Validating running memory span: Measurement of working memory capacity and links with fluid intelligence

The common factor of executive functions measures nothing but speed of information uptake

There is an ongoing debate about the unity and diversity of executive functions and their relationship with other cognitive abilities such as processing speed, working memory capacity, and intelligence. Specifically, the initially proposed unity and diversity of executive functions is challenged by discussions about (1) the factorial structure of executive functions and (2) unfavorable psychometric properties of measures of executive functions. The present study addressed two methodological limitations of previous work that may explain conflicting results: The inconsistent use of (a) accuracy-based vs. reaction time-based indicators and (b) average performance vs. difference scores. In a sample of 148 participants who completed a battery of executive function tasks, we tried to replicate the three-factor model of the three commonly distinguished executive functions shifting, updating, and inhibition by adopting data-analytical choices of previous work. After addressing the identified methodological limitations using drift-diffusion modeling, we only found one common factor of executive functions that was fully accounted for by individual differences in the speed of information uptake. No variance specific to executive functions remained. Our results suggest that individual differences common to all executive function tasks measure nothing more than individual differences in the speed of information uptake. We therefore suggest refraining from using typical executive function tasks to study substantial research questions, as these tasks are not valid for measuring individual differences in executive functions.

Latent Network Analysis of Executive Functions Across Development

Executive functions (EFs) are crucial for academic achievement, physical health, and mental well-being. Previous studies using structural equation models revealed EFs' developmental organization, evolving from one factor in childhood to three factors in adults: inhibition, cognitive flexibility, and updating. Recent network model studies confirmed this differentiation from childhood to adulthood. Reanalyzing previously published data from 1019 children (aged 7.8 to 15.3; 50.4% female; 59.1% White, 15.0% Latinx, 14.3% Bi-racial, 6.7% African American, 4.2% Asian American, 0.6% Other), this study compared three analytical methods to explore EF development: structural equation model, network model, and the novel latent variable network model. All approaches supported fine-grained EF-specific trajectories and differentiation throughout development, with inhibition being central in childhood and updating in early adolescence.

Replication and extension of the toolbox approach to measuring attention control

There is an increasing consensus among researchers that traditional attention tasks do not validly index the attentional mechanisms that they are often used to assess. We recently tested and validated several existing, modified, and new tasks and found that accuracy-based and adaptive tasks were more reliable and valid measures of attention control than traditional ones, which typically rely on speeded responding and/or contrast comparisons in the form of difference scores (Draheim et al. Journal of Experimental Psychology: General, 150(2), 242-275, 2021). With these improved measures, we found that attention control fully mediated the working memory capacity-fluid intelligence relationship, a novel finding that we argued has significant theoretical implications. The present study was both a follow-up and extension to this "toolbox approach" to measuring attention control. Here, we tested updated versions of several attention control tasks in a new dataset (N = 301) and found, with one exception, that these tasks remain strong indicators of attention control. The present study also replicated two important findings: (1) that attention control accounted for nearly all the variance in the relationship between working memory capacity and fluid intelligence, and (2) that the strong association found between attention control and other cognitive measures is not because the attention control tasks place strong demands on processing speed. These findings show that attention control can be measured as a reliable and valid individual differences construct, and that attention control shares substantial variance with other executive functions.

Image response regression via deep neural networks

Delineating associations between images and covariates is a central aim of imaging studies. To tackle this problem, we propose a novel non-parametric approach in the framework of spatially varying coefficient models, where the spatially varying functions are estimated through deep neural networks. Our method incorporates spatial smoothness, handles subject heterogeneity, and provides straightforward interpretations. It is also highly flexible and accurate, making it ideal for capturing complex association patterns. We establish estimation and selection consistency and derive asymptotic error bounds. We demonstrate the method's advantages through intensive simulations and analyses of two functional magnetic resonance imaging data sets.

Transdiagnostic Predictors of Everyday Functioning: Examining the Relationships of Depression and Reinforcement Learning

BACKGROUND AND HYPOTHESIS

Impairments in function (ie, the ability to independently accomplish daily tasks) have been established in psychotic disorders. Identifying factors that contribute to these deficits is essential to developing effective interventions. The current study had several goals: examine potential differential relationships across domains of neurocognition, assess whether reinforcement learning is related to function, identify if predictors of function are transdiagnostic, determine whether depression and positive symptoms contribute to function, and to explore whether the modality of assessment impacts observed relationships.

STUDY DESIGN

Data from 274 participants were examined with schizophrenia/schizoaffective disorder (SZ; n = 195) and bipolar disorder (BD; n = 79). To reduce dimensionality, a PCA was completed on neurocognitive tasks which resulted in 3 components. These components and clinical interview data were used to investigate predictors of functional domains across measures of function (self- and informant-report SLOF and UPSA).

RESULTS

Two components, working memory/processing speed/episodic memory (βs = 0.18-0.42), and negative/positive reinforcement learning (β = -0.04), predicted different functional domains. Predictors of function were largely transdiagnostic with two exceptions: reinforcement learning had a positive association with self-reported interpersonal relationships for SZ and a negative association for BD (β = 0.34), and the negative association between positive symptoms and self-reported social acceptability was stronger for BD than for SZ (β = 0.93). Depression robustly predicted self-reported but not informant-reported function, and anhedonia predicted all domains of informant-reported function.

CONCLUSIONS

These findings imply that reinforcement learning may differentially relate to function across disorders, traditional domains of neurocognition can be effective transdiagnostic targets for interventions, and positive symptoms and depression play a critical role in self-perceived functional impairments.

