Wm. Drew

2010-01-01

Recent efforts have been made to elucidate the commonly observed link between working memory and reasoning ability. The results have been inconsistent, with some work suggesting the emphasis placed on retrieval from secondary memory by working memory tests is the driving force behind this association (Mogle, Lovett, Stawski, & Sliwinski, 2008), while other research suggests retrieval from secondary memory is only partly responsible for the observed link between working memory and reasoning (Unsworth & Engle, 2006, 2007b). The present study investigates the relationship between processing speed, working memory, secondary memory, primary memory, and fluid intelligence. Although our findings show all constructs are significantly correlated with fluid intelligence, working memory, but not secondary memory, accounts for significant unique variance in fluid intelligence. Our data support predictions made by Unsworth and Engle, and suggest that the combined need for maintenance and retrieval processes present in working memory tests makes them “special” in their prediction of higher-order cognition. PMID:20438278

A functional MRI study of working memory task in euthymic bipolar disorder: evidence for task-specific dysfunction.

PubMed

Monks, Paul J; Thompson, Jill M; Bullmore, Edward T; Suckling, John; Brammer, Michael J; Williams, Steve C R; Simmons, Andrew; Giles, Nicola; Lloyd, Adrian J; Harrison, C Louise; Seal, Marc; Murray, Robin M; Ferrier, I Nicol; Young, Allan H; Curtis, Vivienne A

2004-12-01

Even when euthymic bipolar disorder patients can have persistent deficits in working memory, but the neural basis of this deficit remains unclear. We undertook an functional magnetic resonance imaging investigation of euthymic bipolar disorder patients performing two working memory paradigms; the two-back and Sternberg tasks, selected to examine the central executive and the phonological loop respectively. We hypothesized that neuronal dysfunction would be specific to the network underlying the executive rather than the phonological loop component of working memory. Twelve right-handed euthymic bipolar I males receiving lithium carbonate monotherapy were matched with 12 controls. The two-back task comprised a single working memory load contrasted with baseline vigilance condition. The Sternberg paradigm used a parametric design incorporating variable working memory load with fixed delay between presentation of an array of items to be remembered and a target item. Functional activation data were acquired during performance of the tasks and were analysed to produce brain activation maps representing significant group differences in activation (ANOVA). Load-response curves were derived from the Sternberg task data set. There were no significant between-group differences (t-test) in performance of the two-back task, or in 2 x 5 group by memory load ANOVA for the performance data from Sternberg task. In the two-back task, compared with controls bipolar disorder patients showed reductions in bilateral frontal, temporal and parietal activation, and increased activations with the left precentral, right medial frontal and left supramarginal gyri. No between-group differences were observed in the Sternberg task at any working memory load. Our findings support the notion that, in euthymic bipolar disorder, failure to engage fronto-executive function underpins the core neuropsychological deficits. Blackwell Munksgaard, 2004

Using Functional Near-Infrared Spectroscopy to Measure Effects of Delta 9-Tetrahydrocannabinol on Prefrontal Activity and Working Memory in Cannabis Users.

PubMed

Keles, Hasan O; Radoman, Milena; Pachas, Gladys N; Evins, A Eden; Gilman, Jodi M

2017-01-01

Intoxication from cannabis impairs cognitive performance, in part due to the effects of Δ9-tetrahydrocannabinol (THC, the primary psychoactive compound in cannabis) on prefrontal cortex (PFC) function. However, a relationship between impairment in cognitive functioning with THC administration and THC-induced change in hemodynamic response has not been demonstrated. We explored the feasibility of using functional near-infrared spectroscopy (fNIRS) to examine the functional changes of the human PFC associated with cannabis intoxication and cognitive impairment. Eighteen adult regular cannabis users (final sample, n = 13) performed a working memory task ( n -back) during fNIRS recordings, before and after receiving a single dose of oral synthetic THC (dronabinol; 20-50 mg). Functional data were collected using a continuous-wave NIRS device, in which 8 Sources and 7 detectors were placed on the forehead, resulting in 20 channels covering PFC regions. Physiological changes and subjective intoxication measures were collected. We found a significant increase in the oxygenated hemoglobin (HbO) concentration after THC administration in several channels on the PFC during both the high working memory load (2-back) and the low working memory load (0-back) condition. The increased HbO response was accompanied by a trend toward an increased number of omission errors after THC administration. The current study suggests that cannabis intoxication is associated with increases in hemodynamic blood flow to the PFC, and that this increase can be detected with fNIRS.

GABA level, gamma oscillation, and working memory performance in schizophrenia

PubMed Central

Chen, Chi-Ming A.; Stanford, Arielle D.; Mao, Xiangling; Abi-Dargham, Anissa; Shungu, Dikoma C.; Lisanby, Sarah H.; Schroeder, Charles E.; Kegeles, Lawrence S.

2014-01-01

A relationship between working memory impairment, disordered neuronal oscillations, and abnormal prefrontal GABA function has been hypothesized in schizophrenia; however, in vivo GABA measurements and gamma band neural synchrony have not yet been compared in schizophrenia. This case–control pilot study (N = 24) compared baseline and working memory task-induced neuronal oscillations acquired with high-density electroencephalograms (EEGs) to GABA levels measured in vivo with magnetic resonance spectroscopy. Working memory performance, baseline GABA level in the left dorsolateral prefrontal cortex (DLPFC), and measures of gamma oscillations from EEGs at baseline and during a working memory task were obtained. A major limitation of this study is a relatively small sample size for several analyses due to the integration of diverse methodologies and participant compliance. Working memory performance was significantly lower for patients than for controls. During the working memory task, patients (n = 7) had significantly lower amplitudes in gamma oscillations than controls (n = 9). However, both at rest and across working memory stages, there were significant correlations between gamma oscillation amplitude and left DLPFC GABA level. Peak gamma frequency during the encoding stage of the working memory task (n = 16) significantly correlated with GABA level and working memory performance. Despite gamma band amplitude deficits in patients across working memory stages, both baseline and working memory-induced gamma oscillations showed strong dependence on baseline GABA levels in patients and controls. These findings suggest a critical role for GABA function in gamma band oscillations, even under conditions of system and cognitive impairments as seen in schizophrenia. PMID:24749063

GABA level, gamma oscillation, and working memory performance in schizophrenia.

PubMed

Chen, Chi-Ming A; Stanford, Arielle D; Mao, Xiangling; Abi-Dargham, Anissa; Shungu, Dikoma C; Lisanby, Sarah H; Schroeder, Charles E; Kegeles, Lawrence S

2014-01-01

A relationship between working memory impairment, disordered neuronal oscillations, and abnormal prefrontal GABA function has been hypothesized in schizophrenia; however, in vivo GABA measurements and gamma band neural synchrony have not yet been compared in schizophrenia. This case-control pilot study (N = 24) compared baseline and working memory task-induced neuronal oscillations acquired with high-density electroencephalograms (EEGs) to GABA levels measured in vivo with magnetic resonance spectroscopy. Working memory performance, baseline GABA level in the left dorsolateral prefrontal cortex (DLPFC), and measures of gamma oscillations from EEGs at baseline and during a working memory task were obtained. A major limitation of this study is a relatively small sample size for several analyses due to the integration of diverse methodologies and participant compliance. Working memory performance was significantly lower for patients than for controls. During the working memory task, patients (n = 7) had significantly lower amplitudes in gamma oscillations than controls (n = 9). However, both at rest and across working memory stages, there were significant correlations between gamma oscillation amplitude and left DLPFC GABA level. Peak gamma frequency during the encoding stage of the working memory task (n = 16) significantly correlated with GABA level and working memory performance. Despite gamma band amplitude deficits in patients across working memory stages, both baseline and working memory-induced gamma oscillations showed strong dependence on baseline GABA levels in patients and controls. These findings suggest a critical role for GABA function in gamma band oscillations, even under conditions of system and cognitive impairments as seen in schizophrenia.

Dissociating Working Memory Updating and Automatic Updating: The Reference-Back Paradigm

ERIC Educational Resources Information Center

Rac-Lubashevsky, Rachel; Kessler, Yoav

2016-01-01

Working memory (WM) updating is a controlled process through which relevant information in the environment is selected to enter the gate to WM and substitute its contents. We suggest that there is also an automatic form of updating, which influences performance in many tasks and is primarily manifested in reaction time sequential effects. The goal…

Working Memory Load and Reminder Effect on Event-Based Prospective Memory of High- and Low-Achieving Students in Math

ERIC Educational Resources Information Center

Chen, Youzhen; Lian, Rong; Yang, Lixian; Liu, Jianrong; Meng, Yingfang

2017-01-01

The effects of working memory (WM) demand and reminders on an event-based prospective memory (PM) task were compared between students with low and high achievement in math. WM load (1- and 2-back tasks) was manipulated as a within-subject factor and reminder (with or without reminder) as a between-subject factor. Results showed that high-achieving…

Do complaints of everyday cognitive failures in high schizotypy relate to emotional working memory deficits in the lab?

PubMed

Carrigan, Nicole; Barkus, Emma; Ong, Adriel; Wei, Maryann

2017-10-01

Individuals high on schizotypy complain of increased cognitive failures in everyday life. However, the neuropsychological performance of this group does not consistently indicate underlying ability deficits. It is possible that current neuropsychological tests lack ecological validity. Given the increased affective reactivity of high schizotypes, they may be more sensitive to emotional content interfering with cognitive ability. This study sought to explore whether an affective n-back working memory task would elicit impaired performance in schizotypy, echoing complaints concerning real world cognition. 127 healthy participants completed self-report measures of schizotypy and cognitive failures and an affective n-back working memory task. This task was varied across three levels of load (1- to 3-back) and four types of stimulus emotion (neutral, fearful, happy, sad). Differences between high (n=39) and low (n=48) schizotypy groups on performance outcomes of hits and false alarms were examined, with emotion and load as within-groups variables. As expected, high schizotypes reported heightened vulnerability to cognitive failures. They also demonstrated a relative working memory impairment for emotional versus neutral stimuli, whereas low schizotypes did not. High schizotypes performed most poorly in response to fearful stimuli. For false alarms, there was an interaction between schizotypy, load, and emotion, such that high schizotypy was associated with deficits in response to fearful stimuli only at higher levels of task difficulty. Inclusion of self-reported cognitive failures did not account for this. These findings suggest that the "gap" between subjective and objective cognition in schizotypy may reflect the heightened emotional demands associated with cognitive functioning in the real world, although other factors also seem to play a role. There is a need to improve the ecological validity of objective assessments, whilst also recognizing that self

Low-Arousal Speech Noise Improves Performance in N-Back Task: An ERP Study

PubMed Central

Zhang, Dandan; Jin, Yi; Luo, Yuejia

2013-01-01

The relationship between noise and human performance is a crucial topic in ergonomic research. However, the brain dynamics of the emotional arousal effects of background noises are still unclear. The current study employed meaningless speech noises in the n-back working memory task to explore the changes of event-related potentials (ERPs) elicited by the noises with low arousal level vs. high arousal level. We found that the memory performance in low arousal condition were improved compared with the silent and the high arousal conditions; participants responded more quickly and had larger P2 and P3 amplitudes in low arousal condition while the performance and ERP components showed no significant difference between high arousal and silent conditions. These findings suggested that the emotional arousal dimension of background noises had a significant influence on human working memory performance, and that this effect was independent of the acoustic characteristics of noises (e.g., intensity) and the meaning of speech materials. The current findings improve our understanding of background noise effects on human performance and lay the ground for the investigation of patients with attention deficits. PMID:24204607

Spatial working memory impairment in primary onset middle-age type 2 diabetes mellitus: An ethology and BOLD-fMRI study.

PubMed

Huang, Ran-Ran; Jia, Bao-Hui; Xie, Lei; Ma, Shu-Hua; Yin, Jing-Jing; Sun, Zong-Bo; Le, Hong-Bo; Xu, Wen-Can; Huang, Jin-Zhuang; Luo, Dong-Xue

2016-01-01

To explore mild cognitive dysfunction and/or spatial working memory impairment in patients with primary onset middle-age type 2 diabetes mellitus (T2DM] using ethology (behavior tests) and blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI). Eighteen primary onset T2DM patients and 18 matched subjects with normal blood glucose levels were all tested using the Montreal cognitive assessment scale test, the Wechsler Memory Scale Chinese-revised test, and scanned using BOLD-fMRI (1.5T, EPI sequence) while performing the n-back task to find the activation intensity of some cognition-related areas. The ethology results showed that T2DM patients had a mild cognitive impairment and memory dysfunction (P < 0.05). The fMRI scan identified a neural network consisting of bilateral dorsolateral prefrontal cortex (DLPFC), bilateral premotor area (PreMA), bilateral parietal lobe (PA), and anterior cingulate cortex (ACC) / supplementary motor area (SMA) that was activated during the n-back task, with right hemisphere dominance. However, only the right PA and ACC/SMA showed a load effect via quantitative analysis in the T2DM group; the activation intensity of most working memory-related brain areas for the T2DM group were lower than for the control group under three memory loads. Furthermore, we found that the activation intensity of some cognition-related areas, including the right insular lobe, left caudate nucleus, and bilateral hippocampus/parahippocampal gyrus were lower than the control group under the memory loads. Diabetes-related brain damage of primary onset middle-age T2DM patients with right DLPFC-posterior parietal lobe and parahippocampal gyrus default network causes impairment of spatial working memory and mild cognitive dysfunction. © 2015 Wiley Periodicals, Inc.

Age differences in short-term memory binding are related to working memory performance across the lifespan.

PubMed

Fandakova, Yana; Sander, Myriam C; Werkle-Bergner, Markus; Shing, Yee Lee

2014-03-01

Memory performance increases during childhood and adolescence, and decreases in old age. Among younger adults, better ability to bind items to the context in which they were experienced is associated with higher working memory performance (Oberauer, 2005). Here, we examined the extent to which age differences in binding contribute to life span age differences in short-term memory (STM). Younger children (N = 85; 10 to 12 years), teenagers (N = 41; 13 to 15 years), younger adults (N = 84; 20 to 25 years), and older adults (N = 86; 70 to 75 years) worked on global and local short-term recognition tasks that are assumed to measure item and item-context memory, respectively. Structural equation models showed that item-context bindings are functioning less well in children and older adults compared with younger adults and teenagers. This result suggests protracted development of the ability to form and recollect detailed short-term memories, and decline of this ability in aging. Across all age groups, better item-context binding was associated with higher working memory performance, indicating that developmental differences in binding mechanisms are closely related to working memory development in childhood and old age. (c) 2014 APA, all rights reserved.

Working memory capacity and redundant information processing efficiency.

PubMed

Endres, Michael J; Houpt, Joseph W; Donkin, Chris; Finn, Peter R

2015-01-01

Working memory capacity (WMC) is typically measured by the amount of task-relevant information an individual can keep in mind while resisting distraction or interference from task-irrelevant information. The current research investigated the extent to which differences in WMC were associated with performance on a novel redundant memory probes (RMP) task that systematically varied the amount of to-be-remembered (targets) and to-be-ignored (distractor) information. The RMP task was designed to both facilitate and inhibit working memory search processes, as evidenced by differences in accuracy, response time, and Linear Ballistic Accumulator (LBA) model estimates of information processing efficiency. Participants (N = 170) completed standard intelligence tests and dual-span WMC tasks, along with the RMP task. As expected, accuracy, response-time, and LBA model results indicated memory search and retrieval processes were facilitated under redundant-target conditions, but also inhibited under mixed target/distractor and redundant-distractor conditions. Repeated measures analyses also indicated that, while individuals classified as high (n = 85) and low (n = 85) WMC did not differ in the magnitude of redundancy effects, groups did differ in the efficiency of memory search and retrieval processes overall. Results suggest that redundant information reliably facilitates and inhibits the efficiency or speed of working memory search, and these effects are independent of more general limits and individual differences in the capacity or space of working memory.

Confident failures: Lapses of working memory reveal a metacognitive blind spot.

PubMed

Adam, Kirsten C S; Vogel, Edward K

2017-07-01

Working memory performance fluctuates dramatically from trial to trial. On many trials, performance is no better than chance. Here, we assessed participants' awareness of working memory failures. We used a whole-report visual working memory task to quantify both trial-by-trial performance and trial-by-trial subjective ratings of inattention to the task. In Experiment 1 (N = 41), participants were probed for task-unrelated thoughts immediately following 20% of trials. In Experiment 2 (N = 30), participants gave a rating of their attentional state following 25% of trials. Finally, in Experiments 3a (N = 44) and 3b (N = 34), participants reported confidence of every response using a simple mouse-click judgment. Attention-state ratings and off-task thoughts predicted the number of items correctly identified on each trial, replicating previous findings that subjective measures of attention state predict working memory performance. However, participants correctly identified failures on only around 28% of failure trials. Across experiments, participants' metacognitive judgments reliably predicted variation in working memory performance but consistently and severely underestimated the extent of failures. Further, individual differences in metacognitive accuracy correlated with overall working memory performance, suggesting that metacognitive monitoring may be key to working memory success.

Working memory consolidation: insights from studies on attention and working memory.

PubMed

Ricker, Timothy J; Nieuwenstein, Mark R; Bayliss, Donna M; Barrouillet, Pierre

2018-04-10

Working memory, the system that maintains a limited set of representations for immediate use in cognition, is a central part of human cognition. Three processes have recently been proposed to govern information storage in working memory: consolidation, refreshing, and removal. Here, we discuss in detail the theoretical construct of working memory consolidation, a process critical to the creation of a stable working memory representation. We present a brief overview of the research that indicated the need for a construct such as working memory consolidation and the subsequent research that has helped to define the parameters of the construct. We then move on to explicitly state the points of agreement as to what processes are involved in working memory consolidation. © 2018 New York Academy of Sciences.

Brain and effort: brain activation and effort-related working memory in healthy participants and patients with working memory deficits.

PubMed

Engström, Maria; Landtblom, Anne-Marie; Karlsson, Thomas

2013-01-01

Despite the interest in the neuroimaging of working memory, little is still known about the neurobiology of complex working memory in tasks that require simultaneous manipulation and storage of information. In addition to the central executive network, we assumed that the recently described salience network [involving the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC)] might be of particular importance to working memory tasks that require complex, effortful processing. Healthy participants (n = 26) and participants suffering from working memory problems related to the Kleine-Levin syndrome (KLS) (a specific form of periodic idiopathic hypersomnia; n = 18) participated in the study. Participants were further divided into a high- and low-capacity group, according to performance on a working memory task (listening span). In a functional magnetic resonance imaging (fMRI) study, participants were administered the reading span complex working memory task tapping cognitive effort. The fMRI-derived blood oxygen level dependent (BOLD) signal was modulated by (1) effort in both the central executive and the salience network and (2) capacity in the salience network in that high performers evidenced a weaker BOLD signal than low performers. In the salience network there was a dichotomy between the left and the right hemisphere; the right hemisphere elicited a steeper increase of the BOLD signal as a function of increasing effort. There was also a stronger functional connectivity within the central executive network because of increased task difficulty. The ability to allocate cognitive effort in complex working memory is contingent upon focused resources in the executive and in particular the salience network. Individual capacity during the complex working memory task is related to activity in the salience (but not the executive) network so that high-capacity participants evidence a lower signal and possibly hence a larger dynamic response.

Brain and effort: brain activation and effort-related working memory in healthy participants and patients with working memory deficits

PubMed Central

Engström, Maria; Landtblom, Anne-Marie; Karlsson, Thomas

2013-01-01

Despite the interest in the neuroimaging of working memory, little is still known about the neurobiology of complex working memory in tasks that require simultaneous manipulation and storage of information. In addition to the central executive network, we assumed that the recently described salience network [involving the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC)] might be of particular importance to working memory tasks that require complex, effortful processing. Method: Healthy participants (n = 26) and participants suffering from working memory problems related to the Kleine–Levin syndrome (KLS) (a specific form of periodic idiopathic hypersomnia; n = 18) participated in the study. Participants were further divided into a high- and low-capacity group, according to performance on a working memory task (listening span). In a functional magnetic resonance imaging (fMRI) study, participants were administered the reading span complex working memory task tapping cognitive effort. Principal findings: The fMRI-derived blood oxygen level dependent (BOLD) signal was modulated by (1) effort in both the central executive and the salience network and (2) capacity in the salience network in that high performers evidenced a weaker BOLD signal than low performers. In the salience network there was a dichotomy between the left and the right hemisphere; the right hemisphere elicited a steeper increase of the BOLD signal as a function of increasing effort. There was also a stronger functional connectivity within the central executive network because of increased task difficulty. Conclusion: The ability to allocate cognitive effort in complex working memory is contingent upon focused resources in the executive and in particular the salience network. Individual capacity during the complex working memory task is related to activity in the salience (but not the executive) network so that high-capacity participants evidence a lower signal and possibly

Effects of Negative Affect, Urge to Smoke, and Working Memory Performance (n-back) on Nicotine Dependence.

PubMed

Lechner, William V; L Gunn, Rachel; Minto, Alexia; Philip, Noah S; Brown, Richard A; Uebelacker, Lisa A; Price, Lawrence H; Abrantes, Ana M

2018-06-07

Three key domains including negative emotionality, incentive salience, and executive function form the core functional elements of addictive behaviors. Variables related to these broader domains have been studied extensively in relation to one another; however, no studies to date, have examined models including variables from all three domains, in relation to nicotine dependence. Smokers (N = 117), 65.8% female, 78% white, mean age of 44.4 (SD = 10.8), enrolled in a smoking cessation program completed measures of negative affect (a component of negative emotionality), urge to smoke (incentive salience), and working memory (WM; a core executive function), during a baseline assessment period prior to initiating treatment. Negative affect was associated with greater urge to smoke, and this elevated urge to smoke was associated with higher levels of nicotine dependence. Further, a significant moderated mediation indicated that WM moderated the relationship between increased urge to smoke and nicotine dependence. For those with low to average WM, urge to smoke was significantly related to nicotine dependence; however, for those with higher WM (+1 SD), urge to smoke stemming from negative affect was not associated with nicotine dependence. To our knowledge, this is the first reported relationship between negative affect, urge to smoke, WM, and nicotine dependence. Although preliminary, results indicate that WM may moderate the relationship between urge to smoke associated with negative affect and nicotine dependence. Treatments targeting WM may be particularly useful for individuals with average to low WM who experience urge to smoke related to negative affect.

