Test–retest reliability of five frequently used executive tasks in healthy adults

The structure of executive functions in athletes: A latent variable approach

The role of executive function (EF) in expert sport performance has become a popular topic in sport and exercise psychology research. Research in this area often adopts the unity/diversity framework of EF (i.e., inhibition, shifting, and updating). However, recent investigations into the suitability of this unity/diversity model, and other competing models (e.g., the nested model of EF), has questioned whether this model is suitable for across all populations (e.g., athletes). The aim of the present study was to use confirmatory factor analysis to outline the most suitable EF model in a sample of athletes. In total, 131 participants with varying levels of athletic expertise completed two inhibition, shifting, and updating tasks. All analyses were performed in RStudio. The results revealed the nested model of EF provided the best fit to the data indicating its suitability for athletes. Acceptable fit was also found for the unity/diversity mode of EF. Overall, the results suggest that, despite recent criticism of the nested model and unity/diversity framework of EF, such structures appear to be suitable for use with athletic populations.

Influence of transcutaneous electrical stimulation on marksmanship, cognition, and the healthy stress response

Transcutaneous electrical stimulation of the trigeminal and cervical nerves (TEN) has been proposed as a safe, noninvasive method of reducing stress. However, its effects on human performance and stress physiology have yet to be explored. This study explored the effects of TEN on physiological responses to stress and cognitive performance using both laboratory-standard tests of executive function and attention and a complex marksmanship task requiring sustained discrimination of friend or foe targets. Thirty healthy male and female participants completed two, single-blinded experimental sessions in which TEN or sham (order counterbalanced, n = 15 each group) was administered for 20 min prior to marksmanship and cognitive assessment. Heart rate variability was monitored continuously via electrocardiography and photoplethysmography while salivary markers of stress (cortisol, α-amylase) were collected at regular intervals. Linear mixed model analyses with standardized regression coefficients (βstan) and 95 % confidence intervals (CI) indicated no effects of stimulation condition (TEN versus sham) on marksmanship performance, cognition, salivary cortisol, or α-amylase. However, significant effects of stimulation condition were observed on heart rate variability, including increased photoplethysmography mean heart rate (βstan = -0.42 (95 % CI -0.69 - -0.14), p = 0.04) and decreased very low frequency power (βstan = 1.51 (95 % CI 0.53-2.49), p = 0.04) during marksmanship and increased electrocardiography high-frequency power at rest (βstan = -0.63 (95 % CI -1.06 - -0.21), p = 0.05). These results suggest that TEN may modulate the stress response via paradoxical effects on both sympathetic and parasympathetic nervous system activity.

Interpreting the direct- and derived-Trail Making Test scores in Argentinian children: regression-based norms, convergent validity, test-retest reliability, and practice effects

Objective: We carried out two research studies (using a cross-sectional and a longitudinal design) to establish regression-based normative data, and to examine the convergent validity, the test-retest reliability, and the changes in performance with practice (1-month and 1-year interval) of the direct- and derived- (B-A, B + A, and B/A ratio) Trail Making Test (TMT) scores in Spanish-speaking children. Method: In S1 (n = 413 6- to 15-year-old children and adolescents), regression-based norming procedure and partial correlations were employed. In S2 (n = 110 6- to 12-year-old children), intraclass correlation coefficient (ICC2,1), Pearson's r-product-moment correlations, and paired t-tests were used. Results: S1 demonstrated that age was associated with better performance on both TMT-A and TMT-B. This improvement was more strongly related to direct scores than derived measures B-A and B/A. Additionally, TMT-B was found to be more related to other executive functions (EF) compared to the performance of TMT-A. Among the derived scores, only the B-A was related primarily to cognitive flexibility, while the B + A index was associated with most EF, suggesting a general measure of cognitive functioning. In S2, fair to good test-retest reliability coefficients were found at Time 2 for TMT-A and TMT-B, as well as the B + A index, both in 6 to 8-year-olds (ICCs .61 to .74) and 9 to 12-year-olds (ICCs .53 to .65). There was a significant increase in performance on TMT-A and TMT-B from the first assessment (Time 1) to the follow-up testing at Time 2 in older children. However, this significant improvement was not observed for TMT-B in the younger group. Test scores on the TMT direct measures improved significantly across 1-year. The B-A and B/A ratio scores did not change across examinations. Conclusions: These findings have important implications for assessing EF and developing interventions that target cognitive flexibility in pediatric populations.

Improvements in executive functions by domain-specific cognitive training in youth elite soccer players

This study examined the impact of sport-specific cognitive training (CT) on executive functions (EFs) in youth soccer players. Thirty-one athletes (13-15 years) participated, 13 in the intervention group (IG) and 18 in the control group (CG). The IG underwent an 8-week soccer-focused CT program, while the CG maintained regular training. The assessments included working memory, inhibition, and cognitive flexibility tasks. The results revealed no significant improvements in EFs in the IG compared to those in the CG. Both groups showed enhanced cognitive flexibility, possibly due to general cognitive development or learning effects. The study suggested that an 8-week sport-specific CT may not enhance EFs in young soccer players, potentially due to a ceiling effect in highly skilled athletes. These findings should be considered when designing cognitive training programs for athletes, and future research could explore the optimal duration of such programs.

OpenWMB: An open-source and automated working memory task battery for OpenSesame

Working memory capacity (WMC) has been measured with a plethora of cognitive tasks. Several preeminent automated batteries of working memory (WM) tasks have been developed recently. However, despite all their advantages, most batteries were programmed in paid platforms and/or only included a single WM paradigm. To address these issues, we developed the OpenWMB, an automated battery comprising seven tasks from three distinct paradigms (complex spans, updating tasks, and binding tasks) that tap into several functional aspects of WM (simultaneous storage and processing, updating, and binding). The battery runs on open-source software (OpenSesame) and is freely available online in a ready-to-download format. The OpenWMB possesses flexible features and includes a data processing script (that converts data into a format ready for statistical analysis). The instrument is available in Portuguese and English. However, we only assessed the psychometric properties of the former version. The Portuguese version presented good internal consistency and considerable internal and predictive validity: all tasks loaded into a single factor. Additionally, the WMC estimate was strongly correlated with a fluid intelligence factor. This study also tried to contribute to the ongoing debate regarding the best method to assess WMC. We computed a permutation analysis to compare the amount of variance shared between a fluid intelligence factor and (1) each WM task, (2) homogenous WMC factors (based on multiple tasks from the same paradigm), and (3) heterogeneous WMC factors (derived from triplets of tasks from different paradigms). Our results suggested that heterogeneous factors provided the best estimates of WMC.

Investigating the relationship between resting-state EEG microstates and executive functions: A null finding

Recent advances in cognitive neurosciences suggest that intrinsic brain networks dynamics are associated with cognitive functioning. Despite this emerging perspective, limited research exists to validate this hypothesis. This Registered Report aimed to specifically test the relationship between intrinsic brain spatio-temporal dynamics and executive functions. Resting-state EEG microstates were used to assess brain spatio-temporal dynamics, while a comprehensive battery of nine cognitive function tasks was employed to evaluate executive functions in 140 participants. We hypothesized that microstates (class C and D) metrics would correlate with an executive functions composite score. Contrary to expectations, our hypotheses were not supported by the data. We however observed a small, non-significant trend with a negative correlation between microstate D occurrences and executive functions scores (r = -.18, 95% CI [-.33, -.01]) which however did not meet the adjusted threshold for significance. In light of the inconclusive or minor effect sizes observed, the assertion that intrinsic brain networks dynamics - as measured by resting-state EEG microstate metrics - are a reliable signature of executive functioning remains unsupported.

