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Reorganization of brain networks in aging: a review of functional connectivity studies

Roser Sala-Llonch, David Bartrés-Faz, Carme Junqué
2015 Frontiers in Psychology  
(2014) 18 young (22-33 years) 22 old (60-80 years) Seed-based DMN SN CN DAN Visual = Selective vulnerability of networks - Sala-Llonch et al.  ...  ., 2012; Sala-Llonch et al., 2014) . Decreased functional connectivity has been also correlated with decreased structural connectivity in aging (Andrews-Hanna et al., 2007) .  ... 
doi:10.3389/fpsyg.2015.00663 pmid:26052298 pmcid:PMC4439539 fatcat:bv2utufknbf2zffeq6klcbcbiu

3D face recognition using sparse spherical representations

Roser Sala Llonch, Effrosyni Kokiopoulou, Ivana Tosic, Pascal Frossard
2008 Pattern Recognition (ICPR), Proceedings of the International Conference on  
This paper addresses the problem of 3D face recognition using spherical sparse representations. We first propose a fully automated registration process that permits to align the 3D face point clouds. These point clouds are then represented as signals on the 2D sphere, in order to take benefit of the geometry information. Simultaneous sparse approximations implement a dimensionality reduction process by subspace projection. Each face is typically represented by a few spherical basis functions
more » ... t are able to capture the salient facial characteristics. The dimensionality reduction step preserves the discriminant facial information and eventually permits an effective matching in the reduced space, where it can further be combined with LDA for improved recognition performance. We evaluate the 3D face recognition algorithm on the FRGC v.1.0 data set, where it outperforms classical state-of-the-art solutions based on PCA or LDA on depth face images.
doi:10.1109/icpr.2008.4761682 dblp:conf/icpr/LlonchKTF08 fatcat:lci5b4dqdnbnromykwradojjq4

Functional networks and structural connectivity of visuospatial and visuoperceptual working memory

Roser Sala-Llonch, Eva M. Palacios, Carme Junqué, Núria Bargalló, Pere Vendrell
2015 Frontiers in Human Neuroscience  
Neural correlates of working memory (WM) in healthy subjects have been extensively investigated using functional MRI (fMRI). However it still remains unclear how cortical areas forming part of functional WM networks are also connected by white matter fiber bundles, and whether DTI measures, used as indices of microstructural properties and directionality of these connections, can predict individual differences in task performance. fMRI data were obtained from 23 healthy young subjects while
more » ... orming one visuospatial (square location) and one visuoperceptual (face identification) 2-back task. Diffusion tensor imaging (DTI) data were also acquired. We used independent component analysis (ICA) of fMRI data to identify the main functional networks involved in WM tasks. Voxel-wise DTI analyses were performed to find correlations between structural white matter and task performance measures, and probabilistic tracking of DTI data was used to identify the white matter bundles connecting the nodes of the functional networks. We found that functional recruitment of the fusiform and the inferior frontal cortex was specific for the visuoperceptual working memory task, while there was a high overlap in brain activity maps in parietal and middle frontal areas for both tasks. Axial diffusivity and fractional anisotropy, of the tracts connecting the fusiform with the inferior frontal areas correlated with processing speed in the visuoperceptual working memory task. Although our findings need to be considered as exploratory, we conclude that both tasks share a highly-overlapping pattern of activity in areas of frontal and parietal lobes with the only differences in activation between tasks located in the fusiform and inferior frontal regions for the visuoperceptual task. Moreover, we have found that the DTI measures are predictive of the processing speed.
doi:10.3389/fnhum.2015.00340 pmid:26124716 pmcid:PMC4463024 fatcat:2gb5n6dnh5fdvdpkiz3stbb5qi

