Working memory and intelligence are highly related constructs, but why?

Individual differences in attention control: A meta-analysis and re-analysis of latent variable studies

A meta-analysis and re-analysis of prior latent variable studies was conducted in order to assess whether there is evidence for individual differences in broad attention control abilities. Data from 90 independent samples and over 23,000 participants suggested that most (84.4%) prior studies find evidence for a coherent attention control factor with average factor loadings of .51. This latent attention control factor was related to other cognitive ability factors including working memory, shifting, fluid intelligence, long-term memory, reading comprehension, and processing speed, as well as to self-reports of task-unrelated thoughts and task specific motivation. Further re-analyses and meta-analyses suggest that the results remained largely unchanged when considering various possible measurement issues. Examining the factor structure of attention control suggested evidence for sub-components of attention control (restraining, constraining and sustaining attention) which could be accounted for a by a higher-order factor. Additional re-analyses suggested that attention control represents a broad ability within models of cognitive abilities. Overall, these results provide evidence for attention control abilities as an important individual differences construct.

Effects of psychopathic traits on preferential recall and recognition of emotionally evocative photos

Psychopathic traits are associated with impaired emotional processing. The present study examines the potential association between psychopathic traits and memory for emotional stimuli. Although a significant body of research suggests that memory is heightened for emotional stimuli, it is unclear how psychopathic traits may disrupt this process. Eighty-two male jail inmates completed an emotional memory task as well as portions of a standardised memory assessment. Psychopathic traits were not associated with the ability to freely recall images of positive, negative or neutral valence that participants had seen more than 15 min prior; psychopathic traits were also not associated with the ability to recognise these previously viewed images when shown them again. Exploratory analyses indicated trends toward reduced accuracy in recognising both positive and negative, but not neutral, emotional stimuli in individuals with higher levels of interpersonal and affective traits of psychopathy. As expected, psychopathy was unrelated to non-emotion-related memory functioning in auditory and visual domains as measured by the Wechsler Memory Scales 4th Edition. Overall, these results do not support the hypothesis that psychopathic traits significantly interfere with memory for emotional stimuli.

Using the Indonesian Computer-Based Game Prototype as a Computer-Based Game Inventory for Executive Function in Children and Adolescents: A Confirmatory Factor Analysis and Concurrent Validity Study

Executive function influences children's learning abilities and organizes their cognitive processes, behaviors, and emotions. This cross-sectional study examined whether an Indonesian Computer-Based Game (ICbG) prototype could be used as a Computer-Based Game Inventory for Executive Function (CGIEF) in children and adolescents. The study was conducted with 200 children, adolescents, and their parents. The parents completed the Behavior Rating Inventory of Executive Functioning (BRIEF) questionnaire, and the children and adolescents completed the CGIEF. Confirmatory factor analysis (CFA) and structural equation modeling (SEM) were performed using LISREL Version 8.80. The construct of CGIEF was valid/fit with normal theory-weighted least squares = 15.75 (p > .05). SEM analysis showed that the theoretical construct of the CGIEF was a valid predictor of executive function. The critical t value of the pathway was 2.45, and normal theory-weighted least squares was 5.74 (p > .05). The construct reliability (CR) for CGIEF was 0.91. Concurrent validity was assessed using the Bland-Altman plot, and the coefficient of repeatability (bias/mean) was nearly zero between the t scores of total executive functions of the CGIEF and BRIEF. This preliminary study showed that the CGIEF can be useful as a screening tool for executive dysfunction, metacognitive deficits, and behavioral regulation problems among children and adolescents in clinical samples.

Neural correlates of intelligence: ERP Components of temporary storage predict fluid intelligence over and above those of executive functions

Previous research has revealed that individuals with different levels of intelligence exhibit distinct patterns of event-related potentials (ERPs) related to executive functions and temporary storage. However, there is a lack of studies investigating the relative contributions of these ERPs in predicting individual differences in fluid intelligence. This study aims to examine the extent to which ERPs associated with executive functions and temporary storage can predict individual differences in fluid intelligence. Special attention is given to determining whether electrophysiological activities of temporary storage can predict fluid intelligence after accounting for executive functions, and vice versa. Both executive attention and temporary storage were measured by two experimental tasks, while electroencephalographic data were collected simultaneously. Fluid intelligence was assessed by two established tests. To address previous inconsistencies due to small sample sizes, a relatively large sample of young adults (N = 136) was recruited. The results revealed that participants with lower fluid intelligence displayed larger P3 amplitudes in the executive functions and temporary storage tasks compared to those with higher fluid intelligence. Additionally, the amplitudes of frontal and parietal P3s elicited by both executive functions and temporary storage significantly predicted fluid intelligence. Interestingly, the frontal and parietal P3s associated with temporary storage predicted fluid intelligence beyond the contributions of executive functions, supporting the storage account of individual differences in fluid intelligence. This study provides an original and fresh understanding of how executive functions and temporary storage contribute to fluid intelligence, offering new insights into the neurocognitive mechanisms underlying intelligence.