Evaluating the efficacy of cranial electrotherapy stimulation in mitigating anxiety-induced cognitive deficits

Cranial electrotherapy stimulation (CES) is a form of non-invasive brain stimulation (NIBS) that has demonstrated potential to modulate neural activity in a manner that may be conducive to improved cognitive performance. While other forms of NIBS, such as transcranial direct current stimulation (tDCS), have received attention in the field as potential acute cognitive enhancers, CES remains relatively unexplored. The current study aimed to assess the efficacy of CES in improving acute cognitive performance under normal experimental conditions, as well as during sessions of induced situational anxiety (threat of shock or ToS). To study this question, participants completed a cognitive battery assessing processing speed and distinct aspects of executive functioning (working memory, inhibition, and task switching) in two separate sessions in which they received active and sham CES. Participants were randomly assigned to between subject groups of either situational anxiety (ToS) or control condition (no ToS). We predicted that active CES would improve performance on assessments of executive functioning (working memory, inhibition, and task switching) relative to sham CES under ToS. We did not find any significant effects of ToS, CES, or an interaction between ToS and CES for any measures of executive functioning or processing speed. These findings suggest that a single dose of CES does not enhance executive functioning or processing speed under normal conditions or during ToS.

Extended ambulatory assessment of executive function: within-person reliability of working memory and inhibitory control tasks

INTRODUCTION

Ambulatory assessment of executive function - particularly in the form working memory (WM) - is increasingly common. Few studies to date, however, have also incorporated ambulatory measures of inhibitory control. Critically, the extended within-person reliability of ambulatory tasks tapping each of these constructs has been largely overlooked.

METHOD

Participants (N = 283, Mage = 23.74 years, SD = 9.04) received notifications every 3 days (for 4 weeks) to undertake ambulatory assessment versions of the n-Back and Stop-Signal Tasks (SST) via the smartphone application CheckCog. Within-person reliability of these measures was explored.

RESULTS

Compliance ranged from 66% (for eight sessions) to 89% (for four sessions). Our results reveal significant changes in performance within the first two sessions for both the n-Back and SST, with performance remaining largely consistent across the remaining (two to eight) sessions. In terms of test-retest reliability, the ICC (C, 1) values ranged from .29 to .68 on the n-Back (with overall accuracy being .51) and .31-.73 on the SST (with stop-signal reaction time being .53).

CONCLUSION

The results of the current study contribute to the literature by demonstrating the reliability of brief measures of executive function - in the form of inhibitory control and WM - delivered using smartphones in participants' natural environments. Based on our findings, the CheckCog app reliability tracks baseline systematic changes in WM and response inhibition across multiple time points and for an extended period in healthy individuals.

Reliability and Validity of Smartphone Cognitive Testing for Frontotemporal Lobar Degeneration

Importance

Frontotemporal lobar degeneration (FTLD) is relatively rare, behavioral and motor symptoms increase travel burden, and standard neuropsychological tests are not sensitive to early-stage disease. Remote smartphone-based cognitive assessments could mitigate these barriers to trial recruitment and success, but no such tools are validated for FTLD.

Objective

To evaluate the reliability and validity of smartphone-based cognitive measures for remote FTLD evaluations.

Design, Setting, and Participants

In this cohort study conducted from January 10, 2019, to July 31, 2023, controls and participants with FTLD performed smartphone application (app)-based executive functioning tasks and an associative memory task 3 times over 2 weeks. Observational research participants were enrolled through 18 centers of a North American FTLD research consortium (ALLFTD) and were asked to complete the tests remotely using their own smartphones. Of 1163 eligible individuals (enrolled in parent studies), 360 were enrolled in the present study; 364 refused and 439 were excluded. Participants were divided into discovery (n = 258) and validation (n = 102) cohorts. Among 329 participants with data available on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3%), 66 had prodromal FTLD (20.1%), and 68 had symptomatic FTLD (20.7%) with a range of clinical syndromes.

Exposure

Participants completed standard in-clinic measures and remotely administered ALLFTD mobile app (app) smartphone tests.

Main Outcomes and Measures

Internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.

Results

In the 360 participants (mean [SD] age, 54.0 [15.4] years; 209 [58.1%] women), smartphone tests showed moderate-to-excellent reliability (intraclass correlation coefficients, 0.77-0.95). Validity was supported by association of smartphones tests with disease severity (r range, 0.38-0.59), criterion-standard neuropsychological tests (r range, 0.40-0.66), and brain volume (standardized β range, 0.34-0.50). Smartphone tests accurately differentiated individuals with dementia from controls (area under the curve [AUC], 0.93 [95% CI, 0.90-0.96]) and were more sensitive to early symptoms (AUC, 0.82 [95% CI, 0.76-0.88]) than the Montreal Cognitive Assessment (AUC, 0.68 [95% CI, 0.59-0.78]) (z of comparison, -2.49 [95% CI, -0.19 to -0.02]; P = .01). Reliability and validity findings were highly similar in the discovery and validation cohorts. Preclinical participants who carried pathogenic variants performed significantly worse than noncarrier family controls on 3 app tasks (eg, 2-back β = -0.49 [95% CI, -0.72 to -0.25]; P < .001) but not a composite of traditional neuropsychological measures (β = -0.14 [95% CI, -0.42 to 0.14]; P = .32).

Conclusions and Relevance

The findings of this cohort study suggest that smartphones could offer a feasible, reliable, valid, and scalable solution for remote evaluations of FTLD and may improve early detection. Smartphone assessments should be considered as a complementary approach to traditional in-person trial designs. Future research should validate these results in diverse populations and evaluate the utility of these tests for longitudinal monitoring.

Reliable affordances: A generative modeling approach for test-retest reliability of the affordances task

The affordances task serves as an important tool for the assessment of cognition and visuomotor functioning, and yet its test-retest reliability has not been established. In the affordances task, participants attend to a goal-directed task (e.g., classifying manipulable objects such as cups and pots) while suppressing their stimulus-driven, irrelevant reactions afforded by these objects (e.g., grasping their handles). This results in cognitive conflicts manifesting at the task level and the response level. In the current study, we assessed the reliability of the affordances task for the first time. While doing so, we referred to the "reliability paradox," according to which behavioral tasks that produce highly replicable group-level effects often yield low test-retest reliability due to the inadequacy of traditional correlation methods in capturing individual differences between participants. Alongside the simple test-retest correlations, we employed a Bayesian generative model that was recently demonstrated to result in a more precise estimation of test-retest reliability. Two hundred and ninety-five participants completed an online version of the affordances task twice, with a one-week gap. Performance on the online version replicated results obtained under in-lab administrations of the task. While the simple correlation method resulted in weak test-retest measures of the different effects, the generative model yielded a good reliability assessment. The current results support the utility of the affordances task as a reliable behavioral tool for the assessment of group-level and individual differences in cognitive and visuomotor functioning. The results further support the employment of generative modeling in the study of individual differences.

What Is Mental Effort: A Clinical Perspective

Although mental effort is a frequently used term, it is poorly defined and understood. Consequently, its usage is frequently loose and potentially misleading. In neuroscience research, the term is used to mean both the cognitive work that is done to meet task demands and the subjective experience of performing that work. We argue that conflating these two meanings hampers progress in understanding cognitive impairments in neuropsychiatric conditions because cognitive work and the subjective experience of it have distinct underlying mechanisms. We suggest that the most coherent and clinically useful perspective on mental effort is that it is a subjective experience. This makes a clear distinction between cognitive impairments that arise from changes in the cognitive apparatus, as in dementia and brain injury, and those that arise from subjective difficulties in carrying out the cognitive work, as in attention-deficit/hyperactivity disorder, depression, and other motivational disorders. We review recent advances in neuroscience research that suggests that the experience of effort has emerged to control task switches so as to minimize costs relative to benefits. We consider how these advances can contribute to our understanding of the experience of increased effort perception in clinical populations. This more specific framing of mental effort will offer a deeper understanding of the mechanisms of cognitive impairments in differing clinical groups and will ultimately facilitate better therapeutic interventions.

