Torkel Klingberg

Karolinska Institutet | KI · Department of Neuroscience

Digital media (DM) takes an increasingly large part of children’s time, yet the long-term effect on brain development remains unclear. We investigated how individual effects of DM use (i.e., using social media, playing video games, or watching television/videos) on the development of the cortex (i.e., global cortical surface area), striatum, and ce...

On some days we feel like we are not performing at our best. However, whether these experiences align with substantive differences in cognitive performance has not been studied systematically. We analyse dense time-series data of children’s performance on nonverbal reasoning (n=449; t=454,913) and visuospatial working memory (n=4150; t=1,048,576) t...

Our performance on cognitive tasks fluctuates: the same individual completing the same task will differ in their response’s moment-to-moment. For decades cognitive fluctuations have been implicitly ignored – treated as measurement error – with a focus instead on aggregates such as mean performance. Leveraging dense trial-by-trial data and novel tim...

A key goal in cognitive training research is understanding whether cognitive training enhances general cognitive capacity or provides only task-specific improvements. Here, we developed a quantitative model for describing the temporal dynamics of these two processes. We analyzed data from 1300 children enrolled in an 8 week working memory training...

Aim: The neuronal mechanism linking the association between maternal diabetes mellitus (DM) and risk of attention deficit hyperactivity disorder (ADHD) symptoms and working memory deficits in children was investigated. Methods: A total of 6291 children (52% boys) born beyond 28 weeks of gestation were included and underwent brain magnetic resona...

Schooling, socioeconomic status (SES), and genetics all impact intelligence. However, it is unclear to what extent their contributions are unique and if they interact. Here we used a multi-trait polygenic score for cognition (cogPGS) with a quasi-experimental regression discontinuity design to isolate how months of schooling relate to intelligence...

In this paper, we experimentally evaluate a cognitive training tool that aims to improve children's mathematical ability through the use of technology in rural primary schools in Argentina. We conducted a large cluster randomized trial: schools in the treatment group used an app to train mathematical skills, while those in the control group receive...

Digital media takes an increasingly large part of children’s time, however, the long-term effect on brain development is unclear. Here, we investigated the individual effects of digital media use (watching television and videos, using social media, or playing video games, respectively), while controlling for genetic predisposition and socioeconomic...

Background Using transcranial alternating current stimulation (tACS) to improve visuospatial working memory (vsWM) has received considerable attention over the past few years. However, fundamental issues remain, such as the optimal frequency, the generality of behavioral effects, and the anatomical specificity of stimulation. Objectives Here we ex...

Cognitive training aims to improve skills such as working memory capacity and spatial ability, which have been linked to math skills. In this study, we fit Deep Knowledge Tracing with Transformers (DKTT), Dynamic Key-Value Memory Networks (DKVMN), and Knowledge Tracing Machines (KTM) to a large dataset from a cognitive training system. DKVMN achiev...

Digital media defines modern childhood, but its cognitive effects are unclear and hotly debated. We believe that studies with genetic data could clarify causal claims and correct for the typically unaccounted role of genetic predispositions. Here, we estimated the impact of different types of screen time (watching, socializing, or gaming) on childr...

Spatial and mathematical abilities are strongly associated. Here, we analysed data from 17,648 children, aged 6–8 years, who performed 7 weeks of mathematical training together with randomly assigned spatial cognitive training with tasks demanding more spatial manipulation (mental rotation or tangram), maintenance of spatial information (a visuospa...

Digital media defines modern childhood, but its cognitive effects are unclear and hotly debated. We estimated the impact of different types of screen time (watching, socializing, or gaming) on children’s intelligence while controlling for genetic differences in cognition and socioeconomic background. We analyzed 9855 children from the ABCD dataset...

In this paper, we experimentally evaluate a cognitive training tool that aims to improve children's mathematical ability through the use of technology in rural primary schools in Argentina. We conducted a large cluster randomized trial: schools in the treatment group used an app to train mathematical skills, while those in the control group receive...

Schooling, socioeconomic status (SES), and genetics all play large roles in intelligence differences. However, it is unclear to what extent their contributions are unique and if they interact. Here we used a multitrait polygenic score for cognition (cog-PGS) with a quasi-experimental regression discontinuity design to isolate how months of schoolin...