Disentangling Processing and Storage Accounts of Working Memory Development in Childhood

Researchers have been asking the question of what drives the development of working memory (WM) during childhood for decades. This question is particularly challenging because so many aspects of cognition develop with age that it is difficult to disentangle them and find out which factors are causal or fundamental. In this review, we first prepare to discuss this issue by inquiring whether increases in storage, processing, or both are the fundamental driving factor(s) of the age-related increase in WM capability in childhood. We contend that by experimentally manipulating either factor and observing changes in the other, it is possible to learn about causal roles in WM development. We discuss research on school-aged children that seems to suggest, by means of such an approach, that the growth of storage is causal for some phases or steps in WM tasks, but that the growth of processing is causal for other steps. In our theoretical proposal, storage capacity of the focus of attention determines earlier steps of information processing by constraining the selective encoding of information into WM, whereas processing dependent on the focus of attention determines later steps, like the detection of patterns that can simplify the effective memory load and adoption of a proactive stance of maintenance in dual-task settings. Future directions for research are discussed.

Association between adolescents' socioeconomic status and working memory updating functioning: Role of parental educational involvement

Family socioeconomic status (SES) is positively associated with executive functioning. This study tested whether parental educational involvement mediates this association. Two hundred and sixty, 12-15-year-old adolescents completed working memory updating (WMU) and general intelligence tasks, and questionnaires on SES and parental educational involvement. SES and WMU ability were positively associated; there was no difference between the fathers and mothers for three types of educational involvement. The mothers' behavioural involvement positively mediated the SES-WM updating association, whereas a negative mediation was observed for the mothers' intellectual involvement. The fathers' educational involvement did not play a significant mediating role. These results might inform interventions targeting educational involvement for enhancing the cognitive development of children from low SES families.

Using a picture (or a thousand words) for supporting spatial knowledge of a complex virtual environment

External representations powerfully support and augment complex human behavior. When navigating, people often consult external representations to help them find the way to go, but do maps or verbal instructions improve spatial knowledge or support effective wayfinding? Here, we examine spatial knowledge with and without external representations in two studies where participants learn a complex virtual environment. In the first study, we asked participants to generate their own maps or verbal instructions, partway through learning. We found no evidence of improved spatial knowledge in a pointing task requiring participants to infer the direction between two targets, either on the same route or on different routes, and no differences between groups in accurately recreating a map of the target landmarks. However, as a methodological note, pointing was correlated with the accuracy of the maps that participants drew. In the second study, participants had access to an accurate map or set of verbal instructions that they could study while learning the layout of target landmarks. Again, we found no evidence of differentially improved spatial knowledge in the pointing task, although we did find that the map group could recreate a map of the target landmarks more accurately. However, overall improvement was high. There was evidence that the nature of improvement across all conditions was specific to initial navigation ability levels. Our findings add to a mixed literature on the role of external representations for navigation and suggest that more substantial intervention-more scaffolding, explicit training, enhanced visualization, perhaps with personalized sequencing-may be necessary to improve navigation ability.

Measuring cognitive flexibility in anorexia nervosa: Wisconsin Card Sorting Test versus cued task-switching

PURPOSE

The Wisconsin Card Sorting Test (WCST) is the most common measure of cognitive flexibility in anorexia nervosa (AN), but task-switching paradigms are beginning to be utilized. The current study directly compared performance on a cued task-switching measure and the WCST to evaluate their association in participants with a lifetime diagnosis of AN, and to assess which measure is more strongly associated with clinical symptoms.

METHODS

Forty-five women with a lifetime diagnosis of AN completed the WCST, cued color-shape task-switching paradigm, Anti-saccade Keyboard Task, Running Memory Span, Eating Disorder Examination Questionnaire, Depression Anxiety Stress Scales short form and Eating Disorder Flexibility Index.

RESULTS

There was no evidence of a significant association between WCST perseverative errors and cued task-switching switch costs. Results suggest lower working memory capacity is a determinant of higher perseverative error rate. When controlling for mood variables, neither cognitive flexibility measure was a significant independent predictor of symptom severity.

CONCLUSIONS

Results provide support for previous suggestions that WCST perseverative errors could occur due to difficulties with working memory, sensitivity to feedback, and issues with concept formation. Cued task-switching paradigms may provide a useful measure of cognitive flexibility for future eating disorders research by reducing task-specific confounds.

LEVEL OF EVIDENCE

Level III Case-control analytic study.

Are two naïve and distributed heads better than one? Factors influencing the performance of teams in a challenging real-time task

Introduction

Collective decisions in dynamic tasks can be influenced by multiple factors, including the operational conditions, quality and quantity of communication, and individual differences. These factors may influence whether two heads perform better than one. This study examined the "two heads are better than one" effect (2HBT1) in distributed two-person driver-navigator teams with asymmetrical roles performing a challenging simulated driving task. We also examined the influence of communication quality and quantity on team performance under different operational conditions. In addition to traditional measures of communication volume (duration and speaking turns), patterns of communication quality (optimality of timing and accuracy of instructions) were captured.

Methods

Participants completed a simulated driving task under two operational conditions (normal and fog) either as individual drivers (N = 134; 87 females, mean age = 19.80, SD = 3.35) or two-person teams (driver and navigator; N = 80; 109 females, mean age = 19.70, SD = 4.69). The normal condition was characterized by high visibility for both driver and navigator. The fog condition was characterized by reduced visibility for the driver but not for the navigator. Participants were also measured on a range of cognitive and personality constructs.

Results

Teams had fewer collisions than individuals during normal conditions but not during fog conditions when teams had an informational advantage over individuals. Furthermore, teams drove slower than individuals during fog conditions but not during normal conditions. Communication that was poorly timed and/or inaccurate was a positive predictor of accuracy (i.e., collisions) during the normal condition and communication that was well timed and accurate was a negative predictor of speed during the fog condition. Our novel measure of communication quality (i.e., content of communication) was a stronger predictor of accuracy, but volume of communication was a stronger predictor of time (i.e., speed).