Cortical Thickness and Behavior Abnormalities in Children Born Preterm

Leire Zubiaurre-Elorza, Sara Soria-Pastor, Carme Junque, Roser Sala-Llonch, Dolors Segarra, Nuria Bargallo, Alfons Macaya, Bogdan Draganski
2012 PLoS ONE  
Aim: To identify long-term effects of preterm birth and of periventricular leukomalacia (PVL) on cortical thickness (CTh). To study the relationship between CTh and cognitive-behavioral abnormalities. Methods: We performed brain magnetic resonance imaging on 22 preterm children with PVL, 14 preterm children with no evidence of PVL and 22 full-term peers. T1-weighted images were analyzed with FreeSurfer software. All participants underwent cognitive and behavioral assessments by means of the
more » ... sler Intelligence Scales for Children-Fourth Edition (WISC-IV) and the Child Behavior Checklist (CBCL). Results: We did not find global CTh differences between the groups. However, a thinner cortex was found in left postcentral, supramarginal, and caudal middle rostral gyri in preterm children with no evidence of PVL than in the full-term controls, while PVL preterm children showed thicker cortex in right pericalcarine and left rostral middle frontal areas than in preterm children with no evidence of PVL. In the PVL group, internalizing and externalizing scores correlated mainly with CTh in frontal areas. Attentional scores were found to be higher in PVL and correlated with CTh increments in right frontal areas. Interpretation: The preterm group with no evidence of PVL, when compared with full-term children, showed evidence of a different pattern of regional thinning in the cortical gray matter. In turn, PVL preterm children exhibited atypical increases in CTh that may underlie their prevalent behavioral problems.
doi:10.1371/journal.pone.0042148 pmid:22860067 pmcid:PMC3408470 fatcat:pjeofkbukjdynk7x57op2lwmdy

Spatial parcellations, spectral filtering, and connectivity measures in fMRI: Optimizing for discrimination

Roser Sala-Llonch, Stephen M. Smith, Mark Woolrich, Eugene P. Duff
2018 Human Brain Mapping  
Roser Sala-Llonch has been supported by the Spanish Ministerio de Economia y Competitividad, grant number: BES-2011-047053.  ...  ACKNOWLEDGMENTS We are very grateful for the multiband pulse sequence and recon- ORCID Roser Sala-Llonch with dimensionalities ranging from 10 to 200.  ... 
doi:10.1002/hbm.24381 pmid:30259597 pmcid:PMC6492132 fatcat:egknkah2hvg6vdfiuyz7nxrsla

Cognitive impairment and resting-state network connectivity in Parkinson's disease

Hugo-Cesar Baggio, Bàrbara Segura, Roser Sala-Llonch, Maria-José Marti, Francesc Valldeoriola, Yaroslau Compta, Eduardo Tolosa, Carme Junqué
2014 Human Brain Mapping  
intrinsic connectivity networks (ICNs) considered to play an important role in cognitive processing: the default-mode network (DMN), the dorsal attention network (DAN) and the frontoparietal networks (FPN) [Sala-Llonch  ... 
doi:10.1002/hbm.22622 pmid:25164875 fatcat:ky25xjx4qfektltzodn5dcikem

Rich Club Organization and Cognitive Performance in Healthy Older Participants

Hugo C. Baggio, Barbara Segura, Carme Junque, Marcel A. de Reus, Roser Sala-Llonch, Martijn P. Van den Heuvel
2015 Journal of Cognitive Neuroscience  
, dorsal attentional, and default mode networks), the dynamical interplay of which is related to attentional performance in healthy participants (Spreng, Sepulcre, Turner, Stevens, & Schacter, 2013; Sala-Llonch  ... 
doi:10.1162/jocn_a_00821 pmid:25941870 fatcat:uo2acd4wfzfvdjbhzymonoyt7i

Dynamic Functional Reorganizations and Relationship with Working Memory Performance in Healthy Aging

Roser Sala-Llonch, Eider M. Arenaza-Urquijo, Cinta Valls-Pedret, Dídac Vidal-Piñeiro, Nuria Bargalló, Carme Junqué, David Bartrés-Faz
2012 Frontiers in Human Neuroscience  
., 1997; Sala-Llonch et al., 2011) .  ... 
doi:10.3389/fnhum.2012.00152 pmid:22701409 pmcid:PMC3369258 fatcat:gs5oqajkvfftdoru2fzanm25xe

Brain connectivity during resting state and subsequent working memory task predicts behavioural performance

Roser Sala-Llonch, Cleofé Peña-Gómez, Eider M. Arenaza-Urquijo, Dídac Vidal-Piñeiro, Nuria Bargalló, Carme Junqué, David Bartrés-Faz
2012 Cortex  
Default mode network Attention ICA a b s t r a c t Brain regions simultaneously activated during any cognitive process are functionally connected, forming large-scale networks. These functional networks can be examined Journal homepage: c o r t e x 4 8 ( 2 0 1 2 ) 1 1 8 7 e1 1 9 6 0010-9452/$ e see front matter ª
doi:10.1016/j.cortex.2011.07.006 pmid:21872853 fatcat:wlxhtbekyjbizhqlpkcf7h2whi

White Matter/Gray Matter Contrast Changes in Chronic and Diffuse Traumatic Brain Injury