Neuropsychological Assessment of the Relationship of Working Memory with K-BIT Matrices and Vocabulary in Normal Development and ADHD Children and Adolescents

BACKGROUND

The present report tries to understand the possible relationship between working memory (WM) and intelligence measurements, using the direct scores of the Working Memory Test Battery for Children (WMTBC) and Kaufman's Brief Intelligence Test (K-BIT), in normal development (ND) and diagnosed attention deficit hyperactivity disorder (ADHD) children and adolescents.

RESULTS

Partial correlations, discounting the effect of age, showed a significant correlation in ND subjects between the central executive (CE) component of WM and the WM visuospatial sketchpad (VSS) component and the WM phonological loop (PL); also, significant correlations were obtained for the WM VSS with the K-BIT Matrices scores, the WM PL with the K-BIT Vocabulary, and the K-BIT Matrices scores with the K-BIT Vocabulary. For ADHD subjects, there were significant correlations between WM VSS and WM CE, and WM VSS and K-BIT Matrices. We tested the robustness of these correlations by selecting a small number of subjects through permutations; a robust correlation between WM CE and WM PL in ND, and between WM VSS and WM CE and WM VSS and K-BIT Matrices scores was obtained. These results were also supported by mediation analysis.

CONCLUSIONS

There is a relationship during development between WM as measured with WMTBC and general intelligence as measured with K-BIT in ND and ADHD subjects. The dysexecutive character of ADHD has been shown, given that by controlling for intelligence, the differences in WM performance between ND and ADHD disappear, except for WM CE. The results suggest that in ADHD subjects, the WM VSS component presents a more pivotal role during cognitive processing compared to ND subjects.

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.

Executive Functions Training for 7- to 10-Year-Old Students With Mathematics Difficulty: Instant Effects and 6-Month Sustained Effects

Executive function (EF) training has shown promise for remedying general EF deficiencies faced by students with mathematics difficulty (MD) and for improving their performance. However, latest research also suggests that the instant and sustained effects of EF training remain inconsistent. In this study, 32 Chinese students with MD, age 7 to 10 years, were recruited and randomly divided into two groups: the training group (n = 16, 25 training sessions) and the control group (n = 16). Both groups took a pretest, a posttest, and a follow-up test (after 6 months) on EF, fluid intelligence, and mathematics skills. In the posttest, the training group's performance significantly improved in 2-back, number shifting, letter shifting, calculation fluency, and mathematics problem-solving tasks, but not in Stroop, Flanker, 1-back, numerical operations, and colored progressive matrices tasks. In the follow-up test after 6 months, the effects of training only on the 2-back and letter shifting tasks were sustained. The effect on the numerical operations task appeared; however, the effects on number shifting, calculation fluency, and mathematics problem-solving tasks disappeared. The results of this study show that EF training has instant effects of improving EF and mathematics skills of students with MD, and 6-month sustained effects on some of the improved skills. However, for fluid intelligence, the effects may be very limited.

Working memory load affects intelligence test performance by reducing the strength of relational item bindings and impairing the filtering of irrelevant information

There is a broad consensus that individual differences in working memory capacity (WMC) are strongly related to individual differences in intelligence. However, correlational studies do not allow conclusions about the causal nature of the relationship between WMC and fluid intelligence. While research on the cognitive basis of intelligence typically assumes that simpler lower-level cognitive processes contribute to individual differences in higher-order reasoning processes, a reversed causality or a third variable giving rise to two intrinsically uncorrelated variables may exist. In two studies (n₁ = 65, n₂ = 113), we investigated the causal nature of the relationship between WMC and intelligence by assessing the experimental effect of working memory load on intelligence test performance. Moreover, we tested if the effect of working memory load on intelligence test performance increased under time constraints, as previous studies have shown that the association between the two constructs increases if intelligence tests are administered with a strict time limit. We show that working memory load impaired intelligence test performance, but that this experimental effect was not affected by time constraints, which suggests that the experimental manipulations of working memory capacity and processing time did not affect the same underlying cognitive process. Using a computational modeling approach, we demonstrated that external memory load affected both the building and maintenance of relational item bindings and the filtering of irrelevant information in working memory. Our results confirm that WMC causally contributes to higher-order reasoning processes. Moreover, they support the hypothesis that working memory capacity in general and the abilities to maintain arbitrary bindings and to disengage from irrelevant information in particular are intrinsically related to intelligence.

The Evolution of Intelligence: Analysis of the Journal of Intelligence and Intelligence

What are the current trends in intelligence research? This parallel bibliometric analysis covers the two premier journals in the field: Intelligence and the Journal of Intelligence (JOI) between 2013 and 2022. Using Scopus data, this paper extends prior bibliometric articles reporting the evolution of the journal Intelligence from 1977 up to 2018. It includes JOI from its inception, along with Intelligence to the present. Although the journal Intelligence's growth has declined over time, it remains a stronghold for traditional influential research (average publications per year = 71.2, average citations per article = 17.07, average citations per year = 2.68). JOI shows a steady growth pattern in the number of publications and citations (average publications per year = 33.2, average citations per article = 6.48, total average citations per year = 1.48) since its inception in 2013. Common areas of study across both journals include cognitive ability, fluid intelligence, psychometrics-statistics, g-factor, and working memory. Intelligence includes core themes like the Flynn effect, individual differences, and geographic IQ variability. JOI addresses themes such as creativity, personality, and emotional intelligence. We discuss research trends, co-citation networks, thematic maps, and their implications for the future of the two journals and the evolution and future of the scientific study of intelligence.