Training and transfer effects of N-back training for brain-injured and healthy subjects.

PubMed

Lindeløv, Jonas Kristoffer; Dall, Jonas Olsen; Kristensen, Casper Daniel; Aagesen, Marie Holt; Olsen, Stine Almgren; Snuggerud, Therese Ruud; Sikorska, Anna

2016-10-01

Working memory impairments are prevalent among patients with acquired brain injury (ABI). Computerised training targeting working memory has been researched extensively using samples from healthy populations but this field remains isolated from similar research in ABI patients. We report the results of an actively controlled randomised controlled trial in which 17 patients and 18 healthy subjects completed training on an N-back task. The healthy group had superior improvements on both training tasks (SMD = 6.1 and 3.3) whereas the ABI group improved much less (SMD = 0.5 and 1.1). Neither group demonstrated transfer to untrained tasks. We conclude that computerised training facilitates improvement of specific skills rather than high-level cognition in healthy and ABI subjects alike. The acquisition of these specific skills seems to be impaired by brain injury. The most effective use of computer-based cognitive training may be to make the task resemble the targeted behaviour(s) closely in order to exploit the stimulus-specificity of learning.

Components of working memory and visual selective attention.

PubMed

Burnham, Bryan R; Sabia, Matthew; Langan, Catherine

2014-02-01

Load theory (Lavie, N., Hirst, A., De Fockert, J. W., & Viding, E. [2004]. Load theory of selective attention and cognitive control. Journal of Experimental Psychology: General, 133, 339-354.) proposes that control of attention depends on the amount and type of load that is imposed by current processing. Specifically, perceptual load should lead to efficient distractor rejection, whereas working memory load (dual-task coordination) should hinder distractor rejection. Studies support load theory's prediction that working memory load will lead to larger distractor effects; however, these studies used secondary tasks that required only verbal working memory and the central executive. The present study examined which other working memory components (visual, spatial, and phonological) influence visual selective attention. Subjects completed an attentional capture task alone (single-task) or while engaged in a working memory task (dual-task). Results showed that along with the central executive, visual and spatial working memory influenced selective attention, but phonological working memory did not. Specifically, attentional capture was larger when visual or spatial working memory was loaded, but phonological working memory load did not affect attentional capture. The results are consistent with load theory and suggest specific components of working memory influence visual selective attention. PsycINFO Database Record (c) 2014 APA, all rights reserved.

A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance

NASA Astrophysics Data System (ADS)

Astrand, Elaine

2018-06-01

Objective. Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Approach. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, n\\in [1,2] . Main results. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. Significance. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain–machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or

The effects of long-term stress on neural dynamics of working memory processing: An investigation using ERP

PubMed Central

Yuan, Yiran; Leung, Ada W. S.; Duan, Hongxia; Zhang, Liang; Zhang, Kan; Wu, Jianhui; Qin, Shaozheng

2016-01-01

This study examined the neural dynamics of working memory (WM) processing under long-term stress. Forty participants who had been exposed to a long period of major exam preparation (six months) and twenty-one control participants performed a numerical n-back task (n = 1, 2) while electroencephalograms were recorded. Psychological and endocrinal measurements confirmed significantly higher levels of long-term stress for participants in the exam group. The exam group showed significantly increased P2 amplitude in the frontal-central sites in the 1-back and 2-back conditions, whereas other ERP components, including the P1, N1 and P3 and behavioral performance, were unchanged. Notably, the P2 effect was most pronounced in participants in the exam group who reported perceiving high levels of stress. The perceived stress scores positively correlated with the P2 amplitude in the 1-back and 2-back conditions. These results suggest that long-term stress has an impact on attention and the initiation of the updating process in WM. PMID:27000528

Double dissociation of working memory and attentional processes in smokers and non-smokers with and without nicotine.

PubMed

Grundey, Jessica; Amu, Rosa; Ambrus, Géza Gergely; Batsikadze, Georgi; Paulus, Walter; Nitsche, Michael A

2015-07-01

Nicotine has been shown to affect cortical excitability measured using transcranial magnetic stimulation in smoking and non-smoking subjects in different ways. In tobacco-deprived smokers, administration of nicotine restores compromised cortical facilitation while in non-smokers, it enhances cortical inhibition. As cortical excitability and activity are closely linked to cognitive processes, we aimed to explore whether nicotine-induced physiological alterations in non-smokers and smokers are associated with cognitive changes. Specifically, we assessed the impact of nicotine on working memory performance (n-back letter task) and on attentional processes (Stroop interference test) in healthy smokers and non-smokers. Both tasks have been shown to rely on prefrontal areas, and nicotinic receptors are relevantly involved in prefrontal function. Sixteen smoking and 16 non-smoking subjects participated in the 3-back letter task and 21 smoking and 21 non-smoking subjects in the Stroop test after the respective application of placebo or nicotine patches. The results show that working memory and attentional processes are compromised in nicotine-deprived smokers compared to non-smoking individuals. After administration of nicotine, working memory performance in smokers improved, while non-smoking subjects displayed decreased accuracy with increased number of errors. The effects have been shown to be more apparent for working memory performance than attentional processes. In summary, cognitive functions can be restored by nicotine in deprived smokers, whereas non-smokers do not gain additional benefit. The respective changes are in accordance with related effects of nicotine on cortical excitability in both groups.

ALE Meta-Analysis of Schizophrenics Performing the N-Back Task

NASA Astrophysics Data System (ADS)

Harrell, Zachary

2010-10-01

MRI/fMRI has already proven itself as a valuable tool in the diagnosis and treatment of many illnesses of the brain, including cognitive problems. By exploiting the differences in magnetic susceptibility between oxygenated and deoxygenated hemoglobin, fMRI can measure blood flow in various regions of interest within the brain. This can determine the level of brain activity in relation to motor or cognitive functions and provide a metric for tissue damage or illness symptoms. Structural imaging techniques have shown lesions or deficiencies in tissue volumes in schizophrenics corresponding to areas primarily in the frontal and temporal lobes. These areas are currently known to be involved in working memory and attention, which many schizophrenics have trouble with. The ALE (Activation Likelihood Estimation) Meta-Analysis is able to statistically determine the significance of brain area activations based on the post-hoc combination of multiple studies. This process is useful for giving a general model of brain function in relation to a particular task designed to engage the affected areas (such as working memory for the n-back task). The advantages of the ALE Meta-Analysis include elimination of single subject anomalies, elimination of false/extremely weak activations, and verification of function/location hypotheses.

Attention and Working Memory in Adolescents with Autism Spectrum Disorder: A Functional MRI Study.

PubMed

Rahko, Jukka S; Vuontela, Virve A; Carlson, Synnöve; Nikkinen, Juha; Hurtig, Tuula M; Kuusikko-Gauffin, Sanna; Mattila, Marja-Leena; Jussila, Katja K; Remes, Jukka J; Jansson-Verkasalo, Eira M; Aronen, Eeva T; Pauls, David L; Ebeling, Hanna E; Tervonen, Osmo; Moilanen, Irma K; Kiviniemi, Vesa J

2016-06-01

The present study examined attention and memory load-dependent differences in the brain activation and deactivation patterns between adolescents with autism spectrum disorders (ASDs) and typically developing (TD) controls using functional magnetic resonance imaging. Attentional (0-back) and working memory (WM; 2-back) processing and load differences (0 vs. 2-back) were analysed. WM-related areas activated and default mode network deactivated normally in ASDs as a function of task load. ASDs performed the attentional 0-back task similarly to TD controls but showed increased deactivation in cerebellum and right temporal cortical areas and weaker activation in other cerebellar areas. Increasing task load resulted in multiple responses in ASDs compared to TD and in inadequate modulation of brain activity in right insula, primary somatosensory, motor and auditory cortices. The changes during attentional task may reflect compensatory mechanisms enabling normal behavioral performance. The inadequate memory load-dependent modulation of activity suggests diminished compensatory potential in ASD.

Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

PubMed Central

Gathmann, Bettina; Schiebener, Johannes; Wolf, Oliver T.; Brand, Matthias

2015-01-01

Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring—an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task). This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST) and the newly developed Balanced Switching Task (BST), measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task. PMID:25741308

Mild Jugular Compression Collar Ameliorated Changes in Brain Activation of Working Memory after One Soccer Season in Female High School Athletes.

PubMed

Yuan, Weihong; Dudley, Jonathan; Barber Foss, Kim D; Ellis, Jonathan D; Thomas, Staci; Galloway, Ryan T; DiCesare, Christopher A; Leach, James L; Adams, Janet; Maloney, Thomas; Gadd, Brooke; Smith, David; Epstein, Jeff N; Grooms, Dustin R; Logan, Kelsey; Howell, David R; Altaye, Mekibib; Myer, Gregory D

2018-06-01

Recent neuroimaging studies have suggested that repetitive subconcussive head impacts, even after only one sport season, may lead to pre- to post-season structural and functional alterations in male high school football athletes. However, data on female athletes are limited. In the current investigation, we aimed to (1) assess the longitudinal pre- to post-season changes in functional MRI (fMRI) of working memory and working memory performance, (2) quantify the association between the pre- to post-season change in fMRI of working memory and the exposure to head impact and working memory performance, and (3) assess whether wearing a neck collar designed to reduce intracranial slosh via mild compression of the jugular veins can ameliorate the changes in fMRI brain activation observed in the female high school athletes who did not wear collars after a full soccer season. A total of 48 female high school soccer athletes (age range: 14.00-17.97 years) were included in the study. These athletes were assigned to the non-collar group (n = 21) or to the collar group (n = 27). All athletes undewent MRI at both pre-season and post-season. In each session, a fMRI verbal N-Back task was used to engage working memory. A significant pre- to post-season increase in fMRI blood oxygen level dependent (BOLD) signal was demonstrated when performing the N-back working memory task in the non-collar group but not in the collar group, despite the comparable exposure to head impacts during the season between the two groups. The collar group demonstrated significantly smaller pre- to post-season change in fMRI BOLD signal than the non-collar group, suggesting a potential protective effect from the collar device. Significant correlations were also found between the pre- to post-season increase in fMRI brain activation and the decrease in task accuracy in the non-collar group, indicating an association between the compensatory mechanism in underlying neurophysiology and the alteration

No differences in performance on test of working memory and executive functioning between healthy elderly postmenopausal women using or not using hormone therapy.

PubMed

Grigorova, M; Sherwin, B B

2006-06-01

On average, ovarian function ceases at the age of 52 years so that estrogen (E) levels are chronically low following the menopause. Numerous studies have found that hormone therapy (HT) helps to protect verbal memory, a hippocampal function. Estrogen receptors are also found in the prefrontal cortex (PFC), suggesting that estrogen may modulate executive and working memory functions, both mediated by the PFC. The possible role of progesterone (P) on executive functions and working memory is unknown. To examine the relationship between neuropsychological performance, age of initiation of HT, and duration of HT use. In this cross-sectional study, the neuropsychological performance of 37 postmenopausal women (mean age, 65 years) who used either estrogen-only or sequential E + P (E-alone group)(n = 22) or E + P continuously (n = 15) was compared to that of 28 healthy postmenopausal women matched for age and education who had never used HT. It was hypothesized that the E-only users would perform better then the E + P and the never-users on neuropsychological tests of verbal memory, executive function and working memory. Results showed only minor between-group differences on working memory scores such that the E + P users were slowest to generate a response on the N-Back test of working memory. No group differences on tests of executive functions were found. There was no relationship between neuropsychological performance, age of initiation of HT, or duration of HT use.

Characterizing "fibrofog": Subjective appraisal, objective performance, and task-related brain activity during a working memory task.

PubMed

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L; Rayhan, Rakib; VanMeter, John W; Gracely, Richard H

2016-01-01

The subjective experience of cognitive dysfunction ("fibrofog") is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, "fibrofog" appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks.

Working Memory in Children with Reading Disabilities and/or Mathematical Disabilities

ERIC Educational Resources Information Center

De Weerdt, Frauke; Desoete, Annemie; Roeyers, Herbert

2013-01-01

Elementary school children with reading disabilities (RD; "n" = 17), mathematical disabilities (MD; "n" = 22), or combined reading and mathematical disabilities (RD+MD; "n" = 28) were compared to average achieving (AA; "n" = 45) peers on working memory measures. On all working memory components, 2 (RD vs. no…

Working memory capacity and visual-verbal cognitive load modulate auditory-sensory gating in the brainstem: toward a unified view of attention.

PubMed

Sörqvist, Patrik; Stenfelt, Stefan; Rönnberg, Jerker

2012-11-01

Two fundamental research questions have driven attention research in the past: One concerns whether selection of relevant information among competing, irrelevant, information takes place at an early or at a late processing stage; the other concerns whether the capacity of attention is limited by a central, domain-general pool of resources or by independent, modality-specific pools. In this article, we contribute to these debates by showing that the auditory-evoked brainstem response (an early stage of auditory processing) to task-irrelevant sound decreases as a function of central working memory load (manipulated with a visual-verbal version of the n-back task). Furthermore, individual differences in central/domain-general working memory capacity modulated the magnitude of the auditory-evoked brainstem response, but only in the high working memory load condition. The results support a unified view of attention whereby the capacity of a late/central mechanism (working memory) modulates early precortical sensory processing.

Central additive effect of Ginkgo biloba and Rhodiola rosea on psychomotor vigilance task and short-term working memory accuracy.

PubMed

Al-Kuraishy, Hayder M

2016-01-01

The present study investigates the effect of combined treatment with Ginkgo biloba and/or Rhodiola rosea on psychomotor vigilance task (PVT) and short-term working memory accuracy. A total number of 112 volunteers were enrolled to study the effect of G. biloba and R. rosea on PVT and short-term working memory accuracy as compared to placebo effects, the central cognitive effect was assessed by critical flicker-fusion frequency, PVT, and computerized N-back test. Placebo produced no significant effects on all neurocognitive tests measure P > 0.05 in normal healthy volunteers, G. biloba or R. rosea improve PVT and low to moderate working memory accuracy, The combined effect of R. rosea and G. biloba leading to more significant effect on PVT, all levels of short-term working memory accuracy and critical fusion versus flicker P < 0.01, more than of G. biloba or R. rosea when they used alone. The combined effect of R. rosea and G. biloba leading to a more significant effect on cognitive function than either G. biloba or R. rosea when they used alone.

Working memory training may increase working memory capacity but not fluid intelligence.

PubMed

Harrison, Tyler L; Shipstead, Zach; Hicks, Kenny L; Hambrick, David Z; Redick, Thomas S; Engle, Randall W

2013-12-01

Working memory is a critical element of complex cognition, particularly under conditions of distraction and interference. Measures of working memory capacity correlate positively with many measures of real-world cognition, including fluid intelligence. There have been numerous attempts to use training procedures to increase working memory capacity and thereby performance on the real-world tasks that rely on working memory capacity. In the study reported here, we demonstrated that training on complex working memory span tasks leads to improvement on similar tasks with different materials but that such training does not generalize to measures of fluid intelligence.

Working Memory Processing In Normal Subjects and Subjects with Dyslexia

NASA Astrophysics Data System (ADS)

Bowyer, S. M.; Lajiness-O'Neill, R.; Weiland, B. J.; Mason, K.; Tepley, N.

2004-10-01

Magnetoencephalography (MEG) was used to determine the neuroanatomical location of working memory (WM) processes. Differences between subjects with dyslexia (SD; n=5) and normal readers (NR; n=5) were studied during two WM tasks. A spatial WM task (SMW) consisted of blocks visually presented in one of 12 positions for 2 s each. Subjects were to determine if the current position matched the position presented 2 slides earlier (N-Back Test). The verbal task (VMW) consisted of presentation of a single letter. The location of cortical activity during SWM in NR (determined with MR-FOCUSS analysis) was in the right superior temporal gyrus (STG) and right angular gyrus (AG). Similar activation was seen in SD with a slight delay of approximately 20 ms. During VWM activity was seen in LEFT STG and LEFT AG in NR. In contrast for SD, activation was in the RIGHT STG and RIGHT AG. This study demonstrates the possibility to differentiate WM processing in subjects with and without learning disorders.

Short-Term Memory Maintenance of Object Locations during Active Navigation: Which Working Memory Subsystem Is Essential?

PubMed Central

Baumann, Oliver; Skilleter, Ashley J.; Mattingley, Jason B.

2011-01-01

The goal of the present study was to examine the extent to which working memory supports the maintenance of object locations during active spatial navigation. Participants were required to navigate a virtual environment and to encode the location of a target object. In the subsequent maintenance period they performed one of three secondary tasks that were designed to selectively load visual, verbal or spatial working memory subsystems. Thereafter participants re-entered the environment and navigated back to the remembered location of the target. We found that while navigation performance in participants with high navigational ability was impaired only by the spatial secondary task, navigation performance in participants with poor navigational ability was impaired equally by spatial and verbal secondary tasks. The visual secondary task had no effect on navigation performance. Our results extend current knowledge by showing that the differential engagement of working memory subsystems is determined by navigational ability. PMID:21629686

Effects of levodopa on corticostriatal circuits supporting working memory in Parkinson's disease.

PubMed

Simioni, Alison C; Dagher, Alain; Fellows, Lesley K

2017-08-01

Working memory dysfunction is common in Parkinson's disease, even in its early stages, but its neural basis is debated. Working memory performance likely reflects a balance between corticostriatal dysfunction and compensatory mechanisms. We tested this hypothesis by examining working memory performance with a letter n-back task in 19 patients with mild-moderate Parkinson's disease and 20 demographically matched healthy controls. Parkinson's disease patients were tested after an overnight washout of their usual dopamine replacement therapy, and again after a standard dose of levodopa. FMRI was used to assess task-related activation and resting state functional connectivity; changes in BOLD signal were related to performance to disentangle pathological and compensatory processes. Parkinson's disease patients off dopamine replacement therapy displayed significantly reduced spatial extent of task-related activation in left prefrontal and bilateral parietal cortex, and poorer working memory performance, compared to controls. Amongst the Parkinson's disease patients off dopamine replacement therapy, relatively better performance was associated with greater activation of right dorsolateral prefrontal cortex compared to controls, consistent with compensatory right hemisphere recruitment. Administration of levodopa remediated the working memory deficit in the Parkinson's disease group, and resulted in a different pattern of performance-correlated activity, with a shift to greater left ventrolateral prefrontal cortex activation in patients on, compared to off dopamine replacement therapy. Levodopa also significantly increased resting-state functional connectivity between caudate and right parietal cortex (within the right fronto-parietal attentional network). The strength of this connectivity contributed to better performance in patients and controls, suggesting a general compensatory mechanism. These findings argue that Parkinson's disease patients can recruit additional

Nanoscale Multigate TiN Metal Nanocrystal Memory Using High-k Blocking Dielectric and High-Work-Function Gate Electrode Integrated on Silcon-on-Insulator Substrate

NASA Astrophysics Data System (ADS)

Lu, Chi-Pei; Luo, Cheng-Kei; Tsui, Bing-Yue; Lin, Cha-Hsin; Tzeng, Pei-Jer; Wang, Ching-Chiun; Tsai, Ming-Jinn

2009-04-01

In this study, a charge-trapping-layer-engineered nanoscale n-channel trigate TiN nanocrystal nonvolatile memory was successfully fabricated on silicon-on-insulator (SOI) wafer. An Al2O3 high-k blocking dielectric layer and a P+ polycrystalline silicon gate electrode were used to obtain low operation voltage and suppress the back-side injection effect, respectively. TiN nanocrystals were formed by annealing TiN/Al2O3 nanolaminates deposited by an atomic layer deposition system. The memory characteristics of various samples with different TiN wetting layer thicknesses, post-deposition annealing times, and blocking oxide thicknesses were also investigated. The sample with a thicker wetting layer exhibited a much larger memory window than other samples owing to its larger nanocrystal size. Good retention with a mere 12% charge loss for up to 10 years and high endurance were also obtained. Furthermore, gate disturbance and read disturbance were measured with very small charge migrations after a 103 s stressing bias.

Low back pain, work absenteeism, chronic back disorders, and clinical findings in the low back as predictors of hospitalization due to low back disorders: a 28-year follow-up of industrial employees.

PubMed

Kääriä, Sanna; Kaila-Kangas, Leena; Kirjonen, Juhani; Riihimäki, Hilkka; Luukkonen, Ritva; Leino-Arjas, Päivi

2005-05-15

Prospective cohort study. To study symptoms, chronic disorders, and clinical findings in the low back, and work absenteeism, as predictors of hospitalization. Socioeconomic and lifestyle factors are associated with back-related hospitalization, but the significance in the working normal population of low back symptoms and clinical findings are not known. The cohort (n = 902) was drawn in 1973 from among employees in the metal industry (n = 2,653). The data were collected by questionnaire and a structured clinical assessment by a physiotherapist. Weight was measured. A sum score of local and radiating low back symptoms (frequency during the past year on a 4-point Likert scale) was categorized as no/yes and no/infrequent/frequent. Local and radiating symptoms were considered also separately. The data were linked with those from the Finnish Hospital Discharge Register during 1973 to 2000. Logistic regression and the Cox proportional hazard models were used. As compared with persons without low back pain, those with frequent or radiating low back pain had an increased risk of hospitalization due to low back disorders (hazard rate ratio (HRR), 3.0; 95% confidence interval (CI), 1.4-6.5, and 3.7; 1.8-7.7, respectively) after adjustment for age, gender, and occupational class. Similarly, clinical findings (HRR, 2.4; 95% CI, 1.3-4.7), back-related absenteeism (HRR, 3.3; 95% CI, 1.6-6.7), and chronic low back disorders (HRR, 2.8; 95% CI, 1.5-5.4) predicted hospitalization. The associations persisted when further adjusted for smoking, body mass index, and distress symptoms at baseline. Frequent or radiating low back symptoms, chronic low back disorders, back-related work absenteeism, and having clinical findings in the low back predicted inpatient hospital care for low back disorders.

Factors affecting recovery from work-related, low back disorders in autoworkers.