Reliability and Usefulness of the SKILLCOURT as a Computerized Agility and Motor-Cognitive Testing Tool

INTRODUCTION

Agility and cognitive skills are essential in sports. However, standardized agility assessment tools often lack a reactive component, and cognitive assessments are performed using computer-based or paper-pencil tests. The SKILLCOURT is a newly developed testing and training device allowing agility and cognitive assessments in a more ecologically valid setting. This study evaluated the reliability and sensitivity to changes in performance (usefulness) of the SKILLCOURT technology.

METHODS

In a test-retest (7 d, 3 months) design, 27 healthy adults (♀ = 12; age, 24.9 ± 3.3 yr) performed three trials of agility (Star Run, Random Star Run) and motor-cognitive tests (1-back, 2-back, executive function). Absolute and relative intersession and intrasession reliability was determined using the intraclass coefficient (ICC) and coefficient of variation (CV). A repeated-measures ANOVA was applied to identify potential learning effects between trials and test sessions. The smallest worthwhile change and typical error (TE) were calculated to investigate the intrasession and intersession usefulness of the tests.

RESULTS

Agility tests revealed good relative and absolute intersession (ICC, 83-0.89; CV, 2.7%-4.1%) and intrasession (ICC, 7-0.84; CV, 2.4%-5.5%) reliability accompanied by adequate usefulness from test day 3 onward. Motor-cognitive tests showed good relative intersession reliability (ICC, 0.7-0.77) with marginal CV values (4.8%-8.6%). Adequate intrasession reliability and usefulness can be assumed from test day 2 (1-back test, executive function test) and day 3 (2-back test) onward. For all tests, learning effects were observed within and compared with test day 1.

CONCLUSIONS

The SKILLCOURT is a reliable diagnostic tool for assessing reactive agility and motor-cognitive performance. Because of learning effects, sufficient familiarization with the tests is required when used for diagnostic purposes.

A true reflection of executive functioning or a representation of task-specific variance? Re-evaluating the unity/diversity framework

The unity/diversity framework, originally published by Miyake et al. (2000) has become the most cited model of executive functioning. Consequently, when researchers operationalise executive function (EF) they often exclusively assess the three "core" EFs: updating, shifting, and inhibition. However, rather than core EFs representing domain general cognitive abilities, these three EFs may instead represent specific procedural skills from the overlapping methodologies of the tasks selected. In this study, we conducted a confirmatory factor analysis (CFA) which showed both the traditional three-factor and nested-factor model from the unity/diversity framework failed to reach satisfactory levels of fit. Subsequently, an exploratory factor analysis supported a three-factor model reflecting: an expanded working memory factor, a combined shifting/inhibition factor representing cognitive flexibility, and a factor comprised solely of the Stroop task. These results demonstrate that working memory remains the most robustly operationalised EF construct, whereas shifting and inhibition may represent task-specific mechanisms of a broader domain-general cognitive flexibility factor. Ultimately, there is little evidence to suggest that updating, shifting, and inhibition encapsulates all core EFs. Further research is needed to develop an ecologically valid model of executive functioning that captures the cognitive abilities associated with real world goal-directed behaviour.

Changes in task performance and frontal cortex activation within and over sessions during the n-back task

The n-back task is a popular paradigm for studying neurocognitive processing at varying working memory loads. Although much is known about the effects of load on behavior and neural activation during n-back performance, the temporal dynamics of such effects remain unclear. Here, we investigated the within- and between-session stability and consistency of task performance and frontal cortical activation during the n-back task using functional near-infrared spectroscopy (fNIRS). Forty healthy young adults performed the 1-back and 3-back conditions three times per condition. They then undertook identical retest sessions 3 weeks later (M = 21.2 days, SD = 0.9). Over the course of the task, activation in the participants' frontopolar, dorsomedial, dorsolateral, ventrolateral, and posterolateral frontal cortices was measured with fNIRS. We found significantly improved working memory performance (difference between 1-back and 3-back accuracies) over time both within and between sessions. All accuracy and reaction time measures exhibited good to excellent consistency within and across sessions. Additionally, changes in frontal oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) concentration were maintained over time across timescales, except that load-dependent (3-back > 1-back) HbO changes, particularly in the ventrolateral PFC, diminished over separate sessions. The consistency of fNIRS measures varied greatly, with changes in 3-back dorsolateral and ventrolateral HbO demonstrating fair-to-good consistency both within and between sessions. Overall, this study clarified the temporal dynamics of task performance and frontal activation during the n-back task. The findings revealed the neural mechanisms underlying the change in n-back task performance over time and have practical implications for future n-back research.

Cognitive performance of military men and women during prolonged load carriage

BACKGROUND

This study evaluated cognitive workload in soldiers undertaking a long duration march wearing different loads.

METHODS

Military participants (n=12 men and n=10 women) performed four 3-hour loaded marches (12.25 km at 4.9 km/hour) wearing either 21 kg, 26 kg, 33 kg or 43 kg. During the march, accuracy and response time were measured using the verbal working memory n-back test (0, 1, 2 and 3) and two bespoke Go/No Go tests (visual/auditory) to assess inhibition of a pre-potent response.

RESULTS

The physical demands of the march increased with load and march duration but remained at moderate intensity. N-back test accuracy ranged from 74% to 98% in men and 62% to 98% in women. Reduced accuracy was observed as load and time increased. Accuracy during the visual Go/No Go test also reduced with load, accuracy ranged from 69% to 89% in men and 65% to 90% in women. No differences due to load or time were observed during completion of the auditory Go/No Go task; accuracy ranged from 93% to 97% in men and 77% to 95% in women. A number of participants were unable to complete the march due to discomfort. Reports of discomfort were more frequent in women, which may have contributed to the greater reductions in accuracy observed.

CONCLUSION

These data provide further evidence that cognitive performance of military personnel can be affected during long duration loaded marching. Women reported discomfort from equipment more frequently than men, which may make them more susceptible to declines in cognitive performance. These findings highlight important considerations for equipment procurement.

Effect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis

The plant extract guarana is known for its caffeine content and other bioactive ingredients, which purportedly may improve cognitive performance. Recent reviews have examined the effects of chronic supplementation of guarana in clinical populations; however, the acute effects of guarana on cognitive tasks, while of interest, have produced mixed results. Whether acute guarana ingestion improves human cognitive performance was assessed by performing a systematic review coupled with a meta-analysis. Eight placebo-controlled studies were identified and met the inclusion criteria providing data on 328 participants. The dose of guarana (37.5 to 500 mg) with reported caffeine content (4.3 to 100 mg) varied. Effect sizes (ESs) were calculated as the standardized mean difference and meta-analyses were completed using a random-effects model. The ESs for guarana averaged across a variety of cognitive measures and outcome variables were less than trivial (Hedge’s g = 0.076, p = 0.14). Using a subgroup meta-analysis (Q = 12.9, p < 0.001), ESs indicating a faster response time for guarana vs. a placebo (g = 0.202, p = 0.005) differed from the accuracy measures (g = −0.077, p = 0.4) which were non-significant. For response time, guarana ingested in a capsule (g = 0.111) tended to differ (Q = 2.96, p = 0.085) compared to guarana when dissolved in liquid (g = 0.281). Meta-regression of the study ESs of overall cognitive task performance was not related to the guarana dose (R2 < 0.001) or to the time allowed prior to cognitive testing (R2 < 0.001). Acute guarana ingestion had a small effect on the response time (faster performance) during a variety of cognitive tasks without affecting the accuracy. Whether the changes were linked to the caffeine content or other bioavailable substances in guarana is unknown. Additional studies that directly compare matched doses of caffeine versus guarana are needed to understand its effects on cognitive performance.

