A5065638346- Functional Brain Connectivity Studies
- Advanced Neuroimaging Techniques and Applications
- Advanced MRI Techniques and Applications
- Neurobiology of Language and Bilingualism
- Mental Health Research Topics
- Dementia and Cognitive Impairment Research
- Neural dynamics and brain function
- Alzheimer's disease research and treatments
- Neurological disorders and treatments
- Medical Image Segmentation Techniques
- Neural Networks and Applications
- EEG and Brain-Computer Interfaces
- Health, Environment, Cognitive Aging
- Neural and Behavioral Psychology Studies
- Visual perception and processing mechanisms
- Transcranial Magnetic Stimulation Studies
- Hemispheric Asymmetry in Neuroscience
- Neuroscience and Neuropharmacology Research
- Epilepsy research and treatment
- Bioinformatics and Genomic Networks
- Action Observation and Synchronization
- Health disparities and outcomes
- Electroconvulsive Therapy Studies
- MRI in cancer diagnosis
- NMR spectroscopy and applications
University of Lausanne
2016-2025
University Hospital of Lausanne
2013-2023
University of Oxford
2019
Wellcome Centre for Human Neuroimaging
2008-2011
University College London
2008-2011
National Hospital for Neurology and Neurosurgery
2008
Wellcome Trust
2008
MRC Cognition and Brain Sciences Unit
2003-2006
Medical Research Council
2006
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2001-2004
Detailed knowledge of the anatomy and connectivity pattern cortico-basal ganglia circuits is essential to an understanding abnormal cortical function pathophysiology associated with a wide range neurological neuropsychiatric diseases. We aim study spatial extent topography human basal in vivo . Additionally, we explore at anatomical level hypothesis coexistent segregated integrative loops. use probabilistic tractography on magnetic resonance diffusion weighted imaging data segment thalamus...
The processing of spoken language has been attributed to areas in the superior temporal lobe, where speech stimuli elicit greatest activation. However, neurobiological and psycholinguistic models have long postulated that knowledge about articulatory features individual phonemes an important role their perception comprehension. To probe possible involvement specific motor circuits speech-perception process, we used event-related functional MRI presented experimental subjects with syllables,...
Normal ageing is associated with characteristic changes in brain microstructure. Although vivo neuroimaging captures spatial and temporal patterns of age-related anatomy at the macroscopic scale, our knowledge underlying (patho)physiological processes cellular molecular levels still limited. The aim this study to explore tissue properties normal using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach cohort 26 adults,...
Neuroscience and clinical researchers are increasingly interested in quantitative magnetic resonance imaging (qMRI) due to its sensitivity micro-structural properties of brain tissue such as axon, myelin, iron water concentration. We introduce the hMRI-toolbox, an open-source, easy-to-use tool available on GitHub, for qMRI data handling processing, presented together with a tutorial example dataset. This toolbox allows estimation high-quality multi-parameter maps (longitudinal effective...
Anatomical structures and mechanisms linking genes to neuropsychiatric disorders are not deciphered. Reciprocal copy number variants at the 16p11.2 BP4-BP5 locus offer a unique opportunity study intermediate phenotypes in carriers high risk for autism spectrum disorder (ASD) or schizophrenia (SZ). We investigated variation brain anatomy deletion duplication carriers. Beyond gene dosage effects on global metrics, we show that of genomic copies negatively correlated gray matter volume white...
Abstract When speech is degraded, word report higher for semantically coherent sentences (e.g., her new skirt was made of denim) than anomalous good slope done in carrot). Such increased intelligibility often described as resulting from “top–down” processes, reflecting an assumption that higher-level (semantic) neural processes support lower-level (perceptual) mechanisms. We used time-resolved sparse fMRI to test top–down mechanisms, measuring activity while participants heard and presented...
Significance Electroconvulsive therapy is controversial: How does a major electrical discharge over half the brain result in recovery disorders such as refractory depression and manic depression, which are apparently different diseases? We find local but not general anatomy changes following electroconvulsive that differently distributed each disease, areas affected those implicated abnormal disorder. An interaction between specific pathology appears to be responsible for therapeutic effect....
Despite the constant improvement of algorithms for automated brain tissue classification, accurate delineation subcortical structures using magnetic resonance images (MRI) data remains challenging. The main difficulties arise from low gray-white matter contrast iron rich areas in T1-weighted (T1w) MRI and lack adequate priors basal ganglia thalamus. most recent attempts to obtain such were based on cohorts with limited size that included subjects a narrow age range, failing account...