Assessing IQ in adolescents with mild to moderate cerebral palsy using the WISC-V

Objective: To examine the influence of subtests that require fine motor responses on measures of intellectual ability, and compare three approaches to minimizing motor demands while assessing cognitive abilities in adolescents with cerebral palsy (CP) to the traditional method of the Wechsler Intelligence Scale for Children - Fifth edition (WISC-V). Method: Seventy adolescents with CP (M = 14 years 6 months, SD = 10 months) who were able to provide either a verbal or point response were assessed using the WISC-V administered via Q-interactive. The pencil-to-paper version of Coding was also administered. Performance on Block Design and pencil-to-paper Coding was compared to Visual Puzzles and Coding on Q-interactive, respectively. Full Scale IQ (FSIQ) scores derived according to the Traditional method of the WISC-V were compared to alternative estimates of FSIQ derived according to the Q-interactive, Nonmotor, and Motor-free methods, which minimized motor demands. Results: An additional 7-12% of participants were able to respond to Visual puzzles and Coding on Q-interactive compared to Block Design and pencil-to-paper Coding, respectively, and performance was marginally but significantly better. For 54 adolescents (Gross Motor Function Classification System (GMFCS) Level I-III) who were able to obtain FSIQ scores, the Traditional method underestimated FSIQ by 3-6 points compared to the alternative methods and the difference was most pronounced for those with more severe CP as measured by the GMFCS. Conclusion: Adolescents with CP are at an inherent disadvantage when cognitive ability is assessed using the Traditional method of the WISC-V. Findings suggest clinicians should employ the Nonmotor or Motor-free methods when assessing IQ in adolescents with CP.

The roles of familial transmission and smoking during pregnancy on executive function skills: A sibling-comparison study

This research examines maternal smoking during pregnancy and risk for poorer executive function in siblings discordant for exposure. Data (N = 173 families) were drawn from the Missouri Mothers and Their Children study, a sample, identified using birth records (years 1998-2005), in which mothers changed smoking behavior between two pregnancies (Child 1 [older sibling]: M age = 12.99; Child 2 [younger sibling]: M age = 10.19). A sibling comparison approach was used, providing a robust test for the association between maternal smoking during pregnancy and different aspects of executive function in early-mid adolescence. Results suggested within-family (i.e., potentially causal) associations between maternal smoking during pregnancy and one working memory task (visual working memory) and one response inhibition task (color-word interference), with increased exposure associated with decreased performance. Maternal smoking during pregnancy was not associated with stop-signal reaction time, cognitive flexibility/set-shifting, or auditory working memory. Initial within-family associations between maternal smoking during pregnancy and visual working memory as well as color-word interference were fully attenuated in a model including child and familial covariates. These findings indicate that exposure to maternal smoking during pregnancy may be associated with poorer performance on some, but not all skills assessed; however, familial transmission of risk for low executive function appears more important.

Cognitive segmentation and fluid reasoning in childhood

The ability to solve novel complex problems predicts success in a wide range of areas. Recent research suggests that the ability to cognitively segment complex problems into smaller parts constrains nonverbal reasoning in adults. This study aimed to test whether cognitively segmenting problems improves nonverbal reasoning performance for children as it does for adults. A total of 115 children aged 6-10 years completed two versions of a modified traditional matrix reasoning task in which demands on working memory, integration, and processing speed were minimised, such that the only significant requirement was to break each problem into its constituent parts. In one version of the task, participants were presented with a traditional 2×2 Matrix and asked to draw the missing matrix item into a response box below. In a second version, the problem was broken down into its component features across three separate cells, reducing the need for participants to segment the problem. As with adults, performance was better in the condition in which the problems were separated into component parts. Children with lower fluid intelligence did not benefit more in the separated condition than children with higher fluid intelligence, and there was no evidence that segmenting problems was more beneficial for younger than older children. This study demonstrates that cognitive segmentation is a critical component of complex problem-solving for children, as it is for adults. By forcing children to focus their attention on separate parts of a complex visual problem, their performance can be dramatically improved.

Fluid Intelligence Emerges from Representing Relations

Based on recent findings in cognitive neuroscience and psychology as well as computational models of working memory and reasoning, I argue that fluid intelligence (fluid reasoning) can amount to representing in the mind the key relation(s) for the task at hand. Effective representation of relations allows for enormous flexibility of thinking but depends on the validity and robustness of the dynamic patterns of argument–object (role–filler) bindings, which encode relations in the brain. Such a reconceptualization of the fluid intelligence construct allows for the simplification and purification of its models, tests, and potential brain mechanisms.

What components of working memory are associated with children's reading skills?

Working memory (WM) is a potentially important factor related to the development of and performance in reading skills. This study examined the differential relations between two components of the WM system (i.e., storage, processing) and reading. Latent variables were created based on data from 1900 children (1146 children in preschool-second grade and 754 children in third-fifth grade) recruited for a larger study concerning the development of reading comprehension. Results indicated that a general-specific model of WM was a good fit to the data and effectively isolated the variance unique to WM-processing from that of WM-storage. Using the general-specific model, relations between the components of WM and reading (e.g., reading comprehension, decoding) and reading-related (e.g., oral language, phonological awareness, nonverbal IQ) outcomes were examined. In contrast with previous studies that have suggested WM is consistently associated with reading comprehension, our findings indicate that both aspects of WM (i.e., storage, processing) operate primarily indirectly through foundational reading-related skills. In sum, the WM system is not specifically associated with reading comprehension as most of the effects of WM-processing are indirect via the effects on foundational reading-related skills.