Spatial cognitive abilities, including mental rotation (MR) and visuo-spatial working memory (vsWM) are correlated with mathematical performance, and several studies have shown that training of these abilities can enhance mathematical performance. Here, we investigated the behavioral and neural correlates of MR and vsWM training combined with numbe...

The interplay of genetic and environmental factors behind cognitive development has preoccupied multiple fields of science and sparked heated debates over the decades. Here we tested the hypothesis that developmental genes rely heavily on cognitive challenges—as opposed to natural maturation. Starting with a polygenic score (cogPGS) that previously...

Classically, neuropsychological evaluation only estimates an individual’s performance at one time point. For example, working memory (WM) capacity is commonly determined in a single test session. However, recent research in WM plasticity and variability has suggested performance over several sessions/days might aid in evaluating children. Here, we...

Spatial and mathematical abilities are strongly associated. Here we analyzed data from 17,648 children, aged 6-8 years, who performed 7 weeks of mathematical training together with randomly assigned, spatial cognitive training with tasks demanding more spatial manipulation (mental rotation or tangram), maintenance of spatial information (a visuo-sp...

Significance The influence of socioeconomic status (SES) inequalities on brain and cognitive development is a hotly debated topic. However, previous studies have not considered that genetic factors overlap with SES. Here we show that SES and EduYears-PGS (a score from thousands of genetic markers for educational attainment) have independent associa...

Genetic factors and socioeconomic (SES) inequalities play a large role in educational attainment, and both have been associated with variations in brain structure and cognition. However, genetics and SES are correlated, and no prior study has assessed their neural associations independently. Here we used polygenic score for educational attainment (...

The striatum has long been associated with cognitive functions, but the mechanisms behind this are still unclear. Here we tested a new hypothesis that the striatum contributes to executive function (EF) by strengthening cortico-cortical connections. Striatal connectivity was evaluated by measuring the resting-state functional connectivity between v...

There is substantial interest in the possibility that cognitive skills can be improved by dedicated behavioral training. Yet despite the large amount of work being conducted in this domain, there is not an explicit and widely agreed upon consensus around the best methodological practices. This document seeks to fill this gap. We start from the pers...

There is substantial interest in the possibility that cognitive skills can be improved by dedicated behavioral training. Yet despite the large amount of work being conducted in this domain, there is not an explicit and widely agreed upon consensus around the best methodological practices. This document seeks to fill this gap. We start from the pers...

The adult brain contains cortical areas thought to be specialized for the analysis of numbers (the putative number form area, NFA) and letters (the visual word form area, VWFA). Although functional development of the VWFA has been investigated, it is largely unknown when and how the NFA becomes specialized and connected to the rest of the brain. On...

Background Alcohol use disorder (AUD) is associated with cognitive deficits such as impaired executive functions, which are hypothesized to contribute to the progression of the disease and worsen treatment outcome. Training of working memory (WM) to improve cognitive functions and thereby reduce alcohol use has been proposed as a novel treatment st...

Using a randomized placebo controlled design, we examined the direct and follow-up effects (at 6 and 12 months) of a mathematics tablet intervention. Math training focused primarily on basic arithmetic (addition and subtraction facts up to 12), and secondarily on number knowledge and word problems. We investigated the moderating effects of IQ and s...

Developmental Language Disorder (DLD) is a common neurodevelopmental disorder with largely unknown etiology. Rare copy number variants (CNVs) have been implicated in the genetic architecture of other neurodevelopmental disorders (NDDs) which have led to clinical genetic testing recommendations for these disorders; however, the evidence is still lac...

There is considerable inter-individual variability in the rate at which working memory (WM) develops during childhood and adolescence, but the neural and genetic basis for these differences are poorly understood. Dopamine-related genes, striatal activation and morphology have been associated with increased WM capacity after training. Here we tested...

Most cortical areas send projections to the striatum. In some parts of the striatum, the connections converge from several cortical areas. It is unknown whether the convergence and non-convergence zones of the striatum differ functionally. Here, we used diffusion-weighted magnetic resonance imaging and probabilistic fiber tracking to parcellate the...

A whole-genome linkage analysis in a Finnish pedigree of eight cases with developmental dyslexia (DD) revealed several regions shared by the affected individuals. Analysis of coding variants from two affected individuals identified rs146011974G > A (Ala1039Thr), a rare variant within the NCAN gene co-segregating with DD in the pedigree. This varian...

