636 research outputs found
Edinburgh_NIH10
No full textThis data set contains 10 normal healthy subjects ('sub-001' to 'sub-010') from a larger NIH funded project (NIH grant R01 EB004155) investigating changes in water diffusion parameters with age. Subjects underwent structural and diffusion MRI at 1.5 T and provided images suitable for a wide range of analyses, e.g. tractography, connectome etc
Quantifying the time course of visual object processing using ERPs: it's time to up the game
No full textHundreds of studies have investigated the early ERPs to faces and objects using scalp and intracranial recordings. The vast majority of these studies have used uncontrolled stimuli, inappropriate designs, peak measurements, poor figures, and poor inferential and descriptive group statistics. These problems, together with a tendency to discuss any effect p < 0.05 rather than to report effect sizes, have led to a research field very much qualitative in nature, despite its quantitative inspirations, and in which predictions do not go beyond condition A > condition B. Here we describe the main limitations of face and object ERP research and suggest alternative strategies to move forward. The problems plague intracranial and surface ERP studies, but also studies using more advanced techniques – e.g., source space analyses and measurements of network dynamics, as well as many behavioral, fMRI, TMS, and LFP studies. In essence, it is time to stop amassing binary results and start using single-trial analyses to build models of visual perception
Masks2Metrics (M2M): A Matlab Toolbox for Gold Standard Morphometrics
No full textHuman brains undergo morphometric changes over a lifetime, from conception through to birth, infancy, adolescence, adulthood, and old age (Thambisetty et al. (2010); Madan and Kensinger (2016)). This is further compounded by the changes associated with var-ious brain pathologies such as tumours (e.g. Bauer et al. (2013)) and dementia (e.g., B. C. Dickerson et al. (2011)). It is therefore essential to accurately and scientifically characterise such changes by using an array of morphologic measurements, for a better un-derstanding of the natural progression of ageing and disease (Mills et al. (2016); Madan (2017)). While many existing brain image analysis tools (e.g., FreeSurfer (Fischl et al. (2004); Desikan et al. (2006)), BrainSuite (Shattuck and Leahy (2002)), and BrainVISA (Kochunov et al. (2012))) automatically compute such data from a 3-dimensional (3D) brain image, they lack the ability to do so for the equivalent manually-traced regions of interest (ROIs). This is all the more significant as such ROIs are considered as the gold standard, thus making knowledge of their metrics essential. We have developed an automated Matlab-based tool, Masks2Metrics (Mikhael and Gray (2017)), that calculates three metrics for a given ROI in a 3D image: thickness, volume and suface area. An ROI is defined by a pair of binary masks (in NIfTI file format) representing its outer and inner borders, each of which are drawn continuously along one direction (x-, y-or z-axis). In the specific case of brain images, when the ROI describes a gyrus, its paired masks would correspond to grey matter (GM) and white matter (WM) curves. The paired ROI NIfTI (.nii) masks are expected to be of the form subjroihemgm/wmsegments.nii. For example, a pair corresponding to subject 1's right SFG (superior frontal gyrus) would be 1sfgrgm1.nii and 1sfgrwm1.nii. A special feature of M2M is that multiple pairs, or segments, can be used rather than a single continuous ROI. These segments can be manually or automatically derived. The gener-ated ROI metrics are grey matter thickness (GMth), grey matter volume (GMvol),and white matter surface area (WMsa), also classically calculated by popular existing au-tomated tools (Fischl2000; Shattuck2002) . Additionally, the ROI's corresponding mean Fréchet(Ursell (2013)) and mean Modified Hausdorff Distance (SasiKanth (2011)) are calculated and saved as matrices
Solidarité du travail et du capital ou Organisation du crédit en France / par C. Pernet
No full textAvec mode text
La monnaie celtique, de la Guerre des Gaules à l’avènement d’Auguste, 60-30 av. J.-C.
No full textInternational audienc
Auditory comprehension: from the voice up to the single word level
No full textAuditory comprehension, the ability to understand spoken language, consists of a
number of different auditory processing skills. In the five studies presented in this
thesis I investigated both intact and impaired auditory comprehension at different
levels: voice versus phoneme perception, as well as single word auditory
comprehension in terms of phonemic and semantic content.
In the first study, using sounds from different continua of ‘male’-/pæ/ to ‘female’-/tæ/
and ‘male’-/tæ/ to ‘female’-/pæ/, healthy participants (n=18) showed that phonemes
are categorised faster than voice, in contradistinction with the common hypothesis that
voice information is stripped away (or normalised) to access phonemic content.
Furthermore, reverse correlation analysis suggests that gender and phoneme are
processed on the basis of different perceptual representations. A follow-up study (same
paradigm) in stroke patients (n=25, right or left hemispheric brain lesions, both with
and without aphasia) showed that lesions of the right frontal cortex (likely ventral
inferior frontal gyrus) leads to systematic voice perception deficits while left
hemispheric lesions can elicit both voice and phoneme deficits. Together these results
show that phoneme processing is lateralized while voice information processing
requires both hemispheres. Furthermore, this suggests that commencing Speech and
Language Therapy at a low level of acoustic processing/voice perception may be an
appropriate method in the treatment of phoneme perception impairments.
A longitudinal case study (CF) of crossed aphasia (rare acquired communication
impairment secondary to lesion ipsilateral to the dominant hand) is then presented
alongside a mini-review of the literature. Extensive clinical investigation showed that
CF presented with word-finding difficulties related to impaired auditory phonological
analysis, while functional Magnetic Resonance Imaging (fMRI) analyses showed right
hemispheric lateralization of language functions (reading, repetition and verb
generation). These results, together with the co-morbidity analysis from the mini-review,
suggest that crossed aphasia can be explained by developmental disorders
which cause partial right lateralization shift of language processes. Interestingly, in CF
this process did not affect voice lateralization and information processing, suggesting
partial segregation of voice and speech processing.
