76 research outputs found

    Eye movements in response to different cognitive activities measured by eyetracking: a prospective study on some of the neurolinguistics programming theories

    Get PDF
    The eyes are in constant movement to optimize the interpretation of the visual scene by the brain. Eye movements are controlled by complex neural networks that interact with the rest of the brain. The direction of our eye movements could thus be influenced by our cognitive activity (imagination, internal dialogue, memory, etc.). A given cognitive activity could then cause the gaze to move in a specific direction (a brief movement that would be instinctive and unconscious). Neuro Linguistic Programming (NLP), which was developed in the 1970s by Richard Bandler and John Grinder (psychologist and linguist respectively), issued a comprehensive theory associating gaze directions with specific mental tasks. According to this theory, depending on the visual path observed, one could go back to the participant's thoughts and cognitive processes. Although NLP is widely used in many disciplines (communication, psychology, psychotherapy, marketing, etc), to date, few scientific studies have examined the validity of this theory. Using eye tracking, this study explores one of the hypotheses of this theory, which is one of the pillars of NLP on visual language. We created a protocol based on a series of questions of different types (supposed to engage different brain areas) and we recorded by eye tracking the gaze movements at the end of each question while the participants were thinking and elaborating on the answer. Our results show that 1) complex questions elicit significantly more eye movements than control questions that necessitate little reflection, 2) the movements are not random but are oriented in selected directions, according to the different question types, 3) the orientations observed are not those predicted by the NLP theory. This pilot experiment paves the way for further investigations to decipher the close links between eye movements and neural network activities in the brain

    How Does an Enriched Environment Impact Hippocampus Brain Plasticity?

    Get PDF
    Brain plasticity is profoundly impacted by one’s living environment. The hippocampus, involved in learning and memory, is highly susceptible to plasticity. Raising rodents in an “enriched environment” (EE) increases learning and memorization aptitudes and decreases the anxiety of the animals. EE consists of a combination of running wheels for voluntary physical exercise, complex inanimate toys, nests, mazes, etc. all of which favor sensory stimulations and social enrichment. EE housing concomitantly increases proliferation and survival of neurons and glia in the dentate gyrus of the hippocampus, induces changes in neuronal morphology, modifies synaptic plasticity, and favors angiogenesis. The mechanisms underlying the effects of EE on plasticity, which have recently been investigated are reviewed here, including the role of glia, the involvement of molecular factors including neurotransmitters (glutamate), neurotrophic factors (BDNF), adipokines (leptin and adiponectin), chemokines, cytokines, and hormones (corticosteroid and thyroid hormones), and at a higher level, the various systems involved (neural networks and hormonal systems). We emphasize recent findings that demonstrate the major role of the immune system in modulating EE-induced changes to hippocampal plasticity. This process involves a variety of immune cells (including macrophages, microglia, natural killer, B-cells, and T-cells), although the mechanisms are yet to be fully elucidated

    End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Get PDF
    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it

    On the action of the anti-absence drug ethosuximide in the rat and cat thalamus

    Get PDF
    The action of ethosuximide (ETX) on Na+, K+, and Ca2+ currents and on tonic and burst-firing patterns was investigated in rat and cat thalamic neurons in vitro by using patch and sharp microelectrode recordings. In thalamocortical (TC) neurons of the rat dorsal lateral geniculate nucleus (LGN), ETX (0.75-1 mM) decreased the noninactivating Na+ current, INaP, by 60% but had no effect on the transient Na+ current. In TC neurons of the rat and cat LGN, the whole-cell transient outward current was not affected by ETX (up to 1 mM), but the sustained outward current was decreased by 39% at 20 mV in the presence of ETX (0.25-0.5 mM): this reduction was not observed in a low Ca2+ (0.5 mM) and high Mg2+ (8 mM) medium or in the presence of Ni2+ (1 mM) and Cd2+ (100 µm). In addition, ETX (up to 1 mM) had no effect on the low-threshold Ca2+ current, I T, of TC neurons of the rat ventrobasal (VB) thalamus and LGN and in neurons of the rat nucleus reticularis thalami nor on the high-threshold Ca2+ current in TC neurons of the rat LGN. Sharp microelectrode recordings in TC neurons of the rat and cat LGN and VB showed that ETX did not change the resting membrane potential but increased the apparent input resistance at potentials greater than -60 mV, resulting in an increase in tonic firing. In contrast, ETX decreased the number of action potentials in the burst evoked by a low-threshold Ca2+ potential. The frequency of the remaining action potentials in a burst also was decreased, whereas the latency of the first action potential was increased. Similar effects were observed on the burst firing evoked during intrinsic δ oscillations. These results indicate an action of ETX on / NaP and on the Ca2+-activated K+ current, which explains the decrease in burst firing and the increase in tonic firing, and, together with the lack of action on low- and high-threshold Ca2+ currents, the results cast doubts on the hypothesis that a reduction of / τ in thalamic neurons underlies the therapeutic action of this anti-absence medicine

    End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Get PDF
    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance

    Utilisation de l'analyse automatisée de la parole et des mesures des émotions faciales sur des vidéos pour évaluer les effets des dispositifs de relaxation: une étude pilote

