Publications

@article{Zacharopoulos2020,
title = {Cortical surface area of the left frontal pole is associated with visuospatial working memory capacity},
author = {George Zacharopoulos, Torkel Klingberg, Roi Cohen Kadosh},
url = {https://www.sciencedirect.com/science/article/pii/S0028393220301573},
doi = {https://doi.org/10.1016/j.neuropsychologia.2020.107486},
year = {2020},
date = {2020-06-01},
journal = {Neuropsychologia},
volume = {143},
abstract = {Working memory, the ability to maintain and manipulate information over seconds, is central to cognition and it is impaired in many clinical populations. However, our knowledge of the structural properties associated with individual variation in visuospatial working memory capacity is currently poor. Across two locations (Stockholm and Oxford), we examined how regional surface area and cortical thickness in frontal and parietal regions were related to visuospatial working memory capacity. We found a negative association between visuospatial working memory capacity and the surface area of the left frontal pole across both locations, and this finding was consistently present in each of the two locations separately. Importantly, this association was specific to (i) the surface area (not cortical thickness), (ii) the left side of the brain, (iii) and the visuospatial rather than the verbal modality. This result reveals a novel and highly specific neurobiological association with visuospatial working memory which could be further explored in studies with a wider range of psychological tests and in clinical populations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Olesen2003,
title = {Combined analysis of DTI and fMRI data reveals a joint maturation of white and grey matter in a fronto-parietal network},
author = {Pernille J Olesen and Zoltan Nagy and Helena Westerberg and Torkel Klingberg},
url = {https://linkinghub.elsevier.com/retrieve/pii/S092664100300212X},
doi = {10.1016/j.cogbrainres.2003.09.003},
issn = {09266410},
year = {2003},
date = {2003-12-01},
journal = {Cognitive Brain Research},
volume = {18},
number = {1},
pages = {48--57},
abstract = {The aim of this study was to explore whether there are networks of regions where maturation of white matter and changes in brain activity show similar developmental trends during childhood. In a previous study, we showed that during childhood, grey matter activity increases in frontal and parietal regions. We hypothesized that this would be mediated by maturation of white matter. Twenty-three healthy children aged 8-18 years were investigated. Brain activity was measured using the blood oxygen level-dependent (BOLD) contrast with functional magnetic resonance imaging (fMRI) during performance of a working memory (WM) task. White matter microstructure was investigated using diffusion tensor imaging (DTI). Based on the DTI data, we calculated fractional anisotropy (FA), an indicator of myelination and axon thickness. Prior to scanning, WM score was evaluated. WM score correlated independently with FA values and BOLD response in several regions. FA values and BOLD response were extracted for each subject from the peak voxels of these regions. The FA values were used as covariates in an additional BOLD analysis to find brain regions where FA values and BOLD response correlated. Conversely, the BOLD response values were used as covariates in an additional FA analysis. In several cortical and sub-cortical regions, there were positive correlations between maturation of white matter and increased brain activity. Specifically, and consistent with our hypothesis, we found that FA values in fronto-parietal white matter correlated with BOLD response in closely located grey matter in the superior frontal sulcus and inferior parietal lobe, areas that could form a functional network underlying working memory function. textcopyright 2003 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}