Non-verbal intelligence outperforms selective attention in a visual short-term memory test

Short-term memory is a dynamic psychological process that operates within a network in which non-verbal intelligence and attentional domains are connected. However, no consensus has been reached about which process has the greatest effect on this memory ability, which was the main objective of the present study. A sample of 1448 Brazilian participants (mean age = 26.62 years, standard deviation = 9.97 years; 53.9% females) were collectively tested on pen-and-paper standardized and validated measures of selective (ROTAS-C), alternating (ROTAS-A), and divided (ROTAS-D) attention. They also performed the R1 Non-verbal Intelligence Test and a visual short-term memory test (Memória Visual de Curto Prazo [MEMORE] test). The statistical analyses consisted of a data mining procedure, in which exhaustive automatic selection screening was performed. The results were compared with Corrected Akaike Information Criteria. The linear model met the classic assumptions of ordinary least squares and only included main effects of selective attention (standardized β = 0.39) and non-verbal intelligence (standardized β = 0.37) as main predictors (F2,39 = 7.01, p < 0.01, adjusted R2 = 24%). The results are discussed within a cognitive psychology framework.

Network-wise surface-based morphometric insight into the cortical neural circuitry underlying irritability in adolescents

Previous studies examining structural brain correlates of irritability have taken a region-specific approach and have been relatively inconsistent. In a sample of adolescents with and without clinically impairing irritability, the current study examines: (i) cortical volume (CV) in canonical functional networks; (ii) the association between the CV of functional networks and severity of irritability; and (iii) the extent to which IQ mediates the association between structural abnormalities and severity of irritability. Structural MRI and IQ data were collected from 130 adolescents with high irritability (mean age = 15.54±1.83 years, 58 females, self-reported Affective Reactivity Index [ARI] ≥ 4) and 119 adolescents with low irritability (mean age = 15.10±1.93 years, 39 females, self-reported ARI < 4). Subject-specific network-wise CV was estimated after parcellating the whole brain into 17 previously reported functional networks. Our Multivariate Analysis of Covariance (MANCOVA) revealed that adolescents with high irritability had significantly reduced CV of the bilateral control and default-mode networks (p < 0.05) relative to adolescents with low irritability. Multiple regression analyses showed a significant negative association between the control network CV and the severity of irritability. Mediation analysis showed that IQ partially mediated the association between the control network CV and the severity of irritability. Follow-up analysis on subcortical volume (SCV) showed that adolescents with high irritability had reduced bilateral SCV within the amygdala relative to adolescents with low irritability. Reduced CV within bilateral control and default networks and reduced SCV within bilateral amygdala may represent core features of the pathophysiology of irritability. The current data also indicate the potential importance of a patient's IQ in determining how pathophysiology related to the control network is expressed.

Is the n-back task a measure of unstructured working memory capacity? Towards understanding its connection to other working memory tasks

Working memory is fundamental to human cognitive functioning, and it is often measured with the n-back task. However, it is not clear whether the n-back task is a valid measure of working memory. Importantly, previous studies have found poor correlations with measures of complex span, whereas a recent study (Frost et al., 2019) showed that n-back performance was correlated with a transsaccadic memory task but dissociated from performance on the change detection task, a well-accepted measure of working memory capacity. To test whether capacity is involved in the n-back task we correlated a spatial version of the test with different versions of the change detection task. Experiment 1 introduced perceptual and cognitive disruptions to the change detection task. This impacted task performance, however, all versions of the change detection task remained highly correlated with one another whereas there was no significant correlation with the n-back task. Experiment 2 removed spatial and non-spatial context from the change detection task. This produced a correlation with n-back. Our results indicate that the n-back task is supported by faculties similar to those that support change detection, but that this commonality is hidden when contextual information is available to be exploited in a change detection task such that structured representations can form. We suggest that n-back might be a valid measure of working memory, and that the ability to exploit contextual information is an important faculty captured by some versions of the change detection task.

In Search of the Executive Cognitive Processes Proposed by Process-Overlap Theory

Process-Overlap Theory (POT) suggests that measures of cognitive abilities sample from sets of independent cognitive processes. These cognitive processes can be separated into domain-general executive processes, sampled by the majority of cognitive ability measures, and domain-specific processes, sampled only by measures within a certain domain. According to POT, fluid intelligence measures are related because different tests sample similar domain-general executive cognitive processes to some extent. Re-analyzing data from a study by De Simoni and von Bastian (2018), we assessed domain-general variance from executive processing tasks measuring inhibition, shifting, and efficiency of removal from working memory, as well as examined their relation to a domain-general factor extracted from fluid intelligence measures. The results showed that domain-general factors reflecting general processing speed were moderately and negatively correlated with the domain-general fluid intelligence factor (r = -.17--.36). However, domain-general factors isolating variance specific to inhibition, shifting, and removal showed only small and inconsistent correlations with the domain-general fluid intelligence factor (r = .02--.22). These findings suggest that (1) executive processing tasks sample only few domain-general executive processes also sampled by fluid intelligence measures, as well as (2) that domain-general speed of processing contributes more strongly to individual differences in fluid intelligence than do domain-general executive processes.

