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

Frontoparietal Brain Network Plays a Crucial Role in Working Memory Capacity during Complex Cognitive Task

Recent neurophysiological studies provide inconsistent results of frontoparietal network (FPN) stimulation for altering working memory (WM) capacity. This study aimed to boost WM capacity by manipulating the activity of the FPN via dual-site high-definition transcranial direct current stimulation. Forty-eight participants were randomly assigned to three stimulation groups, receiving either simultaneous anodal stimulation of the frontal and parietal areas (double stimulation), or stimulation of the frontal area only (single stimulation), or the placebo stimulation (sham) to frontal and parietal areas. After the stimulation, we used an operation span task to test memory accuracy, mathematical accuracy, time of calculation and memorizing, and recall response time across the three groups. The results revealed an enhancement of memory accuracy and a reduction of time of calculation in the double stimulation group compared with that in others. In addition, recall response time was significantly decreased in the double and single stimulation groups compared with that in sham. No differences in mathematical accuracy were observed. Our results confirm the pivotal role of the FPN in WM and suggest its functional dissociation, with the frontal component more implicated in the retrieval stage and the parietal component in the processing and retention stages.

Does working memory training improve emotion regulation and reduce internalizing symptoms? A pair of three-level meta-analyses

BACKGROUND

Emotional dysfunction is a core feature of many mental disorders. Working memory training (WM-T) is promising to improve emotion regulation and reduce internalizing symptoms (anxiety and depressive symptoms), but the results are mixed. Therefore, we conducted meta-analyses to clarify these mixed results.

METHODS

We searched Web of Science, PubMed, ScienceDirect, and EBSCO to identify relevant studies and screened the references. The effect size was calculated using Hedges' g. Three-level, random-effects models were run using metafor in R.

RESULTS

The current study included 44 articles, of which 29 were involved with emotion regulation, and 30 were involved with internalizing symptoms. The results showed that WM-T could yield emotional benefits, but the benefits were confined to enhancing explicit emotional regulation capacity and reducing anxiety symptoms. For the meta-analysis regarding the effect of WM-T on emotion regulation, there was no significant moderator. For the meta-analysis regarding the effect of WM-T on internalizing symptoms, the emotional valence of the material and control group were statistically significant moderators.

CONCLUSION

WM-T could yield certain emotional effects, but only to improve explicit emotion regulation capacity and reduce anxiety symptoms. In addition, some measures could enhance the effect, such as targeting specific populations, increasing the number of training sessions (≥15) or duration (>450 minutes), using negative material, and using n-back training tasks.

The effect of working memory training on test anxiety symptoms and attentional control in adolescents

OBJECTIVE

The percentage of adolescents with test anxiety is increasing rapidly. Working memory (WM) training has been demonstrated to reduce anxiety levels and enhance attentional control in individuals. Therefore, we investigated whether adaptive dual n-back WM training could lower test anxiety level and improve attentional control in adolescents.

METHODS

Forty adolescents were allocated to either adaptive dual n-back WM training (n = 21) or non-adaptive dual 1-back WM training (n = 19) for 10 days. The Test Anxiety Scale was applied to measure individuals' test anxiety symptoms. The Attentional Control Scale (ACS), the flanker task, and the Go/Nogo task were used to measure attentional control.

RESULTS

Compared with the control group, the training group reported significantly relief of test anxiety symptoms; however, there were no significant differences between the two groups in pre-to-post changes in ACS scores or performance on the flanker task and Go/Nogo task.

CONCLUSION

In sum, adaptive dual n-back WM training effectively reduced adolescents' level of test anxiety but did not improve their attentional control.

