Publications

@article{Sauce2021,
title = {Change by challenge: A common genetic basis behind childhood cognitive development and cognitive training},
author = {Bruno Sauce, John Wiedenhoeft, Nicholas Judd, Torkel Klingberg},
doi = {10.1038/s41539-021-00096-6},
year = {2021},
date = {2021-06-02},
journal = {Nature Science of Learning},
abstract = {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 explained variation in cognitive performance in adults, we estimated its effect in 344 children and adolescents (mean age of 12 years old, ranging from 6 to 25) who showed changes in working memory (WM) in two distinct samples: (1) a developmental sample showing significant WM gains after 2 years of typical, age-related development, and (2) a training sample showing significant, experimentally-induced WM gains after 25 days of an intense WM training. We found that the same genetic factor, cogPGS, significantly explained the amount of WM gain in both samples. And there was no interaction of cogPGS with sample, suggesting that those genetic factors are neutral to whether the WM gains came from development or training. These results represent evidence that cognitive challenges are a central piece in the gene-environment interplay during cognitive development. We believe our study sheds new light on previous findings of interindividual differences in education (rich-get-richer and compensation effects), brain plasticity in children, and the heritability increase of intelligence across the lifespan.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Judd2020b,
title = {Training spatial cognition enhances mathematical learning in a randomized study of 17,000 children},
author = {Nicholas Judd, Torkel Klingberg},
doi = {10.1038/s41562-021-01118-4},
year = {2021},
date = {2021-05-01},
journal = {Nature Human Behaviour},
abstract = {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 visuospatial working memory task) or spatial, non-verbal reasoning. We found that the type of cognitive training children performed had a significant impact on mathematical learning, with training of visuospatial working memory and reasoning being the most effective. This large, community-based study shows that spatial cognitive training can result in transfer to academic abilities, and that reasoning ability and maintenance of spatial information is relevant for mathematics learning in young children.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Bozzoli2020b,
title = {Digital, mathematical and cognitive training: Evidence from a randomized trial},
author = {Carlos Guillermo Bozzoli, Maria Luz Gonzalez-Gadea, Maria Julia Hermida, Lucía Navarro, Tomás Olego, Torkel Klingberg},
url = {https://psyarxiv.com/24ej7/},
doi = {10.31234/osf.io/24ej7},
year = {2020},
date = {2020-11-02},
journal = {PsyArXiv},
abstract = {In this paper, we experimentally evaluate a cognitive training tool that aims to improve children’s mathematical ability through 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 schools in the control group received a literacy book. We tested the math skills of 1,304 children in the 2nd through 6th grades from 80 rural schools and applied three cognitive tests: digit-span (working memory), face-perception (attention to objects), and block design (visuospatial reasoning), directly before and after the 10-week intervention period. In schools that received the treatment, we found no improvement in the digit-span or face-perception tests, but significant and positive effects in visuospatial reasoning and mathematical abilities. The improvement among students from treatment schools was 54 percentage points higher in math skills and 42 percentage points higher in visuospatial abilities than the gains by students in control schools. This study suggests this intervention is a feasible and effective way of enhancing the mathematical and cognitive abilities of children in rural areas.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Bozzoli2020,
title = {Digital, mathematical and cognitive training: Evidence from a randomized trial},
author = {Carlos Bozzoli, Maria Gonzalez-Gadea, Maria Hermida, Lucía Navarro, Tomás Olego, Torkel Klingberg},
url = {https://psyarxiv.com/24ej7/},
doi = {https://doi.org/10.31234/osf.io/24ej7},
year = {2020},
date = {2020-11-01},
journal = {PsyArXiv},
abstract = {In this paper, we experimentally evaluate a cognitive training tool that aims to improve children’s mathematical ability through 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 schools in the control group received a literacy book. We tested the math skills of 1,304 children in the 2nd through 6th grades from 80 rural schools and applied three cognitive tests: digit-span (working memory), face-perception (attention to objects), and block design (visuospatial reasoning), directly before and after the 10-week intervention period. In schools that received the treatment, we found no improvement in the digit-span or face-perception tests, but significant and positive effects in visuospatial reasoning and mathematical abilities. The improvement among students from treatment schools was 54 percentage points higher in math skills and 42 percentage points higher in visuospatial abilities than the gains by students in control schools. This study suggests this intervention is a feasible and effective way of enhancing the mathematical and cognitive abilities of children in rural areas.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Khemiri2019,