PubMed

Oleske, Denise M; Neelakantan, Janani; Andersson, Gunnar B; Hinrichs, Bradley G; Lavender, Steven A; Morrissey, Mary J; Zold-Kilbourn, Phyllis; Taylor, Emily

2004-08-01

To simultaneously evaluate personal, medical, and job factors that could affect recovery from work-related, low back disorders, specifically focusing on an active working sample. Observational, longitudinal study. Two US automotive plants. Employees (N=352; 289 men, 63 women; mean age +/- standard deviation, 45.1+/-7.5 y) who were active hourly autoworkers, diagnosed with work-related, low back disorder by the plant's medical department. Not applicable. Oswestry Disability Questionnaire for back pain was used to evaluate recovery. Factors associated with better recovery were lower stress levels (P<.001) and exercise or physical activity outside work (P<.001); factors associated with higher disability levels over time were current cigarette smoking (P<.01) and bedrest (P<.001). Personal modifiable factors are major influences in the recovery from work-related, low back disorders, even in active working populations. Interventions aimed at increasing exercise and decreasing stress should also be considered as a part of rehabilitation in employed persons with low levels of disability.

The Relationships of Working Memory, Secondary Memory, and General Fluid Intelligence: Working Memory Is Special

ERIC Educational Resources Information Center

Shelton, Jill Talley; Elliott, Emily M.; Matthews, Russell A.; Hill, B. D.; Gouvier, Wm. Drew

2010-01-01

Recent efforts have been made to elucidate the commonly observed link between working memory and reasoning ability. The results have been inconsistent, with some work suggesting that the emphasis placed on retrieval from secondary memory by working memory tests is the driving force behind this association (Mogle, Lovett, Stawski, & Sliwinski,…

Working memory dysfunctions predict social problem solving skills in schizophrenia.

PubMed

Huang, Jia; Tan, Shu-ping; Walsh, Sarah C; Spriggens, Lauren K; Neumann, David L; Shum, David H K; Chan, Raymond C K

2014-12-15

The current study aimed to examine the contribution of neurocognition and social cognition to components of social problem solving. Sixty-seven inpatients with schizophrenia and 31 healthy controls were administrated batteries of neurocognitive tests, emotion perception tests, and the Chinese Assessment of Interpersonal Problem Solving Skills (CAIPSS). MANOVAs were conducted to investigate the domains in which patients with schizophrenia showed impairments. Correlations were used to determine which impaired domains were associated with social problem solving, and multiple regression analyses were conducted to compare the relative contribution of neurocognitive and social cognitive functioning to components of social problem solving. Compared with healthy controls, patients with schizophrenia performed significantly worse in sustained attention, working memory, negative emotion, intention identification and all components of the CAIPSS. Specifically, sustained attention, working memory and negative emotion identification were found to correlate with social problem solving and 1-back accuracy significantly predicted the poor performance in social problem solving. Among the dysfunctions in schizophrenia, working memory contributed most to deficits in social problem solving in patients with schizophrenia. This finding provides support for targeting working memory in the development of future social problem solving rehabilitation interventions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Working memory network alterations in high-functioning adolescents with an autism spectrum disorder.

PubMed

Barendse, Evelien M; Schreuder, Lisanne J; Thoonen, Geert; Hendriks, Marc P H; Kessels, Roy P C; Backes, Walter H; Aldenkamp, Albert P; Jansen, Jacobus F A

2018-02-01

People with autism spectrum disorder (ASD) typically have deficits in the working memory (WM) system. WM is found to be an essential chain in successfully navigating in the social world. We hypothesize that brain networks for WM have an altered network integrity in ASD compared to controls. Thirteen adolescents (one female) with autistic disorder (n = 1), Asperger's disorder (n = 7), or pervasive developmental disorder not otherwise specified (n = 5), and 13 typically developing healthy control adolescents (one female) participated in this study. Functional magnetic resonance imaging (MRI) was performed using an n-back task and in resting state. The analysis of the behavioral data revealed deficits in WM performance in ASD, but only when tested to the limit. Adolescents with ASD showed lower binary global efficiency in the WM network than the healthy control group with n-back and resting-state data. This correlated with diagnostic scores for total problems, reciprocity, and language. Adolescents with higher-functioning autism have difficulty with the WM system, which is typically compensated. Functional MRI markers of brain network organization in ASD are related to characteristics of autism as represented in diagnostic scores. Therefore, functional MRI provides neuronal correlates for memory difficulties in adolescents with ASD. © 2017 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.

Characterizing “fibrofog”: Subjective appraisal, objective performance, and task-related brain activity during a working memory task

PubMed Central

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L.; Rayhan, Rakib; VanMeter, John W.; Gracely, Richard H.

2016-01-01

The subjective experience of cognitive dysfunction (“fibrofog”) is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, “fibrofog” appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks. PMID:26955513

Working Memory after Traumatic Brain Injury: The Neural Basis of Improved Performance with Methylphenidate.

PubMed

Manktelow, Anne E; Menon, David K; Sahakian, Barbara J; Stamatakis, Emmanuel A

2017-01-01

Traumatic brain injury (TBI) often results in cognitive impairments for patients. The aim of this proof of concept study was to establish the nature of abnormalities, in terms of activity and connectivity, in the working memory network of TBI patients and how these relate to compromised behavioral outcomes. Further, this study examined the neural correlates of working memory improvement following the administration of methylphenidate. We report behavioral, functional and structural MRI data from a group of 15 Healthy Controls (HC) and a group of 15 TBI patients, acquired during the execution of the N-back task. The patients were studied on two occasions after the administration of either placebo or 30 mg of methylphenidate. Between group tests revealed a significant difference in performance when HCs were compared to TBI patients on placebo [ F (1, 28) = 4.426, p < 0.05, η p 2 = 0.136]. This difference disappeared when the patients took methylphenidate [ F (1, 28) = 3.665, p = 0.66]. Patients in the middle range of baseline performance demonstrated the most benefit from methylphenidate. Changes in the TBI patient activation levels in the Left Cerebellum significantly and positively correlated with changes in performance ( r = 0.509, df = 13, p = 0.05). Whole-brain connectivity analysis using the Left Cerebellum as a seed revealed widespread negative interactions between the Left Cerebellum and parietal and frontal cortices as well as subcortical areas. Neither the TBI group on methylphenidate nor the HC group demonstrated any significant negative interactions. Our findings indicate that (a) TBI significantly reduces the levels of activation and connectivity strength between key areas of the working memory network and (b) Methylphenidate improves the cognitive outcomes on a working memory task. Therefore, we conclude that methylphenidate may render the working memory network in a TBI group more consistent with that of an intact working memory network.

Analogous selection processes in declarative and procedural working memory: N-2 list-repetition and task-repetition costs.

PubMed

Gade, Miriam; Souza, Alessandra S; Druey, Michel D; Oberauer, Klaus

2017-01-01

Working memory (WM) holds and manipulates representations for ongoing cognition. Oberauer (Psychology of Learning and Motivation, 51, 45-100, 2009) distinguishes between two analogous WM sub-systems: a declarative WM which handles the objects of thought, and a procedural WM which handles the representations of (cognitive) actions. Here, we assessed whether analogous effects are observed when participants switch between memory sets (declarative representations) and when they switch between task sets (procedural representations). One mechanism assumed to facilitate switching in procedural WM is the inhibition of previously used, but currently irrelevant task sets, as indexed by n-2 task-repetition costs (Mayr & Keele, Journal of Experimental Psychology: General, 129(1), 4-26, 2000). In this study we tested for an analogous effect in declarative WM. We assessed the evidence for n-2 list-repetition costs across eight experiments in which participants switched between memory lists to perform speeded classifications, mental arithmetic, or a local recognition test. N-2 list-repetition costs were obtained consistently in conditions assumed to increase interference between memory lists, and when lists formed chunks in long-term memory. Further analyses across experiments revealed a substantial contribution of episodic memory to n-2 list-repetition costs, thereby questioning the interpretation of n-2 repetition costs as reflecting inhibition. We reanalyzed the data of eight task-switching experiments, and observed that episodic memory also contributes to n-2 task-repetition costs. Taken together, these results show analogous processing principles in declarative and procedural WM, and question the relevance of inhibitory processes for efficient switching between mental sets.

Selective attention supports working memory maintenance by modulating perceptual processing of distractors.

PubMed

Sreenivasan, Kartik K; Jha, Amishi P

2007-01-01

Selective attention has been shown to bias sensory processing in favor of relevant stimuli and against irrelevant or distracting stimuli in perceptual tasks. Increasing evidence suggests that selective attention plays an important role during working memory maintenance, possibly by biasing sensory processing in favor of to-be-remembered items. In the current study, we investigated whether selective attention may also support working memory by biasing processing against irrelevant and potentially distracting information. Event-related potentials (ERPs) were recorded while subjects (n = 22) performed a delayed-recognition task for faces and shoes. The delay period was filled with face or shoe distractors. Behavioral performance was impaired when distractors were congruent with the working memory domain (e.g., face distractor during working memory for faces) relative to when distractors were incongruent with the working memory domain (e.g., face distractor during shoe working memory). If attentional biasing against distractor processing is indeed functionally relevant in supporting working memory maintenance, perceptual processing of distractors is predicted to be attenuated when distractors are more behaviorally intrusive relative to when they are nonintrusive. As such, we predicted that perceptual processing of distracting faces, as measured by the face-sensitive N170 ERP component, would be reduced in the context of congruent (face) working memory relative to incongruent (shoe) working memory. The N170 elicited by distracting faces demonstrated reduced amplitude during congruent versus incongruent working memory. These results suggest that perceptual processing of distracting faces may be attenuated due to attentional biasing against sensory processing of distractors that are most behaviorally intrusive during working memory maintenance.

Reduced ERPs and theta oscillations underlie working memory deficits in Toxoplasma gondii infected seniors.

PubMed

Gajewski, Patrick D; Falkenstein, Michael; Hengstler, Jan G; Golka, Klaus

2016-10-01

Toxoplasma gondii is one of the most widespread infections in humans. Recent studies give evidence for memory deficits in infected older adults. To investigate working memory dysfunction in infected elderly, a double-blinded electrophysiological study was conducted. 84 persons derived from a sample of 131 healthy participants with the mean age of 70 years were assigned to two groups of 42 non-infected and 42 infected individuals. The outcome measures were behavioral performance, target and response-related ERPs, and time-frequency wavelets during performance in a n-back working-memory task. The infected individuals showed a reduced rate of detected targets and diminished P3b amplitude both in target-locked as well as response-locked data compared to the non-infected group. Time-frequency decomposition of the EEG-signals revealed lower evoked power in the theta frequency range in the target-locked as well as in the response-locked data in infected individuals. The reported effects were comparable with differences between healthy young and old adults described previously. Taking together, the reduced working-memory performance accompanied by an attenuated P3b and frontal theta activity may suggest neurotransmitter imbalance like dopamine and norepinephrine in T. gondii infected individuals. In face of a high prevalence of T. gondii infection and the increasing ratio of older population their accelerated memory decline may have substantial socioeconomic consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

Reevaluating the effectiveness of n-back training on transfer through the Bayesian lens: Support for the null.

PubMed

Dougherty, Michael R; Hamovitz, Toby; Tidwell, Joe W

2016-02-01

A recent meta-analysis by Au et al. Psychonomic Bulletin & Review, 22, 366-377, (2015) reviewed the n-back training paradigm for working memory (WM) and evaluated whether (when aggregating across existing studies) there was evidence that gains obtained for training tasks transferred to gains in fluid intelligence (Gf). Their results revealed an overall effect size of g = 0.24 for the effect of n-back training on Gf. We reexamine the data through a Bayesian lens, to evaluate the relative strength of the evidence for the alternative versus null hypotheses, contingent on the type of control condition used. We find that studies using a noncontact (passive) control group strongly favor the alternative hypothesis that training leads to transfer but that studies using active-control groups show modest evidence in favor of the null. We discuss these findings in the context of placebo effects.

Back to Work

ERIC Educational Resources Information Center

Fernandez, Kim

2010-01-01

The economic downturn hit working America particularly hard, as agricultural, automotive, manufacturing, and retail jobs in many corners of the country all but evaporated. Consumers continue to cut back, and jobless rates in many states have eclipsed levels not seen in decades. Out of work and under pressure, many Americans are turning to the…

Increased Cortical Activity in Binge Drinkers during Working Memory Task: A Preliminary Assessment through a Functional Magnetic Resonance Imaging Study

PubMed Central

Campanella, Salvatore; Peigneux, Philippe; Petit, Géraldine; Lallemand, Frédéric; Saeremans, Mélanie; Noël, Xavier; Metens, Thierry; Nouali, Mustapha; De Tiège, Xavier; De Witte, Philippe; Ward, Roberta; Verbanck, Paul

2013-01-01

Background Cerebral dysfunction is a common feature of both chronic alcohol abusers and binge drinkers. Here, we aimed to study whether, at equated behavioral performance levels, binge drinkers exhibited increased neural activity while performing simple cognitive tasks. Methods Thirty-two participants (16 binge drinkers and 16 matched controls) were scanned using functional magnetic resonance imaging (fMRI) while performing an n-back working memory task. In the control zero-back (N0) condition, subjects were required to press a button with the right hand when the number “2″ was displayed. In the two-back (N2) condition, subjects had to press a button when the displayed number was identical to the number shown two trials before. Results fMRI analyses revealed higher bilateral activity in the pre-supplementary motor area in binge drinkers than matched controls, even though behavioral performances were similar. Moreover, binge drinkers showed specific positive correlations between the number of alcohol doses consumed per occasion and higher activity in the dorsomedial prefrontal cortex, as well as between the number of drinking occasions per week and higher activity in cerebellum, thalamus and insula while performing the N2 memory task. Conclusions Binge alcohol consumption leads to possible compensatory cerebral changes in binge drinkers that facilitate normal behavioral performance. These changes in cerebral responses may be considered as vulnerability factors for developing adult substance use disorders. PMID:23638017

Enhanced working memory performance via transcranial direct current stimulation: The possibility of near and far transfer.

PubMed

Trumbo, Michael C; Matzen, Laura E; Coffman, Brian A; Hunter, Michael A; Jones, Aaron P; Robinson, Charles S H; Clark, Vincent P

2016-12-01

Although working memory (WM) training programs consistently result in improvement on the trained task, benefit is typically short-lived and extends only to tasks very similar to the trained task (i.e., near transfer). It is possible that pairing repeated performance of a WM task with brain stimulation encourages plasticity in brain networks involved in WM task performance, thereby improving the training benefit. In the current study, transcranial direct current stimulation (tDCS) was paired with performance of a WM task (n-back). In Experiment 1, participants performed a spatial location-monitoring n-back during stimulation, while Experiment 2 used a verbal identity-monitoring n-back. In each experiment, participants received either active (2.0mA) or sham (0.1mA) stimulation with the anode placed over either the right or the left dorsolateral prefrontal cortex (DLPFC) and the cathode placed extracephalically. In Experiment 1, only participants receiving active stimulation with the anode placed over the right DLPFC showed marginal improvement on the trained spatial n-back, which did not extend to a near transfer (verbal n-back) or far transfer task (a matrix-reasoning task designed to measure fluid intelligence). In Experiment 2, both left and right anode placements led to improvement, and right DLPFC stimulation resulted in numerical (though not sham-adjusted) improvement on the near transfer (spatial n-back) and far transfer (fluid intelligence) task. Results suggest that WM training paired with brain stimulation may result in cognitive enhancement that transfers to performance on other tasks, depending on the combination of training task and tDCS parameters used. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced working memory performance via transcranial direct current stimulation: The possibility of near and far transfer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trumbo, Michael C.; Matzen, Laura E.; Coffman, Brian A.

Although working memory (WM) training programs consistently result in improvement on the trained task, benefit is typically short-lived and extends only to tasks very similar to the trained task (i.e., near transfer). It is possible that pairing repeated performance of a WM task with brain stimulation encourages plasticity in brain networks involved in WM task performance, thereby improving the training benefit. In the current study, transcranial direct current stimulation (tDCS) was paired with performance of a WM task (n-back). In Experiment 1, participants performed a spatial location-monitoring n-back during stimulation, while Experiment 2 used a verbal identity-monitoring n-back. In eachmore » experiment, participants received either active (2.0 mA) or sham (0.1 mA) stimulation with the anode placed over either the right or the left dorsolateral prefrontal cortex (DLPFC) and the cathode placed extracephalically. In Experiment 1, only participants receiving active stimulation with the anode placed over the right DLPFC showed marginal improvement on the trained spatial n-back, which did not extend to a near transfer (verbal n-back) or far transfer task (a matrix-reasoning task designed to measure fluid intelligence). Here, in Experiment 2, both left and right anode placements led to improvement, and right DLPFC stimulation resulted in numerical (though not sham-adjusted) improvement on the near transfer (spatial n-back) and far transfer (fluid intelligence) task. Results suggest that WM training paired with brain stimulation may result in cognitive enhancement that transfers to performance on other tasks, depending on the combination of training task and tDCS parameters used.« less

Enhanced working memory performance via transcranial direct current stimulation: The possibility of near and far transfer

DOE PAGES

Trumbo, Michael C.; Matzen, Laura E.; Coffman, Brian A.; ...

2016-10-15

Although working memory (WM) training programs consistently result in improvement on the trained task, benefit is typically short-lived and extends only to tasks very similar to the trained task (i.e., near transfer). It is possible that pairing repeated performance of a WM task with brain stimulation encourages plasticity in brain networks involved in WM task performance, thereby improving the training benefit. In the current study, transcranial direct current stimulation (tDCS) was paired with performance of a WM task (n-back). In Experiment 1, participants performed a spatial location-monitoring n-back during stimulation, while Experiment 2 used a verbal identity-monitoring n-back. In eachmore » experiment, participants received either active (2.0 mA) or sham (0.1 mA) stimulation with the anode placed over either the right or the left dorsolateral prefrontal cortex (DLPFC) and the cathode placed extracephalically. In Experiment 1, only participants receiving active stimulation with the anode placed over the right DLPFC showed marginal improvement on the trained spatial n-back, which did not extend to a near transfer (verbal n-back) or far transfer task (a matrix-reasoning task designed to measure fluid intelligence). Here, in Experiment 2, both left and right anode placements led to improvement, and right DLPFC stimulation resulted in numerical (though not sham-adjusted) improvement on the near transfer (spatial n-back) and far transfer (fluid intelligence) task. Results suggest that WM training paired with brain stimulation may result in cognitive enhancement that transfers to performance on other tasks, depending on the combination of training task and tDCS parameters used.« less

A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance.

PubMed

Astrand, Elaine

2018-06-01

Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, [Formula: see text]. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain-machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as

Rethinking the connection between working memory and language impairment.

PubMed

Archibald, Lisa M D; Harder Griebeling, Katherine

2016-05-01

Working memory deficits have been found for children with specific language impairment (SLI) on tasks imposing increasing short-term memory load with or without additional, consistent (and simple) processing load. To examine the processing function of working memory in children with low language (LL) by employing tasks imposing increasing processing loads with constant storage demands individually adjusted based on each participant's short-term memory capacity. School-age groups with LL (n = 17) and typical language with either average (n = 28) or above-average nonverbal intelligence (n = 15) completed complex working memory-span tasks varying processing load while keeping storage demands constant, varying storage demands while keeping processing load constant, simple storage-span tasks, and measures of language and nonverbal intelligence. Teachers completed questionnaires about cognition and learning. Significantly lower scores were found for the LL than either matched group on storage-based tasks, but no group differences were found on the tasks varying processing load. Teachers' ratings of oral expression and mathematics abilities discriminated those who did or did not complete the most challenging cognitive tasks. The results implicate a deficit in the phonological storage but not in the central executive component of working memory for children with LL. Teacher ratings may reveal personality traits related to perseverance of effort in cognitive research. © 2015 Royal College of Speech and Language Therapists.

Improving Working Memory Efficiency by Reframing Metacognitive Interpretation of Task Difficulty

ERIC Educational Resources Information Center

Autin, Frederique; Croizet, Jean-Claude

2012-01-01

Working memory capacity, our ability to manage incoming information for processing purposes, predicts achievement on a wide range of intellectual abilities. Three randomized experiments (N = 310) tested the effectiveness of a brief psychological intervention designed to boost working memory efficiency (i.e., state working memory capacity) by…

Neural correlates of visuospatial working memory in attention-deficit/hyperactivity disorder and healthy controls.

PubMed

van Ewijk, Hanneke; Weeda, Wouter D; Heslenfeld, Dirk J; Luman, Marjolein; Hartman, Catharina A; Hoekstra, Pieter J; Faraone, Stephen V; Franke, Barbara; Buitelaar, Jan K; Oosterlaan, Jaap

2015-08-30

Impaired visuospatial working memory (VSWM) is suggested to be a core neurocognitive deficit in attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural activation patterns are poorly understood. Furthermore, it is unclear to what extent age and gender effects may play a role in VSWM-related brain abnormalities in ADHD. Functional magnetic resonance imaging (fMRI) data were collected from 109 individuals with ADHD (60% male) and 103 controls (53% male), aged 8-25 years, during a spatial span working memory task. VSWM-related brain activation was found in a widespread network, which was more widespread compared with N-back tasks used in the previous literature. Higher brain activation was associated with higher age and male gender. In comparison with controls, individuals with ADHD showed greater activation in the left inferior frontal gyrus (IFG) and the lateral frontal pole during memory load increase, effects explained by reduced activation on the low memory load in the IFG pars triangularis and increased activation during high load in the IFG pars opercularis. Age and gender effects did not differ between controls and individuals with ADHD. Results indicate that individuals with ADHD have difficulty in efficiently and sufficiently recruiting left inferior frontal brain regions with increasing task difficulty. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Detailed sensory memory, sloppy working memory.

PubMed

Sligte, Ilja G; Vandenbroucke, Annelinde R E; Scholte, H Steven; Lamme, Victor A F

2010-01-01

Visual short-term memory (VSTM) enables us to actively maintain information in mind for a brief period of time after stimulus disappearance. According to recent studies, VSTM consists of three stages - iconic memory, fragile VSTM, and visual working memory - with increasingly stricter capacity limits and progressively longer lifetimes. Still, the resolution (or amount of visual detail) of each VSTM stage has remained unexplored and we test this in the present study. We presented people with a change detection task that measures the capacity of all three forms of VSTM, and we added an identification display after each change trial that required people to identify the "pre-change" object. Accurate change detection plus pre-change identification requires subjects to have a high-resolution representation of the "pre-change" object, whereas change detection or identification only can be based on the hunch that something has changed, without exactly knowing what was presented before. We observed that people maintained 6.1 objects in iconic memory, 4.6 objects in fragile VSTM, and 2.1 objects in visual working memory. Moreover, when people detected the change, they could also identify the pre-change object on 88% of the iconic memory trials, on 71% of the fragile VSTM trials and merely on 53% of the visual working memory trials. This suggests that people maintain many high-resolution representations in iconic memory and fragile VSTM, but only one high-resolution object representation in visual working memory.