Can Emotional Working Memory Training Improve Cognitive Behavioral Therapy Outcomes for Social Anxiety Disorder: A Pilot Study

Social anxiety disorder (SAD) models highlight maladaptive attention as a maintaining factor of SAD, potentially negatively impacting how individuals with SAD engage with cognitive behavioral therapy (CBT) content in a therapist's presence. Emotional working memory training (eWMT) has been shown to improve affective attentional control. This pilot study assessed the proposed methodology for a randomized controlled trial (RCT) to determine whether eWMT, by improving attentional control prior to internet-based CBT (iCBT), results in better CBT outcomes. The RCT would be considered feasible if the pilot study achieved rates ≥80% for eligible participants recruited, study measures completion, intervention completion, and participant retention. Results from 10 randomized participants showed rates ≥80% for recruitment of eligible participants and iCBT intervention completion. Completion of study measures, eWMT and Placebo training interventions, and participant retention were <80%. Results highlight the need to consider strategies to improve the methodology prior to the RCT.

Symptoms of depression and anxiety in Chinese adolescents: heterogeneity and associations with executive function

BACKGROUND

Depression and anxiety are common symptoms associated with significant morbidity in adolescents. Few studies have explored the relationship between latent profiles of adolescent depression-anxiety symptoms and executive function (EF), which is also a major pediatric public health concern.

METHODS

The sample included 1,306 participants who were recruited from two schools in Ningxia. The Depression Self-Rating Scale for Children (DSRSC) and the Screen for Child Anxiety Related Emotional Disorders (SCARED) were used to assess the level of depression-anxiety symptoms in adolescents, and their executive function state was assessed using the Behavior Rating Inventory of Executive Function-Self-Report version (BRIEF-SR). Latent profile analysis (LPA) was carried out using Mplus 7.0 to explore the most likely number of profiles based on the subscales of DSRSC and SCARED. The relationship between adolescents' executive function and depression-anxiety symptoms were analyzed by multivariable logistic regression, and the odds ratio were used to test the impact of this relationship.

RESULTS

The LPA results show that the three-profile model was the best-fitting model for adolescent depression and anxiety symptoms. The proportions of Profile-1 ("Healthy Group"), Profile-2 ("Anxiety Disorder Group"), and Profile-3 ("Depression-Anxiety Disorder Group") were 61.4%, 23.9%, and 14.7%, respectively. Additional analyses using multivariable logistic regression suggested that poor shifting capacity and emotional control were significantly more likely to be classified into the depression and/or anxiety groups, and worse working memory, task completion, and better inhibition were significantly more likely to be classified into the anxiety group.

CONCLUSIONS

The findings contribute to our understanding of the heterogeneity of adolescents' depression-anxiety symptoms and highlight the important role of executive function in influencing mental health outcomes. These findings will guide the improvement and delivery of interventions for the treatment of anxiety and depression in adolescents, mitigating functional impairments in patients and reducing disease risk.

Anxiety-reducing effects of working memory training: A systematic review and meta-analysis

OBJECTIVE

To assess whether working memory training will relieve anxiety in participants.

METHODS

The PubMed, PsycINFO, Web of Science, and ProQuest databases were searched up to January 25, 2022. We included random controlled trials with low to moderate risk of bias in comparing working memory training with control condition as the only intervention in treating anxiety (PROSPERO ID: CRD42022300404). The language was restricted to English. Data extraction was independently carried out by two authors, following the PRISMA guideline for systematic reviews.

RESULTS

Of the 477 records identified, 19 studies (n = 1051) were included in the meta-analysis. The results showed that the post-training anxiety was reduced with a small but significant value (Hedge's g = -0.392, p = .009) by working memory training. Subgroup analyses confirmed that the moderating effect of anxiety type, anxiety measurement and training environment were significant.

LIMITATIONS

These results should be considered with caution for the heterogeneity of training paradigms, participant population and types of anxiety assessed between studies. Further research is required to support these results.

CONCLUSIONS

Working memory training is a promising intervention to relieve anxiety symptoms.

Specific Pandemic-Related Worries Predict Higher Attention-Related Errors and Negative Affect Independent of Trait Anxiety in UK-Based Students

Background

The COVID-19 pandemic has resulted in many individuals experiencing increased symptoms of anxiety. We predict that this increase may be underpinned by pandemic-related worry (PRW), characterised by repetitive negative thinking about pandemic-specific outcomes; and that this relationship is mediated through reduced attentional capacity required to regulate negative affect.