Intelligence test items varying in capacity demands cannot be used to test the causality of working memory capacity for fluid intelligence

There is a strong relationship between fluid intelligence and working memory capacity (WMC). Yet, the cognitive mechanisms underlying this relationship remain elusive. The capacity hypothesis states that this relationship is due to limitations in the amount of information that can be stored and held active in working memory. Previous research aimed at testing the capacity hypothesis assumed that it implies stronger relationships of intelligence test performance with WMC for test items with higher capacity demands. The present article addresses this assumption through simulations of three theoretical models implementing the capacity hypothesis while systematically varying different psychometric variables. The results show that almost any relation between the capacity demands of items and their correlation with WMC can be obtained. Therefore, the assumption made by previous studies does not hold: The capacity hypothesis does not imply stronger correlations of WMC and intelligence test items with higher capacity demands. Items varying in capacity demands cannot be used to test the causality of WMC (or any other latent variable) for fluid intelligence.

How Executive Processes Explain the Overlap between Working Memory Capacity and Fluid Intelligence: A Test of Process Overlap Theory

Working memory capacity (WMC) and fluid intelligence (Gf) are highly correlated, but what accounts for this relationship remains elusive. Process-overlap theory (POT) proposes that the positive manifold is mainly caused by the overlap of domain-general executive processes which are involved in a battery of mental tests. Thus, executive processes are proposed to explain the relationship between WMC and Gf. The current study aims to (1) achieve a relatively purified representation of the core executive processes including shifting and inhibition by a novel approach combining experimental manipulations and fixed-links modeling, and (2) to explore whether these executive processes account for the overlap between WMC and Gf. To these ends, we reanalyzed data of 215 university students who completed measures of WMC, Gf, and executive processes. Results showed that the model with a common factor, as well as shifting and inhibition factors, provided the best fit to the data of the executive function (EF) task. These components explained around 88% of the variance shared by WMC and Gf. However, it was the common EF factor, rather than inhibition and shifting, that played a major part in explaining the common variance. These results do not support POT as underlying the relationship between WMC and Gf.

Testing the attention-distractibility trait

Forster and Lavie (Journal of Experimental Psychology: Learning, Memory, and Cognition, 40[1], 251-260, 2014; Psychological Science, 27[2], 203-212, 2016) found that task-irrelevant distraction correlated positively with a measure of mind-wandering and a report of attention-deficit/hyperactivity disorder (ADHD) symptomology. Based primarily on these results, Forster and Lavie claimed to establish an attention-distractibility trait. Here, I tested whether these associations could be distinguished from associations with working memory capacity and task-relevant distraction (measured with an antisaccade task). With data collected from 226 subjects (ns differ among analyses), the results from the current study suggest that the measures of task-irrelevant distraction and working memory capacity were not (or only very weakly) associated with measures of mind wandering (measured both with a stand-alone questionnaire and in-task thought probes) and ADHD symptomology. Task-relevant interference (i.e., antisaccade accuracy) was associated with mind-wandering reports from in-task thought probes (presented in a separate task), but not the stand-alone mind wandering questionnaire or ADHD symptomology. Additionally, the measure of irrelevant-distraction exhibited low internal consistency suggesting that (as measured) it may not be a suitable individual difference measure. [Preregistration, data, analysis scripts and output are available via the Open Science Framework: https://osf.io/bhs24/ ].

The developmental trajectories of executive function from adolescence to old age

Executive functions demonstrate variable developmental and aging profiles, with protracted development into early adulthood and declines in older age. However, relatively few studies have specifically included middle-aged adults in investigations of age-related differences in executive functions. This study explored the age-related differences in executive function from late childhood through to old age, allowing a more informed understanding of executive functions across the lifespan. Three hundred and fifty participants aged 10 to 86 years-old completed a battery of tasks assessing the specific roles of inhibitory control, working memory, cognitive flexibility, and planning. Results highlighted continued improvement in working memory capacity across adolescence and into young adulthood, followed by declines in both working memory and inhibitory control, beginning from as early as 30-40 years old and continuing into older age. Analyses of planning abilities showed continued improvement across adolescence and into young adulthood, followed by a decline in abilities across adulthood, with a small (positive) change in older age. Interestingly, a dissociation was found for cognitive flexibility; switch costs decreased, yet mixing costs increased across the lifespan. The results provide a description of the developmental differences in inhibitory control, working memory, cognitive flexibility and planning, above any effects of IQ or SES, and highlight the importance of including middle-aged adults in studies seeking to establish a more comprehensive picture of age-related differences in executive function.