On doing multi-act arithmetic: A multitrait-multimethod approach of performance dimensions in integrated multitasking

Here we present a systematic plan to the experimental study of test-retest reliability in the multitasking domain, adopting the multitrait-multimethod (MTMM) approach to evaluate the psychometric properties of performance in Düker-type speeded multiple-act mental arithmetic. These form of tasks capacitate the experimental analysis of integrated multi-step processing by combining multiple mental operations in flexible ways in the service of the overarching goal of completing the task. A particular focus was on scoring methodology, particularly measures of response speed variability. To this end, we present data of two experiments with regard to (a) test-retest reliability, (b) between-measures correlational structure, (c) and stability (test-retest practice effects). Finally, we compared participants with high versus low performance variability to assess ability-related differences in measurement precision (typically used as proxy to "simulate" patient populations), which is especially relevant in the applied fields of clinical neuropsychology. The participants performed two classic integrated multi-act arithmetic tasks, combining addition and verification (Exp. 1) and addition and comparison (Exp. 2). The results revealed excellent test-retest reliability for the standard and the variability measures. The analysis of between-measures correlational structure revealed the typical pattern of convergent and discriminant relationships, and also, that absolute response speed variability was highly correlated with average speed (r > 0.85), indicating that these measures mainly deliver redundant information. In contrast, speed-adjusted (relativized) variability revealed discriminant validity being correlated to a much lesser degree with average speed, indicating that this measure delivers additional information not already provided by the speed measure. Furthermore, speed-adjusted variability was virtually unaffected by test-retest practice, which makes this measure interesting in situations with repeated testing.

Test-retest reliability for common tasks in vision science

Research in perception and attention has typically sought to evaluate cognitive mechanisms according to the average response to a manipulation. Recently, there has been a shift toward appreciating the value of individual differences and the insight gained by exploring the impacts of between-participant variation on human cognition. However, a recent study suggests that many robust, well-established cognitive control tasks suffer from surprisingly low levels of test-retest reliability (Hedge, Powell, & Sumner, 2018b). We tested a large sample of undergraduate students (n = 160) in two sessions (separated by 1-3 weeks) on four commonly used tasks in vision science. We implemented measures that spanned a range of perceptual and attentional processes, including motion coherence (MoCo), useful field of view (UFOV), multiple-object tracking (MOT), and visual working memory (VWM). Intraclass correlations ranged from good to poor, suggesting that some task measures are more suitable for assessing individual differences than others. VWM capacity (intraclass correlation coefficient [ICC] = 0.77), MoCo threshold (ICC = 0.60), UFOV middle accuracy (ICC = 0.60), and UFOV outer accuracy (ICC = 0.74) showed good-to-excellent reliability. Other measures, namely the maximum number of items tracked in MOT (ICC = 0.41) and UFOV number accuracy (ICC = 0.48), showed moderate reliability; the MOT threshold (ICC = 0.36) and UFOV inner accuracy (ICC = 0.30) showed poor reliability. In this paper, we present these results alongside a summary of reliabilities estimated previously for other vision science tasks. We then offer useful recommendations for evaluating test-retest reliability when considering a task for use in evaluating individual differences.

Putting the individual into reliability: Bayesian testing of homogeneous within-person variance in hierarchical models

Measurement reliability is a fundamental concept in psychology. It is traditionally considered a stable property of a questionnaire, measurement device, or experimental task. Although intraclass correlation coefficients (ICC) are often used to assess reliability in repeated measure designs, their descriptive nature depends upon the assumption of a common within-person variance. This work focuses on the presumption that each individual is adequately described by the average within-person variance in hierarchical models. And thus whether reliability generalizes to the individual level, which leads directly into the notion of individually varying ICCs. In particular, we introduce a novel approach, using the Bayes factor, wherein a researcher can directly test for homogeneous within-person variance in hierarchical models. Additionally, we introduce a membership model that allows for classifying which (and how many) individuals belong to the common variance model. The utility of our methodology is demonstrated on cognitive inhibition tasks. We find that heterogeneous within-person variance is a defining feature of these tasks, and in one case, the ratio between the largest to smallest within-person variance exceeded 20. This translates into a tenfold difference in person-specific reliability! We also find that few individuals belong to the common variance model, and thus traditional reliability indices are potentially masking important individual variation. We discuss the implications of our findings and possible future directions. The methods are implemented in the R package vICC.

Effects of Brief Mindfulness Interventions on the Interference Induced by Experimental Heat Pain on Cognition in Healthy Individuals

Background: Pain captures attention and interferes with competing tasks demanding cognitive effort. Brief mindfulness interventions involving both conceptual learning and meditation exercises have been shown to improve attention and reduce pain sensitivity, and could potentially reduce pain interference. This study assesses the effect of a 5-day mindfulness intervention (20 min/day) on the interference produced by thermal pain on working memory performance using a 2-back task.

Methods: Healthy participants were randomized into three groups exposed to mindfulness meditation training (n = 15), an active educational control intervention comprising only conceptual information on mindfulness (n = 15), or no intervention (n = 15). The two active interventions were administered in a dual-blind fashion and outcomes were assessed by research personnel blind to this allocation. Evaluation sessions were conducted before and after the interventions to assess the effect of pain on 2-back performance (pain interference). Importantly, both pain stimuli and the 2-back task were calibrated individually and in each session before assessing pain interference, thereby controlling for possible changes in baseline pain sensitivity and cognitive performance. Secondary outcomes included heat pain sensitivity, cold pain tolerance, cognitive inhibition, cognitive flexibility, and divided attention.

Results: Manipulation checks confirmed that heat pain interferes with the performance of the working-memory task. Compared to the no-intervention control group, pain interference was significantly reduced following the conceptual intervention but not the meditation intervention, although a corollary analysis suggests the effect might be due to regression toward the mean caused by baseline imbalance in pain interference. Secondary outcomes also suggested an increase in pain tolerance in the conceptual learning group only.

Discussion: A short mindfulness meditation intervention was insufficient to reduce pain interference but conceptual learning about mindfulness produced some unexpected benefits. Although the generalization of experimental findings to clinical pain conditions may be premature, these results highlight the importance of distinguishing the contribution of mindfulness education and meditation training in future studies. Understanding the effects of mindfulness training on pain regulation and management must take into consideration the multiple factors underlying this complex intervention.

The Acute Effects of Standing on Executive Functioning in Vocational Education and Training Students: The Phit2Learn Study

Research suggests that sedentary behavior (SB) is negatively associated with cognitive outcomes. Interrupting prolonged sitting has been shown to improve cognitive functions, including executive functioning (EF), which is important for academic performance. No research has been conducted on the effect of standing on EF in VET students, who make up a large proportion of the adolescent population and who are known to sit more than other students of this age. In this study, we investigated the acute effects of reducing SB by short time standing on EF in vocational education and training (VET) students. In a randomized crossover study, 165 VET students were first taught for 15 min in seated position. After this, they performed while seated the Letter Memory Test for updating, and the Color Shape Test for shifting and inhibition. Students were randomly assigned to a sitting or standing condition. All students were taught again for 15 min and then took the same tests in the condition they were allocated to, respectively, standing or seated. After 1 week, the test procedure was repeated, in which students switched conditions. Mixed model analyses showed no significant effect of sitting or standing on updating, shifting, or inhibition. Also, no significant differences were found for the order of condition on updating, shifting, or inhibition. Our results suggest that 40 min of standing does not significantly influence EF among VET students.

Effects of Exergaming-Based Tai Chi on Cognitive Function and Dual-Task Gait Performance in Older Adults With Mild Cognitive Impairment: A Randomized Control Trial

Background

Declined cognitive function interferes with dual-task walking ability and may result in falls in older adults with mild cognitive impairment (MCI). The mind-body exercise, Tai Chi (TC), improves cognition and dual-task ability. Exergaming is low-cost, safe, highly scalable, and feasible. Whether the effects of exergaming-based TC is beneficial than traditional TC has not been investigated yet.