Chronic back pain and associated work and non-work variables among farmworkers from Starr County, Texas.

PubMed

Shipp, Eva M; Cooper, Sharon P; del Junco, Deborah J; Delclos, George L; Burau, Keith D; Tortolero, Susan; Whitworth, Ryan E

2009-01-01

This study estimated the prevalence of chronic back pain among migrant farmworker family members and identified associated work and non-work variables. Migrant farmworkers (n = 390 from 267 families) from Starr County, Texas were interviewed in their home once a year for 2 years. The original survey included items measuring demographics, smoking, sleep, farm work, and chronic back pain. For this cross-sectional analysis, multi-level logistic regression was used to identify associated work and other variables associated with chronic back pain while accounting for intraclass correlations due to repeated measures and multiple family members. The prevalence of chronic back pain during the last migration season ranged from 9.5% among the youngest children to 33.3% among mothers. Variables significantly associated with chronic back pain were age (odds ratio [OR], 1.03, per year increase), depressive symptoms while migrating (OR, 8.72), fewer than 8 hours of sleep at home in Starr County (OR, 2.26), fairly bad/very bad quality of sleep while migrating (OR, 3.25), sorting crops at work (OR, 0.18), and working tree crops (OR, 11.72). The role of work exposures, depressive symptoms, and sleep in chronic back pain among farmworkers warrants further examination. Refinements in outcome and exposure assessments are also needed given the lack of a standardized case definition and the variety of tasks and crops involved in farm work in the United States.

Memory Retrieval and Interference: Working Memory Issues

ERIC Educational Resources Information Center

Radvansky, Gabriel A.; Copeland, David E.

2006-01-01

Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

Biomechanical and psychosocial risk factors for low back pain at work.

PubMed Central

Kerr, M S; Frank, J W; Shannon, H S; Norman, R W; Wells, R P; Neumann, W P; Bombardier, C

2001-01-01

OBJECTIVES: This study determined whether the physical and psychosocial demands of work are associated with low back pain. METHODS: A case-control approach was used. Case subjects (n = 137) reported a new episode of low back pain to their employer, a large automobile manufacturing complex. Control subjects were randomly selected from the study base as cases accrued (n = 179) or were matched to cases by exact job (n = 65). Individual, clinical, and psychosocial variables were assessed by interview. Physical demands were assessed with direct workplace measurements of subjects at their usual jobs. The analysis used multiple logistic regression adjusted for individual characteristics. RESULTS: Self-reported risk factors included a physically demanding job, a poor workplace social environment, inconsistency between job and education level, better job satisfaction, and better coworker support. Low job control showed a borderline association. Physical-measure risk factors included peak lumbar shear force, peak load handled, and cumulative lumbar disc compression. Low body mass index and prior low back pain compensation claims were the only significant individual characteristics. CONCLUSIONS: This study identified specific physical and psychosocial demands of work as independent risk factors for low back pain. PMID:11441733

NOS1 ex1f-VNTR polymorphism influences prefrontal brain oxygenation during a working memory task.

PubMed

Kopf, Juliane; Schecklmann, Martin; Hahn, Tim; Dresler, Thomas; Dieler, Alica C; Herrmann, Martin J; Fallgatter, Andreas J; Reif, Andreas

2011-08-15

Nitric oxide (NO) synthase produces NO, which serves as first and second messenger in neurons, where the protein is encoded by the NOS1 gene. A functional variable number of tandem repeats (VNTR) polymorphism in the promoter region of the alternative first exon 1f of NOS1 is associated with various functions of human behavior, for example increased impulsivity, while another, non-functional variant was linked to decreased verbal working memory and a heightened risk for schizophrenia. We therefore investigated the influence of NOS1 ex 1f-VNTR on working memory function as reflected by both behavioral measures and prefrontal oxygenation. We hypothesized that homozygous short allele carriers exhibit altered brain oxygenation in task-related areas, namely the dorsolateral and ventrolateral prefrontal cortex and the parietal cortex. To this end, 56 healthy subjects were stratified into a homozygous long allele group and a homozygous short allele group comparable for age, sex and intelligence. All subjects completed a letter n-back task (one-, two-, and three-back), while concentration changes of oxygenated (O(2)Hb) hemoglobin in the prefrontal cortex were measured with functional near-infrared spectroscopy (fNIRS). We found load-associated O(2)Hb increases in the prefrontal and parts of the parietal cortex. Significant load-associated oxygenation differences between the two genotype groups could be shown for the dorsolateral prefrontal cortex and the parietal cortex. Specifically, short allele carriers showed a significantly larger increase in oxygenation in all three n-back tasks. This suggests a potential compensatory mechanism, with task-related brain regions being more active in short allele carriers to compensate for reduced NOS1 expression. Copyright © 2011 Elsevier Inc. All rights reserved.

Neural response to working memory demand predicts neurocognitive deficits in HIV.

PubMed

Cohen, Ronald A; Siegel, S; Gullett, J M; Porges, E; Woods, A J; Huang, H; Zhu, Y; Tashima, K; Ding, M-Z

2018-06-01

Human immunodeficiency virus (HIV) continues to have adverse effects on cognition and the brain in many infected people, despite a reduced incidence of HIV-associated dementia with combined antiretroviral therapy (cART). Working memory is often affected, along with attention, executive control, and cognitive processing speed. Verbal working memory (VWM) requires the interaction of each of the cognitive component processes along with a phonological loop for verbal repetition and rehearsal. HIV-related functional brain response abnormalities during VWM are evident in functional MRI (fMRI), though the neural substrate underlying these neurocognitive deficits is not well understood. The current study addressed this by comparing 24 HIV+ to 27 demographically matched HIV-seronegative (HIV-) adults with respect to fMRI activation on a VWM paradigm (n-back) relative to performance on two standardized tests of executive control, attention and processing speed (Stroop and Trail Making A-B). As expected, the HIV+ group had deficits on these neurocognitive tests compared to HIV- controls, and also differed in neural response on fMRI relative to neuropsychological performance. Reduced activation in VWM task-related brain regions on the 2-back was associated with Stroop interference deficits in HIV+ but not with either Trail Making A or B performance. Activation of the posterior cingulate cortex (PCC) of the default mode network during rest was associated with Hopkins Verbal Learning Test-2 (HVLT-2) learning in HIV+. These effects were not observed in the HIV- controls. Reduced dynamic range of neural response was also evident in HIV+ adults when activation on the 2-back condition was compared to the extent of activation of the default mode network during periods of rest. Neural dynamic range was associated with both Stroop and HVLT-2 performance. These findings provide evidence that HIV-associated alterations in neural activation induced by VWM demands and during rest

The effects of nicotine and non-nicotine smoking factors on working memory and associated brain function.

PubMed

McClernon, Francis Joseph; Froeliger, Brett; Rose, Jed E; Kozink, Rachel V; Addicott, Merideth A; Sweitzer, Maggie M; Westman, Eric C; Van Wert, Dana M

2016-07-01

Smoking abstinence impairs executive function, which may promote continued smoking behavior and relapse. The differential influence of nicotine and non-nicotine (i.e. sensory, motor) smoking factors and related neural substrates is not known. In a fully factorial, within-subjects design, 33 smokers underwent fMRI scanning following 24 hours of wearing a nicotine or placebo patch while smoking very low nicotine content cigarettes or remaining abstinent from smoking. During scanning, blood oxygenation level-dependent (BOLD) signal was acquired while participants performed a verbal N-back task. Following 24-hour placebo (versus nicotine) administration, accuracy on the N-back task was significantly worse and task-related BOLD signal lower in dorsomedial frontal cortex. These effects were observed irrespective of smoking. Our data provide novel evidence that abstinence-induced deficits in working memory and changes in underlying brain function are due in large part to abstinence from nicotine compared with non-nicotine factors. This work has implications both for designing interventions that target abstinence-induced cognitive deficits and for nicotine-reduction policy. © 2015 Society for the Study of Addiction.

Patient clusters in acute, work-related back pain based on patterns of disability risk factors.

PubMed

Shaw, William S; Pransky, Glenn; Patterson, William; Linton, Steven J; Winters, Thomas

2007-02-01

To identify subgroups of patients with work-related back pain based on disability risk factors. Patients with work-related back pain (N = 528) completed a 16-item questionnaire of potential disability risk factors before their initial medical evaluation. Outcomes of pain, functional limitation, and work disability were assessed 1 and 3 months later. A K-Means cluster analysis of 5 disability risk factors (pain, depressed mood, fear avoidant beliefs, work inflexibility, and poor expectations for recovery) resulted in 4 sub-groups: low risk (n = 182); emotional distress (n = 103); severe pain/fear avoidant (n = 102); and concerns about job accommodation (n = 141). Pain and disability outcomes at follow-up were superior in the low-risk group and poorest in the severe pain/fear avoidant group. Patients with acute back pain can be discriminated into subgroups depending on whether disability is related to pain beliefs, emotional distress, or workplace concerns.

Genetically determined measures of striatal D2 signaling predict prefrontal activity during working memory performance.

PubMed

Bertolino, Alessandro; Taurisano, Paolo; Pisciotta, Nicola Marco; Blasi, Giuseppe; Fazio, Leonardo; Romano, Raffaella; Gelao, Barbara; Lo Bianco, Luciana; Lozupone, Madia; Di Giorgio, Annabella; Caforio, Grazia; Sambataro, Fabio; Niccoli-Asabella, Artor; Papp, Audrey; Ursini, Gianluca; Sinibaldi, Lorenzo; Popolizio, Teresa; Sadee, Wolfgang; Rubini, Giuseppe

2010-02-22

Variation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known. Thirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory. Subjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT. Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.

Genetically Determined Measures of Striatal D2 Signaling Predict Prefrontal Activity during Working Memory Performance

PubMed Central

Bertolino, Alessandro; Taurisano, Paolo; Pisciotta, Nicola Marco; Blasi, Giuseppe; Fazio, Leonardo; Romano, Raffaella; Gelao, Barbara; Bianco, Luciana Lo; Lozupone, Madia; Di Giorgio, Annabella; Caforio, Grazia; Sambataro, Fabio; Niccoli-Asabella, Artor; Papp, Audrey; Ursini, Gianluca; Sinibaldi, Lorenzo; Popolizio, Teresa; Sadee, Wolfgang; Rubini, Giuseppe

2010-01-01

Background Variation of the gene coding for D2 receptors (DRD2) has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560) predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic) and D2L (mainly post-synaptic). However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known. Methods Thirty-seven healthy subjects were genotyped for rs1076560 (G>T) and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors) and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors), as well as BOLD fMRI during N-Back working memory. Results Subjects carrying the T allele (previously associated with reduced D2S expression) had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers) and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT. Conclusions Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway. PMID:20179754

Preliminary investigation of the effects of γ-tACS on working memory in schizophrenia.

PubMed

Hoy, Kate E; Whitty, Dean; Bailey, Neil; Fitzgerald, Paul B

2016-10-01

Working memory impairment in schizophrenia has been strongly associated with abnormalities in gamma oscillations within the dorsolateral prefrontal cortex (DLFPC). We recently published the first ever study showing that anodal transcranial direct current stimulation (tDCS) to the left DLPFC was able to significantly improve working memory in schizophrenia and did so seemingly via restoring normal gamma oscillatory function. Transcranial alternating current stimulation (tACS) is a form of electrical brain stimulation that delivers stimulation at a specific frequency and has been shown to entrain endogenous cortical oscillations. Therefore, gamma (γ) tACS may be even more effective than tDCS in improving working memory in schizophrenia. In a randomized repeated-measures study we compared the effects of γ-tACS, tDCS and sham stimulation on the performance of the two back working memory tasks in ten patients with schizophrenia. There was a significant time by stimulation interaction, with tDCS and sham showing trend-level improvements in working memory, while γ-tACS, contrary to our hypothesis, showed no change. The results are discussed in light of posited divergent effects of tACS and tDCS on the pathophysiology of working memory impairment in schizophrenia.

Working memory involved in predicting future outcomes based on past experiences.

PubMed

Dretsch, Michael N; Tipples, Jason

2008-02-01

Deficits in working memory have been shown to contribute to poor performance on the Iowa Gambling Task [IGT: Bechara, A., & Martin, E.M. (2004). Impaired decision making related to working memory deficits in individuals with substance addictions. Neuropsychology, 18, 152-162]. Similarly, a secondary memory load task has been shown to impair task performance [Hinson, J., Jameson, T. & Whitney, P. (2002). Somatic markers, working memory, and decision making. Cognitive, Affective, & Behavioural Neuroscience, 2, 341-353]. In the present study, we investigate whether the latter findings were due to increased random responding [Franco-Watkins, A. M., Pashler, H., & Rickard, T. C. (2006). Does working memory load lead to greater impulsivity? Commentary on Hinson, Jameson, and Whitney's (2003). Journal of Experimental Psychology: Learning, Memory & Cognition, 32, 443-447]. Participants were tested under Low Working Memory (LWM; n=18) or High Working Memory (HWM; n=17) conditions while performing the Reversed IGT in which punishment was immediate and reward delayed [Bechara, A., Dolan, S., & Hindes, A. (2002). Decision making and addiction (part II): Myopia for the future or hypersensitivity to reward? Neuropsychologia, 40, 1690-1705]. In support of a role for working memory in emotional decision making, compared to the LWM condition, participants in the HWM condition made significantly greater number of disadvantageous selections than that predicted by chance. Performance by the HWM group could not be fully explained by random responding.

Enhancement of functional connectivity, working memory and inhibitory control on multi-modal brain MR imaging with Rifaximin in Cirrhosis: implications for the gut-liver-brain axis.

PubMed

Ahluwalia, Vishwadeep; Wade, James B; Heuman, Douglas M; Hammeke, Thomas A; Sanyal, Arun J; Sterling, Richard K; Stravitz, R Todd; Luketic, Velimir; Siddiqui, Mohammad S; Puri, Puneet; Fuchs, Michael; Lennon, Micheal J; Kraft, Kenneth A; Gilles, HoChong; White, Melanie B; Noble, Nicole A; Bajaj, Jasmohan S

2014-12-01

Minimal hepatic encephalopathy (MHE) impairs daily functioning in cirrhosis, but its functional brain impact is not completely understood. To evaluate the effect of rifaximin, a gut-specific antibiotic, on the gut-liver-brain axis in MHE. Rifaximin will reduce endotoxemia, enhance cognition, increase activation during working memory(N-back) and reduce activation needed for inhibitory control tasks. Cirrhotics with MHE underwent baseline endotoxin and cognitive testing, then underwent fMRI, diffusion tensor imaging and MR spectroscopy(MRS). On fMRI, two tasks; N-back (outcome: correct responses) and inhibitory control tests(outcomes: lure inhibition) were performed. All procedures were repeated after 8 weeks of rifaximin. RESULTS were compared before/after rifaximin. 20 MHE patients (59.7 years) were included; sixteen completed pre/post-rifaximin scanning with 92% medication compliance. Pre-rifaximin patients had cognitive impairment. At trial-end, there was a significantly higher correct 2-back responses, ICT lure inhibitions and reduced endotoxemia(p = 0.002). This was accompanied by significantly higher activation from baseline in subcortical structures (thalamus, caudate, insula and hippocampus) and left parietal operculum (LPO) during N-back, decrease in fronto-parietal activation required for inhibiting lures, including LPO during ICT compared to baseline values. Connectivity studies in N-back showed significant shifts in linkages after therapy in fronto-parietal regions with a reduction in fractional anisotropy (FA) but not mean diffusivity (MD), and no change in MRS metabolites at the end of the trial. A significant improvement in cognition including working memory and inhibitory control, and fractional anisotropy without effect on MD or MRS, through modulation of fronto-parietal and subcortical activation and connectivity was seen after open-label rifaximin therapy in MHE.

M18. Lack of Generalization From a High-Dose, Well-Powered Randomized Controlled Trial of Working Memory-Focused Training for Schizophrenia

PubMed Central

Nienow, Tasha; MacDonald, Angus

2017-01-01

Abstract Background: Cognitive deficits contribute to the functional disability associated with schizophrenia. Cognitive training has shown promise as a method of intervention; however, there is considerable variability in the implementation of this approach. The aim of this study was to test the efficacy of a high dose of cognitive training that targeted working memory-related functions. Methods: A randomized, double blind, active placebo-controlled, clinical trial was conducted with 80 outpatients with schizophrenia (mean age 46.44 years, 25% female). Patients were randomized to either working memory-based cognitive training or a computer skills training course that taught computer applications. In both conditions, participants received an average of 3 hours of training weekly for 16 weeks. Cognitive and functional outcomes were assessed with the MATRICS Consensus Cognitive Battery, N-Back performance, 2 measures of functional capacity (UPSA and SSPA) and a measure of community functioning, the Social Functioning Scale. Results: An intent-to-treat analysis found that patients who received cognitive training demonstrated significantly greater change on a trained task (Word N-Back), F(78) = 21.69, P < .0001, and a novel version of a trained task (Picture N-Back) as compared to those in the comparison condition, F(78) = 13.59, P = .002. However, only very modest support was found for generalization of training gains. A trend for an interaction was found on the MCCB Attention Domain score, F(78) = 2.56, P = .12. Participants who received cognitive training demonstrated significantly improved performance, t(39) = 3.79, P = .001, while those in computer skills did not, t(39) = 1.07, P = .37. Conclusion: A well-powered, high-dose, working memory focused, computer-based, cognitive training protocol produced only a small effect in patients with schizophrenia. Results indicate the importance of measuring generalization from training tasks in cognitive

Ventrolateral prefrontal activation during a N-back task assessed with multichannel functional near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Zhou, Yuan; Zhu, Ye; Jiang, Tianzi

2007-05-01

Functional near-infrared spectroscopy (fNIRS) has been used to investigate the changes in the concentration of oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin in brain issue during several cognitive tasks. In the present study, by means of multichannel dual wavelength light-emitting diode continuous-wave (CW) NIRS, we investigated the blood oxygenation changes of prefrontal cortex in 18 healthy subjects while performing a verbal n-back task (0-back and 2-back), which has been rarely investigated by fNIRS. Compared to the 0-back task (control task), we found a significant increase of O2Hb and total amount of hemoglobin (THb) in left and right ventrolateral prefrontal cortex (VLPFC) during the execution of the 2-back task compared to the 0-back task (p<0.05, FDR corrected). This result is consistent with the previous functional neuroimaging studies that have found the VLPFC activation related to verbal working memory. However, we found no significant hemisphere dominance. In addition, the effects of gender and its interaction with task performance on O2Hb concentration change were suggested in the present study. Our findings not only confirm that multichannel fNIRS is suitable to detect spatially specific activation during the performance of cognitive tasks; but also suggest that it should be cautious of gender-dependent difference in cerebral activation when interpreting the fNIRS data during cognitive tasks.

Estimating the executive demands of a one-back choice reaction time task by means of the selective interference paradigm.

PubMed

Szmalec, Arnaud; Vandierendonck, André

2007-08-01

The present study proposes a new executive task, the one-back choice reaction time (RT) task, and implements the selective interference paradigm to estimate the executive demands of the processing components involved in this task. Based on the similarities between a one-back choice RT task and the n-back updating task, it was hypothesized that one-back delaying of a choice reaction involves executive control. In three experiments, framed within Baddeley's (1986) working-memory model, a one-back choice RT task, a choice RT task, articulatory suppression, and matrix tapping were performed concurrently with primary tasks involving verbal, visuospatial, and executive processing. The results demonstrate that one-back delaying of a choice reaction interferes with tasks requiring executive control, while the potential interference at the level of the verbal or visuospatial working memory slave systems remains minimal.

The neuropsychology of emerging psychosis and the role of working memory in episodic memory encoding.

PubMed

Pflueger, Marlon O; Calabrese, Pasquale; Studerus, Erich; Zimmermann, Ronan; Gschwandtner, Ute; Borgwardt, Stefan; Aston, Jacqueline; Stieglitz, Rolf-Dieter; Riecher-Rössler, Anita

2018-01-01

Episodic memory encoding and working memory (WM) deficits are among the first cognitive signs and symptoms in the course of schizophrenia spectrum disorders. However, it is not clear whether the deficit pattern is generalized or specific in nature. We hypothesized that encoding deficits at an early stage of the disease might be due to the more fundamental WM deficits. We examined episodic memory encoding and WM by administering the California Verbal Learning Test, a 2-back task, and the Wisconsin Card Sorting Test in 90 first-episode psychosis (FE) patients and 116 individuals with an at-risk mental state for psychosis (ARMS) compared to 57 healthy subjects. Learning progress, but not span of apprehension, was diminished to a similar extent in both the ARMS and the FE. We showed that this was due to WM impairment by applying a structural equation approach. Thus, we conclude that verbal memory encoding deficits are secondary to primary WM impairment in emerging psychosis.

Structural Connectivity Changes Underlying Altered Working Memory Networks in Mild Cognitive Impairment: A Three-Way Image Fusion Analysis.

PubMed

Teipel, Stefan; Ehlers, Inga; Erbe, Anna; Holzmann, Carsten; Lau, Esther; Hauenstein, Karlheinz; Berger, Christoph

2015-01-01

Working memory impairment is among the earliest signs of cognitive decline in Alzheimer's disease (AD) and mild cognitive impairment (MCI). We aimed to study the functional and structural substrate of working memory impairment in early AD dementia and MCI. We studied a group of 12 MCI and AD subjects compared to 12 age- and gender-matched healthy elderly controls using diffusion tensor imaging (DTI), and functional magnetic resonance imaging (fMRI) during a 2-back versus 1-back letter recognition task. We performed a three-way image fusion analysis with joint independent component analysis of cortical activation during working memory, and DTI derived measures of fractional anisotropy (FA) and the mode of anisotropy. We found significant hypoactivation in posterior brain areas and relative hyperactivation in anterior brain areas during working memory in AD/MCI subjects compared to controls. Corresponding independent components from DTI data revealed reduced FA and reduced mode of anisotropy in intracortical projecting fiber tracts with posterior predominance and increased FA and increased mode along the corticospinal tract in AD/MCI compared to controls. Our findings suggest that impairments of structural fiber tract integrity accompany breakdown of posterior and relatively preserved anterior cortical activation during working memory performance in MCI/AD subjects. Copyright © 2014 by the American Society of Neuroimaging.