Discussion

Results indicate when team performance thrives and succumbs compared with individual performance and informs theory about the 2HBT1 effect and team communication.

A large-scale repository of spoken narratives in French, German and Spanish from Cantonese-speaking learners

Interdisciplinary research on foreign language learning has important implications for learning and education. In this paper, we present the Repository of Third Language (L3) Spoken Narratives from Modern Language Learners in Hong Kong (L3HK Repository). This database contains 906 audio recordings and annotated transcripts of spoken narratives in French, German, and Spanish that were elicited from Cantonese-speaking (L1) young adults using a wordless picture book, "Frog, Where Are You?". All participants spoke English as the second language (L2) and learned the target language as a third language (L3). We collected their demographic information, answers to a motivation questionnaire, parental socioeconomic status, and music background. Furthermore, for a subset of participants, we collected their L1 and L2 proficiency scores and additional experimental data on working memory and music perception. This database is valuable for examining cross-sectional changes in foreign language learning. The extensive data on phenotypes provide opportunities to explore learner-internal and learner-external factors in foreign language learning outcomes. These data may also be helpful for those who work on speech recognition.

Socially Stratified Epigenetic Profiles Are Associated With Cognitive Functioning in Children and Adolescents

Children's cognitive functioning and educational performance are socially stratified. Social inequality, including classism and racism, may operate partly via epigenetic mechanisms that modulate neurocognitive development. Following preregistered analyses of data from 1,183 participants, ages 8 to 19 years, from the Texas Twin Project, we found that children growing up in more socioeconomically disadvantaged families and neighborhoods and children from marginalized racial/ethnic groups exhibit DNA methylation profiles that, in previous studies of adults, were indicative of higher chronic inflammation, lower cognitive functioning, and a faster pace of biological aging. Furthermore, children's salivary DNA methylation profiles were associated with their performance on in-laboratory tests of cognitive and academic skills, including processing speed, general executive function, perceptual reasoning, verbal comprehension, reading, and math. Given that the DNA methylation measures that we examined were originally developed in adults, our results suggest that children show molecular signatures that reflect the early life social determinants of lifelong disparities in health and cognition.

Educational mobility and older adults' working memory updating ability: association and role of resilience

OBJECTIVE

Previous research revealed that a low childhood socioeconomic status, including low parental education, correlates with impaired executive functioning. However, there is a lack of research on the association of working memory updating (WMU) ability, which is one of the major components of executive functioning, and of resilience with educational mobility. The purpose of the present two studies was to further examine these associations.

METHOD

In Study 1, 180, 60-88-year old adults with different levels of educational mobility performed a WMU task. In Study 2, 130, 60-89-year old adults that had experienced different levels of upward educational mobility completed a WMU task and a resilience questionnaire.

RESULTS

Study 1 revealed that extent of educational mobility was significantly positively associated with WMU ability. Study 2 revealed significant positive associations among extent of educational mobility, resilience, and WMU task performance.

CONCLUSION

The results were discussed in terms of possible causal relations between the variables and implications for interventions that aim to enhance upward educational mobility and cognitive functioning in late adulthood.

Near transfer to an unrelated N-back task mediates the effect of N-back working memory training on matrix reasoning

The extent to which working memory training improves performance on untrained tasks is highly controversial. Here we address this controversy by testing the hypothesis that far transfer may depend on near transfer using mediation models in three separate randomized controlled trials (RCTs). In all three RCTs, totalling 460 individuals, performance on untrained N-back tasks (near transfer) mediated transfer to Matrix Reasoning (representing far transfer) despite the lack of an intervention effect in RCTs 2 and 3. Untrained N-back performance also mediated transfer to a working memory composite, which showed a significant intervention effect (RCT 3). These findings support a model of N-back training in which transfer to untrained N-back tasks gates further transfer (at least in the case of working memory at the construct level) and Matrix Reasoning. This model can help adjudicate between the many studies and meta-analyses of working memory training that have provided mixed results but have not examined the relationship between near and far transfer on an individual-differences level.

The role of attention control in complex real-world tasks

Working memory capacity is an important psychological construct, and many real-world phenomena are strongly associated with individual differences in working memory functioning. Although working memory and attention are intertwined, several studies have recently shown that individual differences in the general ability to control attention is more strongly predictive of human behavior than working memory capacity. In this review, we argue that researchers would therefore generally be better suited to studying the role of attention control rather than memory-based abilities in explaining real-world behavior and performance in humans. The review begins with a discussion of relevant literature on the nature and measurement of both working memory capacity and attention control, including recent developments in the study of individual differences of attention control. We then selectively review existing literature on the role of both working memory and attention in various applied settings and explain, in each case, why a switch in emphasis to attention control is warranted. Topics covered include psychological testing, cognitive training, education, sports, police decision-making, human factors, and disorders within clinical psychology. The review concludes with general recommendations and best practices for researchers interested in conducting studies of individual differences in attention control.

Both unmedicated and medicated individuals with schizophrenia show impairments across a wide array of cognitive and reinforcement learning tasks

BACKGROUND

Schizophrenia is a disorder characterized by pervasive deficits in cognitive functioning. However, few well-powered studies have examined the degree to which cognitive performance is impaired even among individuals with schizophrenia not currently on antipsychotic medications using a wide range of cognitive and reinforcement learning measures derived from cognitive neuroscience. Such research is particularly needed in the domain of reinforcement learning, given the central role of dopamine in reinforcement learning, and the potential impact of antipsychotic medications on dopamine function.

METHODS

The present study sought to fill this gap by examining healthy controls (N = 75), unmedicated (N = 48) and medicated (N = 148) individuals with schizophrenia. Participants were recruited across five sites as part of the CNTRaCS Consortium to complete tasks assessing processing speed, cognitive control, working memory, verbal learning, relational encoding and retrieval, visual integration and reinforcement learning.

