Brain, language, and handedness: a family affair

The left planum temporale is a marker of left hemisphere language specialization. We investigated the effect of individual handedness and familial sinistrality on left planum temporale surface area and found the size is reduced in proportion with the number of left-handed immediate family members and is lowest when one's mother is left-handed. This reduction is independent of an individual's handedness or sex and has no counterpart in the right hemisphere

Effects of blood pressure lowering on cerebral white matter hyperintensities in patients with stroke: the PROGRESS (Perindopril Protection Against Recurrent Stroke Study) Magnetic Resonance Imaging Substudy.: The PROGRESS MRI Substudy.

International audienceBACKGROUND: The prevalence of white matter hyperintensities (WMHs) detected on cerebral MRI is associated with hypertension, but it is not known whether blood pressure lowering can arrest their progression. We report here the results of an MRI substudy of PROGRESS (Perindopril Protection Against Recurrent Stroke Study), a randomized trial of blood pressure lowering in subjects with cerebrovascular disease. METHODS AND RESULTS: The substudy comprised 192 participants who had a cerebral MRI both at baseline and after a mean follow-up time of 36 months (SD=6.0 months). At the first MRI, WMHs were graded with a visual rating scale from A (no WMH) to D (severe WMH). Participants were assigned to a combination of perindopril plus indapamide (or their placebos; 58%) or to single therapy with perindopril (or placebo). At the time of the second MRI, the blood pressure reduction in the active arm compared with the placebo arm was 11.2 mm Hg for systolic blood pressure and 4.3 mm Hg for diastolic blood pressure. Twenty-four subjects (12.5%) developed new WMHs at follow-up. The risk of new WMH was reduced by 43% (95% CI -7% to 89%) in the active treatment group compared with the placebo group (P=0.17). The mean total volume of new WMHs was significantly reduced in the active treatment group (0.4 mm3 [SE=0.8]) compared with the placebo group (2.0 mm3 [SE=0.7]; P=0.012). This difference was greatest for patients with severe WMH at entry, 0.0 mm3 (SE=0) in the active treatment group versus 7.6 mm3 (SE=1.0) in the placebo group (P<0.0001). CONCLUSIONS: These results indicate that an active blood pressure-lowering regimen stopped or delayed the progression of WMHs in patients with cerebrovascular disease

Heteromodal brain areas common to production, listening and reading tasks at the word Level: an fMRI study of 144 right-handers from the BIL&GIN

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The Skin-Conductance Component of Error Correction in a Logical Reasoning Task

La Réponse ÉlectroDermale (RED) a été mesurée à deux reprises chez les mêmes sujets qui réalisaient une tâche de logique déductive, d’abord en commettant une erreur de raisonnement et ensuite, après un apprentissage, soit en répondant correctement, soit en persévérant dans l’erreur selon les sujets. La RED s’est accrue entre les deux sessions et était significativement plus importante chez les sujets qui corrigeaient leur erreur initiale de raisonnement que chez les autres, révélant la forte interconnexion entre le raisonnement logique et les indices d’états somatiques impliqués dans l’émotion. Cela corrobore les résultats d’études antérieures d’imagerie cérébrale réalisées dans notre groupe et indiquant que l’accès à la logique déductive dépend du cortex préfrontal ventromédian droit dont on connaît l’implication dans la représentation afférente de la RED et dans l’intégration émotion-cognition.Skin Conductance Responses (SCRs) were measured in a deductive logic task performed twice by the same subjects, first making reasoning errors and then, after training, providing logical responses or making errors again, depending on the subject. SCRs increased between the two sessions and were significantly higher in the subjects who corrected their reasoning errors than in those that did not, showing the strong interplay between logical reasoning and indices of somatic states involved in emotion. This fits well with the results of previous brain imaging studies from our group showing that access to deductive logic depends on a right ventromedial prefrontal area involved in SCRs afferent representation and emotion-cognition integration

Multi-Channel Stochastic Variational Inference for the Joint Analysis of Heterogeneous Biomedical Data in Alzheimer's Disease