Cholinergic blockade under working memory demands encountered by increased rehearsal strategies: evidence from fMRI in healthy subjects.

PubMed

Voss, Bianca; Thienel, Renate; Reske, Martina; Kellermann, Thilo; Sheldrick, Abigail J; Halfter, Sarah; Radenbach, Katrin; Shah, Nadim J; Habel, Ute; Kircher, Tilo T J

2012-06-01

The connection between cholinergic transmission and cognitive performance has been established in behavioural studies. The specific contribution of the muscarinic receptor system on cognitive performance and brain activation, however, has not been evaluated satisfyingly. To investigate the specific contribution of the muscarinic transmission on neural correlates of working memory, we examined the effects of scopolamine, an antagonist of the muscarinic receptors, using functional magnetic resonance imaging (fMRI). Fifteen healthy male, non-smoking subjects performed a fMRI scanning session following the application of scopolamine (0.4 mg, i.v.) or saline in a placebo-controlled, repeated measure, pseudo-randomized, single-blind design. Working memory was probed using an n-back task. Compared to placebo, challenging the cholinergic transmission with scopolamine resulted in hypoactivations in parietal, occipital and cerebellar areas and hyperactivations in frontal and prefrontal areas. These alterations are interpreted as compensatory strategies used to account for downregulation due to muscarinic acetylcholine blockade in parietal and cerebral storage systems by increased activation in frontal and prefrontal areas related to working memory rehearsal. Our results further underline the importance of cholinergic transmission to working memory performance and determine the specific contribution of muscarinic transmission on cerebral activation associated with executive functioning.

Proactive interference and item similarity in working memory.

PubMed

Bunting, Michael

2006-03-01

Proactive interference (PI) may influence the predictive utility of working memory span tasks. Participants in one experiment (N=70) completed Ravens Advanced Progressive Matrices (RAPM) and multiple versions of operation span and probed recall, modified for the type of memoranda (digits or words). Changing memoranda within- or across-trials released PI, but not doing so permitted PI buildup. Scores from PI-build trials, but not PI-release trials, correlated with RAPM and accounted for as much variance in RAPM as unmodified tasks. These results are consistent with controlled attention and inhibition accounts of working memory, and they elucidate a fundamental component of working memory span tasks.

Dynamic Connectivity between Brain Networks Supports Working Memory: Relationships to Dopamine Release and Schizophrenia

PubMed Central

Van Snellenberg, Jared X.; Benavides, Caridad; Slifstein, Mark; Wang, Zhishun; Moore, Holly; Abi-Dargham, Anissa

2016-01-01

Connectivity between brain networks may adapt flexibly to cognitive demand, a process that could underlie adaptive behaviors and cognitive deficits, such as those observed in neuropsychiatric conditions like schizophrenia. Dopamine signaling is critical for working memory but its influence on internetwork connectivity is relatively unknown. We addressed these questions in healthy humans using functional magnetic resonance imaging (during an n-back working-memory task) and positron emission tomography using the radiotracer [11C]FLB457 before and after amphetamine to measure the capacity for dopamine release in extrastriatal brain regions. Brain networks were defined by spatial independent component analysis (ICA) and working-memory-load-dependent connectivity between task-relevant pairs of networks was determined via a modified psychophysiological interaction analysis. For most pairs of task-relevant networks, connectivity significantly changed as a function of working-memory load. Moreover, load-dependent changes in connectivity between left and right frontoparietal networks (Δ connectivity lFPN-rFPN) predicted interindividual differences in task performance more accurately than other fMRI and PET imaging measures. Δ Connectivity lFPN-rFPN was not related to cortical dopamine release capacity. A second study in unmedicated patients with schizophrenia showed no abnormalities in load-dependent connectivity but showed a weaker relationship between Δ connectivity lFPN-rFPN and working memory performance in patients compared with matched healthy individuals. Poor working memory performance in patients was, in contrast, related to deficient cortical dopamine release. Our findings indicate that interactions between brain networks dynamically adapt to fluctuating environmental demands. These dynamic adaptations underlie successful working memory performance in healthy individuals and are not well predicted by amphetamine-induced dopamine release capacity. SIGNIFICANCE

Verbal makes it positive, spatial makes it negative: working memory biases judgments, attention, and moods.

PubMed

Storbeck, Justin; Watson, Philip

2014-12-01

Prior research has suggested that emotion and working memory domains are integrated, such that positive affect enhances verbal working memory, whereas negative affect enhances spatial working memory (Gray, 2004; Storbeck, 2012). Simon (1967) postulated that one feature of emotion and cognition integration would be reciprocal connectedness (i.e., emotion influences cognition and cognition influences emotion). We explored whether affective judgments and attention to affective qualities are biased by the activation of verbal and spatial working memory mind-sets. For all experiments, participants completed a 2-back verbal or spatial working memory task followed by an endorsement task (Experiments 1 & 2), word-pair selection task (Exp. 3), or attentional dot-probe task (Exp. 4). Participants who had an activated verbal, compared with spatial, working memory mind-set were more likely to endorse pictures (Exp. 1) and words (Exp. 2) as being more positive and to select the more positive word pair out of a set of word pairs that went 'together best' (Exp. 3). Additionally, people who completed the verbal working memory task took longer to disengage from positive stimuli, whereas those who completed the spatial working memory task took longer to disengage from negative stimuli (Exp. 4). Interestingly, across the 4 experiments, we observed higher levels of self-reported negative affect for people who completed the spatial working memory task, which was consistent with their endorsement and attentional bias toward negative stimuli. Therefore, emotion and working memory may have a reciprocal connectedness allowing for bidirectional influence.

Working memory capacity does not always support future-oriented mind-wandering.

PubMed

McVay, Jennifer C; Unsworth, Nash; McMillan, Brittany D; Kane, Michael J

2013-03-01

To evaluate the claim that mind-wandering demands executive resources, and more specifically that people with better executive control will have the resources to engage in more future-oriented thought than will those with poorer executive control, we reanalyzed thought-report data from 2 independently conducted studies (J. C. McVay & M. J. Kane, 2012, Why does working memory capacity predict variation in reading comprehension? On the influence of mind wandering and executive attention, Journal of Experimental Psychology: General, Vol. 141, pp. 302-320; N. Unsworth & B. D. McMillan, in press, Mind-wandering and reading comprehension: Examining the roles of working memory capacity, interest, motivation, and topic experience, Journal of Experimental Psychology: Learning, Memory, and Cognition) on working memory capacity (WMC), mind-wandering, and reading comprehension. Both of these individual-differences studies assessed large samples of university subjects' WMC abilities via multiple tasks and probed their immediate thought content while reading; in reporting any task-unrelated thoughts (TUTs), subjects indicated whether those thoughts were about the future or the past, if applicable. In contrast to previously published findings indicating that higher WMC subjects mind-wandered about the future more than did lower WMC subjects (B. Baird, J. Smallwood, & J. W. Schooler, 2011, Back to the future: Autobiographical planning and the functionality of mind-wandering, Consciousness and Cognition, Vol. 20, pp. 1604-1611), we found only weak to modest negative correlations between WMC and future-oriented TUTs. If anything, our findings suggest that higher WMC subjects' TUTs were somewhat less often future-oriented than were lower WMC subjects'. Either WMC is not truly associated with mind-wandering about the future, or we have identified some important boundary conditions around that association.

Dissociation of working memory processing associated with native and second languages: PET investigation.

PubMed

Kim, Jae-Jin; Kim, Myung Sun; Lee, Jae Sung; Lee, Dong Soo; Lee, Myung Chul; Kwon, Jun Soo

2002-04-01

Verbal working memory plays a significant role in language comprehension and problem-solving. The prefrontal cortex has been suggested as a critical area in working memory. Given that domain-specific dissociations of working memory may exist within the prefrontal cortex, it is possible that there may also be further functional divisions within the verbal working memory processing. While differences in the areas of the brain engaged in native and second languages have been demonstrated, little is known about the dissociation of verbal working memory associated with native and second languages. We have used H2(15)O positron emission tomography in 14 normal subjects in order to identify the neural correlates selectively involved in working memory of native (Korean) and second (English) languages. All subjects were highly proficient in the native language but poorly proficient in the second language. Cognitive tasks were a two-back task for three kinds of visually presented objects: simple pictures, English words, and Korean words. The anterior portion of the right dorsolateral prefrontal cortex and the left superior temporal gyrus were activated in working memory for the native language, whereas the posterior portion of the right dorsolateral prefrontal cortex and the left inferior temporal gyrus were activated in working memory for the second language. The results suggest that the right dorsolateral prefrontal cortex and left temporal lobe may be organized into two discrete, language-related functional systems. Internal phonological processing seems to play a predominant role in working memory processing for the native language with a high proficiency, whereas visual higher order control does so for the second language with a low proficiency. (C)2002 Elsevier Science (USA).

Salience of working-memory maintenance and manipulation deficits in schizophrenia

PubMed Central

Hill, S. K.; Griffin, G. B.; Miura, T. Kazuto; Herbener, E. S.; Sweeney, J. A.

2011-01-01

Background Encoding and maintenance of information in working memory, followed by internal manipulation of that information for planning adaptive behavior, are two key components of working-memory systems. Both processes have been reported to be impaired in schizophrenia, but few studies have directly compared the relative severity of these abnormalities, or the degree to which manipulation deficits might be secondary to alterations in maintenance processes. Method Clinically stable schizophrenia patients (n=25) and a demographically similar healthy comparison group (n=24) were administered a verbal span task with three levels of working-memory load. Maintenance was assessed using sequential position questions. Manipulation processes were assessed by requiring comparison of the relative sequential position of test items, which entailed simultaneous serial search strategies regarding item order. Results Both groups showed reduced accuracy and increased reaction time for manipulation compared with maintenance processing. There were significant patient impairments across working-memory loads. There was no differential deficit in manipulation processing, and effect sizes of relative deficit in the patient group were higher for maintenance than manipulation processing. Conclusions The strong correlation for maintenance and manipulation deficits suggest that impairments in the ability to internally manipulate information stored in working-memory systems are not greater than alterations in the encoding and maintaining of information in working memory and that disturbances in maintenance processing may contribute to deficits in higher-order working-memory operations. PMID:20214839

The contributions of handedness and working memory to episodic memory.

PubMed

Sahu, Aparna; Christman, Stephen D; Propper, Ruth E

2016-11-01

Past studies have independently shown associations of working memory and degree of handedness with episodic memory retrieval. The current study takes a step ahead by examining whether handedness and working memory independently predict episodic memory. In agreement with past studies, there was an inconsistent-handed advantage for episodic memory; however, this advantage was absent for working memory tasks. Furthermore, regression analyses showed handedness, and complex working memory predicted episodic memory performance at different times. Results are discussed in light of theories of episodic memory and hemispheric interaction.

Executive Functions and Working Memory Behaviours in Children with a Poor Working Memory

ERIC Educational Resources Information Center

St. Clair-Thompson, Helen L.

2011-01-01

Previous research has suggested that working memory difficulties play an integral role in children's underachievement at school. However, working memory is just one of several executive functions. The extent to which problems in working memory extend to other executive functions is not well understood. In the current study 38 children with a poor…

Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

PubMed Central

Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants’ performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks [3], [4]. Participants’ improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning. PMID:25188356

[Working memory and work with memory: visual-spatial and further components of processing].

PubMed

Velichkovsky, B M; Challis, B H; Pomplun, M

1995-01-01

Empirical and theoretical evidence for the concept of working memory is considered. We argue that the major weakness of this concept is its loose connection with the knowledge about background perceptive and cognitive processes. Results of two relevant experiments are provided. The first study demonstrated the classical chunking effect in a speeded visual search and comparison task, the proper domain of a large-capacity very short term sensory store. Our second study was a kind of extended levels-of-processing experiment. We attempted to manipulate visual, phonological, and (different) executive components of long-term memory in the hope of finding some systematic relationships between these forms of processing. Indeed, the results demonstrated a high degree of systematicity without any apparent need for a concept such as working memory for the explanation. Accordingly, the place for working memory is at all the interfaces where our metacognitive strategies interfere with mostly domain-specific cognitive mechanisms. Working memory is simply our work with memory.

Brain activation and deactivation during location and color working memory tasks in 11-13-year-old children.

PubMed

Vuontela, Virve; Steenari, Maija-Riikka; Aronen, Eeva T; Korvenoja, Antti; Aronen, Hannu J; Carlson, Synnöve

2009-02-01

Using functional magnetic resonance imaging (fMRI) and n-back tasks we investigated whether, in 11-13-year-old children, spatial (location) and nonspatial (color) information is differentially processed during visual attention (0-back) and working memory (WM) (2-back) tasks and whether such cognitive task performance, compared to a resting state, results in regional deactivation. The location 0-back task, compared to the color 0-back task, activated segregated areas in the frontal, parietal and occipital cortices whereas no differentially activated voxels were obtained when location and color 2-back tasks were directly contrasted. Several midline cortical areas were less active during 0- and 2-back task performance than resting state. The task-induced deactivation increased with task difficulty as demonstrated by larger deactivation during 2-back than 0-back tasks. The results suggest that, in 11-13-year-old children, the visual attentional network is differently recruited by spatial and nonspatial information processing, but the functional organization of cortical activation in WM in this age group is not based on the type of information processed. Furthermore, 11-13-year-old children exhibited a similar pattern of cortical deactivation that has been reported in adults during cognitive task performance compared to a resting state.

Neurocognitive architecture of working memory

PubMed Central

Eriksson, Johan; Vogel, Edward K.; Lansner, Anders; Bergström, Fredrik; Nyberg, Lars

2015-01-01

The crucial role of working memory for temporary information processing and guidance of complex behavior has been recognized for many decades. There is emerging consensus that working memory maintenance results from the interactions among long-term memory representations and basic processes, including attention, that are instantiated as reentrant loops between frontal and posterior cortical areas, as well as subcortical structures. The nature of such interactions can account for capacity limitations, lifespan changes, and restricted transfer after working-memory training. Recent data and models indicate that working memory may also be based on synaptic plasticity, and that working memory can operate on non-consciously perceived information. PMID:26447571

Characteristics of a lithium-thionyl chloride battery as a memory back-up power source

NASA Astrophysics Data System (ADS)

Iwamaru, T.; Uetani, Y.

An Li/SOCl 2 battery of R6 size (ER6C) has been evaluated as a memory back-up power source for CMOS RAM. The working voltage is 3.6 V and the discharge capacity is 1900 mA h on a 1OK-ohm load. The cell exhibits satisfactory working voltage and discharge capacity over the temperature range -40 °C to 85 °C. The discharge reaction mechanism has been elucidated. Cumulative self discharge during 10 years discharge at 20 μA is estimated to be 3.5%. No serious problems have been observed during abuse tests.

Neural correlates of the difference between working memory speed and simple sensorimotor speed: an fMRI study.

PubMed

Takeuchi, Hikaru; Sugiura, Motoaki; Sassa, Yuko; Sekiguchi, Atsushi; Yomogida, Yukihito; Taki, Yasuyuki; Kawashima, Ryuta

2012-01-01

The difference between the speed of simple cognitive processes and the speed of complex cognitive processes has various psychological correlates. However, the neural correlates of this difference have not yet been investigated. In this study, we focused on working memory (WM) for typical complex cognitive processes. Functional magnetic resonance imaging data were acquired during the performance of an N-back task, which is a measure of WM for typical complex cognitive processes. In our N-back task, task speed and memory load were varied to identify the neural correlates responsible for the difference between the speed of simple cognitive processes (estimated from the 0-back task) and the speed of WM. Our findings showed that this difference was characterized by the increased activation in the right dorsolateral prefrontal cortex (DLPFC) and the increased functional interaction between the right DLPFC and right superior parietal lobe. Furthermore, the local gray matter volume of the right DLPFC was correlated with participants' accuracy during fast WM tasks, which in turn correlated with a psychometric measure of participants' intelligence. Our findings indicate that the right DLPFC and its related network are responsible for the execution of the fast cognitive processes involved in WM. Identified neural bases may underlie the psychometric differences between the speed with which subjects perform simple cognitive tasks and the speed with which subjects perform more complex cognitive tasks, and explain the previous traditional psychological findings.

Memory systems interaction in the pigeon: working and reference memory.

PubMed

Roberts, William A; Strang, Caroline; Macpherson, Krista

2015-04-01

Pigeons' performance on a working memory task, symbolic delayed matching-to-sample, was used to examine the interaction between working memory and reference memory. Reference memory was established by training pigeons to discriminate between the comparison cues used in delayed matching as S+ and S- stimuli. Delayed matching retention tests then measured accuracy when working and reference memory were congruent and incongruent. In 4 experiments, it was shown that the interaction between working and reference memory is reciprocal: Strengthening either type of memory leads to a decrease in the influence of the other type of memory. A process dissociation procedure analysis of the data from Experiment 4 showed independence of working and reference memory, and a model of working memory and reference memory interaction was shown to predict the findings reported in the 4 experiments. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Neural correlates of training and transfer effects in working memory in older adults.

PubMed

Heinzel, Stephan; Lorenz, Robert C; Pelz, Patricia; Heinz, Andreas; Walter, Henrik; Kathmann, Norbert; Rapp, Michael A; Stelzel, Christine

2016-07-01

As indicated by previous research, aging is associated with a decline in working memory (WM) functioning, related to alterations in fronto-parietal neural activations. At the same time, previous studies showed that WM training in older adults may improve the performance in the trained task (training effect), and more importantly, also in untrained WM tasks (transfer effects). However, neural correlates of these transfer effects that would improve understanding of its underlying mechanisms, have not been shown in older participants as yet. In this study, we investigated blood-oxygen-level-dependent (BOLD) signal changes during n-back performance and an untrained delayed recognition (Sternberg) task following 12sessions (45min each) of adaptive n-back training in older adults. The Sternberg task used in this study allowed to test for neural training effects independent of specific task affordances of the trained task and to separate maintenance from updating processes. Thirty-two healthy older participants (60-75years) were assigned either to an n-back training or a no-contact control group. Before (t1) and after (t2) training/waiting period, both the n-back task and the Sternberg task were conducted while BOLD signal was measured using functional Magnetic Resonance Imaging (fMRI) in all participants. In addition, neuropsychological tests were performed outside the scanner. WM performance improved with training and behavioral transfer to tests measuring executive functions, processing speed, and fluid intelligence was found. In the training group, BOLD signal in the right lateral middle frontal gyrus/caudal superior frontal sulcus (Brodmann area, BA 6/8) decreased in both the trained n-back and the updating condition of the untrained Sternberg task at t2, compared to the control group. fMRI findings indicate a training-related increase in processing efficiency of WM networks, potentially related to the process of WM updating. Performance gains in untrained tasks

Using Spatial Multiple Regression to Identify Intrinsic Connectivity Networks Involved in Working Memory Performance

PubMed Central

Gordon, Evan M.; Stollstorff, Melanie; Vaidya, Chandan J.

2012-01-01

Many researchers have noted that the functional architecture of the human brain is relatively invariant during task performance and the resting state. Indeed, intrinsic connectivity networks (ICNs) revealed by resting-state functional connectivity analyses are spatially similar to regions activated during cognitive tasks. This suggests that patterns of task-related activation in individual subjects may result from the engagement of one or more of these ICNs; however, this has not been tested. We used a novel analysis, spatial multiple regression, to test whether the patterns of activation during an N-back working memory task could be well described by a linear combination of ICNs delineated using Independent Components Analysis at rest. We found that across subjects, the cingulo-opercular Set Maintenance ICN, as well as right and left Frontoparietal Control ICNs, were reliably activated during working memory, while Default Mode and Visual ICNs were reliably deactivated. Further, involvement of Set Maintenance, Frontoparietal Control, and Dorsal Attention ICNs was sensitive to varying working memory load. Finally, the degree of left Frontoparietal Control network activation predicted response speed, while activation in both left Frontoparietal Control and Dorsal Attention networks predicted task accuracy. These results suggest that a close relationship between resting-state networks and task-evoked activation is functionally relevant for behavior, and that spatial multiple regression analysis is a suitable method for revealing that relationship. PMID:21761505

Long-term and within-day variability of working memory performance and EEG in individuals.

PubMed

Gevins, Alan; McEvoy, Linda K; Smith, Michael E; Chan, Cynthia S; Sam-Vargas, Lita; Baum, Cliff; Ilan, Aaron B

2012-07-01

Assess individual-subject long-term and within-day variability of a combined behavioral and EEG test of working memory. EEGs were recorded from 16 adults performing n-back working memory tasks, with 10 tested in morning and afternoon sessions over several years. Participants were also tested after ingesting non-prescription medications or recreational substances. Performance and EEG measures were analyzed to derive an Overall score and three constituent sub-scores characterizing changes in performance, cortical activation, and alertness from each individual's baseline. Long-term and within-day variability were determined for each score; medication effects were assessed by reference to each individual's normal day-to-day variability. Over the several year period, the mean Overall score and sub-scores were approximately zero with standard deviations less than one. Overall scores were lower and their variability higher in afternoon relative to morning sessions. At the group level, alcohol, diphenhydramine and marijuana produced significant effects, but there were large individual differences. Objective working memory measures incorporating performance and EEG are stable over time and sensitive at the level of individual subjects to interventions that affect neurocognitive function. With further research these measures may be suitable for use in individualized medical care by providing a sensitive assessment of incipient illness and response to treatment. Published by Elsevier Ireland Ltd.

[Intensity of negative symptoms, working memory and executive functions disturbances in schizophrenic patients in partial remission period].