    Get PDF
    International audienceRapid relaxation installations in order to reduce stress appear more and more in public or work places. However, the effects of such devices on physiological and psychological parameters have not been scientifically tested yet. This pilot study (N=40) evaluates the variations of vocal speech and facial emotions parameters in 3-minute videos of participant recorded just before and after relaxation, on four different groups, three of them using a different rapid (15 minutes) sensorial immersion relaxation devices and a control group using no device. Vocal speech parameters included sound duration, pause mean duration, sound duration ratio, mean vocal frequency (F0), standard deviation of F0, minimum and maximum of F0, jitter and shimmer. Facial emotion analysis included neutral, happy, sad, surprised, angry, disgusted, scared, contempt, valence and arousal. The objective of this study is to evaluate different parameters of the automated vocal and facial emotions analysis that could be of use to evaluate the relaxation effect of different devices and to measure their variations in the different experimental groups. We identified significant parameters that can be of use for evaluating rapid relaxation devices, particularly voice prosody and minimum vocal frequency, and some facial emotion such as happy, sad, the valence and arousal. Those parameters allowed us to discriminate distinct effects of the different devices used: in G1 (control) and G2 (spatialized sounds), we observed a slowdown in voice prosody; in G3 (Be-Breathe) a decrease in minimum vocal frequency and an increase of arousal; while in G4 (3D-video) we found an increase in facial emotion valence (happy increasing and sad decreasing). Other parameters tested were not affected by relaxation.Les installations de relaxation rapide afin de réduire le stress apparaissent de plus en plus dans les lieux publics ou de travail. Cependant, les effets de ces dispositifs sur les paramètres physiologiques et psychologiques n'ont pas encore été testés scientifiquement. Cette étude pilote (N = 40) évalue les variations des paramètres de la parole vocale et des émotions faciales dans des vidéos de 3 minutes de participant enregistrées juste avant et après la relaxation, sur quatre groupes différents, trois d'entre eux utilisant une immersion sensorielle rapide (15 minutes) différente. des appareils de relaxation et un groupe témoin n'utilisant aucun appareil. Les paramètres de la parole vocale comprenaient la durée du son, la durée moyenne de la pause, le rapport de durée du son, la fréquence vocale moyenne (F0), l'écart type de F0, le minimum et le maximum de F0, la gigue et le miroitement. L'analyse des émotions faciales comprenait la neutralité, la joie, la tristesse, la surprise, la colère, le dégoût, la peur, le mépris, la valence et l'excitation. L'objectif de cette étude est d'évaluer différents paramètres de l'analyse automatisée des émotions vocales et faciales qui pourraient être utiles pour évaluer l'effet de relaxation de différents appareils et mesurer leurs variations dans les différents groupes expérimentaux. Nous avons identifié des paramètres significatifs qui peuvent être utiles pour évaluer les dispositifs de relaxation rapide, en particulier la prosodie de la voix et la fréquence vocale minimale, et certaines émotions faciales telles que le bonheur, la tristesse, la valence et l'excitation. Ces paramètres nous ont permis de discriminer des effets distincts des différents appareils utilisés: pour G1 (contrôle) et G2 (sons spatialisés), nous avons observé un ralentissement de la prosodie vocale; dans le groupe G3 (Be-Breathe) une diminution de la fréquence vocale minimale et une augmentation de l'éveil; enfin, pour G4 (vidéo 3D), nous avons trouvé une augmentation de la valence des émotions faciales (augmentation de la joie et diminution de la tristesse). Les autres paramètres testés n'ont pas été affectés par la relaxation

    Prion Protein Is a Key Determinant of Alcohol Sensitivity through the Modulation of N-Methyl-D-Aspartate Receptor (NMDAR) Activity

    Get PDF
    The prion protein (PrP) is absolutely required for the development of prion diseases; nevertheless, its physiological functions in the central nervous system remain elusive. Using a combination of behavioral, electrophysiological and biochemical approaches in transgenic mouse models, we provide strong evidence for a crucial role of PrP in alcohol sensitivity. Indeed, PrP knock out (PrP−/−) mice presented a greater sensitivity to the sedative effects of EtOH compared to wild-type (wt) control mice. Conversely, compared to wt mice, those over-expressing mouse, human or hamster PrP genes presented a relative insensitivity to ethanol-induced sedation. An acute tolerance (i.e. reversion) to ethanol inhibition of N-methyl-D-aspartate (NMDA) receptor-mediated excitatory post-synaptic potentials in hippocampal slices developed slower in PrP−/− mice than in wt mice. We show that PrP is required to induce acute tolerance to ethanol by activating a Src-protein tyrosine kinase-dependent intracellular signaling pathway. In an attempt to decipher the molecular mechanisms underlying PrP-dependent ethanol effect, we looked for changes in lipid raft features in hippocampus of ethanol-treated wt mice compared to PrP−/− mice. Ethanol induced rapid and transient changes of buoyancy of lipid raft-associated proteins in hippocampus of wt but not PrP−/− mice suggesting a possible mechanistic link for PrP-dependent signal transduction. Together, our results reveal a hitherto unknown physiological role of PrP on the regulation of NMDAR activity and highlight its crucial role in synaptic functions

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

    Get PDF
    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Benefits of Tai Chi for Physical and Mental Health

    No full text
    International audienceTai Chi is an internal martial art that develops skill such as natural breathing, structural alignment, mindfulness, imagery, flexibility and relaxation. In the past 50 years, more than 2000 scientific studies and 350 systematic reviews have been published exploring the effects of Tai Chi on health and trying to understand the physiological basis of its effects. In this narrative review, we will expose the multiple benefits of Tai Chi practice on the body, including muscles, bones and articulations, the central nervous system, the cardiovascular and respiratory system, the immune system, correlated to cognition and psychological benefits. We will show that Tai Chi has no described intervention-related serious adverse events. Finally, we will discuss the advantages of Tai Chi practice as a sustainable activity
    corecore