In the last two studies, auditory comprehension was examined at the single word level
using a word-picture matching task with congruent (correct target) and incongruent
(semantic, phonological and unrelated foils) conditions. fMRI in healthy participants
(n=16) revealed a key role of the pars triangularis (phonological processing), the left
angular gyrus (semantic incongruency) and the left precuneus (semantic relatedness)
in this task – regions typically associated via the arcuate fasciculus and often impaired
in aphasia. Further investigation of stroke patients on the same task (n=15) suggested
that the connections between the angular gyrus and the pars triangularis serve a
fundamental role in semantic processing. The quality of a published word-picture
matching task was also investigated, with results questioning the clinical relevance of
this task as an assessment tool.
Finally, a pilot study looking at the effect of a computer-assisted auditory
comprehension therapy (React2©) in 6 stroke patients (vs. 6 healthy controls and 6
stroke patients without therapy) is presented. Results show that the more therapy
patients carry out the more improvement is seen in the semantic processing of single
nouns. However, these results need to be reproduced on a larger scale in order to
generalise any outcomes.
Overall, the findings from these studies present new insight into, as well as extending
on, current cognitive and neuroanatomical models of voice perception, speech
perception and single word auditory comprehension. A combinatorial approach to
cognitive and neuroanatomical models is proposed in order to further research, and
thus improve clinical care, into impaired auditory comprehension
Co-registration of EEG and eye movements: effects of context on stimulus processing
No full textThe processing of a stimulus in isolation versus within a context was investigated while EEG and eye movements were simultaneously recorded. Specifically, 356 words and 356 nonwords were presented to 8 participants in both a word/nonword task and in sentences for reading over two experimental sessions. EEG (128 BIOSEMI) and eye movement (SR EyeLink 1000) signals were co-registered. Methods for removing eye movement artefacts from the EEG typically require extrapolation from a separate calibration data source to the experimental data. With co-registration, however, artefact detection and rejection is enhanced by matching the independent components of the experimental EEG data to the actual eye movement record. After signal pre-processing, data were analyzed using a single-trial general linear model [Pernet, Chauveau, Gaspar, and Rousselet, 2011, Computational Intelligence and Neuroscience, Article ID 831409, 11 pages, doi:10.1155/2011/831409]. The model included several regressors related to word variables (e.g., length, frequency of occurrence, imageability, number of syllables), task variables (e.g., task, session), and concurrent eye movement behavior (e.g., fixation position and duration, saccade length). The temporal dynamics of information sensitivity and its specificity to task demands is discussed
Non-motivation de la DUP et constitutionnalité de l'article L. 11-1-1-3 du code de l'expropriation
No full textInternational audienceConseil d'État, 26 déc. 2013, n° 364498, Pernet c/ Ministère de l'Écologie, du Développement durable et de l'Énergi
Morphometric data for Edinburgh_NIH10 dataset - all package runs
No full textThis data consists of morphometric measurements for the 10 subjects of the Edinburgh_NIH10 dataset (https://doi.org/10.7488/ds/2239) as well as Matlab code written to derive some statistics for these measurements. The measurements are for the superior frontal gyrus (SFG), supramarginal gyrus (SMG) and cingulate gyrus (CG), and entail:
- cortical thickness, cortical volume and white matter surface area measurements following processing of the T1-weighted volumes in FreeSurfer v5.3 (Desikan-Killiany protocol and Desikan-Killiany-Touriville protocols), BrainSuite v13a, and BrainGyrusMapping.
- cortical thickness, cortical volume and white matter surface area measurements of the manually segmented reference truth data as calculated by Masks2Metrics (https://doi.org/10.21105/joss.00436), FreeSurfer, BrainSuite, and BrainGyrusMapping, where available
- mean modified Hausdorff distance of the manually segmented reference data as calculated by Masks2Metrics (https://doi.org/10.21105/joss.00436). With thanks to SINAPSE-SPIRIT for funding (a Scottish Funding Council HR09021 grant).This data consists of morphometric measurements for the 10 subjects of the Edinburgh_NIH10 dataset (https://doi.org/10.7488/ds/2239) as well as Matlab code written to derive some statistics for these measurements
Jacques Berque, Jean-Paul Charnay et Gabriel Ardant, Kostas Axelos, Charles Bettelheim, Guy de Bosschère, Jean Chesneaux, Pierre Сot, Jean Cuisenier, Jeanne Cuisinier, Jean- Yves Eichenberger, Joseph Foray, Paulette Galand-Pernet, Georges Guéron, Jean Lacouture, Henri Laugier, Lê Thành Khôì, Pierre Marthelot, Pierre Meile, Daniel Pepy, Jean Poncet, Pierre Rondot, Hervé Sicard, J.-C. Sournia, Pierre Vermel, De l'impérialisme à la décolonisation
No full textGuillot Jean. Jacques Berque, Jean-Paul Charnay et Gabriel Ardant, Kostas Axelos, Charles Bettelheim, Guy de Bosschère, Jean Chesneaux, Pierre Сot, Jean Cuisenier, Jeanne Cuisinier, Jean- Yves Eichenberger, Joseph Foray, Paulette Galand-Pernet, Georges Guéron, Jean Lacouture, Henri Laugier, Lê Thành Khôì, Pierre Marthelot, Pierre Meile, Daniel Pepy, Jean Poncet, Pierre Rondot, Hervé Sicard, J.-C. Sournia, Pierre Vermel, De l'impérialisme à la décolonisation. In: Tiers-Monde, tome 7, n°25, 1966. Industrialisation et intégration en Amérique latine. Le cas de l'Argentine. pp. 181-184
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