RESULTS

Individuals with schizophrenia who were not taking antipsychotic medications, as well as those taking antipsychotic medications, showed pervasive deficits across cognitive domains including reinforcement learning, processing speed, cognitive control, working memory, verbal learning and relational encoding and retrieval. Further, we found that chlorpromazine equivalency rates were significantly related to processing speed and working memory, while there were no significant relationships between anticholinergic load and performance on other tasks.

CONCLUSIONS

These findings add to a body of literature suggesting that cognitive deficits are an enduring aspect of schizophrenia, present in those off antipsychotic medications as well as those taking antipsychotic medications.

The relationship between executive function, processing speed, and attention-deficit hyperactivity disorder in middle childhood

Attention-Deficit Hyperactivity Disorder (ADHD) is a heterogeneous disorder that is highly impairing. Early, accurate diagnosis maximizes long-term positive outcomes for youth with ADHD. Tests of executive functioning (EF) are potential tools for screening and differential diagnosis of ADHD subtypes. However, previous research has been inconsistent regarding the specificity and magnitude of EF deficits across ADHD subtypes. Here, we advance knowledge of the EF-ADHD relationship by using: (1) dimensional latent factor models of ADHD that captures the heterogeneity of expression, and (2) a comprehensive, reliable battery of EF tasks and modeling relationships with a general factor of EF ability. We tested 1548 children and adolescents (ages 7-15 years) from the Texas Twin Project, a population-based cohort with a diverse socioeconomic and ethnic composition. We show that EF deficits were specific to the inattention domain of ADHD. Moreover, we found that the association between EF task performance and inattention was stable across sociodemographic groups. Our results demonstrate that failures of executive control are selectively manifested as covert inattentive symptoms, such as trouble with organization, forgetfulness, and distractedness, rather than overt symptoms, such as inappropriate talkativeness and interruption. Future research, utilizing a bifactor characterization of ADHD in clinical samples, is needed to further refine understanding of the nature of cognitive deficits in ADHD across the full range of symptom variation.

The effect of working memory capacity and training on intertemporal decision making in children from low-socioeconomic-status families

Individuals differ in their tendency to discount delayed rewards. Low socioeconomic status (SES) has been found to be associated with strong delayed reward discounting (DRD), which in turn contributes to risky decision making and adverse behaviors. However, research on possible cognitive mediators of the negative association between SES and DRD, and on effects of cognitive training in low-SES adolescents, is largely lacking. In examining Chinese adolescents (aged 11-15 years; N = 207), Study 1 assessed which aspect of working memory (WM)-simple maintenance, simple manipulation, or updating-serves as mediator, which proved to be WM updating. Based on this outcome, in Study 2 Chinese adolescents (aged 12-14 years; N = 73) with low family SES were assigned to a WM updating training condition or a control condition. All participants performed DRD and WM tasks before and after treatment. The trained adolescents showed positive training effects on DRD, and this effect was specifically correlated with beneficial training effects on performance on a WM updating transfer task. These results support the role of WM updating in DRD and might inform training programs to promote more favorable decision making in low-SES adolescents.

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.

Children's long-term retention is directly constrained by their working memory capacity limitations

We explored the causal role of individual and age-related differences in working memory (WM) capacity in long-term memory (LTM) retrieval. Our sample of 160 participants included 120 children (6-13-years old) and 40 young adults (18-24 years). Participants performed a WM task with images of unique everyday items, presented at varying set sizes. Subsequently, we tested participants' LTM for items from the WM task. Using these measures, we estimated the ratio at which items successfully held in WM were recognized in LTM. While WM and LTM generally improved with age, the ability to transfer information from WM to LTM appeared consistent between age groups. Moreover, individual differences in WM capacity appeared to predict LTM encoding. Overall, these results suggested that LTM performance was constrained by experimental, individual, and age-related WM limitations. We discuss the theoretical and practical implications of this WM-to-LTM bottleneck.

Are Individuals Always Aware of Their Trauma-Related Intrusive Thoughts? A Study of Meta-Awareness

Individuals are not always aware of their mental content. We tested whether lack of awareness occurs in those who have experienced trauma, with and without posttraumatic stress disorder (PTSD). We also examined the role of proposed cognitive mechanisms (working memory and inhibition) in explaining unnoticed intrusions. Individuals with PTSD (n = 44), and varying levels of symptoms (high posttraumatic stress [PTS]: n = 24; low PTS: n = 37) reported on intrusive thoughts throughout a reading task. Intermittently, participants responded to probes about whether their thoughts were trauma related. Participants were "caught" engaging in unreported trauma-related thoughts (unnoticed intrusions) for between 24 and 27% of the probes in the PTSD and high PTS groups, compared with 15% of occasions in the low PTS group. For trauma-related intrusions only, participants lacked meta-awareness for almost 40% of probes in the PTSD group, which was significantly less than that observed in the other groups (∼60%). Contrary to predictions, working memory and response inhibition did not predict unnoticed intrusions. The results suggest that individuals who have experienced significant trauma can lack awareness about the frequency of their trauma-related thoughts. Further research is warranted to identify the mechanisms underpinning the occurrence of unnoticed intrusions.

