Filters








611 Hits in 3.1 sec

Coherency and connectivity in oscillating neural networks: linear partialization analysis

S. Kalitzin, Bob W. van Dijk, H. Spekreijse, W. A. van Leeuwen
1997 Biological cybernetics  
.; van Dijk, B.W.; Spekreijse, H.; van Leeuwen, W.A. Abstract.  ...  W. van Dijk, Laboratory for Medical Physics, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (e-mail: b.vandijk@amc.uva.nl) unit activity, multiple unit activity or electroencephalographic  ...  The linear partialization method (van Dijk 1995) can subtract the influence of the correlated source from the cross-correlation functions as long as we can assume that the response to the external source  ... 
doi:10.1007/s004220050322 pmid:9050206 fatcat:7ttybcattray5fu3ol7n3d4gp4

Comparing average network signals and neural mass signals in systems with low-synchrony [article]

Prejaas Tewarie, Andreas Daffertshofer, Bob W van Dijk
2017 bioRxiv   pre-print
Every neuron j is under influence of zero-centered, δ correlated, Gaussian white noise W j with unit variance, i.e. that is E[W j = 0 and E[W j (t)W j (t )] = δ jk δ(t − t ) where δ kl is the Kroneckers  ...  Every neuron j is under influence of zerocentered, δ correlated, Gaussian white noise W j with unit variance, i.e. that is E[W j = 0 and E[W j (t)W j (t )] = δ jk δ(t − t ) where δ kl is the Kroneckers  ... 
doi:10.1101/196113 fatcat:vazyrlsrxnc3xfgrfrvxtpzlmy

A Mapping Between Structural and Functional Brain Networks

Jil Meier, Prejaas Tewarie, Arjan Hillebrand, Linda Douw, Bob W. van Dijk, Steven M. Stufflebeam, Piet Van Mieghem
2016 Brain Connectivity  
., 2008; van den Heuvel et al., 2009 ).  ...  DenotingW: = f (K) (A), we evaluate the goodness of fit of our mappings using the Frobenius norm (Van Mieghem, 2014) .  ... 
doi:10.1089/brain.2015.0408 pmid:26860437 pmcid:PMC4939447 fatcat:mup5y5jfmrdihfqs354nq3chki

Nonlinear synchronization in EEG and whole-head MEG recordings of healthy subjects

Cornelis J. Stam, Michael Breakspear, Anne-Marie van Cappellen van Walsum, Bob W. van Dijk
2003 Human Brain Mapping  
Dijk, 2002] .  ...  Synchronization likelihood The synchronization likelihood is a measure of the degree of synchronization or coupling between two or more time series [Stam and van Dijk, 2002 ].  ... 
doi:10.1002/hbm.10106 pmid:12768531 fatcat:nlbxwmr63vemppxhfqmwd4jluu

Increased Resting-State Functional Connectivity in Obese Adolescents; A Magnetoencephalographic Pilot Study

Kim T. E. Olde Dubbelink, Abraham Felius, Jeroen P. A. Verbunt, Bob W. van Dijk, Henk W. Berendse, Cornelis J. Stam, Henriette A. Delemarre-van de Waal, Brian D. McCabe
2008 PLoS ONE  
Obesity is not only associated with metabolic abnormalities, but also with cognitive dysfunction and changes in the central nervous system. The present pilot study was carried out to investigate functional connectivity in obese and non-obese adolescents using magnetoencephalography (MEG). Methodology/Principal Findings: Magnetoencephalographic recordings were performed in 11 obese (mean BMI 38.864.6 kg/m 2 ) and 8 lean (mean BMI 21.061.5 kg/m 2 ) female adolescents (age 12-19 years) during an
more » ... es-closed resting-state condition. From these recordings, the synchronization likelihood (SL), a common method that estimates both linear and non-linear interdependencies between MEG signals, was calculated within and between brain regions, and within standard frequency bands (delta, theta, alpha1, alpha2, beta and gamma). The obese adolescents had increased synchronization in delta (0.5-4 Hz) and beta (13-30 Hz) frequency bands compared to lean controls (P delta total = 0.001; P beta total = 0.002). Conclusions/Significance: This study identified increased resting-state functional connectivity in severe obese adolescents. Considering the importance of functional coupling between brain areas for cognitive functioning, the present findings strengthen the hypothesis that obesity may have a major impact on human brain function. The cause of the observed excessive synchronization is unknown, but might be related to disturbed motivational pathways, the recently demonstrated increase in white matter volume in obese subjects or altered metabolic processes like hyperinsulinemia. The question arises whether the changes in brain structure and communication are a dynamic process due to weight gain and whether these effects are reversible or not.
doi:10.1371/journal.pone.0002827 pmid:18665257 pmcid:PMC2474698 fatcat:mfy6kh5y5nf2dljynguketj2gy

A Healthy Brain in a Healthy Body: Brain Network Correlates of Physical and Mental Fitness