The joint analysis of biomedical data in Alzheimer's Disease (AD) is important for better clinical diagnosis and to understand the relationship between biomarkers. However, jointly accounting for heterogeneous measures poses important challenges related to the modeling of the variability and the interpretability of the results. These issues are here addressed by proposing a novel multi-channel stochastic generative model. We assume that a latent variable generates the data observed through different channels (e.g., clinical scores, imaging, ...) and describe an efficient way to estimate jointly the distribution of both latent variable and data generative process. Experiments on synthetic data show that the multi-channel formulation allows superior data reconstruction as opposed to the single channel one. Moreover, the derived lower bound of the model evidence represents a promising model selection criterion. Experiments on AD data show that the model parameters can be used for unsupervised patient stratification and for the joint interpretation of the heterogeneous observations. Because of its general and flexible formulation, we believe that the proposed method can find important applications as a general data fusion technique.Comment: accepted for presentation at MLCN 2018 workshop, in Conjunction with MICCAI 2018, September 20, Granada, Spai

Structural brain lesions and restless legs syndrome: a cross-sectional population-based study

Objective: To evaluate the association between white matter lesion (WML) volume, silent infarcts and restless legs syndrome (RLS) in a population-based study of elderly individuals. Design: Cross-sectional study. Setting: Population-based Three-City study. Participants: 1035 individuals from the Dijon, France, centre of the Three-City study who had available information on volume of WMLs from MRIs and who answered questions about the prevalence of RLS. Primary outcome measure Prevalence of RLS. Results: WML volume was measured using an automated tissue segmentation method. Logistic regression was used to evaluate adjusted associations between tertiles of WML volume and RLS and between silent infarcts and RLS. 218 individuals (21.1%) were determined to have RLS. Compared with those in the first tertile of WML volume, individuals in the second tertile (OR=1.09; 95% CI 0.75 to 1.60) or third tertile (OR=1.17; 95% CI 0.79 to 1.74) did not have an increased prevalence of RLS. We also did not observe associations between the volume of deep or periventricular WML and RLS; nor did we observe an association between silent brain infarcts and RLS (OR=0.74; 95% CI 0.40 to 1.39). These findings were not modified by age or gender. Conclusions: Higher volume of WML and the presence of silent infarcts were not associated with an increased prevalence of RLS in this population-based cohort of elderly individuals

Cortical Terminations of the Inferior Fronto-Occipital and Uncinate Fasciculi: Anatomical Stem-Based Virtual Dissection

International audienceWe combined the neuroanatomists' approach of defining a fascicle as all fibers passing through its compact stem with diffusion-weighted tractography to investigate the cortical terminations of two association tracts, the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus (UF), which have recently been implicated in the ventral language circuitry. The aim was to provide a detailed and quantitative description of their terminations in 60 healthy subjects and to do so to apply an anatomical stem-based virtual dissection, mimicking classical post-mortem dissection, to extract with minimal a priori the IFOF and UF from tractography datasets. In both tracts, we consistently observed more extensive termination territories than their conventional definitions, within the middle and superior frontal, superior parietal and angular gyri for the IFOF and the middle frontal gyrus and superior, middle and inferior temporal gyri beyond the temporal pole for the UF. We revealed new insights regarding the internal organization of these tracts by investigating for the first time the frequency, distribution and hemispheric asymmetry of their terminations. Interestingly, we observed a dissociation between the lateral right-lateralized and medial left-lateralized fronto-occipital branches of the IFOF. In the UF, we observed a rightward lateralization of the orbito-frontal and temporal branches. We revealed a more detailed map of the terminations of these fiber pathways that will enable greater specificity for correlating with diseased populations and other behavioral measures. The limitations of the diffusion tensor model in this study are also discussed. We conclude that anatomical stem-based virtual dissection with diffusion tractography is a fruitful method for studying the structural anatomy of the human white matter pathways

Inunditos como análogos de reservatórios: um exemplo nos depósitos gonduânicos triássicos do Gráben Arroio Moirão, RS