We investigate if increased physical activity (PA) leads to enhanced working memory capacity and arithmetic performance, in a 2-year school-based intervention in preadolescent children (age 6–13). The active school (n = 228) increased PA (aimed at increasing cardiovascular fitness) from 2 to 5 days a week while the control school (n = 242) remained...

Transcranial electric stimulation (tES) is a promising technique that has been shown to improve working memory (WM) performance and enhance the effect of cognitive training. However, experimental set up and electrode placement are not always determined based on neurofunctional knowledge about WM, leading to inconsistent results. Additional research...

The axon guidance receptor, Robo1, controls the pathfinding of callosal axons in mice. To determine whether the orthologous ROBO1 gene is involved in callosal development also in humans, we studied polymorphisms in the ROBO1 gene and variation in the white matter structure in the corpus callosum using both structural magnetic resonance imaging and...

This chapter summarises the results of some meta-analyses evaluating the effects of a working memory training programme, and focuses on outcomes examined in the literature that are particularly relevant for ADHD: working memory, inhibitory control, academic performance, and behavioural symptoms of ADHD. It describes the results of the meta-analyses...

[This corrects the article DOI: 10.1371/journal.pone.0119522.].

There is a long-standing interest in the determinants of successful learning in children. “Grit” is an individual trait, reflecting the ability to pursue long-term goals despite temporary setbacks. Although grit is known to be predictive of future success in real-world learning situations, an understanding of the underlying neural basis and mechani...

Mathematical ability, especially perception of numbers and performance of arithmetics, is known to rely on the activation of intraparietal sulcus (IPS). However, reasoning ability and working memory, 2 highly associated abilities also activate partly overlapping regions. Most studies aimed at localizing mathematical function have used group average...

The primary aim of this study was to investigate to what degree the age-related white matter development, here called "brain age", is associated with working memory (WM) and numeric abilities in 6-year-old children. We measured white matter development using diffusion tensor imaging to calculate fractional anisotropy (FA). A "brain age" model was c...

Mathematical performance is highly correlated with several general cognitive abilities, including working memory (WM) capacity. Here we investigated the effect of numerical training using a number-line (NLT), WM training (WMT), or the combination of the two on a composite score of mathematical ability. The aim was to investigate if the combination...

Working memory - the ability to maintain and manipulate information over a period of seconds - is a core component of higher cognitive functions. The storage capacity of working memory is limited but can be expanded by training, and evidence of the neural mechanisms underlying this effect is accumulating. Human imaging studies and neurophysiologica...

This paper gives a brief overview of phases in brain development and discusses the hypothesis that mechanisms of working memory development are partly the same as those of working memory training. Brain development could be related to different, but overlapping phases: (i) structural maturation, with a relatively high reliance of preprogrammed proc...

Developmental dyslexia is the most common learning disorder in children. Problems in reading and writing are likely due to a complex interaction of genetic and environmental factors, resulting in reduced power of studies of the genetic factors underlying developmental dyslexia. Our approach in the current study was to perform exome sequencing of af...

School-age children born preterm are particularly at risk for low mathematical achievement, associated with reduced working memory and number skills. Early identification of preterm children at risk for future impairments using brain markers might assist in referral for early intervention. This study aimed to examine the use of neonatal magnetic re...

Background: Many common disorders across the lifespan feature impaired working memory (WM). Reported benefits of a WM training program include improving inattention in daily life, but this has not been evaluated in a meta-analysis. This study aimed to evaluate whether one WM training method has benefits for inattention in daily life by conducting...

Cytogenetically visible chromosomal translocations are highly informative as they can pinpoint strong effect genes even in complex genetic disorders. Here, we report a mother and daughter, both with borderline intelligence and learning problems within the dyslexia spectrum, and two apparently balanced reciprocal translocations: t(1;8)(p22;q24) and...

Theories view childhood development as being either driven by structural maturation of the brain or being driven by skill-learning. It is hypothesized here that working memory (WM) development during childhood is partly driven by training effects in the environment, and that similar neural mechanisms underlie training-induced plasticity and childho...