The relation between the intelligibility of irrelevant speech and cognitive performance-A revised model based on laboratory studies

Irrelevant background speech causes dissatisfaction and impairs cognitive performance in open-plan offices. The model of Hongisto (2005, Indoor Air, 15, 458-468) predicts the relation between cognitive performance and the intelligibility of speech described with an objectively measured quantity, the Speech Transmission Index (STI). The model has impacted research in psychology and room acoustics as well as the acoustic design guidelines of offices. However, the model was based on scarce empirical data. The aim of this study was to revise the model based on a systematic literature review, focusing on laboratory experiments manipulating the STI of speech by wide-band steady-state noise. Fourteen studies reporting altogether 34 tests of the STI-performance relation were included. According to Model 1 that includes all tests, performance begins to decrease approximately above STI = 0.21 while the maximum decrease is reached at STI = 0.44. Verbal short-term memory tasks were most strongly and very consistently affected by the STI of speech. The model for these tasks showed a deterioration in performance between STI 0.12 and 0.51. Some evidence of an STI-performance relation was found in verbal working memory tasks and limited evidence in complex verbal tasks. Further research is warranted, particularly concerning task-specific effects.

Indexing Early Visual Memory Durability in Infancy

The goal was to examine the scope and development of early visual memory durability. We investigated individual- and age-related differences across three unique tasks in 6- to 12-month-olds (M_age  = 8.87, N = 49) by examining the effect of increased delay on memory performance. Results suggest longer-term memory processes are quantifiable by 8 months using a modified Change Detection paradigm and spatial-attention cueing processes are quantifiable by 10 months using a modified Delayed Response paradigm, utilizing 500-1,250 ms delays. Performance improved from 6 to 12 months and longer delays impaired performance. We found no evidence for success on the Delayed Match Retrieval task at any age. These outcomes help inform our understanding of infant visual memory durability and its emergence throughout early development.

Relationship between working memory and complex syntax in children with Developmental Language Disorder

Some theories of Developmental Language Disorder (DLD) explain the linguistic deficits observed in terms of limitations in non-linguistic cognitive systems such as working memory. The goal of this research is to clarify the relationship between working memory and the processing of complex sentences by exploring the performance of 28 French-speaking children with DLD aged five to fourteen years and 48 typically developing children of the same age in memory and linguistic tasks. We identified predictive relationships between working memory and the comprehension and repetition of complex sentences in both groups. As for syntactic measures in spontaneous language, it is the complex spans that explain the major part of the variance in the control children. In children with DLD, however, simple spans are predictive of these syntactic measures. Our results thus reveal a robust relationship between working memory and syntactic complexity, with clinical implications for the treatment of children with DLD.

Using the delayed spatial alternation task to assess environmentally associated changes in working memory in very young children

BACKGROUND

Working memory (WM) is critical for problem solving and reasoning. Beginning in infancy, children show WM capacity increasing with age but there are few validated tests of WM in very young children. Because rapid brain development may increase susceptibility to adverse impacts of prenatal neurotoxicant exposure, such as lead, tests of WM in very young children would help to delineate onset of developmental problems and windows of susceptibility.

PURPOSE

Our objective was to assess the feasibility of administering a Delayed Spatial Alternation Task (DSAT) to measure WM among 18- and 24-month old children enrolled in an ongoing longitudinal birth cohort study and compare DSAT performance with age and general cognitive development. We further explored whether prenatal lead exposure impacted DSAT performance.

METHODS

We assessed 457 mother-child pairs participating in the Programming Research in Obesity, GRowth, Environment and Social Stressors (PROGRESS) Study in Mexico City. The DSAT and Bayley Scales of Infant Development (BSID-III) were administered at 18- and 24-months. Lead was measured in maternal blood collected during pregnancy (MBPb) and in a subsample of children at 24-months (CBPb). We regressed DSAT measures on MBPb and CBPb, child sex, and maternal age, education, socioeconomic status, and household smoking. We compared DSAT performance to BSID-III performance with adjusted residuals.

RESULTS

24-month children perform better on the DSAT than 18-month children; 24-month subjects reached a higher level on the DSAT (3.3 (0.86) vs. 2.4 (0.97), p < 0.01), and had a higher number of correct responses (20.3 vs. 17.2, p < 0.01). In all DSAT parameters, females performed better than males. Maternal education predicted better DSAT performance; household smoking predicted worse DSAT performance. A higher number of correct responses was associated with higher BSID-III Cognitive scales at 18 months (r = 0.20, p < 0.01) and 24 months (r = 0.27, p < 0.01). MBPb and CPBb did not significantly predict DSAT performance.

CONCLUSION

Improved performance on the DSAT with increasing age, the positive correlation with the BSID-III cognitive and language scales and the correlation with common sociodemographic predictors of neurodevelopment demonstrate the validity of the DSAT as a test of infant development.