title = {Working Memory Training in Alcohol Use Disorder: A Randomized Controlled Trial},
author = {Lotfi Khemiri and Christoffer Brynte and Angela Stunkel and Torkel Klingberg and Nitya Jayaram-Lindström},
url = {http://doi.wiley.com/10.1111/acer.13910},
doi = {10.1111/acer.13910},
issn = {01456008},
year = {2019},
date = {2019-01-01},
journal = {Alcoholism: Clinical and Experimental Research},
volume = {43},
number = {1},
pages = {135--146},
abstract = {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 strategy. METHODS: Patients with AUD (n = 50) who were recruited to an outpatient addiction clinic were randomized to receive 5 weeks of active WM training or control training. Participants had weekly follow-up visits, and all cognitive training sessions were done online at home. Primary outcomes were WM function and change in self-reported heavy drinking. Secondary outcomes were craving, other drinking outcomes, and performance on a range of neuropsychological tasks from the Cambridge Neuropsychological Test Automated Battery. RESULTS: The active training group demonstrated a significantly greater improvement in verbal WM compared with the control group. No statistically significant effect of training was found on the primary drinking outcome, but a trend was observed indicating that WM training reduces the number of drinks per drinking occasion. WM training had no statistically significant effect on any of the other neuropsychological tasks. CONCLUSIONS: Cognitive training can improve WM function in individuals with AUD, suggesting that such interventions are feasible to administer in this patient population. The results do not support an effect of WM training on heavy drinking or transfer effects to other cognitive domains. Future studies should evaluate WM training as an adjunct to evidence-based treatments for AUD to assess potential synergistic effects.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Nemmi2016,
title = {Behavior and neuroimaging at baseline predict individual response to combined mathematical and working memory training in children},
author = {Federico Nemmi and Elin Helander and Ola Helenius and Rita Almeida and Martin Hassler and Pekka Räsänen and Torkel Klingberg},
url = {http://dx.doi.org/10.1016/j.dcn.2016.06.004 https://linkinghub.elsevier.com/retrieve/pii/S1878929316300500},
doi = {10.1016/j.dcn.2016.06.004},
issn = {18789293},
year = {2016},
date = {2016-08-01},
journal = {Developmental Cognitive Neuroscience},
volume = {20},
pages = {43--51},
publisher = {Elsevier Ltd},
abstract = {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 contributed to the outcome, and determine if baseline performance or neuroimaging predict the magnitude of improvement. We randomly assigned 308, 6-year-old children to WMT, NLT, WMT + NLT or a control intervention. Overall, there was a significant effect of NLT but not WMT. The WMT + NLT was the only group that improved significantly more than the controls, although the interaction NLTxWM was non-significant. Higher WM and maths performance predicted larger benefits for WMT and NLT, respectively. Neuroimaging at baseline also contributed significant information about training gain. Different individuals showed as much as a three-fold difference in their responses to the same intervention. These results show that the impact of an intervention is highly dependent on individual characteristics of the child. If differences in responses could be used to optimize the intervention for each child, future interventions could be substantially more effective.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Soderqvist2012,
title = {Dopamine, working memory, and training induced plasticity: Implications for developmental research},
author = {Stina Söderqvist and Sissela Bergman Nutley and Myriam Peyrard-Janvid and Hans Matsson and Keith Humphreys and Juha Kere and Torkel Klingberg},
doi = {10.1037/a0026179},
issn = {00121649},
year = {2012},
date = {2012-01-01},
journal = {Developmental Psychology},
volume = {48},
number = {3},
pages = {836--843},
abstract = {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 for improving WM capacity. For example, pharmacological interventions acting on the dopaminergic system, such as methylphenidate, improve WM performance. In addition, behavioral interventions for improving WM performance in the form of intensive computerized training have recently been associated with changes in dopamine receptor density. These two different means of improving WM performance--pharmacological and behavioral--are thus associated with similar biological mechanisms in the brain involving dopaminergic systems. This article reviews some of the evidence for the role of dopamine in WM functioning, in particular concerning the link to WM development and cognitive plasticity. Novel data are presented showing that variation in the dopamine transporter gene (DAT1) influences improvements in WM and fluid intelligence in preschool-age children following cognitive training. Our results emphasize the importance of the role of dopamine in determining cognitive plasticity.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}