Objectives

The objective of this study was to investigate effects of exergaming-based TC on cognitive function and dual-task walking among older adults with MCI.

Methods

Fifty patients with MCI were randomly assigned to an exergaming-based TC (EXER-TC) group, a traditional TC (TC) group, or a control group. The EXER-TC and TC groups received 36 training sessions (three, 50-min sessions per week) during a 12-week period. The control group received no intervention and were instructed to maintain their usual daily physical activities. The outcome variables measured included those related to cognitive function, dual-task cost (DTC), and gait performance.

Results

The EXER-TC and TC groups performed better than the control group on the Chinese version of the Stroop Color and Word Test, the Trail Making Test Parts A and B, the one-back test, gait speed, and DTC of gait speed in cognitive dual-task conditions after training. However, there were no significant differences between the EXER-TC and TC groups. Compared with the control group, only the EXER-TC group experienced beneficial effects for the Montreal Cognitive Assessment.

Conclusion

EXER-TC was comparable to traditional TC for enhancement of dual-task gait performance and executive function. These results suggested that the EXER-TC approach has potential therapeutic use in older adults with MCI.

Inhibition and Calendar Age Explain Variance in Game Performance of Youth Soccer Athletes

The assessment of core executive functions (EFs; i.e., inhibition, working memory, cognitive flexibility) has often been presented as a diagnostic tool for evaluating cognitive functions in recent publications. For example, EFs are essential in soccer because players must quickly adapt, change strategies, and inhibit responses in rapidly changing game situations. Previous research has shown relations between (subjectively rated) game performance and the EFs of soccer players. Nevertheless, the previous studies' samples were heterogeneous in their performance level (experts vs. amateurs), and the ratings were rather unsystematic (no validated rating protocol). Therefore, the current study aimed to predict soccer players' game performance (i.e., systematically rated by coaches) with the help of EF performance. Therefore, we assessed the game performance (small-sided game, Game Performance Assessment Instrument [GPAI]) and EFs (inhibition: flanker task; working memory: 3-back task; cognitive flexibility: number-letter task) of 94 male soccer players (12-19 years old) from Germany's highest competitive level. Multiple regression model results indicate that inhibition (i.e., flanker effect) and calendar age explain ~18% of players' game performance variance. Results have to be interpreted with regard to the age-dependency of game performance and EFs. In conclusion, even though the results are based on a cross-sectional study, it appears that calendar age needs to be considered when assessing EFs.

Training and transfer effects of working memory updating training in male abstinent long-term methamphetamine users

Methamphetamine use is associated with cognitive impairments, including executive functioning. These impairments might be cause and/or effect of the drug (re-)use and have, therefore, motivated interventions to improve cognitive functioning. Until now, only very few studies have examined the effect of training working memory updating (WMU), one of the core executive functions, in this population. In the present study, 32 long-term male abstinent methamphetamine inpatients received either a multiple-session WMU training or an active control treatment. All participants performed a number of tasks assessing WMU, inhibition, and task-switching ability- before and after treatment. The WMU-trained patients improved their performance on the trained task and on a non-trained WMU task, reflecting near transfer. However, there was no beneficial training-induced effect for the other tasks, indicating the absence of far transfer. Possible treatment implications of these findings were discussed.

Effects of an exercise and sport intervention among refugees living in a Greek refugee camp on mental health, physical fitness and cardiovascular risk markers: study protocol for the SALEEM pragmatic randomized controlled trial

BACKGROUND

Due to ongoing political and social conflicts, the number of international refugees has been increasing. Refugees are exposed to severe mental and physical strain, as well as traumatic experiences during their flight. Therefore, the risk of psychiatric disorders is markedly increased among international refugees. International organizations have criticized the lack of early interventions as a key problem, because untreated mental disorders are often difficult to cure at a later stage. Today, exercise and sport have been successfully employed to treat a wide range of psychiatric disorders. With patients with post-traumatic stress disorders (PTSD), very limited empirical evidence exists, and studies carried out with international refugees are nearly non-existent.

METHODS

We intend to implement a pragmatic randomized controlled trial (RCT) with an exercise and sport intervention group (n = 68, 50% women) and a wait-list control group (n = 68, 50% women) in the Koutsochero refugee camp, located close to the city of Larissa (Greece). During the RCT, exercise and sport will be offered five times per week (60 min/session) for 10 weeks. Participants will be asked to participate in at least two sessions per week. The programme is developed according to the participants' needs and preferences and they will be able to choose between a range of activities. PTSD symptoms will serve as primary outcome, and several secondary outcomes will be assessed. Qualitative data collection methods will be used to gain a more in-depth appraisal of the participants' perception of the intervention programme. In the second year of study, the programme will be opened to all camp residents. A strategy will be developed how the programme can be continued after the end of the funding period, and how the programme can be scaled up beyond the borders of the Koutsochero camp.

DISCUSSION

By moving towards the primary prevention of chronic physical conditions and psychiatric disorders, a relevant contribution can be done to enhance the quality and quantity of life of refugee camp residents in Greece. Our findings may also strengthen the evidence for exercise as medicine as a holistic care option in refugee camps, by helping camp residents to adopt and maintain a physically active lifestyle.

TRIAL REGISTRATION

The study was registered prospectively on the 8 February 2021 with ISRCTN https://www.isrctn.com/ISRCTN16291983.

The Influence of Media Exposure on Anxiety and Working Memory during Lockdown Period in Italy

The rapid spread of the coronavirus pandemic has caused anxiety around the world. During lockdown, the media became a point of reference for people seeking information. However, little is known on the relationships between anxiety resulting from persistent media exposure to coronavirus-related programs and the effects produced on working memory. In this work, a total of 101 Italian citizens (53.7% female) aged between 18 and 45 years old, who were from 14 provinces in Italy, participated in an online survey. Participants were presented with media exposure and anxiety questionnaires and they were instructed to carry out working memory tasks (visual and auditory n-back). The results showed that media exposure is related to anxiety. It was also found that high levels of anxiety have a negative influence on the performance of both visual and auditory working memory tasks in terms of increased reaction times of responses and decreased accuracy. The results were critically discussed in the light of the Social Compensation Hypothesis.

Replicability and reliability of the background and target velocity effects in smooth pursuit eye movements

When we follow a slowly moving target with our eyes, we perform smooth pursuit eye movements (SPEM). Previous investigations point to significantly and robustly reduced SPEM performance in the presence of a stationary background and at higher compared to lower target velocities. However, the reliability of these background and target velocity effects has not yet been investigated systematically. To address this issue, 45 healthy participants (17 m, 28 f) took part in two experimental sessions 7 days apart. In each session, participants were instructed to follow a horizontal SPEM target moving sinusoidally between ±7.89° at three different target velocities, corresponding to frequencies of 0.2, 0.4 and 0.6 Hz. Each target velocity was presented once with and once without a stationary background, resulting in six blocks. The blocks were presented twice per session in order to additionally explore potential task length effects. To assess SPEM performance, velocity gain was calculated as the ratio of eye to target velocity. In line with previous research, detrimental background and target velocity effects were replicated robustly in both sessions with large effect sizes. Good to excellent test-retest reliabilities were obtained at higher target velocities and in the presence of a stationary background, whereas lower reliabilities occurred with slower targets and in the absence of background stimuli. Target velocity and background effects resulted in largely good to excellent reliabilities. These findings not only replicated robust experimental effects of background and target velocity at group level, but also revealed that these effects can be translated into reliable individual difference measures.