Complexity of interruptions: Evidence supporting a non-interruption-based theory

Interruptions are known to be pervasive and harmful for concentration. It is also known that many factors can influence their effect, such as the complexity of the interrupting task. Less, however, is known about the processes underlying the resumption of the primary task, especially if the interrupting task is complex. Many hypotheses have been proposed but, as yet, it has not been possible to distinguish between their various qualities. In the current study, we carried out two experiments in which we manipulated the complexity of the interrupting task (either simple or complex) and the time between the end of the interrupting task and the resumption of the primary task (i.e., a break). Results showed that complex interrupting tasks led to longer resumption lags (RL) when there was no break, as has already been shown many times. However, while RL after simple interrupting tasks did not change as the break before resumption lengthened up to 1,500 ms, those after complex interrupting tasks decreased. Moreover, after a break of 3,000 ms, RL were longer overall. These results can only support the hypothesis based on task-switching theories, but not hypotheses derived from interruption-based models. Our findings therefore provide empirical evidence in support of explanations of complexity effects and the implications for research and application are discussed.

Genetic Associations Between Executive Functions and a General Factor of Psychopathology

OBJECTIVE

Symptoms of psychopathology covary across diagnostic boundaries, and a family history of elevated symptoms for a single psychiatric disorder places an individual at heightened risk for a broad range of other psychiatric disorders. Both twin-based and genome-wide molecular methods indicate a strong genetic basis for the familial aggregation of psychiatric disease. This has led researchers to prioritize the search for highly heritable childhood risk factors for transdiagnostic psychopathology. Cognitive abilities that involve the selective control and regulation of attention, known as executive functions (EFs), are a promising set of risk factors.

METHOD

In a population-based sample of child and adolescent twins (n = 1,913, mean age = 13.1 years), we examined genetic overlap between both EFs and general intelligence (g) and a transdiagnostic dimension of vulnerability to psychopathology, comprising symptoms of anxiety, depression, neuroticism, aggression, conduct disorder, oppositional defiant disorder, hyperactivity, and inattention. Psychopathology symptoms in children were rated by children and their parents.

RESULTS

Latent factors representing general EF and g were highly heritable (h2 = 86%-92%), and genetic influences on both sets of cognitive abilities were robustly correlated with transdiagnostic genetic influences on psychopathology symptoms (genetic r values ranged from -0.20 to -0.38).

CONCLUSION

General EF and g robustly index genetic risk for transdiagnostic symptoms of psychopathology in childhood. Delineating the developmental and neurobiological mechanisms underlying observed associations between cognitive abilities and psychopathology remains a priority for ongoing research.

When working memory mechanisms compete: Predicting cognitive flexibility versus mental set

Cognitive flexibility is a hallmark of individuals with higher working memory capacity (WMC). Yet, individuals with higher WMC sometimes demonstrate greater rigidity in problem solving. The present research examines a novel account for these contradictory findings-that different WMC mechanisms support versus constrain cognitive flexibility. Across three studies, participants completed the water jug task-a problem-solving task requiring them to first establish and then break mental set. Predictor measures targeted three WMC mechanisms: attention control, primary memory, and secondary memory. In Study 1, primary and secondary memory predicted breaking mental set in opposite directions. Higher primary memory facilitated breaking mental set, whereas higher secondary memory hindered it. Study 2 demonstrated that attention control moderates these effects. Study 3 replicated these results using a less restrictive sampling procedure (i.e., participants were provided the strategy needed to establish mental set). The present research supports the proposed theory of functional opponency in WMC.

ASPM-lexical tone association in speakers of a tone language: Direct evidence for the genetic-biasing hypothesis of language evolution

How language has evolved into more than 7000 varieties today remains a question that puzzles linguists, anthropologists, and evolutionary scientists. The genetic-biasing hypothesis of language evolution postulates that genes and language features coevolve, such that a population that is genetically predisposed to perceiving a particular linguistic feature would tend to adopt that feature in their language. Statistical studies that correlated a large number of genetic variants and linguistic features not only generated this hypothesis but also specifically pinpointed a linkage between ASPM and lexical tone. However, there is currently no direct evidence for this association and, therefore, the hypothesis. In an experimental study, we provide evidence to link ASPM with lexical tone perception in a sample of over 400 speakers of a tone language. In addition to providing the first direct evidence for the genetic-biasing hypothesis, our results have implications for further studies of linguistic anthropology and language disorders.

Severity of Topiramate-Related Working Memory Impairment Is Modulated by Plasma Concentration and Working Memory Capacity

Drug side effects that impair cognition can lead to diminished quality of life and discontinuation of therapy. Topiramate is an antiepileptic drug that elicits cognitive deficits more frequently than other antiepileptic drugs, impairing multiple cognitive domains including language, attention, and memory. Although up to 40% of individuals taking topiramate may experience cognitive deficits, we are currently unable to predict which individuals will be most severely affected before administration. The objective of this study was to show the contributions of plasma concentration and working memory capacity in determining the severity of an individual's topiramate-related cognitive impairment. Subjects were enrolled in a double-blind, placebo-controlled crossover study during which they received a single dose of either 100, 150, or 200 mg topiramate. Working memory function was assessed using a modified Sternberg working memory task with 3 memory loads administered 4 hours after dosing. After adjustment for differences in working memory capacity, each 1 μg/mL of topiramate plasma concentration was associated with a 3.6% decrease in accuracy for all memory loads. Placebo effects occurred as a function of working memory capacity, with individuals with high working memory capacity experiencing less severe placebo-related impairment compared with those with low working memory capacity. Our results demonstrate that severity of topiramate-related cognitive deficits occurs as a function of both drug exposure and baseline cognitive function. By identifying patient- and exposure-related characteristics that modulate the severity of cognitive side effects, topiramate dosing strategies may be individually tailored in the future to prevent unwanted cognitive impairment.