Linda Douw, Dagmar Nieboer, Bob W. van Dijk, Cornelis J. Stam, Jos W. R. Twisk, Renaud Lambiotte
2014 PLoS ONE  
Citation: Douw L, Nieboer D, van Dijk BW, Stam CJ, Twisk JWR (2014) A Healthy Brain in a Healthy Body: Brain Network Correlates of Physical and Mental Fitness. PLoS ONE 9(2): e88202.  ...  It was defined as follows: z w i~k w i m i ð Þ{ k w m i ð Þ s k w m i ð Þ Here, m i is the module containing node i, k w i m i ð Þ is the within module strength of node i (the sum of all weights of the  ...  The cost C was defined as {Q w m .  ... 
doi:10.1371/journal.pone.0088202 pmid:24498438 pmcid:PMC3912221 fatcat:4hnm7rvju5ed3bz4em4vj3vdmi

Integrating cross-frequency and within band functional networks in resting-state MEG: A multi-layer network approach

Prejaas Tewarie, Arjan Hillebrand, Bob W. van Dijk, Cornelis J. Stam, George C. O'Neill, Piet Van Mieghem, Jil M. Meier, Mark W. Woolrich, Peter G. Morris, Matthew J. Brookes
2016 NeuroImage  
., 2015; Van Mieghem, 2016) .  ...  metrics for nodes (Van Mieghem, 2014) .  ... 
doi:10.1016/j.neuroimage.2016.07.057 pmid:27498371 fatcat:rbs76jefqnev7pltpz6ndqma4i

Resting-State Oscillatory Activity in Children Born Small for Gestational Age: An MEG Study

Maria Boersma, Henrica M. A. de Bie, Kim J. Oostrom, Bob W. van Dijk, Arjan Hillebrand, Bernadette C. M. van Wijk, Henriëtte A. Delemarre-van de Waal, Cornelis J. Stam
2013 Frontiers in Human Neuroscience  
M. van Wijk. The authors declare that they have no conflict of interest.  ... 
doi:10.3389/fnhum.2013.00600 pmid:24068993 pmcid:PMC3781344 fatcat:nvgsreff6vh6fliaootmksav44

Cognitive and Clinical Dysfunction, Altered MEG Resting-State Networks and Thalamic Atrophy in Multiple Sclerosis

Prejaas Tewarie, Menno M. Schoonheim, Cornelis J. Stam, Marieke L. van der Meer, Bob W. van Dijk, Frederik Barkhof, Chris H. Polman, Arjan Hillebrand, Gareth Robert Barnes
2013 PLoS ONE  
Citation: Tewarie P, Schoonheim MM, Stam CJ, van der Meer ML, van Dijk BW, et al. (2013) Cognitive and Clinical Dysfunction, Altered MEG Resting-State Networks and Thalamic Atrophy in Multiple Sclerosis  ... 
doi:10.1371/journal.pone.0069318 pmid:23935983 pmcid:PMC3729968 fatcat:yor6dvad7rftzfvgbys5isopei

Relation between carotid stiffness, cognitive performance and brain connectivity in a healthy middle-aged population: an observational neurophysiological cohort study with magnetoencephalography

Dagmar Nieboer, Linda Douw, Bob W van Dijk, Martijn W Heymans, Cornelis J Stam, Jos W R Twisk
2016 BMJ Open  
To cite: Nieboer D, Douw L, van Dijk BW, et al.  ...  Luteijn and Van der Ploeg reported Cronbach's α of the total GIT to be 0.97 and a correlation with the shortened version of 0.94 with the complete test. 28 The shortened version of the GIT was used as  ...  described in detail elsewhere. 25 26 During the measurement, the arterial diameter (D), intima-media-thickness (IMT) and distension (ΔD) were quantified by ultrasonography, determined according to the Van  ... 
doi:10.1136/bmjopen-2016-013441 pmid:27979838 pmcid:PMC5168642 fatcat:2u2htqyh5nd57d5w7wcypy3m6m

Top-down modulation in human visual cortex predicts the stability of a perceptual illusion

Niels A. Kloosterman, Thomas Meindertsma, Arjan Hillebrand, Bob W. van Dijk, Victor A. F. Lamme, Tobias H. Donner
2015 Journal of Neurophysiology  
Kloosterman NA, Meindertsma T, Hillebrand A, van Dijk BW, Lamme VA, Donner TH. Top-down modulation in human visual cortex predicts the stability of a perceptual illusion.  ...  Cohen, Simon van Gaal, Tomas Knapen, Anouk van Loon, Sander Nieuwenhuis, Jan Brascamp, and all members of the Donner laboratory for comments on the manuscript. GRANTS  ...  reports, which can reflect the content of the report (Aston-Jones and Cohen 2005; de Gee et al. 2014; Einhauser et al. 2008; Hupe et al. 2009; Parikh et al. 2007 ; also Kloosterman NA, Meindertsma T, van  ... 
doi:10.1152/jn.00338.2014 pmid:25411458 pmcid:PMC4329440 fatcat:yry73vrz6nhwlb5yce2pmidapa

Long-term effects of cranial irradiation and intrathecal chemotherapy in treatment of childhood leukemia: a MEG study of power spectrum and correlated cognitive dysfunction