Effect of exergaming versus combined exercise on cognitive function and brain activation in frail older adults: A randomised controlled trial

BACKGROUND

Cognitive impairment is prevalent among frail older adults. Traditional exercise and exergaming positively affect cognition in healthy older people. However, few studies have investigated the effects of exergaming on cognition and brain activation in frail older adults.

OBJECTIVE

This study compared the effect of Kinect based exergaming (EXER) and combined physical exercise (CPE) training on cognitive function and brain activation in frail older adults in Taiwan. We hypothesised that EXER would be superior to CPE in this population.

METHODS

We randomised 46 community-dwelling frail older adults to the EXER or CPE group for 36 sessions (three 60-min training sessions per week) over 12 weeks. Outcome measures for cognitive function included global cognition measured by the Montreal Cognitive Assessment, executive function measured by the Executive Interview 25, verbal memory measured by the Chinese version of the California Verbal Learning Test, attention measured by the Stroop Colour and Word Test and Trail Making Test (part B), and working memory measured by spatial n-back tests. Prefrontal cortex activation during the global cognition test was documented with functional near-infrared spectroscopy (fNIRS).

RESULTS

Both groups improved significantly in global cognition (P<0.05), executive function (P<0.05), and attention (P<0.05) after the 12-week intervention. The group×time interaction indicated that EXER training significantly enhanced global cognition more than CPE training (F(1,44)=5.277, P=0.026). Moreover, only the EXER group showed significant improvements in verbal (P<0.05) and working (P<0.05) memory after the intervention. The fNIRS hemodynamics data revealed decreased activation in prefrontal cortices of both groups (P<0.05) during the post-training cognitive assessment, thereby suggesting greater neural efficiency; however, we found no significant group difference.

CONCLUSION

In frail older adults, exergaming and CPE could improve cognitive function, most likely by increasing neural efficiency. Moreover, exergaming may be superior to CPE, particularly in improving global cognition.

Transcranial Direct Current Stimulation (tDCS) over the Intraparietal Sulcus Does Not Influence Working Memory Performance

Mixed results of the impact of transcranial direct current stimulation (tDCS) on working memory have been reported. Contrarily to previous studies who focused mainly on stimulating the dorsolateral prefrontal cortex, we modulated the left intraparietal sulcus (IPS) area which is considered to support attentional control aspects of working memory. Using a within-participant experimental design, participants completed three different conditions: anodal stimulation of the IPS, cathodal stimulation of the IPS, and sham stimulation of the IPS. Both visual and verbal working memory tasks were administered. In the visual task, participants had to memorize a random set of colored figures. In the verbal task, participants had to memorize a string of letters. Working memory load was manipulated in both tasks (six figures/letters vs. two figures/letters). No significant differences in accuracy or reaction time between the anodal, cathodal and sham conditions were found. Bayesian analysis supported evidence for an absence of effect. The results of the present study add to the growing body of contradictory evidence regarding the modulatory effects of single session tDCS on working memory performance.

Cognitive Control and Ruminative Responses to Stress: Understanding the Different Facets of Cognitive Control

Rumination has been linked to the onset and course of depression. Theoretical models and empirical evidence suggest that deficits controlling negative material in working memory underlie rumination. However, we do not know which component of cognitive control (inhibition, shifting, or updating) contributes most to rumination, and whether different components predict the more maladaptive (brooding) versus the more adaptive (reflection) forms of rumination. We aimed to advance theory and research by examining the contribution of different facets of cognitive control to the level and trajectory of brooding and reflection. At baseline, participants completed three cognitive tasks that assessed their inhibition, shifting, and updating biases, respectively. Next, using experience sampling methodology, participants rated their level of rumination and negative affect nine times during the 48 h after their most stressful exam. At each time point, higher levels of brooding, but not reflection, predicted higher levels of negative affect at the next time point. Furthermore, several facets of shifting and inhibition, but not updating, predicted brooding immediately after the exam and its trajectory of change over 48 h. Additionally, difficulty inhibiting neutral words predicted both brooding and reflection. These findings inform theoretical models describing the role of cognitive control in brooding and reflection.

Effects of Marathon Running on Cognition and Retinal Vascularization: A Longitudinal Observational Study

INTRODUCTION

Physical activity has beneficial effects on both cardiovascular and neurocognitive parameters, and these 2 modalities are known to interact at rest. However, findings on their interaction during exercise are inconclusive.

PURPOSE

Therefore, this longitudinal study aimed to investigate the effects of different forms of exercise (training period, marathon race, recovery period) on both parameters and their interaction.

METHODS

We included 100 marathon runners (MA) (mean [SD] age: 43.6 [10.0] years, 80 male) and 46 age- and sex-matched sedentary controls (SC, for baseline comparison). Over the 6-month study period with 6 visits (12 and 2 weeks before the marathon; immediately, 24 hours, 72 hours and 12 weeks after the marathon), we assessed cognitive parameters by evaluating 1-to 3-back d prime, the d2 task, and the Trail Making Test A (TMTA) and B (TMTB); retinal vessel parameters by assessing arteriolar-to-venular ratio (AVR), central retinal arteriolar and venular equivalents (CRAE/CRVE).

RESULTS

In the long-term analysis, 3-back d prime correlated positively with AVR (P = 0.024, B = 1.86,SE = 0.824) and negatively with CRVE (P = 0.05,B = -0.006,SE = 0.003) and TMTB correlated negatively with CRAE (P = 0.025,B = -0.155,SE = 0.069), even after correcting for age and systolic blood pressure as possible confounders. Acute effects were inconsistent with maximal cognitive improvement 24 hours after the marathon. AVR was significantly smaller in SC compared to MA.

CONCLUSION

Chronic exercise seems to prime the central nervous system for acute, intensive bouts of exercise. Our findings indicate a possible relationship between cognitive performance in high-demand tasks and retinal vasculature and support the idea of a neuroplastic effect of exercise.

CPNE3 moderates the association between anxiety and working memory

Mutual influences between anxiety and working memory (WM) have been extensively studied, and their curvilinear relationship resembles the classic Yerkes-Dodson law of arousal and performance. Given the genetic bases of both anxiety and WM, it is likely that the individual differences in the Yerkes-Dodson law of anxiety and WM may have genetic correlates. The current genome wide association study (GWAS) enrolled 1115 healthy subjects to search for genes that are potential moderators of the association between anxiety and WM. Results showed that CPNE3 rs10102229 had the strongest effect, p = 3.38E−6 at SNP level and p = 2.68E−06 at gene level. Anxiety and WM had a significant negative correlation (i.e., more anxious individuals performed worse on the WM tasks) for the TT genotype of rs10102229 (resulting in lower expression of CPNE3), whereas the correlation was positive (i.e., more anxious individuals performed better on the WM tasks) for the CC carriers. The same pattern of results was found at the gene level using gene score analysis. These effects were replicated in an independent sample (N = 330). The current study is the first to report a gene that moderates the relation between anxiety and WM and potentially provides a genetic explanation for the classic Yerkes-Dodson law.

The Effects of Bilateral Theta-burst Stimulation on Executive Functions and Affective Symptoms in Major Depressive Disorder

Major depressive disorder (MDD) is characterized by severe affective as well as cognitive symptoms. Moreover, cognitive impairment in MDD can persist after the remission of affective symptoms. Theta-burst stimulation (TBS) is a promising tool to manage the affective symptoms of major depressive disorder (MDD); however, its cognition-enhancing effects are sparsely investigated. Here, we aimed to examine whether the administration of bilateral TBS has pro-cognitive effects in MDD. Ten daily sessions of neuronavigated active or sham TBS were delivered bilaterally over the dorsolateral prefrontal cortex to patients with MDD. The n-back task and the attention network task were administered to assess working memory and attention, respectively. Affective symptoms were measured using the 21-item Hamilton Depression Rating Scale. We observed moderate evidence that the depressive symptoms of patients receiving active TBS improved compared to participants in the sham stimulation. No effects of TBS on attention and working memory were detected, supported by a moderate-to-strong level of evidence. The effects of TBS on psychomotor processing speed should be further investigated. Bilateral TBS has a substantial antidepressive effect with no immediate adverse effects on executive functions.