Developmental transformations in the structure of executive functions

Comparisons of results from studies of executive function (EF) in early childhood to those of EF in middle and late childhood suggest that individual differences in EFs may differentiate from a unitary factor in early childhood to an increasingly multidimensional structure in middle childhood and adolescence. We tested whether associations among EFs strengthened from middle childhood to adolescence using cross-sectional data from a population-based sample of 1019 children aged 7-15 years (M = 10.79 years). Participants completed a comprehensive EF battery consisting of 15 measures tapping working memory, updating, switching, and inhibition domains. Moderated factor analysis, local structural equation modeling, and network modeling were applied to assess age-related differences in the factor structure of EF. Results from all three approaches indicated that working memory and updating maintained uniformly high patterns of covariation across the age range, whereas inhibition became increasingly differentiated from the other three domains beginning around 10 years of age. However, consistent with past research, inhibition tasks were only weakly intercorrelated. Age-related differences in the organization of switching abilities were mixed.

The time course of updating in running span

Running span can be performed by either passively listening to memory items or actively updating the target set. Previous research suggests that the active updating process is demanding and time consuming and is favored at slow rates of presentation while the passive strategy is employed at fast rates. Two experiments examined the time course of recruitment of resources during task performance and its sensitivity to presentation rate. In Experiment 1, participants performed 1 of 3 serial recall tasks: running span, simple span, and modified span. The tasks were completed at the same time as a choice reaction time (RT; CRT) task and the RTs were used to index the resource demands of the memory task. Running span generated higher RT costs than simple span. The costs were present only for positions at and beyond the point in the sequence when the target memory set was changed, indicating a shift to a more cognitively demanding mode of updating. At these positions there was a generalized increase in RT costs that peaked 1,000 ms following item presentation. In Experiment 2 the resource demands of running span varied with presentation rate and a peak demand at 1,000 ms was again evident, but only with a slow presentation rate. In conjunction with strategy reports, these data establish that the process of active updating in running span is slow and cognitively demanding, making it difficult to use when presentation rates are fast.

Relation Between Working Memory Capacity of Biological Movements and Fluid Intelligence

Studies have revealed that there is an independent buffer for holding biological movements (BM) in working memory (WM), and this BM-WM has a unique link to our social ability. However, it remains unknown as to whether the BM-WM also correlates to our cognitive abilities, such as fluid intelligence (Gf). Since BM processing has been considered as a hallmark of social cognition, which distinguishes from canonical cognitive abilities in many ways, it has been hypothesized that only canonical object-WM (e.g., memorizing color patches), but not BM-WM, emerges to have an intimate relation with Gf. We tested this prediction by measuring the relationship between WM capacity of BM and Gf. With two Gf measurements, we consistently found moderate correlations between BM-WM capacity, the score of both Raven's advanced progressive matrix (RAPM), and the Cattell culture fair intelligence test (CCFIT). This result revealed, for the first time, a close relation between WM and Gf with a social stimulus, and challenged the double-dissociation hypothesis for distinct functions of different WM buffers.

Genetic overlap between executive functions and BMI in childhood

BACKGROUND

Executive functions (EFs) comprise a group of cognitive processes that selectively control and regulate attention. Inverse relations have been reported between EFs and BMI. However, the mechanisms underlying this association are not well understood.

OBJECTIVES

We aimed to decompose the inverse relation between EFs and BMI into genetic and environmental components.

METHODS

We employed a cross-sectional analysis of data from 869 twins aged 7-15 y from the Texas Twin Project, who completed a neuropsychological test battery measuring 4 EFs (switching, inhibitory control, working memory, and updating); academic achievement (reading and mathematics); and general cognitive abilities (general intelligence/intelligence quotient; crystallized and fluid intelligence; and processing speed). Participants also had their height and weight measured.

RESULTS

After controlling for age, sex, and race/ethnicity, BMI was inversely associated with a general EF factor representing the capacity to control and regulate goal-oriented behaviors (r = -0.125; P = 0.01; Q = 0.04). This inverse BMI-EF association was due to a significant overlap in genetic factors contributing to each phenotype (genetic correlation, rA, = -0.15; P < 0.001). Shared genetic influences accounted for 80% of the phenotypic association.

CONCLUSIONS

Children with higher general EF have lower BMIs, and this association is primarily attributable to shared genetic influences on both phenotypes. The results emphasize that higher weight associates not only with physical sequelae, but also with important cognitive attributes. This work adds to a growing body of research suggesting there are sets of genetic variants common across physical health and cognitive functioning.

A Validation Study of the German Complex-Span Tasks and Some General Considerations on Task Translation Procedures in Cognitive Psychology

Abstract. Automated complex-span tasks are widely used to assess working-memory capacity and the English versions show good psychometric properties ( Unsworth, Heitz, Schrock, & Engle, 2005 ). However, it is generally an open question whether translated task versions have the same properties as the original versions and whether results obtained with translated tasks can be interpreted equivalently to those obtained with the original tasks. We translated the complex-span tasks and had a sample of German participants perform these tasks as well as a running-memory-span task and a reasoning test. We assessed the reliabilities of the German complex-span tasks and their construct and criterion-related validities. Extrapolating from cross-cultural literature, we also employed a test of measurement invariance to compare the correlational patterns as well as the construct structure between the German sample and a similar North-American sample. Results show that the German complex-span tasks are reliable and valid indicators of working-memory capacity and that they are metrically and functionally equivalent to the original versions. As measurement equivalence is an important but often neglected topic in basic cognitive psychology, we also highlight the general benefits of using equivalence tests when translating cognitive tasks.

Working Memory Impairment Across Psychotic disorders

BACKGROUND

Working memory (WM) has been a central focus of cognitive neuroscience research because WM is a resource that is involved in many different cognitive operations. The goal of this study was to evaluate the clinical utility of WM paradigms developed in the basic cognitive neuroscience literature, including methods designed to estimate storage capacity without contamination by lapses of attention.