Marita Daams, Ilse Schuitema, Bob W van Dijk, Eline van Dulmen-den Broeder, Anjo JP Veerman, Cor van den Bos, Leo MJ de Sonneville
2012 BMC Neurology  
Prophylaxis to prevent relapses in the central nervous system after childhood acute lymphoblastic leukemia (ALL) used to consist of both intrathecal chemotherapy (CT) and cranial irradiation (CRT). CRT was mostly abolished in the eighties because of its neurotoxicity, and replaced with more intensive intrathecal CT. In this study, a group of survivors treated with CRT before 1983 and another group treated without CRT thereafter are investigated 20-25 years later, giving a much stronger
more » ... ve on long-term quality of life than previous studies. The outcomes will help to better understand these groups' current needs and will aid in anticipating late effects of prophylactic CRT that is currently applied for other diseases. This study evaluates oscillatory neuronal activity in these long-term survivors. Power spectrum deviations are hypothesized to correlate with cognitive dysfunction. Methods: Resting state eyes-closed magnetoencephalography (MEG) recordings were obtained from 14 ALL survivors treated with CT + CRT, 18 treated with CT alone and 35 controls. Relative spectral power was calculated in the δ, θ, α1, α2, β and γ frequency bands. The Amsterdam Neuropsychological Tasks (ANT) program was used to assess cognition in the executive functions domain. MEG data and ANT scores were correlated. Results: In the CT + CRT group, relative θ power was slightly increased (p = 0.069) and α2 power was significantly decreased (p = 0.006). The CT + CRT group performed worse on various cognitive tests. A deficiency in visuomotor accuracy, especially of the right hand, could be clearly associated with the deviating regional θ and α2 powers (0.471 < r < 0.697). A significant association between decreased regional α2 power and less attentional fluctuations was found for CT + CRT patients as well as controls (0.078 < r < 0.666). Patients treated with CT alone displayed a power spectrum similar to controls, except for a significantly increased level of left frontal α2 power (p = 0.030). Conclusions: The tendency towards global slowing of brain oscillatory activity, together with the fact that dementia has been reported as a late effect of CRT and the neuropsychological deficiencies currently present, suggest that the irradiated brain might be aging faster and could be at risk for early-onset dementia. The CT group showed no signs of early aging.
doi:10.1186/1471-2377-12-84 pmid:22928913 pmcid:PMC3517522 fatcat:evybqkygongezful7iytmoj6ei

Magnetoencephalography as a Putative Biomarker for Alzheimer's Disease

Edward Zamrini, Fernando Maestu, Eero Pekkonen, Michael Funke, Jyrki Makela, Myles Riley, Ricardo Bajo, Gustavo Sudre, Alberto Fernandez, Nazareth Castellanos, Francisco del Pozo, C. J. Stam (+3 others)
2011 International Journal of Alzheimer's Disease  
However, "(w)hether one of these measures or a combination of them is more sensitive than the other, and whether quantitative values provide more information than a dichotomous rating are yet to be determined  ... 
doi:10.4061/2011/280289 pmid:21547221 pmcid:PMC3087473 fatcat:bids2l5aqrgn3izh6gab2pgbwu

Disturbed functional brain networks and neurocognitive function in low-grade glioma patients: a graph theoretical analysis of resting-state MEG

Ingeborg Bosma, Jaap C Reijneveld, Martin Klein, Linda Douw, Bob W van Dijk, Jan J Heimans, Cornelis J Stam
2009 Nonlinear Biomedical Physics  
Manshanden, G. de Vos for technical assistance, Els van Deventer for providing us with the relevant literature, and Dr L.J.A.  ... 
doi:10.1186/1753-4631-3-9 pmid:19698149 pmcid:PMC2745411 fatcat:5h7jpcl6eva2xd3swrc3vwebji

Reproducibility of hippocampal atrophy rates measured with manual, FreeSurfer, AdaBoost, FSL/FIRST and the MAPS-HBSI methods in Alzheimer's disease

Keith S. Cover, Ronald A. van Schijndel, Adriaan Versteeg, Kelvin K. Leung, Emma R. Mulder, Remko A. Jong, Peter J. Visser, Alberto Redolfi, Jerome Revillard, Baptiste Grenier, David Manset, Soheil Damangir (+5 others)
2016 Psychiatry Research : Neuroimaging  
Cover, KS., van Schijndel, RA., Popescu, V., van Dijk, BW., Redolfi, A., Knol, KL., Frisoni, GB., Barkhof, F., Vrenken H., 2014 .  ...  de Jong, L.W., van der Hiele, K., Veer, I.M., Houwing, J.J., Westendorp, R.G.J., Bollen, E.L.E.M., de Bruin, P.W., Middelkoop, H.A.M., van Buchem, M.A., van der Grond, J., 2008.  ... 
doi:10.1016/j.pscychresns.2016.04.006 pmid:27179313 fatcat:czuhtwha2rb7doxpmvy72ggm5e
« Previous Showing results 1 — 15 out of 611 results