PubMed

Hintze, Beata; Borkowska, Alina

2011-01-01

The aim of the study was to assess the correlation between the level of working memory and executive functions impairment in schizophrenic subjects in their partial remission period and the intensity of psychopathological symptoms measured by PANSS scale. 45 patients with schizophrenia were included in the study (28 male and 17 female), aged 18-46 (mean 27 +/- 7) years during partial remission of psychopathological symptoms (PANSS < 70). The control group consisted in 35 age, gender and education matched healthy persons (13 male i 22 female), aged 21-49 (mean 30 +/- 8) years. To assess the intensity of psychopathological symptoms the PANSS scale was used, neuropsychological assessment included the Wisconsin Card Sorting Test (WCST), N-back test and Stroop test from the Vienna Tests Battery. In schizophrenic patients in partial remission period, the significant dysfunctions of working memory and executive functions show association with negative (not positive) schizophrenic symptoms.

New low back pain in nurses: work activities, work stress and sedentary lifestyle.

PubMed

Yip, Vera Yin Bing

2004-05-01

Low back pain is common among nurses. Previous studies have shown that the risk of low back pain increases rapidly with greater amounts of physical work and psychological stress, but is inversely related to leisure activities. However, these previous studies were predominantly retrospective in design and not many took account of three factors simultaneously. This 12-month prospective study examined the relationships between work activities, work stress, sedentary lifestyle and new low back pain. A total of 144 nurses from six Hong Kong district hospitals completed a face-to-face baseline interview, which was followed-up by a telephone interview. The main study measures were demographic characteristics, work activities, work stress, physical leisure activities and the nature of new low back pain during the 12-month follow-up period. Level of work stress, quality of relationships at work, level of enjoyment experienced at work, and work satisfaction were self-reported. Fifty-six (38.9%) nurses reported experiencing new low back pain. Sedentary leisure time activity was not associated with new low back pain. Being comparatively new on a ward (adjusted relative risk 2.90), working in bending postures (adjusted relative risk 2.76) and poor work relationships with colleagues (adjusted relative risk 2.52) were independent predictors of new low back pain. The findings of this study suggest that low back pain is a common problem in the population of nurses in Hong Kong. Being comparatively new on a ward, bending frequently during work and having poor work relationships with colleagues are independent predictors of new low back pain. Training for high-risk work activities and ergonomic assessment of awkward work postures are essential. Moreover, relaxation and team-building workshops for nurses, especially those who are less experienced in the type of work on their current ward, are recommended.

Functional magnetic resonance imaging of working memory in Huntington's disease: cross-sectional data from the IMAGE-HD study.

PubMed

Georgiou-Karistianis, Nellie; Stout, Julie C; Domínguez D, Juan F; Carron, Sarah P; Ando, Ayaka; Churchyard, Andrew; Chua, Phyllis; Bohanna, India; Dymowski, Alicia R; Poudel, Govinda; Egan, Gary F

2014-05-01

We used functional magnetic resonance imaging (fMRI) to investigate spatial working memory (WM) in an N-BACK task (0, 1, and 2-BACK) in premanifest Huntington's disease (pre-HD, n = 35), early symptomatic Huntington's disease (symp-HD, n = 23), and control (n = 32) individuals. Overall, both WM conditions (1-BACK and 2-BACK) activated a large network of regions throughout the brain, common to all groups. However, voxel-wise and time-course analyses revealed significant functional group differences, despite no significant behavioral performance differences. During 1-BACK, voxel-wise blood-oxygen-level-dependent (BOLD) signal activity was significantly reduced in a number of regions from the WM network (inferior frontal gyrus, anterior insula, caudate, putamen, and cerebellum) in pre-HD and symp-HD groups, compared with controls; however, time-course analysis of the BOLD response in the dorsolateral prefrontal cortex (DLPFC) showed increased activation in symp-HD, compared with pre-HD and controls. The pattern of reduced voxel-wise BOLD activity in pre-HD and symp-HD, relative to controls, became more pervasive during 2-BACK affecting the same structures as in 1-BACK, but also incorporated further WM regions (anterior cingulate gyrus, parietal lobe and thalamus). The DLPFC BOLD time-course for 2-BACK showed a reversed pattern to that observed in 1-BACK, with a significantly diminished signal in symp-HD, relative to pre-HD and controls. Our findings provide support for functional brain reorganisation in cortical and subcortical regions in both pre-HD and symp-HD, which are modulated by task difficulty. Moreover, the lack of a robust striatal BOLD signal in pre-HD may represent a very early signature of change observed up to 15 years prior to clinical diagnosis. Copyright © 2013 Wiley Periodicals, Inc.

Functional Magnetic Resonance Imaging of Working Memory and Executive Dysfunction in Systemic Lupus Erythematosus and Antiphospholipid Antibody-Positive Patients.

PubMed

Kozora, E; Uluğ, A M; Erkan, D; Vo, A; Filley, C M; Ramon, G; Burleson, A; Zimmerman, R; Lockshin, M D

2016-11-01

Standardized cognitive tests and functional magnetic resonance imaging (fMRI) studies of systemic lupus erythematosus (SLE) patients demonstrate deficits in working memory and executive function. These neurobehavioral abnormalities are not well studied in antiphospholipid syndrome, which may occur independently of or together with SLE. This study compares an fMRI paradigm involving motor skills, working memory, and executive function in SLE patients without antiphospholipid antibody (aPL) (the SLE group), aPL-positive non-SLE patients (the aPL-positive group), and controls. Brain MRI, fMRI, and standardized cognitive assessment results were obtained from 20 SLE, 20 aPL-positive, and 10 healthy female subjects with no history of neuropsychiatric abnormality. Analysis of fMRI data showed no differences in performance across groups on bilateral motor tasks. When analysis of variance was used, significant group differences were found in 2 executive function tasks (word generation and word rhyming) and in a working memory task (N-Back). Patients positive for aPL demonstrated higher activation in bilateral frontal, temporal, and parietal cortices compared to controls during working memory and executive function tasks. SLE patients also demonstrated bilateral frontal and temporal activation during working memory and executive function tasks. Compared to controls, both aPL-positive and SLE patients had elevated cortical activation, primarily in the frontal lobes, during tasks involving working memory and executive function. These findings are consistent with cortical overactivation as a compensatory mechanism for early white matter neuropathology in these disorders. © 2016, American College of Rheumatology.

Enhancement of Functional Connectivity, Working Memory and Inhibitory Control on Multi-modal Brain MR Imaging with Rifaximin in Cirrhosis: Implications for the Gut-Liver-Brain Axis

PubMed Central

Ahluwalia, Vishwadeep; Wade, James B; Heuman, Douglas M; Hammeke, Thomas A; Sanyal, Arun J; Sterling, Richard K; Stravitz, R. Todd; Luketic, Velimir; Siddiqui, Mohammad S; Puri, Puneet; Fuchs, Michael; Lennon, Micheal J; Kraft, Kenneth A; Gilles, HoChong; White, Melanie B; Noble, Nicole A; Bajaj, Jasmohan S

2014-01-01

Objective Minimal hepatic encephalopathy (MHE) impairs daily functioning in cirrhosis, but its functional brain impact is not completely understood. Aim To evaluate the effect of rifaximin, a gut-specific antibiotic, on the gut-liver-brain axis in MHE. Hypothesis Rifaximin will reduce endotoxemia, enhance cognition, increase activation during working memory(N-back) and reduce activation needed for inhibitory control tasks. Methods Cirrhotics with MHE underwent baseline endotoxin and cognitive testing, then underwent fMRI, diffusion tensor imaging and MR spectroscopy(MRS). On fMRI, two tasks; N-back (outcome: correct responses) and inhibitory control tests(outcomes: lure inhibition) were performed. All procedures were repeated after 8 weeks of rifaximin. Results were compared before/after rifaximin. Results 20 MHE patients (59.7 years) were included; sixteen completed pre/post-rifaximin scanning with 92% medication compliance. Pre-rifaximin patients had cognitive impairment. At trial-end, there was a significantly higher correct 2-back responses, ICT lure inhibitions and reduced endotoxemia(p=0.002). This was accompanied by significantly higher activation from baseline in subcortical structures (thalamus, caudate, insula and hippocampus) and left parietal operculum (LPO) during N-back, decrease in fronto-parietal activation required for inhibiting lures, including LPO during ICT compared to baseline values. Connectivity studies in N-back showed significant shifts in linkages after therapy in fronto-parietal regions with a reduction in fractional anisotropy (FA) but not mean diffusivity (MD), and no change in MRS metabolites at the end of the trial. Conclusion A significant improvement in cognition including working memory and inhibitory control, and fractional anisotropy without effect on MD or MRS, through modulation of fronto-parietal and subcortical activation and connectivity was seen after open-label rifaximin therapy in MHE. PMID:24590688

Ego Depletion Does Not Interfere With Working Memory Performance.

PubMed

Singh, Ranjit K; Göritz, Anja S

2018-01-01

Ego depletion happens if exerting self-control reduces a person's capacity to subsequently control themselves. Previous research has suggested that ego depletion not only interferes with subsequent self-control but also with working memory. However, recent meta-analytical evidence casts doubt onto this. The present study tackles the question if ego depletion does interfere with working memory performance. We induced ego depletion in two ways: using an e-crossing task and using a Stroop task. We then measured working memory performance using the letter-number sequencing task. There was no evidence of ego depletion interfering with working memory performance. Several aspects of our study render this null finding highly robust. We had a large and heterogeneous sample of N = 1,385, which provided sufficient power. We deployed established depletion tasks from two task families (e-crossing task and Stroop), thus making it less likely that the null finding is due to a specific depletion paradigm. We derived several performance scores from the working memory task and ran different analyses to maximize the chances of finding an effect. Lastly, we controlled for two potential moderators, the implicit theories about willpower and dispositional self-control capacity, to ensure that a possible effect on working memory is not obscured by an interaction effect. In sum, this experiment strengthens the position that ego depletion works but does not affect working memory performance.

Ego Depletion Does Not Interfere With Working Memory Performance

PubMed Central

Singh, Ranjit K.; Göritz, Anja S.

2018-01-01

Ego depletion happens if exerting self-control reduces a person’s capacity to subsequently control themselves. Previous research has suggested that ego depletion not only interferes with subsequent self-control but also with working memory. However, recent meta-analytical evidence casts doubt onto this. The present study tackles the question if ego depletion does interfere with working memory performance. We induced ego depletion in two ways: using an e-crossing task and using a Stroop task. We then measured working memory performance using the letter-number sequencing task. There was no evidence of ego depletion interfering with working memory performance. Several aspects of our study render this null finding highly robust. We had a large and heterogeneous sample of N = 1,385, which provided sufficient power. We deployed established depletion tasks from two task families (e-crossing task and Stroop), thus making it less likely that the null finding is due to a specific depletion paradigm. We derived several performance scores from the working memory task and ran different analyses to maximize the chances of finding an effect. Lastly, we controlled for two potential moderators, the implicit theories about willpower and dispositional self-control capacity, to ensure that a possible effect on working memory is not obscured by an interaction effect. In sum, this experiment strengthens the position that ego depletion works but does not affect working memory performance. PMID:29706923

The impact of cognitive control, incentives, and working memory load on the P3 responses of externalizing prisoners.

PubMed

Baskin-Sommers, Arielle R; Krusemark, Elizabeth A; Curtin, John J; Lee, Christopher; Vujnovich, Aleice; Newman, Joseph P

2014-02-01

The P3 amplitude reduction is one of the most common correlates of externalizing. However, few studies have used experimental manipulations designed to challenge different cognitive functions in order to clarify the processes that impact this reduction. To examine factors moderating P3 amplitude in trait externalizing, we administered an n-back task that manipulated cognitive control demands, working memory load, and incentives to a sample of male offenders. Offenders with high trait externalizing scores did not display a global reduction in P3 amplitude. Rather, the negative association between trait externalizing and P3 amplitude was specific to trials involving inhibition of a dominant response during infrequent stimuli, in the context of low working memory load, and incentives for performance. In addition, we discuss the potential implications of these findings for externalizing-related psychopathologies. The results complement and expand previous work on the process-level dysfunction contributing to externalizing-related deficits in P3. Copyright © 2013 Elsevier B.V. All rights reserved.

The effect of single and repeated prefrontal intermittent theta burst stimulation on cortical reactivity and working memory.

PubMed

Chung, Sung Wook; Rogasch, Nigel C; Hoy, Kate E; Fitzgerald, Paul B

With an increasing interest in the use of theta burst stimulation (TBS) as a cognitive enhancer and a potential therapeutic tool for psychiatric disorders, there is a need to identify optimal parameters of TBS in the prefrontal cortex. This study examined the effect of two blocks of prefrontal intermittent TBS (iTBS) on cortical reactivity and working memory performance, compared to one block of iTBS and sham stimulation. We hypothesized that greater cortical effects would be obtained with two blocks of iTBS. Eighteen healthy participants attended three experimental sessions and received either sham, one block or two blocks of iTBS with a 15-min interval. Concurrent transcranial magnetic stimulation with electroencephalography (TMS-EEG) was used to assess the change in cortical reactivity via TMS-evoked potentials. Working memory performance was assessed using the N-back task. Cluster-based permutation statistics and two-way ANOVAs were used for neurophysiological and behavioural data, respectively. Both single and two blocks of iTBS resulted in a significant increase in the amplitude of TMS-evoked N100 and P200. No significant differences were observed between active conditions in either neurophysiological changes or working memory performance, and both failed to improve working memory performance relative to sham. Two blocks of iTBS did not result in stronger measured effects as compared to one block of iTBS. Future studies are needed to identify the optimal stimulation pattern in order to achieve a desired effect. It is also important to establish the best approach in quantifying neuromodulatory effects targeting the prefrontal cortex. Copyright © 2018 Elsevier Inc. All rights reserved.

Differences between Presentation Methods in Working Memory Procedures: A Matter of Working Memory Consolidation

PubMed Central

Ricker, Timothy J.; Cowan, Nelson

2014-01-01

Understanding forgetting from working memory, the memory used in ongoing cognitive processing, is critical to understanding human cognition. In the last decade a number of conflicting findings have been reported regarding the role of time in forgetting from working memory. This has led to a debate concerning whether longer retention intervals necessarily result in more forgetting. An obstacle to directly comparing conflicting reports is a divergence in methodology across studies. Studies which find no forgetting as a function of retention-interval duration tend to use sequential presentation of memory items, while studies which find forgetting as a function of retention-interval duration tend to use simultaneous presentation of memory items. Here, we manipulate the duration of retention and the presentation method of memory items, presenting items either sequentially or simultaneously. We find that these differing presentation methods can lead to different rates of forgetting because they tend to differ in the time available for consolidation into working memory. The experiments detailed here show that equating the time available for working memory consolidation equates the rates of forgetting across presentation methods. We discuss the meaning of this finding in the interpretation of previous forgetting studies and in the construction of working memory models. PMID:24059859

Happiness increases verbal and spatial working memory capacity where sadness does not: Emotion, working memory and executive control.

PubMed

Storbeck, Justin; Maswood, Raeya

2016-08-01

The effects of emotion on working memory and executive control are often studied in isolation. Positive mood enhances verbal and impairs spatial working memory, whereas negative mood enhances spatial and impairs verbal working memory. Moreover, positive mood enhances executive control, whereas negative mood has little influence. We examined how emotion influences verbal and spatial working memory capacity, which requires executive control to coordinate between holding information in working memory and completing a secondary task. We predicted that positive mood would improve both verbal and spatial working memory capacity because of its influence on executive control. Positive, negative and neutral moods were induced followed by completing a verbal (Experiment 1) or spatial (Experiment 2) working memory operation span task to assess working memory capacity. Positive mood enhanced working memory capacity irrespective of the working memory domain, whereas negative mood had no influence on performance. Thus, positive mood was more successful holding information in working memory while processing task-irrelevant information, suggesting that the influence mood has on executive control supersedes the independent effects mood has on domain-specific working memory.

Semantic Memory and Verbal Working Memory Correlates of N400 to Subordinate Homographs

ERIC Educational Resources Information Center

Salisbury, Dean F.

2004-01-01

N400 is an event-related brain potential that indexes operations in semantic memory conceptual space, whether elicited by language or some other representation (e.g., drawings). Language models typically propose three stages: lexical access or orthographic- and phonological-level analysis; lexical selection or word-level meaning and associate…

Working Memory, Reasoning, and Task Switching Training: Transfer Effects, Limitations, and Great Expectations?

PubMed Central

Baniqued, Pauline L.; Ward, Nathan; Geyer, Alexandra; Kramer, Arthur F.

2015-01-01

Although some studies have shown that cognitive training can produce improvements to untrained cognitive domains (far transfer), many others fail to show these effects, especially when it comes to improving fluid intelligence. The current study was designed to overcome several limitations of previous training studies by incorporating training expectancy assessments, an active control group, and “Mind Frontiers,” a video game-based mobile program comprised of six adaptive, cognitively demanding training tasks that have been found to lead to increased scores in fluid intelligence (Gf) tests. We hypothesize that such integrated training may lead to broad improvements in cognitive abilities by targeting aspects of working memory, executive function, reasoning, and problem solving. Ninety participants completed 20 hour-and-a-half long training sessions over four to five weeks, 45 of whom played Mind Frontiers and 45 of whom completed visual search and change detection tasks (active control). After training, the Mind Frontiers group improved in working memory n-back tests, a composite measure of perceptual speed, and a composite measure of reaction time in reasoning tests. No training-related improvements were found in reasoning accuracy or other working memory tests, nor in composite measures of episodic memory, selective attention, divided attention, and multi-tasking. Perceived self-improvement in the tested abilities did not differ between groups. A general expectancy difference in problem-solving was observed between groups, but this perceived benefit did not correlate with training-related improvement. In summary, although these findings provide modest evidence regarding the efficacy of an integrated cognitive training program, more research is needed to determine the utility of Mind Frontiers as a cognitive training tool. PMID:26555341

Acute working memory improvement after tDCS in antidepressant-free patients with major depressive disorder.

PubMed

Oliveira, Janaina F; Zanão, Tamires A; Valiengo, Leandro; Lotufo, Paulo A; Benseñor, Isabela M; Fregni, Felipe; Brunoni, André R

2013-03-14

Based on previous studies showing that transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that employs weak, direct currents to induce cortical-excitability changes, might be useful for working memory (WM) enhancement in healthy subjects and also in treating depressive symptoms, our aim was to evaluate whether tDCS could acutely enhance WM in depressed patients. Twenty-eight age- and gender-matched, antidepressant-free depressed subjects received a single-session of active/sham tDCS in a randomized, double-blind, parallel design. The anode was positioned over the left and the cathode over the right dorsolateral prefrontal cortex. The n-back task was used for assessing WM and it was performed immediately before and 15min after tDCS onset. We found that active vs. sham tDCS led to an increase in the rate of correct responses. We also used signal detection theory analyses to show that active tDCS increased both discriminability, i.e., the ability to discriminate signal (correct responses) from noise (false alarms), and response criterion, indicating a lower threshold to yield responses. All effect sizes were large. In other words, one session of tDCS acutely enhanced WM in depressed subjects, suggesting that tDCS can improve "cold" (non affective-loaded) working memory processes in MDD. Based on these findings, we discuss the effects of tDCS on WM enhancement in depression. We also suggest that the n-back task could be used as a biomarker in future tDCS studies investigating prefrontal activity in healthy and depressed samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Trait and state anxiety is marked by increased working memory-related parietal BOLD signal.

PubMed

Ford, Talitha C; Simpson, Tamara; McPhee, Grace; Stough, Con; Downey, Luke A

2018-05-16

Anxiety is associated with compromised cognitive control functions, such as working memory. State and trait anxiety within the non-clinical population can be utilised to investigate potential neural markers for anxiety, which may help to elucidate potential prevention and intervention methods. Thirty-two healthy adults (20 female, 12 male), aged between 30 and 65 years, performed a 2-back task whilst fMRI BOLD signal was acquired using a 3T scanner. Mean BOLD signal was obtained in cognitive control network regions of interest of: left and right dorsolateral prefrontal cortex (DLPFC) and posterior parietal lobe (PPL), and medial prefrontal cortex (MPFC). State and trait anxiety levels were recorded. Higher overall anxiety was moderately associated with more left and right PPL BOLD signal; there was a weak relationship between anxiety and left DLPFC BOLD signal. MPFC BOLD signal and trait anxiety were moderately associated with overall 2-back task performance. These findings suggest that non-clinical anxiety affects the recruitment of cortical resources during working memory, but that anxiety does not impair performance during a 2-back task. Copyright © 2018 Elsevier B.V. All rights reserved.

Working Memory and Processing Efficiency in Children's Reasoning.

ERIC Educational Resources Information Center

Halford, Graeme S.; And Others

A series of studies was conducted to determine whether children's reasoning is capacity-limited and whether any such capacity, if it exists, is based on the working memory system. An N-term series (transitive inference) was used as the primary task in an interference paradigm. A concurrent short-term memory load was employed as the secondary task.…

Object permanence and working memory in cats (Felis catus).

PubMed

Goulet, S; Doré, F Y; Rousseau, R

1994-10-01

Cats (Felis catus) find an object when it is visibly moved behind a succession of screens. However, when the object is moved behind a container and is invisibly transferred from the container to the back of a screen, cats try to find the object at or near the container rather than at the true hiding place. Four experiments were conducted to study search behavior and working memory in visible and invisible displacement tests of object permanence. Experiment 1 compared performance in single and in double visible displacement trials. Experiment 2 analyzed search behavior in invisible displacement tests and in analogs using a transparent container. Experiments 3 and 4 tested predictions made from Experiment 1 and 2 in a new situation of object permanence. Results showed that only the position changes that cats have directly perceived are encoded and activated in working memory, because they are unable to represent or infer invisible movements.

The Relation between the Working Memory Skills of Sign Language Interpreters and the Quality of Their Interpretations

ERIC Educational Resources Information Center

Van Dijk, Rick; Christoffels, Ingrid; Postma, Albert; Hermans, Daan

2012-01-01

In two experiments we investigated the relationship between the working memory skills of sign language interpreters and the quality of their interpretations. In Experiment 1, we found that scores on 3-back tasks with signs and words were not related to the quality of interpreted narratives. In Experiment 2, we found that memory span scores for…

Associations Between White Matter Microstructure and Infants’ Working Memory

PubMed Central

Short, Sarah J.; Elison, Jed T.; Goldman, Barbara Davis; Styner, Martin; Gu, Hongbin; Connelly, Mark; Maltbie, Eric; Woolson, Sandra; Lin, Weili; Gerig, Guido; Reznick, J. Steven; Gilmore, John H.