Methods

We developed a novel scale to measure the contents of PRW in an initial sample of 255 participants, and explored its relationship with cognitive functioning and negative affect in a sample of 382 UK-based university students, whilst controlling for recalled pre-pandemic trait anxiety.

Results

A five-factor model of PRW was identified, with factors reflecting worry about decline in quality of life (QoL) and probability of infection correlating with attention and memory-related errors. Importantly, attention-related errors partially mediated the positive relationship between PRW and negative affect, even when controlling for pre-pandemic trait anxiety.

Conclusion

PRW's relationship with negative affect was partially mediated through attentional function, consistent with models of anxiety and attentional control. In UK-based students PRW may be predominantly focused on the decline in QoL; therefore, interventions targeting worry about the decline in QoL caused by COVID-19 are especially important in this population in the wake of the pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10608-022-10336-7.

Artificial Cognitive Systems Applied in Executive Function Stimulation and Rehabilitation Programs: A Systematic Review

This article presents a systematic review of studies on cognitive training programs based on artificial cognitive systems and digital technologies and their effect on executive functions. The aim has been to identify which populations have been studied, the characteristics of the implemented programs, the types of implemented cognitive systems and digital technologies, the evaluated executive functions, and the key findings of these studies. The review has been carried out following the PRISMA protocol; five databases have been selected from which 1889 records were extracted. The articles were filtered following established criteria, to give a final selection of 264 articles that have been used for the purposes of this study in the analysis phase. The findings showed that the most studied populations were school-age children and the elderly. The most studied executive functions were working memory and attentional processes, followed by inhibitory control and processing speed. Many programs were commercial, customizable, gamified, and based on classic tasks. Some more recent initiatives have begun to incorporate user-machine interfaces, robotics, and virtual reality, although studies on their effects remain scarce. The studies recognize multiple benefits of computerized neuropsychological stimulation and rehabilitation programs for executive functions in different age groups, but there is a lack of studies in specific population sectors and with more rigorous research designs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13369-022-07292-5.

Using clustering algorithms to examine the association between working memory training trajectories and therapeutic outcomes among psychiatric and healthy populations

Working memory (WM) training has gained interest due to its potential to enhance cognitive functioning and reduce symptoms of mental disorders. Nevertheless, inconsistent results suggest that individual differences may have an impact on training efficacy. This study examined whether individual differences in training performance can predict therapeutic outcomes of WM training, measured as changes in anxiety and depression symptoms in sub-clinical and healthy populations. The study also investigated the association between cognitive abilities at baseline and different training improvement trajectories. Ninety-six participants (50 females, mean age = 27.67, SD = 8.84) were trained using the same WM training task (duration ranged between 7 to 15 sessions). An algorithm was then used to cluster them based on their learning trajectories. We found three main WM training trajectories, which in turn were related to changes in anxiety symptoms following the training. Additionally, executive function abilities at baseline predicted training trajectories. These findings highlight the potential for using clustering algorithms to reveal the benefits of cognitive training to alleviate maladaptive psychological symptoms.

EEG correlates of neutral working memory training induce attentional control improvements in test anxiety

Attentional control theory states that high test anxious (HTA) individuals suffer from impaired attentional control. However, through working memory training it may be possible to improve such individuals' attentional control ability. This study investigated whether 20 days of working memory training (with emotionally neutral stimuli) does result in improved HTA individuals' attentional control ability. Pre- and post-outcomes of attentional control were measured using Flanker and Go/Nogo experimental tasks in a test-related stress situation, and EEG data were also collected. Results only showed a significant decrease in Nogo alpha power in HTA individuals after neutral working memory training (i.e., post-outcome versus pre-outcome). However, we failed to provide evidence for beneficial transfer effects of neutral working memory training on enhanced task performance in both the Flanker and the Go/Nogo tasks. So, the present study demonstrates that neutral working memory training is clearly associated with important neurophysiological correlates while performing the Go/Nogo task, but the transfer effect is rather limited.