Believing is achieving - On the role of treatment expectation in neurofeedback applications

In neurofeedback applications, neural activity is recorded, processed in real-time and fed back to the user in order to facilitate self-regulation of the putative neural mechanisms that underlie cognition and behavior. Numerous studies suggest that neurofeedback interventions are an efficacious treatment particularly for patients with attention-deficit/hyperactivity disorder (ADHD). In recent years, however, findings of several well-controlled studies raised doubts concerning the proposed mechanism of action behind the behavioral effect of neurofeedback. This study investigated the impact of expectation on the efficacy of a sensorimotor rhythm (SMR) training. In a within-subjects design 30 blinded volunteers with ADHD symptoms received a standard SMR training session after inducing no (no-expectancy condition), positive (placebo condition), and negative (nocebo condition) expectations regarding the effectiveness of neurofeedback (by telling them that they would train a specific frequency band that was previously shown to be either unrelated to attention, should improve attention, or interfere with attentional processes). After each training, participants were presented with a cognitive test and subsequently requested to rate their performance on it. We could show that participants were able to successfully modify their EEG signal during training. Further, we found an effect over trainings on objective attentional performance. Most importantly, we found that the expectancy of positive or negative treatment effects considerably changed participants' perception of neurofeedback's efficacy even in the absence of any objective evidence. This study presents strong first evidence for a substantial effect of self-confirming response expectancies as one factor underlying the efficacy of neurofeedback. Future research has to carefully consider the impact of such psychosocial mechanisms when evaluating the (specific) efficacy of neuromodulatory treatments.

Pieces of evidences of reliability of the Brazilian version of the Child Executive Functions Battery (CEF-B)

Executive dysfunctions are central symptoms in different neurological, developmental, and context-related conditions. The assessment of these functions is then essential in neuropsychological pediatric clinical practice. Given the need for reliable and valid evaluation batteries for clinical practice in Brazil, this study aimed to present the pieces of evidences of reliability of the Child Executive Functions Battery (CEF-B). A total of 230 Brazilian children with typical development aged between 7 and 12 years participated in the study. Internal consistency was determined by the split-half method, Cronbach’s α, and Ω. In addition, measurements of test-retest reliability and intraclass coefficient were also performed. Retest indicators were mostly weak and moderate (between .43 and .75). Overvall, coefficients show a satisfactory internal consistency reliability for planning and inhibition measures (between .72 and .92). Considering the measures of WM, results were also satisfactory for both α and Ω indexes. This study revealed that the CEF-B has satisfactory internal consistency reliability coefficients. However, several tests have shown low reliability assessed through the test-retest method. In general, findings reveal interesting pieces of initial evidence of reliability of the Brazilian version. The methodological approach could be improved in future studies by including children with executive disorders.

Test-retest reliability on the Cambridge Neuropsychological Test Automated Battery: Comment on Karlsen et al. (2020)

Test-retest reliability is essential to the development and validation of psychometric tools. Here we respond to the article by Karlsen et al. (Applied Neuropsychology: Adult, 2020), reporting test-retest reliability on the Cambridge Neuropsychological Test Automated Battery (CANTAB), with results that are in keeping with prior research on CANTAB and the broader cognitive assessment literature. However, after adopting a high threshold for adequate test-retest reliability, the authors report inadequate reliability for many measures. In this commentary we provide examples of stable, trait-like constructs which we would expect to remain highly consistent across longer time periods, and contrast these with measures which show acute within-subject change in response to contextual or psychological factors. Measures characterized by greater true within-subject variability typically have lower test-retest reliability, requiring adequate powering in research examining group differences and longitudinal change. However, these measures remain sensitive to important clinical and functional outcomes. Setting arbitrarily elevated test-retest reliability thresholds for test adoption in cognitive research limits the pool of available tools and precludes the adoption of many well-established tests showing consistent contextual, diagnostic, and treatment sensitivity. Overall, test-retest reliability must be balanced with other theoretical and practical considerations in study design, including test relevance and sensitivity.

Spontaneous strategy use during a working memory updating task

Cognitive skill learning postulates strategy generation and implementation when people learn to perform new tasks. Here we followed self-reported strategy use and objective performance in a working memory (WM) updating task to reveal strategy development that should take place when faced with this novel task. In two pre-registered online experiments with healthy adults, we examined short-term strategy acquisition in a ca 20-30-minute adaptive n-back WM task with 15 task blocks by collecting participants' strategy reports after each block. Experiment 1 showed that (a) about half of the participants reported using a strategy already during the very first task block, (b) changes in selected strategy were most common during the initial task blocks, and (c) more elaborated strategy descriptions predicted better task performance. Experiment 2 mostly replicated these findings, and it additionally showed that compared to open-ended questions, the use of repeated list-based strategy queries influenced subsequent strategy use and task performance, and also indicated higher rates of strategy implementation and strategy change during the task. Strategy use was also a significant predictor of n-back performance, albeit some of the variance it explained was shared with verbal productivity that was measured with a picture description task. The present results concur with the cognitive skill learning perspective and highlight the dynamics of carrying out a demanding cognitive task.

Executive function, motivation, and emotion recognition in high-functioning autism spectrum disorder

BACKGROUND

Several neurocognitive theories have been put forward to explain autism spectrum disorder (ASD). However, the specificity of executive cognitive, motivational (i.e., reward-related), and emotion-recognition impairments in ASD, and the role of early language delay in these impairments remain largely unclear.

AIM

This study aimed to examine executive cognitive, motivational, and emotion-recognition functions while considering the potential effect of language delay in ASD.

METHODS

Twenty-two adolescents with high-functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11-18 years were recruited. Each completed seven computerized tasks measuring executive cognitive (i.e., set-shifting, inhibition, updating, and access/generativity), motivational (i.e., flexible reinforcement learning and affective decision-making), and emotion-recognition functions (i.e., facial emotion recognition).

RESULTS

We found that ASD participants with early language delay (n = 10) had poorer executive cognitive, motivational, and emotion-recognition functioning than TD controls, and had poorer executive cognitive and motivational functioning than ASD participants without language delay (n = 12). ASD participants without language delay only had poorer emotion recognition than TD controls.

CONCLUSION AND IMPLICATIONS

These preliminary findings suggest impairments in executive cognitive and motivational functions as well as emotion recognition in ASD with language delay, and impairment only in emotion recognition in ASD without language delay. They implicate a potential partial distinction in mental abilities between ASD with and without early language delay, highlighting the importance of considering language delay when evaluating executive cognitive and motivational functions in ASD.

Test-retest reliability of the simon task: a short version proposal

Background: The standard version of the Simon task (an instrument for assessing attentional demands, inhibitory control and the perception-action cycle) comprises a total of 168 trials. Different versions of this task are used in the literature, but it is not clear whether the Simon effect can be found using brief versions of the test.Purpose: This study aims to investigate the presence of the Simon effect and its test-retest reliability in a brief version of 28 trials of the Simon task.Material and Methods: Ninety-two (92) subjects between the ages of 18-30 participated in this study. Participants performed two sessions (test and retest) in which the brief battery of the Simon task was used. Latency (reaction time - RT) and the accuracy (number of errors) were measured for the two typical conditions of the test (corresponding and non-corresponding).Results: A significant interaction (two-way ANOVA) between condition and moment (test vs. retest) was found for RT. Main effects were observed for both conditions (corresponding vs. non- corresponding) and moment (test vs. retest). A good measurement of reliability (α Cronbach = 0.883) was also observed.Conclusions: The 28-trial battery of the Simon Task seems to be efficient for eliciting the Simon Effect and it can therefore be considered reliable.