Eva M. Palacios, Roser Sala-Llonch, Carme Junque, Teresa Roig, Jose M. Tormos, Nuria Bargallo, Pere Vendrell
2013 Journal of Neurotrauma  
Signal-intensity contrast of T1-weighted magnetic resonance imaging scans has been associated with tissue integrity and reported as a sign of neurodegenerative changes in diseases such as Alzheimer's disease. After severe traumatic brain injury (TBI), progressive structural changes occur in white (WM) and gray matter (GM). In the current study, we assessed the signal-intensity contrast of GM and WM in patients with diffuse TBI in the chronic stage to (1) characterize the regional pattern of
more » ... M changes in intensity contrast associated with traumatic axonal injury, (2) evaluate possible associations between this measure and diffusion tensor image (DTI)/fractional anisotropy (FA) for detecting WM damage, and (3) investigate the correlates of both measures with cognitive outcomes. Structural T1 scans were processed with FreeSurfer software to identify the boundary and calculate the WM/GM contrast maps. DTIs were processed with the FMRIB software library to obtain FA maps. The WM/GM contrast in TBI patients showed a pattern of reduction in almost all of the brain, except the visual and motor primary regions. Global FA values obtained from DTI correlated with the intensity contrast of all associative cerebral regions. WM/GM contrast correlated with memory functions, whereas FA global values correlated with tests measuring memory and mental processing speed. In conclusion, tissue-contrast intensity is a very sensitive measure for detecting structural brain damage in chronic, severe and diffuse TBI, but is less sensitive than FA for reflecting neuropsychological sequelae, such as impaired mental processing speed.
doi:10.1089/neu.2012.2836 pmid:23822854 fatcat:ssyzwl2uw5dudca2zwtlkvga6a

Resting State Networks in the TgF344-AD Rat Model of Alzheimer's Disease Are Altered From Early Stages

Raúl Tudela, Emma Muñoz-Moreno, Roser Sala-Llonch, Xavier López-Gil, Guadalupe Soria
2019 Frontiers in Aging Neuroscience  
A better and non-invasive characterization of the preclinical phases of Alzheimer's disease (AD) is important to advance its diagnosis and obtain more effective benefits from potential treatments. The TgF344-AD rat model has been well characterized and shows molecular, behavioral and brain connectivity alterations that resemble the silent period of the pathology. Our aim was to longitudinally investigate functional brain connectivity in established resting-state networks (RSNs) obtained by
more » ... endent component analysis (ICA) in a cohort of TgF344-AD and control rats every 3 months, from 5 to 18 months of age, to cover different stages of the disease. Before each acquisition, working memory performance was evaluated by the delayed non match-to-sample (DNMS) task. Differences in the temporal evolution were observed between groups in the amplitude and shape of the somatosensorial and sensorimotor networks but not in the whole default mode network (DMN). Subsequent high dimensional ICA analysis showed early alterations in the anterior DMN subnetwork activity of TgF344-AD rats compared to controls. Performance of DNMS task was positively correlated with somatosensorial network at 5 months of age in the wild-type (WT) animals but not in the Tg-F344 rats. At different time points, DMN showed negative correlation with cognitive performance in the control group while in the transgenic group the correlation was positive. In addition, behavioral differences observed at 5 months of age correlated with alterations in the posterior DMN subnetwork. We have demonstrated that functional connectivity using ICA represents a useful biomarker also in animal models of AD such as the TgF344AD rats, as it allows the identification of alterations associated with the progression of the disease, detecting differences in specific networks even at very early stages.
doi:10.3389/fnagi.2019.00213 pmid:31440158 pmcid:PMC6694297 fatcat:kztbilyewzcvbh7wuxewjdbpum

Epileptogenic Zone Localization With 18FDG PET Using a New Dynamic Parametric Analysis

Maria Mayoral, Aida Niñerola-Baizán, Berta Marti-Fuster, Antonio Donaire, Andrés Perissinotti, Jordi Rumià, Núria Bargalló, Roser Sala-Llonch, Javier Pavia, Domènec Ros, Mar Carreño, Francesca Pons (+1 others)
2019 Frontiers in Neurology  
Copyright © 2019 Mayoral, Niñerola-Baizán, Marti-Fuster, Donaire, Perissinotti, Rumià, Bargalló, Sala-Llonch, Pavia, Ros, Carreño, Pons and Setoain.  ... 
doi:10.3389/fneur.2019.00380 pmid:31057476 pmcid:PMC6478660 fatcat:lmnbydeccnbavd3ialfkpfrs2y

Corrección de atenuación en equipos PET-RM. Comparación de métodos mediante simulación Monte Carlo