O estudo de reservatórios de óleo e gás de sistemas continentais tem enfatizado, na última década, arenitos associados a inunditos, provenientes de fluxos hiperpicnais. Contudo, há poucos estudos para entender sua arquitetura e heterogeneidade, resultando em dificuldades de reconhecimento e de exploração. O presente trabalho visa à análise de pacotes triássicos da Bacia do Paraná pertencentes à Formação Santa Maria, que ocorrem como fragmentos isolados sobre o Escudo Sul-Rio-Grandense na região do Gráben Arroio Moirão (RS). Para tanto, fez-se uso de mapeamento sistemático, análise de heterogeneidade de fácies e estratigrafia de sequências, que incluem levantamento de perfis colunares, identificação de associações e sucessões de fácies e superfícies-chave. Além disso, classificaram-se os arenitos e qualificou-se a porosidade com base na análise petrográfica. Foi possível delimitar os principais depósitos de arenitos, no quais predomina geometria tabular, grãos mal selecionados e matriz argilosa. Distinguiram-se cinco ciclos deposicionais granodecrescentes ascendentes, limitados na base e no topo por superfícies erosivas, que marcam heterogeneidades recorrentes. As fácies-reservatório foram classificadas como subarcósios, de matriz argilosa oxidada, com agregados de caulinita, e porosidade intergranular do tipo shrinkage. A integração dos dados resultou na elaboração de um modelo de variação lateral e vertical de fácies de depósitos de inunditos. Nele, identificaram-se fácies constituídas por arenitos grossos a conglomeráticos, com estratificações cruzada tangencial e plano-paralela, como potenciais modelos análogos de reservatórios. Esses resultados possibilitam prospectar outros depósitos arenosos dessa unidade estratigráfica da Bacia do Paraná, para fins de dimensionar regionalmente o análogo de reservatório.The study of oil and gas reservoirs in continental systems has emphasized, in the last decade, sandstones associated with inundites, coming from hyperpicnal flows. However, there are few studies to understand its architecture and heterogeneity, resulting in difficulties for exploration and exploitation. The current work aims at the analysis of Triassic strata from the Paraná Basin belonging to the Santa Maria Formation, which occur as isolated fragments on the Sul-rio-grandense Shield in Arroio Moirão Graben (RS). For this, systematic mapping, facies heterogeneity analysis and sequence stratigraphy were used, including columnar profiles, identification of associations and sequences of facies and key surfaces. In addition, the sandstones were classified and the porosity was qualified based on the petrographic analysis. It was possible to define the main deposits of sandstones, in which predominate tabular geometry, poorly selected grains and clayey matrix. Five ascending granodecrescent depositional cycles were distinguished, limited at the base and at the top by erosive surfaces, which marked recurrent heterogeneities. The reservoir facies were classified as subarcósios, of oxidized clay matrix, with aggregates of kaolinite, and intergranular porosity of the shrinkage type. The integration of the data resulted in the elaboration of a model of lateral and vertical variation inundites deposits facies. In it, facies composed of conglomeratic thick sandstones were identified, with tangential cross stratification and planar stratification, as potential analog models of reservoirs. These results allow the prospection of other sandy deposits from this stratigraphic unit of the Paraná Basin, in order to size the reservoir analogue regionally

Motor function in the elderly: evidence for the reserve hypothesis.

International audienceThe reserve hypothesis accounts for the lack of direct relationship between brain pathology and its clinical manifestations. Research has mostly focused on cognition; our objective is to examine whether the reserve hypothesis applies to motor function. We investigated whether education, a marker of reserve, modifies the association between white matter lesions (WMLs), a marker of vascular brain damage, and maximum walking speed (WS), an objective measure of motor function. We also examined the cross-sectional and longitudinal association between education and WS. Data are from 4,010 participants aged 65-85 years in the longitudinal Three-City-Dijon Study with up to 4 WS measures over 10 years. We examined the interaction between education and WMLs for baseline WS. We studied the association between education and repeated WS measures using linear mixed models, and the role of covariates in explaining the education-WS association. Education was strongly associated with baseline WS; the difference in mean WS between the high and low education groups (0.145 m/s, 95% confidence interval = 0.125-0.165) was equivalent to 7.4 years of age. WMLs were associated with slow WS only in the low education group (p interaction = 0.026). WS declined significantly over time (-0.194 m/s/10 years, 95% confidence interval = -0.206, -0.182), but education did not influence rate of decline. Anthropometric characteristics, parental education, general health, and cognition had the strongest role in explaining the baseline education-WS association. Participants with more education were less susceptible to WMLs' effect on motor function. Higher education was associated with better motor performances but not with motor decline. These results are consistent with the passive reserve hypothesis