Cognitive control training for children with anxiety and depression: A systematic review

Cognitive control training has gained traction as an intervention for reducing anxiety and depression vulnerability in adults. There are, however, a limited number of studies investigating such training interventions for reducing symptomology of anxiety and depression in children and adolescents. Thus, we aimed to provide a robust review and qualitative synthesis of the available research in young people. Twelve articles met the inclusion criteria, and all were randomised control trials. Evidence of the efficacy of cognitive control training for relief of symptoms are reported separately for anxiety, depression, and other related psychological factors, and on the basis of type of cognitive control training paradigm. A lack of standardisation in relation to type of intervention, duration and context, outcome measures and population was observed. Results are discussed in terms of these variations and recommendations for future research are provided.

Individual differences associated with treatment adherence and transfer effects following gamified web-based cognitive control training for repetitive negative thinking

Recent research suggests beneficial effects of cognitive control training (CCT) on repetitive negative thinking (RNT), a key risk factor for internalizing symptomatology. However, relatively little is known regarding predictors of adherence to internet-delivered CCT as well as moderators of treatment effects for this intervention. Answering these questions could improve efficiency of clinical implementation of CCT as an eHealth intervention. The current pre-registered single-arm trial set-out to address these questions using a web-based gamified CCT procedure based on the adaptive Paced Auditory Serial Addition Task. Participants (N = 382) entered the internet-based study, where we observed considerable drop-out during the assessment phase and the first training sessions. Emotional stability and resilience emerged as predictors for deciding not to commence the intervention. Drop-out throughout the course of CCT was explained by age, emotion regulation-, and personality factors. We used latent profile analysis, a probabilistic modeling approach, to identify clusters of participants (User Profiles) based on indicators of baseline cognitive- and emotional functioning, training progress, and user experience. We obtained three User Profiles, reflecting low-, moderate-, and high-risk status. Effortful control, emotion regulation, internalizing symptomatology, resilience, and emotional stability played a central role in these User Profiles. Interestingly, User Profile predicted training related cognitive gains, as well as effects of CCT on anxiety- and stress symptoms, and reappraisal. Our findings suggest that CCT is most effective for the moderate- and high-risk groups. In addition, the high-risk group would likely benefit from a more intensive training procedure or repeated administration of the training procedure over time to foster long-term retention of training related gains.

Internalising and externalising in early adolescence predict later executive function, not the other way around: a cross-lagged panel analysis

Developmental changes in the brain networks involved in emotion regulation are thought to contribute to vulnerability to mental health problems during adolescence. Executive control is often viewed as allowing top-down regulation of emotional responses. However, while associations between executive control and mental health are commonly observed in both clinical and non-clinical populations, the direction of these associations remains unclear. Low, or immature, cognitive control could limit emotion regulation. Reversely, high emotionality could impede cognitive functioning. The scarcity of longitudinal studies testing for bi-directional effects, particularly in adolescence, has made it difficult to draw conclusions. This study analysed data from 1,445 participants of a longitudinal cohort in a cross-lagged panel design to understand bi-directional longitudinal associations between executive function and emotional behaviours across adolescence. Executive function was assessed using experimental working memory and inhibitory control tasks, emotional behaviours through parental report of internalising and externalising behaviours. Cross-sectional associations were replicated. Controlling for cross-sectional associations, early executive functions were not found to predict later emotional behaviours. Instead, early emotional behaviours predicted later executive function, with the strongest link observed between early externalising and later working memory. These results suggest that emotional well-being may affect the maturation of executive function during adolescence.