2013-01-01

Working memory emerges in infancy and plays a privileged role in subsequent adaptive cognitive development. The neural networks important for the development of working memory during infancy remain unknown. We used diffusion tensor imaging (DTI) and deterministic fiber tracking to characterize the microstructure of white matter fiber bundles hypothesized to support working memory in 12-month-old infants (n=73). Here we show robust associations between infants’ visuospatial working memory performance and microstructural characteristics of widespread white matter. Significant associations were found for white matter tracts that connect brain regions known to support working memory in older children and adults (genu, anterior and superior thalamic radiations, anterior cingulum, arcuate fasciculus, and the temporal-parietal segment). Better working memory scores were associated with higher FA and lower RD values in these selected white matter tracts. These tract-specific brain-behavior relationships accounted for a significant amount of individual variation above and beyond infants’ gestational age and developmental level, as measured with the Mullen Scales of Early Learning. Working memory was not associated with global measures of brain volume, as expected, and few associations were found between working memory and control white matter tracts. To our knowledge, this study is among the first demonstrations of brain-behavior associations in infants using quantitative tractography. The ability to characterize subtle individual differences in infant brain development associated with complex cognitive functions holds promise for improving our understanding of normative development, biomarkers of risk, experience-dependent learning and neuro-cognitive periods of developmental plasticity. PMID:22989623

Visuospatial working memory underlies choice-impulsivity in boys with attention-deficit/hyperactivity disorder.

PubMed

Patros, Connor H G; Alderson, R Matt; Lea, Sarah E; Tarle, Stephanie J; Kasper, Lisa J; Hudec, Kristen L

2015-03-01

The present study examined the directional relationship between choice-impulsivity and separate indices of phonological and visuospatial working memory performance in boys (aged 8-12 years) with (n=16) and without ADHD (n=19). Results indicated that high ratings of overall ADHD, inattention, and hyperactivity were significantly associated with increased impulsivity and poorer phonological and visuospatial working memory performance. Further, results from bias-corrected bootstrapped mediation analyses revealed a significant indirect effect of visuospatial working memory performance, through choice-impulsivity, on overall ADHD, inattention, and hyperactivity/impulsivity. Collectively, the findings suggest that deficits of visuospatial working memory underlie choice-impulsivity, which in turn contributes to the ADHD phenotype. Moreover, these findings are consistent with a growing body of literature that identifies working memory as a central neurocognitive deficit of ADHD. Copyright © 2015 Elsevier Ltd. All rights reserved.

Integrative assessment of brain function in PTSD: brain stability and working memory.

PubMed

Veltmeyer, Melinda D; McFarlane, Alexander C; Bryant, Richard A; Mayo, Therese; Gordon, Evian; Clark, C Richard

2006-03-01

Posttraumatic Stress Disorder (PTSD) is characterized by symptoms of hyperarousal, avoidance and intrusive trauma-related memories and deficits in everyday memory and attention. Separate studies in PTSD have found abnormalities in electroencephalogram EEG, in event-related potential (ERP) and behavioral measures of working memory and attention. The present study seeks to determine whether these abnormalities are related and the extent to which they share this relationship with clinical symptoms. EEG data were collected during an eyes-open paradigm and a one-back working memory task. Behavioral and clinical data (CAPS) were also collected. The PTSD group showed signs of altered cortical arousal as indexed by reduced alpha power and an increased theta/alpha ratio, and clinical and physiological measures of arousal were found to be related. The normal relationship between theta power and ERP indices of working memory was not affected in PTSD, with both sets of measures reduced in the disordered group. Medication appeared to underpin a number of abnormal parameters, including P3 amplitude to targets and the accuracy, though not speed, of target detection. The present study helps to overcome a limitation of earlier studies that assess such parameters independently in different groups of patients that vary in factors such as comorbidity, medication status, gender and symptom profile. The present study begins to shed light on the relationship between these measures and suggests that abnormalities in brain working memory may be linked to underlying abnormalities in brain stability.

Mental Imagery and Visual Working Memory

PubMed Central

Keogh, Rebecca; Pearson, Joel

2011-01-01

Visual working memory provides an essential link between past and future events. Despite recent efforts, capacity limits, their genesis and the underlying neural structures of visual working memory remain unclear. Here we show that performance in visual working memory - but not iconic visual memory - can be predicted by the strength of mental imagery as assessed with binocular rivalry in a given individual. In addition, for individuals with strong imagery, modulating the background luminance diminished performance on visual working memory and imagery tasks, but not working memory for number strings. This suggests that luminance signals were disrupting sensory-based imagery mechanisms and not a general working memory system. Individuals with poor imagery still performed above chance in the visual working memory task, but their performance was not affected by the background luminance, suggesting a dichotomy in strategies for visual working memory: individuals with strong mental imagery rely on sensory-based imagery to support mnemonic performance, while those with poor imagery rely on different strategies. These findings could help reconcile current controversy regarding the mechanism and location of visual mnemonic storage. PMID:22195024

Mental imagery and visual working memory.

PubMed

Keogh, Rebecca; Pearson, Joel

2011-01-01

Visual working memory provides an essential link between past and future events. Despite recent efforts, capacity limits, their genesis and the underlying neural structures of visual working memory remain unclear. Here we show that performance in visual working memory--but not iconic visual memory--can be predicted by the strength of mental imagery as assessed with binocular rivalry in a given individual. In addition, for individuals with strong imagery, modulating the background luminance diminished performance on visual working memory and imagery tasks, but not working memory for number strings. This suggests that luminance signals were disrupting sensory-based imagery mechanisms and not a general working memory system. Individuals with poor imagery still performed above chance in the visual working memory task, but their performance was not affected by the background luminance, suggesting a dichotomy in strategies for visual working memory: individuals with strong mental imagery rely on sensory-based imagery to support mnemonic performance, while those with poor imagery rely on different strategies. These findings could help reconcile current controversy regarding the mechanism and location of visual mnemonic storage.

Estradiol concentrations and working memory performance in women of reproductive age.

PubMed

Hampson, Elizabeth; Morley, Erin E

2013-12-01

Estrogen has been proposed to exert a regulatory influence on the working memory system via actions in the female prefrontal cortex. Tests of this hypothesis have been limited almost exclusively to postmenopausal women and pharmacological interventions. We explored whether estradiol discernibly influences working memory within the natural range of variation in concentrations characteristic of the menstrual cycle. The performance of healthy women (n=39) not using hormonal contraceptives, and a control group of age- and education-matched men (n=31), was compared on a spatial working memory task. Cognitive testing was done blind to ovarian status. Women were retrospectively classified into low- or high-estradiol groups based on the results of radioimmunoassays of saliva collected immediately before and after the cognitive testing. Women with higher levels of circulating estradiol made significantly fewer errors on the working memory task than women tested under low estradiol. Pearson's correlations showed that the level of salivary estradiol but not progesterone was correlated inversely with the number of working memory errors produced. Women tested at high levels of circulating estradiol tended to be more accurate than men. Superior performance by the high estradiol group was seen on the working memory task but not on two control tasks, indicating selectivity of the effects. Consistent with previous studies of postmenopausal women, higher levels of circulating estradiol were associated with better working memory performance. These results add further support to the hypothesis that the working memory system is modulated by estradiol in women, and show that the effects can be observed under non-pharmacological conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study.

PubMed

Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P; Crewther, Sheila G

2016-01-01

Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial stimuli (3D cube shapes) utilizing a 1-back task while functional magnetic resonance imaging (fMRI) scans were acquired. Sixteen healthy participants (9 women, M = 23.94 years, SD = 2.49) were required to perform the 1-back task with or without mentally rotating the shapes 90° on a vertical axis. When no rotation was required (maintenance-only condition), a right hemispheric lateralization was revealed across fronto-parietal areas. However, when the task involved maintaining and manipulating the same stimuli through 90° rotation, activation was primarily seen in the bilateral parietal lobe and left fusiform gyrus. The findings confirm that the well-established right lateralized fronto-parietal networks are likely to underlie simple maintenance of visuo-spatial stimuli. The results also suggest that the added demand of manipulation of information maintained online appears to require further neural recruitment of functionally related areas. In particular mental rotation of visuospatial stimuli required bilateral parietal areas, and the left fusiform gyrus potentially to maintain a categorical or object representation. It can be concluded that WM is a complex neural process involving the interaction of an increasingly large network.

Early working memory and maternal communication in toddlers born very low birth weight.

PubMed

Lowe, Jean; Erickson, Sarah J; Maclean, Peggy; Duvall, Susanne W

2009-04-01

Early working memory is emerging as an important indicator of developmental outcome predicting later cognitive, behavioural and academic competencies. The current study compared early working memory in a sample of toddlers (18-22 months) born very low birth weight (VLBW; n = 40) and full term (n = 51) and the relationship between early working memory, mental developmental index (MDI), and maternal communication in both samples. Early working memory, measured by object permanence; Bayley mental developmental index; and maternal communication, coded during mother-toddler play interaction, were examined in 39 toddlers born VLBW and 41 toddlers born full term. Toddlers born VLBW were found to be 6.4 times less likely to demonstrate attainment of object permanence than were toddlers born full term, adjusting for age at testing. MDI and maternal communication were found to be positively associated with attainment of object permanence in the VLBW group only. The difference found in the early working memory performance of toddlers born VLBW, compared with those born full term, emphasizes the importance of assessing early working memory in at-risk populations, while the maternal communication finding highlights potential targets of intervention for improving working memory in toddlers born VLBW.

Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM).

PubMed

Cabbage, Kathryn; Brinkley, Shara; Gray, Shelley; Alt, Mary; Cowan, Nelson; Green, Samuel; Kuo, Trudy; Hogan, Tiffany P

2017-06-12

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of working memory in young school-age children. Working memory deficits have been identified in children with language-based learning disabilities, including dyslexia 1 , 2 and language impairment 3 , 4 , but it is not clear whether these children exhibit deficits in subcomponents of working memory, such as visuospatial or phonological working memory. The CABC-WM is administered on a desktop computer with a touchscreen interface and was specifically developed to be engaging and motivating for children. Although the long-term goal of the CABC-WM is to provide individualized working memory profiles in children, the present study focuses on the initial success and utility of the CABC-WM for measuring central executive, visuospatial, phonological loop, and binding constructs in children with typical development. Immediate next steps are to administer the CABC-WM to children with specific language impairment, dyslexia, and comorbid specific language impairment and dyslexia.

Coaching positively influences the effects of working memory training on visual working memory as well as mathematical ability.

PubMed

Nelwan, Michel; Vissers, Constance; Kroesbergen, Evelyn H

2018-05-01

The goal of the present study was to test whether the amount of coaching influenced the results of working memory training on both visual and verbal working memory. Additionally, the effects of the working memory training on the amount of progress after specific training in mathematics were evaluated. In this study, 23 children between 9 and 12 years of age with both attentional and mathematical difficulties participated in a working memory training program with a high amount of coaching, while another 25 children received no working memory training. Results of these groups were compared to 21 children who completed the training with a lower amount of coaching. The quality of working memory, as well as mathematic skills, were measured three times using untrained transfer tasks. Bayesian statistics were used to test informative hypotheses. After receiving working memory training, the highly coached group performed better than the group that received less coaching on visual working memory and mathematics, but not on verbal working memory. The highly coached group retained their advantage in mathematics, even though the effect on visual working memory decreased. However, no added effect of working memory training was found on the learning curve during mathematical training. Moreover, the less-coached group was outperformed by the group that did not receive working memory training, both in visual working memory and mathematics. These results suggest that motivation and proper coaching might be crucial for ensuring compliance and effects of working memory training, and that far transfer might be possible. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reasoning=working Memory<>attention

ERIC Educational Resources Information Center

Buehner, M.; Krumm, S.; Pick, M.

2005-01-01

The purpose of this study was to clarify the relationship between attention, components of working memory, and reasoning. Therefore, twenty working memory tests, two attention tests, and nine intelligence subtests were administered to 135 students. Using structural equation modeling, we were able to replicate a functional model of working memory…

Tone series and the nature of working memory capacity development.

PubMed

Clark, Katherine M; Hardman, Kyle O; Schachtman, Todd R; Saults, J Scott; Glass, Bret A; Cowan, Nelson

2018-04-01

Recent advances in understanding visual working memory, the limited information held in mind for use in ongoing processing, are extended here to examine auditory working memory development. Research with arrays of visual objects has shown how to distinguish the capacity, in terms of the number of objects retained, from the precision of the object representations. We adapt the technique to sequences of nonmusical tones, in an investigation including children (6-13 years, N = 84) and adults (26-50 years, N = 31). For each series of 1 to 4 tones, the participant responded by using an 80-choice scale to try to reproduce the tone at a queried serial position. Despite the much longer-lasting usefulness of sensory memory for tones compared with visual objects, the observed tone capacity was similar to previous findings for visual capacity. The results also constrain theories of childhood working memory development, indicating increases with age in both the capacity and the precision of the tone representations, similar to the visual studies, rather than age differences in time-based memory decay. The findings, including patterns of correlations between capacity, precision, and some auxiliary tasks and questionnaires, establish capacity and precision as dissociable processes and place important constraints on various hypotheses of working memory development. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Working Memory Systems in the Rat.

PubMed

Bratch, Alexander; Kann, Spencer; Cain, Joshua A; Wu, Jie-En; Rivera-Reyes, Nilda; Dalecki, Stefan; Arman, Diana; Dunn, Austin; Cooper, Shiloh; Corbin, Hannah E; Doyle, Amanda R; Pizzo, Matthew J; Smith, Alexandra E; Crystal, Jonathon D

2016-02-08

A fundamental feature of memory in humans is the ability to simultaneously work with multiple types of information using independent memory systems. Working memory is conceptualized as two independent memory systems under executive control [1, 2]. Although there is a long history of using the term "working memory" to describe short-term memory in animals, it is not known whether multiple, independent memory systems exist in nonhumans. Here, we used two established short-term memory approaches to test the hypothesis that spatial and olfactory memory operate as independent working memory resources in the rat. In the olfactory memory task, rats chose a novel odor from a gradually incrementing set of old odors [3]. In the spatial memory task, rats searched for a depleting food source at multiple locations [4]. We presented rats with information to hold in memory in one domain (e.g., olfactory) while adding a memory load in the other domain (e.g., spatial). Control conditions equated the retention interval delay without adding a second memory load. In a further experiment, we used proactive interference [5-7] in the spatial domain to compromise spatial memory and evaluated the impact of adding an olfactory memory load. Olfactory and spatial memory are resistant to interference from the addition of a memory load in the other domain. Our data suggest that olfactory and spatial memory draw on independent working memory systems in the rat. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can we improve the clinical assessment of working memory? An evaluation of the Wechsler Adult Intelligence Scale-Third Edition using a working memory criterion construct.

PubMed

Hill, B D; Elliott, Emily M; Shelton, Jill T; Pella, Russell D; O'Jile, Judith R; Gouvier, W Drew

2010-03-01

Working memory is the cognitive ability to hold a discrete amount of information in mind in an accessible state for utilization in mental tasks. This cognitive ability is impaired in many clinical populations typically assessed by clinical neuropsychologists. Recently, there have been a number of theoretical shifts in the way that working memory is conceptualized and assessed in the experimental literature. This study sought to determine to what extent the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Working Memory Index (WMI) measures the construct studied in the cognitive working memory literature, whether an improved WMI could be derived from the subtests that comprise the WAIS-III, and what percentage of variance in individual WAIS-III subtests is explained by working memory. It was hypothesized that subtests beyond those currently used to form the WAIS-III WMI would be able to account for a greater percentage of variance in a working memory criterion construct than the current WMI. Multiple regression analyses (n = 180) revealed that the best predictor model of subtests for assessing working memory was composed of the Digit Span, Letter-Number Sequencing, Matrix Reasoning, and Vocabulary. The Arithmetic subtest was not a significant contributor to the model. These results are discussed in the context of how they relate to Unsworth and Engle's (2006, 2007) new conceptualization of working memory mechanisms.

Working memory and the memory distortion component of hindsight bias.

PubMed

Calvillo, Dustin P

2012-01-01

One component of hindsight bias is memory distortion: Individuals' recollections of their predictions are biased towards known outcomes. The present study examined the role of working memory in the memory distortion component of hindsight bias. Participants answered almanac-like questions, completed a measure of working memory capacity, were provided with the correct answers, and attempted to recollect their original judgements in two conditions: with and without a concurrent working memory load. Participants' recalled judgements were more biased by feedback when they recalled these judgements with a concurrent memory load and working memory capacity was negatively correlated with memory distortion. These findings are consistent with reconstruction accounts of the memory distortion component of hindsight bias and, more generally, with dual process theories of cognition. These results also relate the memory distortion component of hindsight bias with other cognitive errors, such as source monitoring errors, the belief bias in syllogistic reasoning and anchoring effects. Implications for the separate components view of hindsight bias are discussed.

Neural hyperactivity related to working memory in drug-naive boys with attention deficit hyperactivity disorder.

PubMed

Li, Yuanyuan; Li, Fei; He, Ning; Guo, Lanting; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

2014-08-04

Impaired working memory is thought to be a core feature of attention deficit hyperactivity disorder (ADHD). Previous imaging studies investigating working memory in ADHD have used tasks involving different cognitive resources and ignoring the categorical judgments about objects that are essential parts of performance in visual working memory tasks, thus complicating the interpretation of their findings. In the present study, we explored differential neural activation in children and adolescents with ADHD and in healthy controls using functional magnetic resonance imaging (fMRI) with the categorical n-back task (CN-BT), which maximized demands for executive reasoning while holding memory demands constant. A total of 33 drug-naive, right-handed male ADHD without comorbidity (mean age 9.9±2.4 years) and 27 right-handed, healthy male controls (mean age 10.9±2.7 years) were recruited in the present study. Event-related fMRI was used to study differences in brain activity during the CN-BT between the two groups. The two groups did not differ in their accuracy in the CN-BT, although the ADHD patients showed significantly shorter reaction times to correct responses than did the controls. During the CN-BT, both ADHD patients and controls showed significant positive and negative activations by the correct responses, mainly in the sensory-motor pathways and the striato-cerebellum circuit. Additionally, the ADHD patients showed significantly higher activation in the bilateral globus pallidus and the right hippocampus compared with the controls. There was also a positive correlation between hyperactivation of the left globus pallidus and the reaction time to correct responses in ADHD. In contrast to controls, ADHD patients showed neural hyperactivation in the striatum and mediotemporal areas during a working memory task involving categorization. Hyperfunction in these areas might be the pathophysiological foundation of ADHD, related to the deficits of working memory and the

When memory is not enough: Electrophysiological evidence for goal-dependent use of working memory representations in guiding visual attention

PubMed Central

Carlisle, Nancy B.; Woodman, Geoffrey F.

2014-01-01

Biased competition theory proposes that representations in working memory drive visual attention to select similar inputs. However, behavioral tests of this hypothesis have led to mixed results. These inconsistent findings could be due to the inability of behavioral measures to reliably detect the early, automatic effects on attentional deployment that the memory representations exert. Alternatively, executive mechanisms may govern how working memory representations influence attention based on higher-level goals. In the present study, we tested these hypotheses using the N2pc component of participants’ event-related potentials (ERPs) to directly measure the early deployments of covert attention. Participants searched for a target in an array that sometimes contained a memory-matching distractor. In Experiments 1–3, we manipulated the difficulty of the target discrimination and the proximity of distractors, but consistently observed that covert attention was deployed to the search targets and not the memory-matching distractors. In Experiment 4, we showed that when participants’ goal involved attending to memory-matching items that these items elicited a large and early N2pc. Our findings demonstrate that working memory representations alone are not sufficient to guide early deployments of visual attention to matching inputs and that goal-dependent executive control mediates the interactions between working memory representations and visual attention. PMID:21254796

Working memory, long-term memory, and medial temporal lobe function

PubMed Central

Jeneson, Annette; Squire, Larry R.

2012-01-01

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL. PMID:22180053

Back muscle strength, lifting, and stooped working postures.

PubMed

Poulsen, E; Jørgensen, K

1971-09-01

When lifting loads and working in a forward stooped position, the muscles of the back rather than the ligaments and bony structures of the spine should overcome the gravitational forces. Formulae, based on measurements of back muscle strength, for prediction of maximal loads to be lifted, and for the ability to sustain work in a stooped position, have been worked out and tested in practical situations. From tests with 50 male and female subjects the simplest prediction formulae for maximum loads were: max. load = 1.10 x isometric back muscle strength for men; and max. load = 0.95 x isometric back muscle strength - 8 kg for women. Some standard values for maximum lifts and permissible single and repeated lifts have been calculated for men and women separately and are given in Table 1. From tests with 65 rehabilitees it was found that the maximum isometric strength of the back muscles measured at shoulder height should exceed 2/3 of the body weight, if fatigue and/or pain in the back muscles is to be avoided during work in a standing stooped position.

Back pain - returning to work

MedlinePlus

... matter what kind of work you do. Long car rides and getting in and out of the car can be hard on your back. If you ... work, consider some of these changes: Adjust your car seat to make it easier to enter, sit ...

fMRI: blood oxygen level-dependent activation during a working memory-selective attention task in children born extremely preterm.

PubMed

Griffiths, Silja Torvik; Gundersen, Hilde; Neto, Emanuel; Elgen, Irene; Markestad, Trond; Aukland, Stein M; Hugdahl, Kenneth

2013-08-01

Extremely preterm (EPT)/extremely low-birth-weight (ELBW) children attaining school age and adolescence often have problems with executive functions such as working memory and selective attention. Our aim was to investigate a hypothesized difference in blood oxygen level-dependent (BOLD) activation during a selective attention-working memory task in EPT/ELBW children as compared with term-born controls. A regional cohort of 28 EPT/ELBW children and 28 term-born controls underwent functional magnetic resonance imaging (fMRI) scanning at 11 y of age while performing a combined Stroop n-back task. Group differences in BOLD activation were analyzed with Statistical Parametric Mapping 8 analysis software package, and reaction times (RTs) and response accuracy (RA) were compared in a multifactorial ANOVA test. The BOLD activation pattern in the preterm group involved the same areas (cingulate, prefrontal, and parietal cortexes), but all areas displayed significantly less activation than those in the control group, particularly when the cognitive load was increased. The RA results corresponded with the activation data in that the preterm group had significantly fewer correct responses. No group difference was found regarding RTs. Children born EPT/ELBW displayed reduced working memory and selective attention capacity as compared with term-born controls. These impairments had neuronal correlates with reduced BOLD activation in areas responsible for online stimulus monitoring, working memory, and cognitive control.