METHODS

A total of 61 people with schizophrenia, 49 with schizoaffective disorder, 47 with bipolar disorder with psychosis, and 59 healthy volunteers were recruited. Participants received multiple WM tasks, including two versions each of a multiple Change Detection paradigm, a visual Change Localization paradigm, and a Running Span task.

RESULTS

Healthy volunteers performed better than the combined patient group on the visual Change Localization and running span measures. The multiple Change Detection tasks provided mixed evidence about WM capacity reduction in the patient groups, but a mathematical model of performance suggested that the patient groups differed from controls in their rate of attention lapsing. The 3 patient groups performed similarly on the WM tasks. Capacity estimates from the Change Detection and Localization tasks showed significant correlations with functional capacity and functional outcome.

CONCLUSIONS

The patient groups generally performed in a similarly impaired fashion across tasks, suggesting that WM impairment and attention lapsing are general features of psychotic disorders. Capacity estimates from the Change Localization and Detection tasks were related to functional capacity and outcome, suggesting that these methods may be useful in a clinical context.

The Influence of Individual Differences in Cognitive Ability on Working Memory Training Gains

Working memory training research has produced mixed results in terms of finding benefits beyond the trained tasks (i.e., transfer). One potential limitation is that the research thus far has failed to isolate the specific combination of factors that makes working memory training work best. Individual differences in cognitive ability at pretest may be an important factor, suggesting possible aptitude-by-treatment interactions. Baseline cognitive ability could be (a) positively related, (b) negatively related, or (c) unrelated to training task improvements. The relationship between ability and training gains is important given the idea that larger training improvements should lead to greater transfer. However, the majority of training studies tend to be under-powered to examine individual differences. We pooled studies conducted in related labs to increase power while minimizing differences between studies. In the studies that were identified for this project, young adults completed complex span training and working memory and/or fluid intelligence as pretest measures. The combined samples from seven studies resulted in a sample of 192 participants. Analyses focused on the relationship between pretest cognitive ability and training performance across training days. There was no evidence that individuals lower in cognitive ability improved more than high-ability subjects on the training tasks. Instead, we found a positive relationship for both working memory and fluid intelligence measured at pretest with the amount of training improvement. In addition, the association between pretest working memory and working memory training performance appears to be domain-general - verbal and visuospatial content do not produce differential relationships.

"Same but different": Associations between multiple aspects of self-regulation, cognition, and academic abilities

Self-regulation describes the ability to control both behaviors and internal states against a backdrop of conflicting or distracting situations, drives, or impulses. In the cognitive psychology tradition, individual differences in self-regulation are commonly measured with performance-based tests of executive functioning, whereas in the personality psychology tradition, individual differences in self-regulation are typically assessed with report-based measures of impulse control, sustained motivation, and perseverance. The goal of this project was (a) to comprehensively examine the structure of associations between multiple self-regulatory constructs stemming from the cognitive and personality psychology traditions; (b) to estimate how these constructs, individually and collectively, related to mathematics and reading ability beyond psychometric measures of processing speed and fluid intelligence; and (c) to estimate the extent to which genetic and environmental factors mediated the observed associations. Data were available for 1,019 child participants from the Texas Twin Project (M age = 10.79, range = 7.8-15.5). Results highlighted the differentiation among cognitive and personality aspects of self-regulation, both at observed and genetic levels. After accounting for processing speed and fluid intelligence, EF remained a significant predictor of reading and mathematics ability. Educationally relevant measures of personality-particularly an openness factor representing curiosity and intellectual self-concept-incrementally contributed to individual differences in reading ability. Collectively, measures of cognition, self-regulation, and other educationally relevant aspects of personality accounted for the entirety of genetic variance in mathematics and reading ability. The current findings point to the important independent role that each construct plays in academic settings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Working memory span tasks: Group administration and omitting accuracy criterion do not change metric characteristics

The study examined the psychometric characteristics of three automated working memory span tasks: operational, reading, and symmetry span task, administered in groups of participants. For each task, the metric characteristics of six scoring procedures were evaluated: partial, absolute, partial non-weighted, absolute non-weighted, partial weighted, and absolute weighted scoring. Metric characteristics of all measures were compared across two parallel analyses: with and without application of a typical 85% accuracy criterion on the processing component of the tasks. The study demonstrates that the group administration of span tasks does not compromise their psychometric characteristics. All the tasks had an adequate internal consistency with Cronbach’s αs equal to or above .70; the exception being all types of the symmetry span task absolute scores with α values close to .60. Furthermore, all tasks have satisfactory convergent construct validity as well as criterion validity estimated in relation to measures of fluid intelligence. Omitting the 85% accuracy criterion on the processing component of the span tasks did not impair their psychometric properties. Thus, it is recommended that researchers discard this accuracy criterion as a criterion for filtering the results for further statistical analyses.

The Reciprocal Influences of Working Memory and Linguistic Knowledge on Language Performance: Considerations for the Assessment of Children With Developmental Language Disorder

Purpose

This article considers how the language performance of school-age children with language impairments, such as developmental language disorder, is influenced by the reciprocal relationship of existing linguistic knowledge and working memory resources and the resultant implications for assessment.

Method

A viewpoint is provided by reviewing working memory theory, empirical evidence of the reciprocal relationship between working memory and existing language knowledge, and critically evaluating available standardized and nonstandardized tools designed to assess working memory or linguistic skills.

Conclusions

Speech-language pathologists with an excellent understanding of the reciprocal relationship between working memory and linguistic knowledge will need to examine performance across tasks and contexts varying in these demands in order to achieve an accurate clinical profile of relevant strengths and weaknesses for individual children.