Rethinking cognitive training: The moderating roles of emotional vulnerability and perceived cognitive impact of training in high worriers

Trait worry is a hallmark feature of anxiety and depression, interfering with attentional control and impairing cognitive performance. Previous research has shown the adaptive dual n-back training is effective in improving attentional control and reducing emotional vulnerability, but not for everyone. The current randomised controlled trial explored the role of baseline emotional vulnerability and perceived cognitive impact in training-related cognitive and emotional improvements in 60 high worriers randomly assigned to 10 sessions of the adaptive dual n-back training or non-adaptive 1-back training. Pre-training, post-training and one-month follow-up measures of cognitive performance were assessed using an emotional Flanker task, a cued task-switching task, and the MaRs-IB task. Self-report questionnaires assessed worry, anxiety, depression, somatisation, and self-efficacy, as well as participants' perceived cognitive impact of the training. Participants with higher levels of baseline emotional vulnerability presented the largest improvements in non-verbal reasoning and emotional vulnerability one month after the training, as well as the greatest perceived cognitive impact. Perceived cognitive impact was predicted by working memory improvement on the adaptive n-back training at high baseline levels of anxiety. These results suggest that the adaptive n-back training presents the greatest emotional and cognitive benefits for individuals experiencing severe levels of emotional vulnerability.

Working memory updating training reduces state repetitive negative thinking: Proof-of-concept for a novel cognitive control training

Repetitive negative thinking (RNT) is a proximal risk factor implicated in the onset and maintenance of common mental health problems such as depression and anxiety. Adolescence may be a key developmental window in which to target RNT and prevent the emergence of such disorders. Impairments in updating the contents of working memory are hypothesised to causally contribute to RNT, and some theorists have suggested these difficulties may be specific to the manipulation of negative information. The present study compared the effects of computerised adaptive working memory updating training (in which the task becomes more difficult as performance improves) to a non-adaptive control task in reducing levels of RNT. 124 healthy young people were randomised to 20 sessions of (i) working memory updating training using neutral stimuli, (ii) working memory updating training using negative stimuli, or (iii) non-adaptive working memory updating training. Adaptive working memory updating training using neutral, but not negative, stimuli resulted in significant improvements to working memory updating for negative material, as assessed using an unpractised task, and significant reductions in susceptibility to state RNT. These findings demonstrate proof-of-concept that working memory updating training has the potential to reduce susceptibility to episodes of state RNT.

Personalized cognitive training: Protocol for individual-level meta-analysis implementing machine learning methods

Accumulating evidence suggests that cognitive training may enhance well-being. Yet, mixed findings imply that individual differences and training characteristics may interact to moderate training efficacy. To investigate this possibility, the current paper describes a protocol for a data-driven individual-level meta-analysis study aimed at developing personalized cognitive training. To facilitate comprehensive analysis, this protocol proposes criteria for data search, selection and pre-processing along with the rationale for each decision. Twenty-two cognitive training datasets comprising 1544 participants were collected. The datasets incorporated diverse training methods, all aimed at improving well-being. These training regimes differed in training characteristics such as targeted domain (e.g., working memory, attentional bias, interpretation bias, inhibitory control) and training duration, while participants differed in diagnostic status, age and sex. The planned analyses incorporate machine learning algorithms designed to identify which individuals will be most responsive to cognitive training in general and to discern which methods may be a better fit for certain individuals.

Deficits in maintenance and interference control of working memory in major depression: evidence from the visuospatial change detection task

INTRODUCTION

Recent theories in cognitive psychology suggest that working memory (WM) processing involves a set of specific functions, in particular the WM functions of maintenance and interference control. Previous findings on WM impairments in patients with major depressive disorder (MDD) had been inconsistent, partly because earlier studies did not take into account these two different functions of WM.

METHOD

Forty-two participants with MDD and 39 controls completed the visuospatial change detection task. We estimated the WM function of maintenance, based on performance in trials using the targets only, and the WM function of interference control, based on performance in trials with distractor rectangles.

RESULTS

Our results showed that participants with MDD had poorer WM function of maintenance and interference control than controls. However, the results of filtering efficiency did not show significant group difference, thus patients with MDD showed comparable impairments in WM function of maintanance as well as in WM function of interference control.

CONCLUSION

Our findings suggested that patients with MDD appear to show generalised impairments on visuospatial WM function of maintenance and interference control. Future studies should use refined paradigms to assess the different functions of WM and their distinctive contributions to symptomatology of depression.