The effects of cannabidiol on impulsivity and memory during abstinence in cigarette dependent smokers.

PubMed

Hindocha, C; Freeman, T P; Grabski, M; Crudgington, H; Davies, A C; Stroud, J B; Das, R K; Lawn, W; Morgan, C J A; Curran, H V

2018-05-15

Acute nicotine abstinence in cigarette smokers results in deficits in performance on specific cognitive processes, including working memory and impulsivity which are important in relapse. Cannabidiol (CBD), the non-intoxicating cannabinoid found in cannabis, has shown pro-cognitive effects and preliminary evidence has indicated it can reduce the number of cigarettes smoked in dependent smokers. However, the effects of CBD on cognition have never been tested during acute nicotine withdrawal. The present study therefore aimed to investigate if CBD can improve memory and reduce impulsivity during acute tobacco abstinence. Thirty, non-treatment seeking, dependent, cigarette smokers attended two laboratory-based sessions after overnight abstinence, in which they received either 800 mg oral CBD or placebo (PBO), in a randomised order. Abstinence was biologically verified. Participants were assessed on go/no-go, delay discounting, prose recall and N-back (0-back, 1-back, 2-back) tasks. The effects of CBD on delay discounting, prose recall and the N-back (correct responses, maintenance or manipulation) were null, confirmed by a Bayesian analysis, which found evidence for the null hypothesis. Contrary to our predictions, CBD increased commission errors on the go/no-go task. In conclusion, a single 800 mg dose of CBD does not improve verbal or spatial working memory, or impulsivity during tobacco abstinence.

Differences between Presentation Methods in Working Memory Procedures: A Matter of Working Memory Consolidation

ERIC Educational Resources Information Center

Ricker, Timothy J.; Cowan, Nelson

2014-01-01

Understanding forgetting from working memory, the memory used in ongoing cognitive processing, is critical to understanding human cognition. In the past decade, a number of conflicting findings have been reported regarding the role of time in forgetting from working memory. This has led to a debate concerning whether longer retention intervals…

A multisensory perspective of working memory

PubMed Central

Quak, Michel; London, Raquel Elea; Talsma, Durk

2015-01-01

Although our sensory experience is mostly multisensory in nature, research on working memory representations has focused mainly on examining the senses in isolation. Results from the multisensory processing literature make it clear that the senses interact on a more intimate manner than previously assumed. These interactions raise questions regarding the manner in which multisensory information is maintained in working memory. We discuss the current status of research on multisensory processing and the implications of these findings on our theoretical understanding of working memory. To do so, we focus on reviewing working memory research conducted from a multisensory perspective, and discuss the relation between working memory, attention, and multisensory processing in the context of the predictive coding framework. We argue that a multisensory approach to the study of working memory is indispensable to achieve a realistic understanding of how working memory processes maintain and manipulate information. PMID:25954176

Working Memory: A Selective Review.

PubMed

Kent, Phillip L

2016-01-01

The purpose of this paper is to provide a selective overview of the evolution of the concept and assessment of working memory, and how its assessment has been confused with the assessment of some components of attention. A literature search using PsychNet Gold was conducted using the terms working memory. In addition, the writer reviewed recommendations from a sampling of recent neuropsychology texts in regard to the assessment of attention and working memory, as well as the two most recent editions of the Wechsler Memory Scale. It is argued that many clinicians have an incomplete understanding of the relationship between attention and working memory, and often conflate the two in assessment and treatment. Suggestions were made for assessing these abilities.

Working memory deficits in adults with ADHD: is there evidence for subtype differences?

PubMed Central

Schweitzer, Julie B; Hanford, Russell B; Medoff, Deborah R

2006-01-01

Background Working memory performance is important for maintaining functioning in cognitive, academic and social activities. Previous research suggests there are prevalent working memory deficits in children with attention deficit hyperactivity disorder (ADHD). There is now a growing body of literature characterizing working memory functioning according to ADHD subtypes in children. The expression of working memory deficits in adults with ADHD and how they vary according to subtype, however, remains to be more fully documented. Methods This study assessed differences in working memory functioning between Normal Control (NC) adults (N = 18); patients with ADHD, Combined (ADHD-CT) Type ADHD (N = 17); and ADHD, Inattentive (ADHD-IA) Type (N = 16) using subtests from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III and the Paced Auditory Serial Addition Task (PASAT). Results The ADHD groups displayed significant weaknesses in contrast to the NC group on working memory tests requiring rapid processing and active stimulus manipulation. This included the Letter-Number-Sequencing test of the Wechsler scales, PASAT omission errors and the longest sequence of consecutive correct answers on the PASAT. No overall ADHD group subtype differences emerged; however differences between the ADHD groups and the NC group varied depending on the measure and the gender of the participants. Gender differences in performance were evident on some measures of working memory, regardless of group, with males performing better than females. Conclusion In general, the data support a dimensional interpretation of working memory deficits experienced by the ADHD-CT and ADHD-IA subtypes, rather than an absolute difference between subtypes. Future studies should test the effects of processing speed and load on subtype performance and how those variables interact with gender in adults with ADHD. PMID:17173676

Can verbal working memory training improve reading?

PubMed

Banales, Erin; Kohnen, Saskia; McArthur, Genevieve

2015-01-01

The aim of the current study was to determine whether poor verbal working memory is associated with poor word reading accuracy because the former causes the latter, or the latter causes the former. To this end, we tested whether (a) verbal working memory training improves poor verbal working memory or poor word reading accuracy, and whether (b) reading training improves poor reading accuracy or verbal working memory in a case series of four children with poor word reading accuracy and verbal working memory. Each child completed 8 weeks of verbal working memory training and 8 weeks of reading training. Verbal working memory training improved verbal working memory in two of the four children, but did not improve their reading accuracy. Similarly, reading training improved word reading accuracy in all children, but did not improve their verbal working memory. These results suggest that the causal links between verbal working memory and reading accuracy may not be as direct as has been assumed.

Contribution of underlying processes to improved visuospatial working memory associated with physical activity.

PubMed

Ji, Qingchun; Wang, Yingying; Guo, Wei; Zhou, Chenglin

2017-01-01

Working memory is critical for various cognitive processes and can be separated into two stages: short-term memory storage and manipulation processing. Although previous studies have demonstrated that increased physical activity (PA) improves working memory and that males outperform females on visuospatial working memory tasks, few studies have determined the contribution of the two underlying stages to the visuospatial working memory improvement associated with PA. Thus, the aims of the present study were to verify the relationship between physical activity and visuospatial working memory, determine whether one or both stages were affected by PA, and investigate any sex differences. A total of 56 undergraduate students were recruited for this study. Their scores on the International Physical Activity Questionnaire (IPAQ) were used to separate them into either a lower PA ( n  = 26; IPAQ score ≤3,000 metabolic equivalent [MET]-min/week) or higher PA ( n  = 30; IPAQ score >3,000 MET-min/week) group. Participants were required to complete three tasks: a visuospatial working memory task, a task that examines the short-term memory storage stage, and a mental rotation task that examines the active manipulation stage. Participants in the higher PA group maintained similar accuracy but displayed significantly faster reaction times (RT) than those in the lower PA group on the visuospatial working memory and manipulation tasks. By contrast, no difference was observed between groups on the short-term memory storage task. In addition, no effects of sex were detected. Our results confirm that PA was positively to visuospatial working memory and that this positive relationship was associated with more rapid cognitive processing during the manipulation stage, with little or no relationship between PA and the memory storage stage of visuospatial working memory.

Concurrent working memory load can facilitate selective attention: evidence for specialized load.

PubMed

Park, Soojin; Kim, Min-Shik; Chun, Marvin M

2007-10-01

Load theory predicts that concurrent working memory load impairs selective attention and increases distractor interference (N. Lavie, A. Hirst, J. W. de Fockert, & E. Viding). Here, the authors present new evidence that the type of concurrent working memory load determines whether load impairs selective attention or not. Working memory load was paired with a same/different matching task that required focusing on targets while ignoring distractors. When working memory items shared the same limited-capacity processing mechanisms with targets in the matching task, distractor interference increased. However, when working memory items shared processing with distractors in the matching task, distractor interference decreased, facilitating target selection. A specialized load account is proposed to describe the dissociable effects of working memory load on selective processing depending on whether the load overlaps with targets or with distractors. (c) 2007 APA

Decrease in fMRI brain activation during working memory performed after sleeping under 10 lux light.

PubMed

Kang, Seung-Gul; Yoon, Ho-Kyoung; Cho, Chul-Hyun; Kwon, Soonwook; Kang, June; Park, Young-Min; Lee, Eunil; Kim, Leen; Lee, Heon-Jeong

2016-11-09

The aim of this study was to investigate the effect of exposure to dim light at night (dLAN) when sleeping on functional brain activation during a working-memory tasks. We conducted the brain functional magnetic resonance imaging (fMRI) analysis on 20 healthy male subjects. All participants slept in a polysomnography laboratory without light exposure on the first and second nights and under a dim-light condition of either 5 or 10 lux on the third night. The fMRI scanning was conducted during n-back tasks after second and third nights. Statistical parametric maps revealed less activation in the right inferior frontal gyrus (IFG) after exposure to 10-lux light. The brain activity in the right and left IFG areas decreased more during the 2-back task than during the 1- or 0-back task in the 10-lux group. The exposure to 5-lux light had no significant effect on brain activities. The exposure to dLAN might influence the brain function which is related to the cognition.

Working Memory, Cognitive Style, and Behavioural Predictors of GCSE Exam Success

ERIC Educational Resources Information Center

Grimley, Michael; Banner, Gloria

2008-01-01

This study investigates the interplay of working memory, cognitive style, and behaviour. Year 8 (aged 13 years) students (n = 205) at a UK urban secondary school were tested to ascertain predictors of General Certificate of School Education (GCSE) achievement. Assessment included Riding's cognitive style dimensions, working memory capacity, and a…

An exploratory study of the effects of spatial working-memory load on prefrontal activation in low- and high-performing elderly.

PubMed

Vermeij, Anouk; van Beek, Arenda H E A; Reijs, Babette L R; Claassen, Jurgen A H R; Kessels, Roy P C

2014-01-01

Older adults show more bilateral prefrontal activation during cognitive performance than younger adults, who typically show unilateral activation. This over-recruitment has been interpreted as compensation for declining structure and function of the brain. Here we examined how the relationship between behavioral performance and prefrontal activation is modulated by different levels of working-memory load. Eighteen healthy older adults (70.8 ± 5.0 years; MMSE 29.3 ± 0.9) performed a spatial working-memory task (n-back). Oxygenated ([O2Hb]) and deoxygenated ([HHb]) hemoglobin concentration changes were registered by two functional Near-Infrared Spectroscopy (fNIRS) channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition. [O2Hb] increased with rising working-memory load in both fNIRS channels. Based on the performance in the high working-memory load condition, the group was divided into low and high performers. A significant interaction effect of performance level and hemisphere on [O2Hb] increase was found, indicating that high performers were better able to keep the right prefrontal cortex engaged under high cognitive demand. Furthermore, in the low performers group, individuals with a larger decline in task performance from the control to the high working-memory load condition had a larger bilateral increase of [O2Hb]. The high performers did not show a correlation between performance decline and working-memory load related prefrontal activation changes. Thus, additional bilateral prefrontal activation in low performers did not necessarily result in better cognitive performance. Our study showed that bilateral prefrontal activation may not always be successfully compensatory. Individual behavioral performance should be taken into account to be able to distinguish successful and unsuccessful compensation or declined neural efficiency.

Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory.

PubMed

Katus, Tobias; Grubert, Anna; Eimer, Martin

2015-12-01

Sensory recruitment models of working memory assume that information storage is mediated by the same cortical areas that are responsible for the perceptual processing of sensory signals. To test this assumption, we measured somatosensory event-related brain potentials (ERPs) during a tactile delayed match-to-sample task. Participants memorized a tactile sample set at one task-relevant hand to compare it with a subsequent test set on the same hand. During the retention period, a sustained negativity (tactile contralateral delay activity, tCDA) was elicited over primary somatosensory cortex contralateral to the relevant hand. The amplitude of this component increased with memory load and was sensitive to individual limitations in memory capacity, suggesting that the tCDA reflects the maintenance of tactile information in somatosensory working memory. The tCDA was preceded by a transient negativity (N2cc component) with a similar contralateral scalp distribution, which is likely to reflect selection of task-relevant tactile stimuli at the encoding stage. The temporal sequence of N2cc and tCDA components mirrors previous observations from ERP studies of working memory in vision. The finding that the sustained somatosensory delay period activity varies as a function of memory load supports a sensory recruitment model for spatial working memory in touch. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Changing concepts of working memory

PubMed Central

Ma, Wei Ji; Husain, Masud; Bays, Paul M

2014-01-01

Working memory is widely considered to be limited in capacity, holding a fixed, small number of items, such as Miller's ‘magical number’ seven or Cowan's four. It has recently been proposed that working memory might better be conceptualized as a limited resource that is distributed flexibly among all items to be maintained in memory. According to this view, the quality rather than the quantity of working memory representations determines performance. Here we consider behavioral and emerging neural evidence for this proposal. PMID:24569831

Early working memory and maternal communication in toddlers born very low birth weight

PubMed Central

Lowe, Jean; Erickson, Sarah J; MacLean, Peggy; Duvall, Susanne W

2010-01-01

Aim Early working memory is emerging as an important indicator of developmental outcome predicting later cognitive, behavioural and academic competencies. The current study compared early working memory in a sample of toddlers (18–22 months) born very low birth weight (VLBW; n = 40) and full term (n = 51) and the relationship between early working memory, mental developmental index (MDI), and maternal communication in both samples. Methods Early working memory, measured by object permanence; Bayley mental developmental index; and maternal communication, coded during mother-toddler play interaction, were examined in 39 toddlers born VLBW and 41 toddlers born full term. Results Toddlers born VLBW were found to be 6.4 times less likely to demonstrate attainment of object permanence than were toddlers born full term, adjusting for age at testing. MDI and maternal communication were found to be positively associated with attainment of object permanence in the VLBW group only. Conclusion The difference found in the early working memory performance of toddlers born VLBW, compared with those born full term, emphasizes the importance of assessing early working memory in at-risk populations, while the maternal communication finding highlights potential targets of intervention for improving working memory in toddlers born VLBW. PMID:19154525

Strain on the back in concrete reinforcement work.

PubMed Central

Wickström, G; Niskanen, T; Riihimäki, H

1985-01-01

To investigate the long term effect of heavy construction work on the back the occurrence of postures, lifting, carrying, and accidents in concrete reinforcement work and in maintenance house painting were measured. The 32 620 observations covering 272 work hours showed that reinforcement work necessitated stooped postures and heavy lifting more often than did painting. Reported minor back accidents were more than ten times as common in reinforcement work than in painting (1.3 compared with 0.11 accidents per man-year, p less than 0.001). Accidents of the musculoskeletal system, registered by the insurance companies, were also several times more common in reinforcement work (81 compared with 25 per 1000 man-years, p less than 0.001). The premature development of lumbar degeneration detected in the clinical study of the reinforcement workers was evidently due to the occupational strain on the back. The different types of hazardous back loads probably potentiate the effects of each other. PMID:3978042

Prospective memory, level of disability, and return to work in severe mental illness.

PubMed

Burton, Cynthia Z; Vella, Lea; Twamley, Elizabeth W

2018-02-25

Prospective memory (the ability to remember to do things) has clear implications for everyday functioning, including employment, in people with severe mental illnesses (SMI). This study aimed to evaluate prospective memory performance and its relationship to real-world functional variables in an employment-seeking sample of people with SMI (Clinical Trial registration number NCT00895258). 153 individuals with DSM-IV diagnosis of depression (n = 58), bipolar disorder (n = 37), or schizophrenia (n = 58) who were receiving outpatient psychiatric care at a university clinic enrolled in a trial of supported employment and completed a baseline assessment. Prospective memory was measured with the Memory for Intentions Test (MIST); real-world functional status included work history variables, clinical history variables, baseline functional capacity (UCSD Performance-based Skills Assessment-Brief), and work outcomes (weeks worked and wages earned during two years of supported employment). Participants with schizophrenia performed worse on the MIST than did those with affective disorders. Independent of diagnosis, education, and estimated intellectual functioning, prospective memory significantly predicted variance in measures of disability and illness burden (disability benefits, hospitalization history, current functional capacity), and work outcomes over two years of supported employment (weeks worked). Worse prospective memory appears to be associated with greater illness burden and functional disability in SMI. Mental health clinicians and employment specialists may counsel clients to use compensatory prospective memory strategies to improve work performance and decrease functional disability associated with SMI.

Polygenic risk for depression and the neural correlates of working memory in healthy subjects.

PubMed

Yüksel, Dilara; Dietsche, Bruno; Forstner, Andreas J; Witt, Stephanie H; Maier, Robert; Rietschel, Marcella; Konrad, Carsten; Nöthen, Markus M; Dannlowski, Udo; Baune, Bernhard T; Kircher, Tilo; Krug, Axel

2017-10-03

Major depressive disorder (MDD) patients show impairments of cognitive functioning such as working memory (WM), and furthermore alterations during WM-fMRI tasks especially in frontal and parietal brain regions. The calculation of a polygenic risk score (PRS) can be used to describe the genetic influence on MDD, hence imaging genetic studies aspire to combine both genetics and neuroimaging data to identify the influence of genetic factors on brain functioning. We aimed to detect the effect of MDD-PRS on brain activation during a WM task measured with fMRI and expect healthy individuals with a higher PRS to be more resembling to MDD patients. In total, n=137 (80 men, 57 women, aged 34.5, SD=10.4years) healthy subjects performed a WM n-back task [0-back (baseline), 2-back and 3-back condition] in a 3T-MRI-tomograph. The sample was genotyped using the Infinium PsychArray BeadChip and a polygenic risk score was calculated for MDD using PGC MDD GWAS results. A lower MDD risk score was associated with increased activation in the bilateral middle occipital gyri (MOG), the bilateral middle frontal gyri (MFG) and the right precentral gyrus (PCG) during the 2-back vs. baseline condition. Moreover, a lower PRS was associated with increased brain activation during the 3-back vs. baseline condition in the bilateral cerebellum, the right MFG and the left inferior parietal lobule. A higher polygenic risk score was associated with hyperactivation in brain regions comprising the right MFG and the right supplementary motor area during the 3-back vs. 2-back condition. The results suggest that part of the WM-related brain activation patterns might be explained by genetic variants captured by the MDD-PRS. Furthermore we were able to detect MDD-associated activation patterns in healthy individuals depending on the MDD-PRS and the task complexity. Additional gene loci could contribute to these task-dependent brain activation patterns. Copyright © 2017 Elsevier Inc. All rights reserved.

70. Cortisol Response to Psychosocial Stress and Working Memory Performance in Schizophrenia

PubMed Central

Reed, Alexandra; Lake, Jessica; Hamilton, Holly; Bachman, Peter; Clayson, Peter; Miller, Gregory; Subotnik, Kenneth; Nuechterlein, Keith; Yee, Cindy

2017-01-01

Abstract Background: Working memory (WM) deficits are part of the constellation of cognitive impairments associated with schizophrenia (SZ). Although WM efficiency may be especially important for patients functioning within academic and employment settings, much of the research on WM in SZ neglects the social context of cognitive performance and fails to consider the extent to which stress may contribute to cognitive dysfunction. This is a crucial oversight considering growing evidence that high levels of cortisol disrupt WM in healthy individuals. Stress may be especially detrimental to cognitive functions in patients who often demonstrate HPA dysregulation including high basal cortisol and attenuated cortisol responses to acute stressors. Methods: The present study examined effects of a laboratory psychosocial stress task, the Trier Social Stress Test (TSST), on WM performance in patients with SZ (n = 87) and healthy comparison subjects (HCs; n = 68). Each participant completed an n-back task before and after the TSST. Salivary cortisol samples collected at baseline, post-TSST, and recovery were available from participants with chronic SZ (n = 23, mean illness duration = 11.21, SD = 6.79 years), first-episode SZ (n = 43, mean illness duration = 0.78, SD = 0.85 years), and HCs (n = 51). Results: As predicted, the TSST disrupted performance accuracy during the WM task, but only in SZ. Post-TSST cortisol levels were positively correlated with sensitivity to detect match trials and overall accuracy on n-back performance in chronic patients but not in first episode patients or in healthy participants. Total cortisol response in chronic patients, summarized as area under the curve, accounted for approximately 26% of the variance in WM accuracy after stress. Conclusion: Results replicate findings of blunted cortisol reactivity in SZ and extend prior work by connecting cortisol stress response to specific changes in WM performance in a chronic sample

Working Memory and Neurofeedback.

PubMed

YuLeung To, Eric; Abbott, Kathy; Foster, Dale S; Helmer, D'Arcy

2016-01-01

Impairments in working memory are typically associated with impairments in other cognitive faculties such as attentional processes and short-term memory. This paper briefly introduces neurofeedback as a treatment modality in general, and, more specifically, we review several of the current modalities successfully used in neurofeedback (NF) for the treatment of working memory deficits. Two case studies are presented to illustrate how neurofeedback is applied in treatment. The development of Low Resolution Electromagnetic Tomography (LORETA) and its application in neurofeedback now makes it possible to specifically target deep cortical/subcortical brain structures. Developments in neuroscience concerning neural networks, combined with highly specific yet practical NF technologies, makes neurofeedback of particular interest to neuropsychological practice, including the emergence of specific methodologies for treating very difficult working memory (WM) problems.

Looking Inward and Back: Real-Time Monitoring of Visual Working Memories

ERIC Educational Resources Information Center

Suchow, Jordan W.; Fougnie, Daryl; Alvarez, George A.

2017-01-01

Confidence in our memories is influenced by many factors, including beliefs about the perceptibility or memorability of certain kinds of objects and events, as well as knowledge about our skill sets, habits, and experiences. Notoriously, our knowledge and beliefs about memory can lead us astray, causing us to be overly confident in eyewitness…