How Does Consecutive Interpreting Training Influence Working Memory: A Longitudinal Study of Potential Links Between the Two

With an intention to contribute to the issue of how language experience may influence working memory (WM), we focused on consecutive interpreting (CI), analyzed its potential links with WM functions and tested these links in a longitudinal experiment, trying to answer the specific question of how CI training may influence WM. Two comparable groups of Chinese learners of English received either CI or general second language (L2) training for one semester, and were tested before and after the training with the tasks of n-back (non-verbal updating), L2 listening span, and letter running span (verbal spans). CI performance was tested in the posttest. The results showed that (1) updating efficiency in both the pretest and posttest predicted CI performance, and CI training enhanced updating efficiency while general L2 training did not; (2) the relationship between verbal spans and CI performance was weaker (i.e., only pretest L2 listening span correlated with CI performance and predicted CI performance with marginal significance), and CI training did not make a unique contribution to these spans (i.e., no group differences). The results indicated an "interpreter advantage" in updating, which was probably due to that updating was more central in the CI task than WM spans. Theoretically, we believe that updating and CI are closely related because they share the same underlying mechanism, or more specifically updating and the recalling process in the CI task share the same attentional control process, a unique link between updating and the CI task. Methodological implications are discussed.

Are training and transfer effects of working memory updating training modulated by achievement motivation?

Previous studies examining effects of working memory (WM) updating training revealed mixed results. One factor that might modulate training gains, and possibly also transfer of those gains to non-trained cognitive tasks, is achievement motivation. In the present Studies 1 and 2, students with either a high (HAM) or low (LAM) achievement motivation completed a 14-day visuospatial WM updating training program. In Study 2, the students also performed a set of tasks measuring other executive functions and fluid intelligence prior to and after training. In both studies, the HAM students displayed a larger training gain than the LAM students. Study 2 revealed that after training, both groups showed better performance on the near-transfer but not far-transfer tasks. Importantly, the differential training gain was not associated with better post-training performance for the HAM compared to the LAM students on any of the transfer tasks. These results are taken to support a modulatory role of achievement motivation on WM training benefits, but not on transfer of those benefits to other tasks. Possible reasons for the general improvement on the near-transfer tasks and the absence of a modulatory role of achievement motivation on transfer-task performance are discussed.

The Dorsal Attention Network Reflects Both Encoding Load and Top–down Control during Working Memory

The dorsal attention network is consistently involved in verbal and visual working memory (WM) tasks and has been associated with task-related, top–down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top–down strategic control. We examined the role of the dorsal attention network in encoding load and top–down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top–down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner.

Working memory capacity and the antisaccade task: A microanalytic-macroanalytic investigation of individual differences in goal activation and maintenance

The association between working memory capacity (WMC) and the antisaccade task, which requires subjects to move their eyes and attention away from a strong visual cue, supports the claim that WMC is partially an attentional construct (Kane, Bleckley, Conway, & Engle, 2001; Unsworth, Schrock, & Engle, 2004). Specifically, the WMC-antisaccade relation suggests that WMC helps maintain and execute task goals despite interference from habitual actions. Related work has recently shown that mind wandering (McVay & Kane, 2009, 2012a, 2012b) and reaction time (RT) variability (Unsworth, 2015) are also related to WMC and they partially explain WMC's prediction of cognitive abilities. Here, we tested whether mind-wandering propensity and intraindividual RT variation account for WMC's associations with 2 antisaccade-cued choice RT tasks. In addition, we asked whether any influences of WMC, mind wandering, or intraindividual RT variation on antisaccade are moderated by (a) the temporal gap between fixation and the flashing location cue, and (b) whether targets switch sides on consecutive trials. Our quasi-experimental study reexamined a published dataset (Kane et al., 2016) comprising 472 subjects who completed 6 WMC tasks, 5 attentional tasks with mind-wandering probes, 5 tasks from which we measured intraindividual RT variation, and 2 antisaccade tasks with varying fixation-cue gap durations. The WMC-antisaccade association was not accounted for by mind wandering or intraindividual RT variation. WMC's effects on antisaccade performance were greater with longer fixation-to-cue intervals, suggesting that goal activation processes-beyond the ability to control mind wandering and RT variability-are partially responsible for the WMC-antisaccade relation. (PsycINFO Database Record

Item-method directed forgetting and working memory capacity: A hierarchical multinomial modeling approach

Intentional forgetting of information that has recently been encoded is regarded an active and adaptive process and is widely studied using the item-method or the list-method directed forgetting (DF) paradigm. In the present research, we tested whether inter-individual differences in working-memory capacity (WMC), that have been identified as a relevant predictor of DF within the list method, are also related to stronger DF effects within the item method. Furthermore, we investigated relationships between WMC and item-method DF at different processing stages by applying the multinomial storage–retrieval model hierarchically to our data. Results showed that individuals with high WMC are better able to store to-be-remembered information than individuals with low WMC, whereas WMC was not related to retrieval of to-be-remembered information or to either storage or retrieval of to-be-forgotten information. Implications for theoretical accounts of item-method DF are discussed.

Variation in strategy use across measures of verbal working memory

The working memory (WM) literature contains a number of tasks that vary on dimensions such as when or how memory items are reported. In addition to the ways in which WM tasks are designed to differ, tasks may also diverge according to the strategies participants use during task performance. The present study included seven tasks from the WM literature, each requiring short-term retention of verbal items. Following completion of a small number of trials from each task, individuals completed a self-report questionnaire to identify their primary strategy. Results indicated substantial variation across individuals for a given task, and within the same individual across tasks. Moreover, while direct comparisons between tasks showed that some tasks evinced similar patterns of strategy use despite differing task demands, others showed markedly different patterns of self-reported strategy use. A community detection algorithm, aimed at identifying groups of individuals based on their profile of strategic choices, revealed unique communities of individuals who are dependent on specific strategies under varying demands. Together, the findings suggest that researchers using common WM paradigms should very carefully consider the implications of variation in strategy use when interpreting their findings.