José Pablo Cabello García, Roser Sala-Llonch, Raúl Tudela Fernández, Domènec Ros Puig, Javier Pavía Segura, Aida Niñerola Baizán
2020 Revista española de Física Médica  
La visualización y cuantificación adecuadas de una imagen de tomografía por emisión de positrones (PET) requiere la corrección por la atenuación que sufren los fotones al atravesar el medio. En un equipo híbrido que combina PET con resonancia magnética (RM), la señal de RM no puede convertirse en valores de atenuación de forma directa. En este trabajo se analizaron dos métodos de estimación del mapa de atenuación, el primero basado en segmentación de la imagen RM y el segundo en un promedio de
more » ... mágenes de tomografía computarizada (TC) a partir de múltiples sujetos. El estudio se realizó utilizando imágenes PET obtenidas mediante simulación Monte Carlo y el parámetro cuantitativo evaluado fue el valor de captación estandarizado relativo (SUVr) tomando como región de referencia el cerebelo. La comparación de los resultados obtenidos con cada método con los correspondientes al utilizar la imagen TC propia de cada paciente (considerado como gold standard) indica que: 1) ambos métodos pierden exactitud en la zona próxima al tejido óseo, 2) en un análisis de SUVr por regiones, el método que utiliza segmentación a partir de la imagen de RM da mejores resultados con diferencias relativas máximas en torno al 5% frente al gold standard.
doi:10.37004/sefm/2020.21.2.004 fatcat:uqx3ooz26jbfffpl7gf63ok7la

CSF neurofilament light levels predict hippocampal atrophy in cognitively healthy older adults

Ane-Victoria Idland, Roser Sala-Llonch, Tom Borza, Leiv Otto Watne, Torgeir Bruun Wyller, Anne Brækhus, Henrik Zetterberg, Kaj Blennow, Kristine Beate Walhovd, Anders Martin Fjell
2017 Neurobiology of Aging  
Sala-Llonch.  ...  paper I, Sala-Llonch inspected reconstructed surfaces and volumes from individual and longitudinal processing steps, e.g. skull stripping, and gray-white matter segmentation, and performed manual corrections  ... 
doi:10.1016/j.neurobiolaging.2016.09.012 pmid:27794264 fatcat:6sgqujw7jjclhg7mxtvoqptvjy

MRI decline pattern in early onset MCI due to Alzheimer's disease

José Contador, Roser Sala‐Llonch, Agnés Pérez‐Millan, Mircea Balasa, Sergi Borrego‐Écija, Raquel Sanchez‐Valle, Albert Lladó, Alzheimer's Disease Neuroimaging Initiative
2020 Alzheimer's & Dementia  
Structural neuroimaging longitudinal studies in Alzheimer's disease (AD) have consistently defined a "cortical signature" of gray matter loss. Apparently, earlyonset AD (EOAD) has a greater density of amyloid, a more generalized atrophy and a more aggressive evolution than late-onset AD (LOAD). We hypothesize EOAD would show pronounced longitudinal cortical atrophy, especially in associative areas like precuneus and in addition to temporal lobe loss. Methods: We investigate longitudinal 3T-MRI
more » ... tructural data from the Alzheimer's disease Neuroimaging Initiative (ADNI) 2 cohort. We included patients aged ≤65 years with a baseline mild cognitive impairment (MCI) diagnosis. According to AD biomarkers at baseline, patients were divided into MCI due to AD with high likelihood (MCI-AD) and MCI unlikely due to AD (MCI-nonAD). We downloaded the summary of longitudinal measures for volume and cortical thickness. We used linear mixed effects in SPSS25 with data at baseline and month 24 to compare atrophy progression between groups. We focused on "AD's cortical signature", including entorhinal, inferior temporal, middle temporal, inferior parietal, fusiform areas, and also precuneus and posterior cingulate. In addition, we studied volume of hippocampus (HpV) and total subcortical supratentorial (SSupratV). We tested for group by time interactions and significance level was set at p<0.05, FDR corrected. Results : We included 22 MCI-AD and 26 MCI-nonAD patients. MMSE mean score was lower in MCI-AD [Table1]. MCI-AD had significant lower baseline Cth in precuneus, middle temporal and entorhinal and lower HpV. At group by time interactions, MCI-AD showed significant greater CTh atrophy in middle temporal, enthorhinal and posterior cingulate, and higher volume decrease in HpV and SSupratV than MCI-nonAD [Figure1]. Notably, the rest of areas studied were not significantly different at baseline or at group by time effects. Conclusion: Compared to MCI-nonAD, MCI-AD showed greater decline in only some of the areas previously defined as the cortical AD signature and in hippocampal volume and global subcortical volume. The study could be biased by the small sample size,
doi:10.1002/alz.037405 fatcat:q33cmf555nfxdgn2hoalt6quf4
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