Three genes, DYX1C1, DCDC2, and KIAA0319, have been previously associated with dyslexia, neuronal migration, and ciliary function. Three polymorphisms within these genes, rs3743204 (DYX1C1), rs793842 (DCDC2), and rs6935076 (KIAA0319) have also been linked to normal variability of left temporoparietal white matter volume connecting the middle tempor...

Mathematical ability is dependent on specific mathematical training but also associated with a range of cognitive factors, including working memory (WM) capacity. Previous studies have shown that WM training leads to improvement in non-trained WM tasks, but the results regarding transfer to mathematics are inconclusive. In the present study, 176 ch...

Motivation is important for learning and cognition. While dopaminergic (D2) transmission in the ventral striatum (VS) is associated with motivation, learning and cognition are more strongly associated with function of the dorsal striatum, including activation in the caudate nucleus. A recent study found an interaction between intrinsic motivation a...

Human working memory capacity develops during childhood and is a strong predictor of future academic performance, in particular, achievements in mathematics and reading. Predicting working memory development is important for the early identification of children at risk for poor cognitive and academic development. Here we show that structural and fu...

The increase in working memory (WM) capacity is an important part of cognitive development during childhood and adolescence. Cross-sectional analyses have associated this development with higher activity, thinner cortex, and white matter maturation in fronto-parietal networks. However, there is still a lack of longitudinal data showing the dynamics...

Practicing a musical instrument is associated with cognitive benefits and structural brain changes in correlational and interventional trials; however, the effect of musical training on cognition during childhood is still unclear. In this longitudinal study of child development we analyzed the association between musical practice and performance on...

There is recognition that biomedical research into the causes of mental disorders and their treatment needs to adopt new approaches to research. Novel biomedical techniques have advanced our understanding of how the brain develops and is shaped by behaviour and environment. This has led to the advent of stratified medicine, which translates advance...

Limitations in the performance of working memory (WM) tasks have been characterized in terms of the number of items retained (capacity) and in terms of the precision with which the information is retained. The neural mechanisms behind these limitations are still unclear. Here we used a biological constrained computational model to study the capacit...

Studying the effects of cognitive training can lead to finding better treatments, but it can also be a tool for investigating factors important for brain plasticity and acquisition of cognitive skills. In this study, we investigated how single-nucleotide polymorphisms (SNPs) and ratings of intrinsic motivation were associated to interindividual dif...

Disrupted-in-schizophrenia-1 (DISC1) is a promising candidate gene for major psychiatric disorders. This gene is involved in key processes of neurodevelopment, such as neuronal proliferation, differentiation and migration. In the brain DISC1 is predominantly expressed within the hippocampus. Two common functional single-nucleotide polymorphisms, Le...

Independent studies have shown that candidate genes for dyslexia and specific language impairment (SLI) impact upon reading/language-specific traits in the general population. To further explore the effect of disorder-associated genes on cognitive functions, we investigated whether they play a role in broader cognitive traits. We tested a panel of...

Children with intellectual disabilities show deficits in both reasoning ability and working memory (WM) that impact everyday functioning and academic achievement. In this study we investigated the feasibility of cognitive training for improving WM and non-verbal reasoning (NVR) ability in children with intellectual disability. Participants were ran...

Volume and integrity of white matter correlate with reading ability, but the underlying factors contributing to this variability are unknown. We investigated single nucleotide polymorphisms in three genes previously associated with dyslexia and implicated in neuronal migration (DYX1C1, DCDC2, KIAA0319) and white matter volume in a cohort of 76 chil...

A developmental increase in working memory capacity is an important part of cognitive development, and low working memory (WM) capacity is a risk factor for developing psychopathology. Brain activity represents a promising endophenotype for linking genes to behavior and for improving our understanding of the neurobiology of WM development. We inves...

Cognitive deficits and particularly deficits in working memory (WM) capacity are common features in neuropsychiatric disorders. Understanding the underlying mechanisms through which WM capacity can be improved is therefore of great importance. Several lines of research indicate that dopamine plays an important role not only in WM function but also...

Visuospatial working memory (WM) capacity is highly correlated with mathematical reasoning abilities and can predict future development of arithmetical performance. Activity in the intraparietal sulcus (IPS) during visuospatial WM tasks correlates with interindividual differences in WM capacity. This region has also been implicated in numerical rep...