Publications

@article{Darki2018,
title = {Functional differentiation between convergence and non-convergence zones of the striatum in children},
author = {Fahimeh Darki and Torkel Klingberg},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1053811918301617},
doi = {10.1016/j.neuroimage.2018.02.054},
issn = {10538119},
year = {2018},
date = {2018-06-01},
journal = {NeuroImage},
volume = {173},
number = {January},
pages = {384--393},
abstract = {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 striatum based on its connections to dorsolateral prefrontal, parietal and orbitofrontal cortices in two different datasets (children aged 6–7 years and adults). In both samples, quantitative susceptibility mapping (QSM) values were significantly correlated with working memory (WM) in convergence zones, but not in non-convergence zones. In children, this was also true for mean diffusivity, MD. The association of MD to WM specifically in the convergent zone was replicated in the Pediatric Imaging, Neurocognition, and Genetics (PING) dataset for 135 children aged 6–9 years. QSM data was not available in the PING dataset, and the association to QSM still needs to be replicated. These results suggest that connectivity-based segments of the striatum exhibit functionally different characteristics. The association between convergence zones and WM performance might relate to a role in integrating and coordinating activity in different cortical areas.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Darki2014,
title = {DCDC2 Polymorphism Is Associated with Left Temporoparietal Gray and White Matter Structures during Development},
author = {F Darki and M Peyrard-Janvid and H Matsson and J Kere and T Klingberg},
doi = {10.1523/jneurosci.1216-14.2014},
issn = {0270-6474},
year = {2014},
date = {2014-01-01},
journal = {Journal of Neuroscience},
volume = {34},
number = {43},
pages = {14455--14462},
abstract = {textcopyright 2014 the authors. 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 temporal cortex to the angular and supramarginal gyri. Here, we assessed whether these polymorphisms are also related to the cortical thickness of the associated regions during childhood development using a longitudinal dataset of 76 randomly selected children and young adults who were scanned up to three times each, 2 years apart. rs793842 in DCDC2 was significantly associated with the thickness of left angular and supramarginal gyri as well as the left lateral occipital cortex. The cortex was significantly thicker for T-allele carriers, who also had lower white matter volume and lower reading comprehension scores. There was a negative correlation between white matter volume and cortical thickness, but only white matter volume predicted reading comprehension 2 years after scanning. These results show how normal variability in reading comprehension is related to gene, white matter volume, and cortical thickness in the inferior parietal lobe. Possibly, the variability of gray and white matter structures could both be related to the role of DCDC2 in ciliary function, which affects both neuronal migration and axonal outgrowth.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Klingberg2006,
title = {Development of a superior frontal–intraparietal network for visuo-spatial working memory},
author = {Torkel Klingberg},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0028393205003830},
doi = {10.1016/j.neuropsychologia.2005.11.019},
issn = {00283932},
year = {2006},
date = {2006-01-01},
journal = {Neuropsychologia},
volume = {44},
number = {11},
pages = {2171--2177},
abstract = {Working memory capacity increases throughout childhood and adolescence, which is important for the development of a wide range of cognitive abilities, including complex reasoning. The spatial-span task, in which subjects retain information about the order and position of a number of objects, is a sensitive task to measure development of spatial working memory. This review considers results from previous neuroimaging studies investigating the neural correlates of this development. Older children and adolescents, with higher capacity, have been found to have higher brain activity in the intraparietal cortex and in the posterior part of the superior frontal sulcus, during the performance of working memory tasks. The structural maturation of white matter has been investigated by diffusion tensor magnetic resonance imaging (DTI). This has revealed several regions in the frontal lobes in which white matter maturation is correlated with the development of working memory. Among these is a superior fronto-parietal white matter region, located close to the grey matter regions that are implicated in the development of working memory. Furthermore, the degree of white matter maturation is positively correlated with the degree of cortical activation in the frontal and parietal regions. This suggests that during childhood and adolescence, there is development of networks related to specific cognitive functions, such as visuo-spatial working memory. These networks not only consist of cortical areas but also the white matter tracts connecting them. For visuo-spatial working memory, this network could consist of the superior frontal and intraparietal cortex. textcopyright 2005 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}