The neural code of intelligence: From correlation to causation

Research into the neural underpinning of intelligence has mainly adopted a construct perspective: trying to find structural and functional brain characteristics that would accommodate the psychological concept of g. Few attempts have been made to explain intelligence exclusively based on brain characteristics - the brain perspective. From a methodological viewpoint the brain intelligence relation has been studied by means of correlational and interventional studies. The later providing a causal elucidation of the brain - intelligence relation. The best neuro-anatomical predictor of intelligence is brain volume showing a modest positive correlation with g, explaining between 9 to 16% of variance. The most likely explanation was that larger brains, containing more neurons, have a greater computational power and in that way allow more complex cognitive processing. Correlations with brain surface, thickness, convolution and callosal shape showed less consistent patterns. The development of diffusion tensor imaging has allowed researchers to look also into the microstructure of brain tissue. Consistently observed was a positively correlation between white matter integrity and intelligence, supporting the idea that efficient information transfer between hemispheres and brain areas is crucial for higher intellectual competence. Based on functional studies of the brain intelligence relationship three theories have been put forward: the neural efficiency, the P-FIT and the multi demand (MD) system theory. On the other hand, The Network Neuroscience Theory of g, based on methods from mathematics, physics, and computer science, is an example for the brain perspective on neurobiological underpinning of intelligence. In this framework network flexibility and dynamics provide the foundation for general intelligence. With respect to intervention studies the most promising results have been achieved with noninvasive brain stimulation and behavioral training providing tentative support for findings put forward by the correlational approach. To date the best consensus based on the diversity of results reported would be that g is predominantly determined by lateral prefrontal attentional control of structured sensory episodes in posterior brain areas. The capacity of flexible transitions between these network states represents the essence of intelligence - g.

Socio-affective and cognitive predictors of social adaptation in vulnerable contexts

People living in vulnerable environments face a harder set of challenges adapting to their context. Nevertheless, an important number of them adapt successfully. However, which cognitive and socio-affective variables are specifically related to these variations in social adaptation in vulnerable contexts has not been fully understood nor directly addressed. Here we evaluated socio-affective variables (anxious attachment style, internal locus of control, self-esteem and stress) and cognitive variables (fluid intelligence, crystallized intelligence, working memory, numeracy, probabilistic reasoning and logical reasoning) to explain variations in social adaptation in a sample of 232 adults living in vulnerable contexts (M = 42.3, SD = 14.9, equal amount of men and women). Our results show that an important amount of variance in social adaptation can be explained by socio-affective variables, principally by self-esteem, while cognitive variables also contributed significantly. As far as we know, this is one of the first steps towards understanding the role of cognitive and socio-affective features on social adaptation. In the long run, this area of research could play an important role on the assignation of resources to ease people's integration into society. Our data and R analysis scripts can be found at: https://osf.io/egxy5/.

Zum Zusammenhang von Arbeitsgedächtnisleistungen und ausgewählten Exekutivfunktionen bei Kindern mit ADHS

Zusammenfassung. Defizite in Exekutivfunktionen werden als ein wesentliches Merkmal einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung angesehen. Bisher liegen wenige standardisierte Testverfahren zur Erfassung solcher exekutiven Defizite vor, die bei Kindern und Jugendlichen besonders eng mit einer ADHS assoziiert scheinen (kognitive Flexibilität, Inhibition, Handlungsplanung, „Switching“). Das Hauptziel der vorliegenden Studie war deshalb die Validierung des neuropsychologischen Moduls des ADHS-Diagnostikums für Kinder und Jugendliche (ADHS-KJ-NPT). Diesbezüglich wurde eine Stichprobe von 58 ADHS-Kindern (77.6 % männlich) im Alter von 6 bis 12 Jahren ( M = 9.01 Jahre; SD = 1.43) mit dem ADHS-KJ-NPT sowie mit den Untertests des Index Arbeitsgedächtnis und des Index Verarbeitungsgeschwindigkeit des Wechsler-Intelligenztests (WISC-V) untersucht. Die Ergebnisse zeigen, dass die ADHS-KJ-NPT-Untertests, die darauf abzielen, Defizite in der Inhibitionsfähigkeit zu erfassen, mit dem WISC-V-Index Arbeitsgedächtnis korrelieren. Zudem wurden Korrelationen zwischen dem WISC-V-Index Verarbeitungsgeschwindigkeit und den ADHS-KJ-NPT-Untertests gefunden, mit denen Defizite in der flexiblen Aufmerksamkeitssteuerung und in der Inhibitionsfähigkeit auf äußere Reize erfasst werden sollen. Diese Korrelationen stellten sich bei 6- bis 9-jährigen Kindern als substanziell heraus, während dies bei 10- bis 12-Jährigen nicht der Fall ist. Die Studie trägt weiter zur Fundierung der Kriteriumsvalidität des neuropsychologischen Moduls des ADHS-KJ bei.

Group analyses can hide heterogeneity effects when searching for a general model: Evidence based on a conflict monitoring task

In experimental psychology, a unique model of general processing is often sought to represent the behaviors of all individuals. We address the question of whether seeking this objective - a unique model - is the most fruitful scientific strategy by studying a specific case example. In order to approach an answer to such a question, we compared the conventional approach in experimental psychology with analyses at the individual level by applying a specific mathematical modeling approach. A sample of 1159 individuals completed an experimental task based on managing conflict (a type of Simon task). Key findings revealed that at least four models are required to properly account for individuals' performance. Interestingly, four out of ten participants failed to show stimulus-response congruency effects in the experimental task, whereas the remaining 60% followed distinguishable theoretical models (consistent with conflict-monitoring theory and/or priming and episodic memory effects). The reported findings suggest that individuals' psychological characteristics might help to explain some of the reproducibility issues that are currently of great concern in psychology. These findings, along with further recent research, support the view that general and differential psychological approaches work better together for addressing relevant theoretical issues in psychological research.

