Towards Measuring states of curiosity through Electroencephalography and body sensors responses

International audienceThe neurophysiological mechanisms underlying curiosity and intrinsic motivation are currently not well understood. However, being able to identify objectively, from neurophysiological signals, the curiosity level of a user, would bring a very useful tool both to neuroscientists and psychologists, to understand curiosity deeper, as well as to designers of human-computer interaction, in order to trigger curiosity or to adapt an interaction to the curiosity levels of its users. A first step to do that, is to collect neurophysiological signals during known states of curiosity, in order to develop signal processing/machine learning tools to recognize those states from such signals. We propose an experimental protocol, that has been designed but has not been tested so far, in order to measure both brain activity through Electroencephalography (EEG) and physiological responses (heart rate, skin conductance, Electrocardiogram) when subjects are induced into different states of curiosity. During the experiment, fun facts will be presented to subjects to induce different levels of curiosity. We obtained those fun facts using the Google functionality "I’m feeling curious" as well as crowdsourcing. A subject will be able to choose a fun fact that makes him curious, and push forward with a 4-to-10 questions chain on this theme. For each question on a given theme, a subject will be able to reveal the answer (interpreted as a curious state) or to skip it (interpreted as a non-curious state). Skipping an answer will automatically break the chain and will point the subject to the next fun fact. Neurophysiological signals will be collected between a question and the choice of revealing the answer. Then the subject will grade the question on a 1-to-7 curiosity level scale. Neurophysiological measures during these states of curiosity will be recorded and we expect to find biological markers of curiosity by analyzing such information

Towards measuring states of epistemic curiosity through electroencephalographic signals

International audienceUnderstanding the neurophysiological mechanisms underlying curiosity and therefore being able to identify the curiosity level of a person, would provide useful information for researchers and designers in numerous fields such as neuroscience, psychology, and computer science. A first step to uncovering the neural correlates of curiosity is to collect neurophysiological signals during states of curiosity, in order to develop signal processing and machine learning (ML) tools to recognize the curious states from the non-curious ones. Thus, we ran an experiment in which we used electroencephalography (EEG) to measure the brain activity of participants as they were induced into states of curiosity, using trivia question and answer chains. We used two ML algorithms, i.e. Filter Bank Common Spatial Pattern (FBCSP) coupled with a Linear Discriminant Algorithm (LDA), as well as a Filter Bank Tangent Space Classifier (FBTSC), to classify the curious EEG signals from the non-curious ones. Global results indicate that both algorithms obtained better performances in the 3-to-5s time windows, suggesting an optimal time window length of 4 seconds (63.09% classification accuracy for the FBTSC, 60.93% classification accuracy for the FBCSP+LDA) to go towards curiosity states estimation based on EEG signals

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

From physical inactivity to immobilization: Dissecting the role of oxidative stress in skeletal muscle insulin resistance and atrophy.

In the literature, the terms physical inactivity and immobilization are largely used as synonyms. The present review emphasizes the need to establish a clear distinction between these two situations. Physical inactivity is a behavior characterized by a lack of physical activity, whereas immobilization is a deprivation of movement for medical purpose. In agreement with these definitions, appropriate models exist to study either physical inactivity or immobilization, leading thereby to distinct conclusions. In this review, we examine the involvement of oxidative stress in skeletal muscle insulin resistance and atrophy induced by, respectively, physical inactivity and immobilization. A large body of evidence demonstrates that immobilization-induced atrophy depends on the chronic overproduction of reactive oxygen and nitrogen species (RONS). On the other hand, the involvement of RONS in physical inactivity-induced insulin resistance has not been investigated. This observation outlines the need to elucidate the mechanism by which physical inactivity promotes insulin resistance

Le comportement de l'arsenic (As) et de l'antimoine (Sb) dans les fluides provenant de différents systèmes hydrothermaux océaniques

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Détermination expérimentale du moment dipolaire de mérocyanines hétérocycliques