A new approach to facilitating attentional disengagement from food cues in unsuccessful dieters: The bouncing image training task

This study tested the capacity of a modified Bouncing Image Training Task (BITT) to enhance unsuccessful dieters' attentional disengagement from food cues. Unsuccessful dieters were assigned to a training group performing daily BITT sessions for one week (n = 57) or a waitlist control group (n = 56). Change in attention was assessed using a visual search task and an odd-one-out task. Impact of the BITT on food craving and food intake were also assessed. Participants in the training group, compared to waitlist controls, showed reduced attention to food cues from pre-to post-training. Moreover, the reduction in AB to food cues exhibited by those who completed the BITT reflected the relative facilitation of attentional disengagement from food cues, rather than a reduction in attention engagement with food cues. The groups did not differ on food craving or intake post-training. It is concluded that the BITT is a promising procedure for directly manipulating individuals' attentional disengagement from food cues, though its capacity to enhance dieting success has not yet been established.

The impact of lifestyle Physical Activity Counselling in IN-PATients with major depressive disorders on physical activity, cardiorespiratory fitness, depression, and cardiovascular health risk markers: study protocol for a randomized controlled trial

BACKGROUND

Major depressive disorder (MDD) is a widespread and burdensome psychiatric issue. Physical activity counselling may increase lifestyle physical activity and cardiorespiratory fitness in this specific and particularly vulnerable population, which often suffers from both mental and physical health problems. Therefore, this study will examine the impact of a lifestyle physical activity counselling intervention on physical activity, cardiorespiratory fitness, depression, and cardiovascular health risk markers among in-patients diagnosed with MDD compared to controls. Secondary purposes are to examine the acceptability and perceived usefulness of the intervention among these patients, to find out whether the effectiveness of the intervention is moderated by genetic factors, and to compare baseline values with an age- and gender-matched group of healthy controls.

METHODS

The study is designed as a multi-centric two-arm randomized clinical trial including an intervention group and a placebo control group, allocation concealment, single-blinding, and intention-to-treat analysis. Participants (N = 334) will be continuously recruited from four clinics specialized in the treatment of MDD. The intervention builds on a standardized, theory-based, low-cost lifestyle physical activity counselling programme, which was specifically designed for an in-patient rehabilitation setting. The placebo control condition consists of general instructions about health-enhancing physical activity. Data assessments will take place 2-3 weeks after admission to in-patient treatment (baseline), and 6 weeks (post) and 12 months (follow-up) after discharge from in-patient treatment. The primary outcome is objectively assessed physical activity at follow-up.

DISCUSSION

Because regular physical activity has proven to be an important predictor of long-term response and remission in patients with major depression, we believe that our planned study may lay important groundwork by showing how individually tailored lifestyle physical activity counselling can be integrated into given clinical structures. Improving physical activity may have important implications for tackling metabolic and cardiovascular disease and increasing mood and cognitive functioning in this at-risk population, hence limiting the future burden of multiple chronic conditions. Increased physical activity may also reduce the likelihood of future depressive episodes. By moving towards the primary prevention of chronic physical conditions, much can be done to enhance the quality and quantity of life of people with MDD.

TRIAL REGISTRATION

ISRCTN, ISRCTN10469580 . Registered on 3 September 2018.

Bringing context to balance: development of a reactive balance test within the injury prevention and return to sport domain

Background

Balance tests are commonly used in clinical practice with applicability in injury prevention and return to sport decisions. While most sports injuries occur in a changing environment where reacting to a non-planned stimulus is of great importance, these balance tests only evaluate pre-planned movements without taking these dynamics environmental aspects into account. Therefore, the goal of this paper was to develop a clinician-friendly test that respects these contextual interactions and to describe the test protocol of an adapted Y-balance test that includes environmental perception and decision-making.

Methods

Within the theoretical construct of balance and adaptability, balance errors were selected as outcome measures for balance ability and, visuomotor reaction time and accuracy are selected as outcome measures for adaptability. A reactive balance task was developed and described using the Y-balance test for the balance component, while the FitLight training system^TM was chosen for the environmental perception and decision-making component of the test.

Results

This paper describes the test protocol of a reactive balance test as an adapted Y-balance test. The LED-lights of the FitLight training systemTM are placed at 80% of the maximal reach distance for each axis along the Y-Balance test kitTM. To induce cognitive load within the visuomotor task, colours were fixed to a corresponding axis, and both the order of the visual stimuli as the interstimulus time were randomised to integrate environmental perception and decision-making.

Conclusion

The reactive balance test is a functional test that allows clinicians to score balance ability and athlete adaptability easily.

On the Reliability of Switching Costs Across Time and Domains

Bilingual speakers are suggested to use control processes to avoid linguistic interference from the unintended language. It is debated whether these bilingual language control (BLC) processes are an instantiation of the more domain-general executive control (EC) processes. Previous studies inconsistently report correlations between measures of linguistic and non-linguistic control in bilinguals. In the present study, we investigate the extent to which there is cross-talk between these two domains of control for two switch costs, namely the n-1 shift cost and the n-2 repetition cost. Also, we address an important problem, namely the reliability of the measures used to investigate cross-talk. If the reliability of a measure is low, then these measures are ill-suited to test cross-talk between domains through correlations. We asked participants to perform both a linguistic- and non-linguistic switching task at two sessions about a week apart. The results show a dissociation between the two types of switch costs. Regarding test-retest reliability, we found a stronger reliability for the n-1 shift cost compared to the n-2 repetition cost within both domains as measured by correlations across sessions. This suggests the n-1 shift cost is more suitable to explore cross-talk of BLC and EC. Next, we do find cross-talk for the n-1 shift cost as demonstrated by a significant cross-domain correlation. This suggests that there are at least some shared processes in the linguistic and non-linguistic task.

The early effects of external and internal strategies on working memory updating training

The mechanisms underlying working memory training remain unclear, but one possibility is that the typically limited transfer effects of this training reflect adoption of successful task-specific strategies. Our pre-registered randomized controlled trial (N = 116) studied the early effects of externally given vs. internally generated strategies in an updating task (n-back) over a 5-day period with a single 30-minute training session. Three groups were employed: n-back training with strategy instruction (n = 40), n-back training without strategy instruction (n = 37), and passive controls (n = 39). We found that both external and internal strategy use was associated with significantly higher posttest performance on the trained n-back task, and that training with n-back strategy instruction yielded positive transfer on untrained n-back tasks, resembling the transfer pattern typically seen after the ordinary uninstructed 4–6-week working memory training. In the uninstructed participants, the level of detail and type of internally generated n-back strategies at posttest was significantly related to their posttest n-back performance. Our results support the view that adoption of task-specific strategies plays an important role in working memory training outcomes, and that strategy-based effects are apparent right at the start of training.

No Effects of Stimulating the Left Ventrolateral Prefrontal Cortex with tDCS on Verbal Working Memory Updating

The effects of transcranial direct current stimulation (tDCS) on dorsolateral prefrontal cortex functions, such as working memory (WM), have been examined in a number of studies. However, much less is known about the behavioral effects of tDCS over other important WM-related brain regions, such as the ventrolateral prefrontal cortex (VLPFC). In a counterbalanced within-subjects design with 33 young healthy participants, we examined whether online and offline single-session tDCS over VLPFC affects WM updating performance as measured by a digit 3-back task. We compared three conditions: anodal, cathodal and sham. We observed no significant tDCS effects on participants' accuracy or reaction times during or after the stimulation. Neither did we find any differences between anodal and cathodal stimulation. Largely similar results were obtained when comparing subgroups of high- and low-performing participants. Possible reasons for the lack of effects, including individual differences in responsiveness to tDCS, features of montage, task and sample characteristics, and the role of VLPFC in WM, are discussed.