What Does the n-Back Task Measure as We Get Older? Relations Between Working-Memory Measures and Other Cognitive Functions Across the Lifespan

Working memory (WM) declines with increasing age. The WM capacity is often measured by means of the computerized version of the n-back task. Although the n-back task is widely used in aging research, little is known about its construct validity and specific cognitive functions involved in this task. Moreover, to date, no studies analyzed the construct validity as a function of age. To this end, we conducted a study in a sample of N = 533 individuals aged between 20 and 80 years. The sample was divided into three age groups: young (20-40), middle-aged (41-60), and old (61-80 years). A number of psychometric tests was selected that measure attention, memory, and executive control to elucidate the impact of these constructs on n-back performance. A series of correlation analyses was conducted to assess the relationship between n-back performance and specific cognitive functions in each age group separately. The results show a progressive increase in reaction times and a decrease in the proportion of detected targets from young to old subjects. Age-related impairments were also found in all psychometric tests except for the vocabulary choice test measuring crystallized intelligence. Most importantly, correlations yielded different age-related patterns of functions contributing to performance in the n-back task: whereas performance was most related to executive functions in young age, a combination of attentional and executive processes was associated with performance in middle-aged subjects. In contrast, in older age, mainly attentional, verbal memory, and updating and to a lesser extent executive processes seem to play a crucial role in the n-back task, suggesting a shift of processing strategies across the lifespan.

Individual differences in working memory and general intelligence indexed by P200 and P300: A latent variable model

A robust relationship between working memory (WM) and general intelligence (g) has been well established. Nevertheless, explanations for this relationship in terms of underlying neurocognitive processes are still inadequate. This study addresses this issue using an individual differences approach in which Central Executive System (CES) and Short-Term Storage (STS) components of WM are measured comprehensively and examined for their relationship with g via event-related potentials components (P200 and P300) as mediators. Participants (n = 115) completed tests of the WM, CES and STS, as well as g. P200 and P300 components were recorded during 3-back WM task performance. Structural equation modelling showed significant negative associations between the P200 latency for target stimuli and CES shifting processes, and between the P300 amplitude for target stimuli and CES inhibition and updating processes. The relationship between CES processes and g was mediated in a localized fashion by the P300 amplitude. These findings further support the notion that the CES has a multidimensional structure and, importantly, reveal that the inhibition and updating functions of the CES are crucial in explaining the relationship between WM and g. Negative relations between ERP indices (P200 latency and P300 amplitude for target stimuli) and g support a neural efficiency hypothesis related to high intelligence.

Temporarily Out of Order: Temporal Perspective Taking in Language in Children With Autism Spectrum Disorder

Clinical reports suggest that children with autism spectrum disorder (ASD) struggle with time perception, but few studies have investigated this. This is the first study to examine these children's understanding of before and after. These temporal conjunctions have been argued to require additional cognitive effort when conjoining two events in a clause order that is incongruent with their order in time. Given the suggested time perception impairment and well-established cognitive deficits of children with ASD, we expected them to have difficulties interpreting temporal conjunctions, especially in an incongruent order. To investigate this, the interpretation of before and after in congruent and incongruent orders was examined in 48 children with ASD and 43 typically developing (TD) children (age 6-12). Additional tasks were administered to measure Theory of Mind (ToM), working memory (WM), cognitive inhibition, cognitive flexibility, IQ, and verbal ability. We found that children with ASD were less accurate in their interpretation of temporal conjunctions than their TD peers. Contrary to our expectations, they did not have particular difficulties in an incongruent order. Furthermore, older children showed better overall performance than younger children. The difference between children with ASD and TD children was explained by WM, ToM, IQ, and verbal ability, but not by cognitive inhibition and flexibility. These cognitive functions are more likely to be impaired in children with ASD than in TD children, which could account for their poorer performance. Thus, the cognitive factors found to affect the interpretation of temporal language in children with ASD are likely to apply in typical development as well. Sufficient WM capacity and verbal ability may help children to process complex sentences conjoined by a temporal conjunction. Additionally, ToM understanding was found to be related to children's interpretation of temporal conjunctions in an incongruent order, indicating that perspective taking is required when events are presented out of order. We conclude from this that perspective-taking abilities are needed for the interpretation of temporal conjunctions, either to shift one's own perspective as a hearer to another point in time, or to shift to the perspective of the speaker to consider the speaker's linguistic choices.

Cognitive Models in Intelligence Research: Advantages and Recommendations for Their Application

Mathematical models of cognition measure individual differences in cognitive processes, such as processing speed, working memory capacity, and executive functions, that may underlie general intelligence. As such, cognitive models allow identifying associations between specific cognitive processes and tracking the effect of experimental interventions aimed at the enhancement of intelligence on mediating process parameters. Moreover, cognitive models provide an explicit theoretical formalization of theories regarding specific cognitive processes that may help in overcoming ambiguities in the interpretation of fuzzy verbal theories. In this paper, we give an overview of the advantages of cognitive modeling in intelligence research and present models in the domains of processing speed, working memory, and selective attention that may be of particular interest for intelligence research. Moreover, we provide guidelines for the application of cognitive models in intelligence research, including data collection, the evaluation of model fit, and statistical analyses.

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

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

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.