A randomised double-blind trial of cognitive training for the prevention of psychopathology in at-risk youth

BACKGROUND

The aim of this study was to evaluate the effectiveness of online cognitive training as a means of reducing psychopathology in at-risk youth.

METHODS

In a double-blind randomised controlled trial, 228 youths (mean age = 18.6, 74.6% female) were randomly allocated to either an intervention group (n = 114; online cognitive training focused on executive functioning) and a control group (n = 114; online cognitive training focused on other cognitive abilities). Participants were assessed online at baseline, post-training, 3-, 6- and 12-month follow-up. The primary outcome of the study was overall psychopathology as measured by the Strengths and Difficulties Questionnaire. Secondary outcomes were executive functioning ability (assessed using the n-back, trail-making and Stroop tasks), day-to-day functioning and risky drinking.

RESULTS

Mixed model intention-to-treat analyses indicated that psychopathology increased and day-to-day functioning decreased, regardless of intervention group. Those in the intervention group improved more than those in the control group in terms of the n-back task, but this was not statistically significant after adjusting for multiple comparisons. There were no statistically significant effects on risky drinking, or the trail-making and Stroop tasks.

CONCLUSION

This study failed to provide evidence for the efficacy of cognitive training as a stand-alone intervention for psychopathology.

Better cognitive efficiency is associated with increased experimental anxiety

There is increased interest in the development of cognitive training targeting working memory (WM) to alleviate anxiety symptoms, but the effectiveness of such an approach is unclear. Improved understanding of the effect of cognitive training on anxiety may facilitate the development of more effective cognitive training treatment for anxiety disorders. This study uses an experimental approach to examine the interplay of WM and anxiety following WM training. Previous studies show that increased demand on WM reduces concurrent anxiety evoked by threat of shock (induced anxiety). However, improving WM pharmacologically or via exercise prevents this anxiolytic effect. Conceivably, improving WM frees up cognitive resources to process threat information, thereby increasing anxiety. The present study tested the hypothesis that practicing a high load WM (i.e., increased demand) task would improve WM, and thus, free cognitive resources to process threat of shock, resulting in more anxiety (i.e., greater startle) during a subsequent WM task. Participants were randomly assigned to two training groups. The active-training group (N = 20) was trained on a 1- (low load) & 3-back (high load) WM task, whereas the control-training group (N = 20) performed a 0-back WM task. The experimental phase, similar in both groups, consisted of a 1- & 3-back WM task performed during both threat of shock and safety. As predicted, active training improved WM accuracy and increased anxiety during the experimental 3-back WM task. Therefore, improving WM efficiency can increase anxiety, possibly by freeing WM resources to process threat information.

Effects of working memory training on emotion regulation: Transdiagnostic review

Working memory training is widely used transdiagnostically to improve cognition. However, more recently, studies using working memory training packages have targeted emotion-regulation outcomes to determine whether far transfer effects can be achieved. A narrative review is conducted of studies that have used standardized computerized working memory training packages across healthy volunteers, affect, anxiety, post-traumatic stress disorder (PTSD), and eating disordered populations with emotion-regulation outcomes. Working memory training has been used in children, adolescents, and adults to improve emotion regulation. Many studies have reported gains in mood as well as emotion-regulation strategies following working memory training, regardless of clinical indication and whether near transfer gains were achieved in cognitive domains. Significant emotion-regulation outcomes include: state and trait anxiety, rumination, brooding, positive appraisal, decreasing maladaptive emotion-regulation strategies, and decreasing intrusive thoughts. It is speculated that these far transfer outcomes from working memory training are possible due to the cognitive and neural overlap between cognitive and affective working memory, and emotion regulation. Working memory training could improve cognitive efficiency, which, in turn, increases the availability of cognitive resources during times when emotion regulation is taxed. Future studies need to consider the role of participant expectancy in predicting outcome measure performance, and including subjective and objective outcomes is paramount to study design. Furthermore, sample sizes require additional attention, given that the current review highlights that individual differences in non-clinical and clinical populations influence the outcomes from working memory training. Working memory training offers a possibility for improving emotion regulation transdiagnostically.