The human brain undergoes dramatic structural change over the life span. In a large imaging cohort of 801 individuals aged 7-84 years, we applied quantitative relaxometry and diffusion microstructure in combination with tractography to investigate tissue property dynamics across Significant nonlinear aging effects were consistently observed tracts measures. age at which white matter (WM) fascicles attain peak maturation varies substantially measurements tracts. These observations...
Abstract The high gray‐white matter contrast and spatial resolution provided by T1‐weighted magnetic resonance imaging (MRI) has made it a widely used protocol for computational anatomy studies of the brain. While image intensity in images is predominantly driven T1, other MRI parameters affect contrast, hence brain morphological measures derived from data. Because are correlates different histological properties tissue, this mixed contribution hampers neurobiological interpretation...
In this paper, we propose a new representation of the cortical surface that may be used to study cortex folding process and recover some putative stable anatomical landmarks called sulcal roots usually buried in depth adult brains. This is primal sketch derived from scale space computed for mean curvature surface. scale-space stems diffusion equation geodesic The made up objects defined minima saddle points. resulting aims first at highlighting significant elementary folds, second...
A methodology for fMRI data analysis confined to the cortex, Cortical Surface Mapping (CSM), is presented. CSM retains flexibility of General Linear Model based estimation, but procedures involved are adapted operate on cortical surface, while avoiding resort explicit flattening. The tested by means simulations and application a real protocol. results compared with those obtained standard, volume-oriented approach (SPM), it shown that leads local differences in sensitivity, generally higher...
Previous studies have demonstrated that a region in the left ventral occipito-temporal (LvOT) cortex is highly selective to visual forms of written words and objects relative closely matched stimuli. Here, we investigated why LvOT activation not higher for reading than picture naming even though pictures grossly different forms. To compare neuronal responses within same area, used functional magnetic resonance imaging adaptation instructed participants name target stimuli followed briefly...
The anatomy of the corpus callosum (CC) has been advocated as a potential marker for functional lateralization because its size is supposedly proportional to number fibers connecting hemispheres. Previous morphometric studies this relationship have compared CC in groups subjects who are more or less likely show differences their (e.g., left vs right handers). findings, however, inconsistent, and our knowledge, no previous study directly with assessed by imaging data. We therefore combined...
Suppressing irrelevant words is essential to successful speech production and expected involve general control mechanisms that reduce interference from task-unrelated processing. To investigate the neural suppress visual word interference, we used fMRI a Stroop task, using block design with an event-related analysis. Participants indicated finger press whether stimulus was colored pink or blue. The either written "BLUE," "PINK," string of four Xs, introduced when meaning its color were...
Category-specific brain activation distinguishing between semantic word types has imposed challenges on theories of representations and processes. However, existing metabolic imaging data are still ambiguous about whether these category-specific activations reflect processes involved in accessing the representation stimuli, or secondary such as deliberate mental imagery. Further information response characteristics is required. Our study for first time investigated differential impact...
Here, we ask whether frontotemporal cortex is functionally dissociated into distributed lexical and category-specific semantic networks. To this end, fMRI activation patterns elicited during the processing of words from different categories were categorized using k-means cluster algorithms. Results showed a pattern inferiorfrontal, superiortemporal, fusiform shared by word categories. This contrasted with in widely neural systems. Clustering revealed congruent functional specificity focal...
Despite advances in understanding basic organizational principles of the human basal ganglia, accurate vivo assessment their anatomical properties is essential to improve early diagnosis disorders with corticosubcortical pathology and optimize target planning deep brain stimulation. Main goal this study was detailed topological characterization limbic, associative, motor subdivisions subthalamic nucleus (STN) relation corresponding circuits. To aim, we used magnetic resonance imaging...
The failure of current strategies to provide an explanation for controversial findings on the pattern pathophysiological changes in Alzheimer's Disease (AD) motivates necessity develop new integrative approaches based multi-modal neuroimaging data that captures various aspects disease pathology. Previous studies using [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) and structural magnetic resonance imaging (sMRI) report results about time-line, spatial extent magnitude glucose...
Evidence from magnetic resonance imaging (MRI) studies shows that healthy aging is associated with profound changes in cortical and subcortical brain structures. The reliable delineation of cortex basal ganglia using automated computational anatomy methods based on T1-weighted images remains challenging, which results controversies the literature. In this study we use quantitative MRI (qMRI) to gain an insight into microstructural mechanisms underlying tissue ageing look for potential...