Les moments dipolaires de mérocyanines α-oxo et γ-oxo benzoLInazoliniqucs, α-oxo benzimidazoliniques et γ-oxo benzodithioliques ont clé déterminés dans le benzène et dans un mélange benzène-chloroforme. Les difficultés expérimentales dues à la très faible solubilité de certains de ces composés et à leur forte coloration nous ont amenés à utiliser les méthodes de Halverstadt et Kumler et de Gilkerson et Srivastava. L’analyse des moments électriques met en évidence une séparation de charge limitée pour les composés azahétérocycliques. La polarisation est pratiquement nulle dans le cas des substrats benzodithioliques. Par ailleurs la forte polarisabilité de certains solutés a pu être constatée

Solvatochromie de mérocyanines analogues aux formes colorées de spiropyrannes photochromes

En utilisant les théories de Mac Rae eL de Kawski sur les diets de solvant et en appliquant la formulation de la variation des déplacements de Stokes [math] en fonction de la polarité des solvants, nous avons déterminé les moments dipolaires de mérocyanines α-oxo benzothiazoliniques α-oxo benzimi- dazoliniques et γ-oxo benzodithioliques, dans leur premier état singulet excité.Ces composés sont analogues aux photomérocyanines obtenues par photolyse de spiropyrannes. Les valeurs ainsi déterminées nous permettent d’envisager des modifications importantes de la distribution électronique de ces formes colorées dans leur état excité et de proposer une première corrélation qualitative entre cette nouvelle répartition électronique et différents résultats expérimentaux concernant les phénomènes de photodécoloration et de photodégradation

Solvatochromie de mérocyanines analogues aux formes colorées de spiropyrannes photochromiques

Les fréquences d’absorption et de fluorescence des transitions de plus basse énergie de quelques mérocyanines α-oxo benzothiazoliniques et benzimidazoliniques et γ-oxo-benzodithioliques ont été mesurées dans trente et un solvants de différentes polarités. La structure de ces composés, surtout pour les dérivés α-oxo est proche de celle des photomérocyanines obtenues par photolyse des spiropyrannes.Les différents termes de la théorie de Mac Rae sont analysés de façon détaillée. Nous avons étudié les effets des interactions dipolaires électriques et de dispersion sur les déplacements de fréquence observés pour des bandes électroniques de plus basse énergie.Le rôle important joué par l’indice de réfraction du solvant a été mis en évidence pour les solutés benzodithioliques présentant une solvatochromie positive. La différence entre les échelles de polarité des solvants χR et χB proposées par Brooker a pu être interprétée. Les solutés benzothiazoliniques et benzimidazoliniques présentent une solvatochromie négative.La solvatochromie particulière observée avec les solvants alcooliques a été attribuée à une interaction spécifique (formation d’une liaison hydrogène) entre le soluté et le solvant et a permis une étude de la basicité de ces composés. Enfin, nous avons expliqué l’inversion de solvatochromie observée pour ces solvants sur les spectres de fluorescence

Yttrium and rare earth elements in fluids from various deep-sea hydrothermal systems

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L'hydrothermalisme océanique

International audienceMots cles.-Dorsale medio-oceanique, Hydrothermalisme. Resume.-Jusque 1979, les etudes oceaniques concernaient principalement l'histoire de l'ouverture d'un ocean (en utilisant la memoire magn£tique des roches formees a l'axe d'une dorsale medio-oc6anique), l'examen des differentes morphologies axiales (fonction du taux d'expansion oceanique, de 1 a 18 cm/an) et la variabilite des proprietes geochimiques des laves basaltiques (rapports isotopiques, terres rares...). Ces etudes ont ete conduites (ou presque) comme s'il n'existait aucune relation entre l'ocean et le systeme dorsale medio-oceanique. La decouverte des sources hydrothermales haute temperature (350°C) a l'axe de la dorsale est-pacifique en 1979 a revele d'une maniere spectaculaire l'importance des echanges entre l'eau de mer et la croflte oceanique jeune, a l'interface ocean-lithosphere. Les observations, mesures et theories qui laissaient prevoir l'importance des echanges ocean-lithosphere bien avant 1979 sont examinees. Les nouvelles decouvertes « ocean-lithosphere » mobilisent plusieurs disciplines, geophysique, geochimie, chimie oceanographique, biologie, dans le cadre de programmes internationaux