496 research outputs found
Three Ways to Bridge the Gap between Perception and Action, and Language
A rallying cry in some sectors of cognitive science, the embodiment of language is understood here in the full content of meaning of phenomenological tradition to help assess the remaining distance from neuroscience to a science of language, provided that tracking down in the brain neural events correlative of verbal behavior would not be sufficient. From an eidetic standpoint, one must build the transition between perceptive, pragmatic and semantic morphologies. From the point of view of subjective experience, one must understand how it is possible that we move from our sensory and kinaesthetic experiences to verbal expressions of a sense that could be shared by others. That is why, in order to prevent neglect of any dimension of embodiment of language, we would rather plead for a threefold approach than concede that the current naturalistic mode is the only possible
Naturalizing Husserlian Phenomenology along a Leibnizian Pathway
A contribution to the history of a formerly hotly discussed, but short-lived scientific project: neurophenomenology , the proposal of weaving together Husserlian phenomenology of consciousness and the neuroscience of brain functioning, this article traces back the opening and closing of an apparent window of opportunity, both in phenomenology and in neuroscience, for the eventually unfulfilled realization of that project
De la neurodégénérescence motrice comme limitation interne du « pouvoir-faire »
La constitution transcendantale est une donation de sens fondée sur le « pouvoir-faire » kinesthésique du corps propre du sujet et qui va des choses perçues aux formations intersubjectives de la Lebenswelt. Mais, qu’advient-il du sujet constituant, lorsque la progressive limitation de son pouvoir-faire tend à réduire l’individu atteint de la maladie de Parkinson à la condition de spectateur passif dans un monde qui n’est plus le domaine de son intervention ? En une régression contre-transcendantale suivant la cascade sans fin des mécanismes fonctionnels sous-jacents et leurs dysfonctionnements, on sonde les abîmes de contingence du fondement transcendantal.Transcendental constitution, a sense-giving process contingent upon the kinaesthetic “I can do” of the ego’s lived-in body, rises stepwise from the things of perception up to intersubjective formations of Lebenswelt. But, what happens to the constituting subject, when a progressive limitation of his can-do tends to reduce the individual suffering from Parkinson’s disease to the condition of passive observer in a world that no longer features as his domain of intervention? Following the endless cascade of underlying functional systems and their dysfunctions in a countertranscendantal regression, we probe the depths of contingency lurking beneath the transcendantal fundament
Ricœur et la théorie de l’action
 AbstractRicoeur’s Philosophy of the Will is reexamined here both as a source of motivation for his project of dialoguing with the analytic theory of action and as an explanation for the lack of response on the part of his Anglo-American interlocutors.Keywords: Actions, Language, Body, Idealism. RésuméLa Philosophie de la volonté de Ricœur est revisitée ici comme source de motivation de son entreprise de dialogue avec la théorie analytique de l’action et comme explication du défaut de réponse de ses interlocuteurs anglo-américains.Mots-clés: Actions, Langage, Corps, Idéalisme
Critique phénoménologique d’une approche neuronale de la conscience
La conscience est toujours conscience de quelque chose, généralement une chose autre qu’elle-même – mais quelle sorte de chose est donc la conscience, considérée en et pour elle-même? Naguère redoutable paradoxe qu’une science sérieuse abandonnait volontiers aux philosophes, la conscience a-t-elle été ramenée finalement à la condition d’un objet de science parmi les autres? Le développement d’une nouvelle «neuroscience de la conscience» depuis une vingtaine d’années est souvent présenté comme une avancée naturelle pour une science forte de son succès dans l’explication des fonctions cognitives sur la base des mécanismes neuronaux du cerveau humain. Conçue, elle aussi, originairement, comme «science de la conscience», mais sur la base de l’immanence du sujet conscient à sa propre expérience vécue, la phénoménologie doit-elle réfréner son sens du paradoxe devant le projet de cette neuroscience de la conscience, pour ne pas être accusée d’irrationalisme? Faisant retour sur le dialogue Changeux-Ricœur, je relève les objections du phénoménologue à l’objectivation de notre expérience de la conscience sur la base de mécanismes corrélatifs dans le cerveau et j’examine sur l’exemple représentatif de la théorie neuronale de Changeux, Dehaene et al. dans quelle mesure cette critique phénoménologique garde une pertinence
Présentation
En octobre 1995 prenait place au Musée d’Art Contemporain de Bordeaux le grand colloque « Actualité cognitive de la Phénoménologie : Les défis de la naturalisation ». La phénoménologie de tradition husserlienne y rencontrait les toutes jeunes sciences de la cognition en une confrontation exemplaire, où se croisaient les lignes directrices de ce qui allait constituer un nouveau domaine de recherche, à l’interface entre phénoménologie et sciences de la nature, un domaine dont l’émergence devait..
Thermal behavior of LV cables in presence of harmonic currents
International audienceThe proliferation of non-linear loads on public and industrial networks causes increases of harmonic current distortion. This paper deals with the thermal impact of harmonic distortion on LV cables, especially LV cables with neutral conductor. The thermal impact of harmonics is shown by measurements and FEM simulations on two different LV cable structures
Taste at first (person) sight: visual perspective modulates brain activity implicitly associated with viewing unhealthy but not healthy foods
Every day, people are exposed to images of appetizing foods that can lead to high-calorie intake and contribute to overweight and obesity. Research has documented that manipulating the visual perspective from which eating is viewed helps resist temptation by altering the appraisal of unhealthy foods. However, the neural basis of this effect has not yet been examined using neuroimaging methods. Moreover, it is not known whether the benefits of this strategy can be observed when people, especially overweight, are not explicitly asked to imagine themselves eating. Last, it remains to be investigated if visual perspective could be used to promote healthy foods. The present work manipulated camera angles and tested whether visual perspective modulates activity in brain regions associated with taste and reward processing while participants watch videos featuring a hand grasping (unhealthy or healthy) foods from a plate during functional magnetic resonance imagining (fMRI). The plate was filmed from the perspective of the participant (first-person perspective; 1PP), or from a frontal view as if watching someone else eating (third-person perspective; 3PP). Our findings reveal that merely viewing unhealthy food cues from a 1PP (vs. 3PP) increases activity in brain regions that underlie representations of rewarding (appetitive) experiences (amygdala) and food intake (superior parietal gyrus). Additionally, our results show that ventral striatal activity is positively correlated with body mass index (BMI) during exposure to unhealthy foods from a 1PP (vs. 3PP). These findings suggest that unhealthy foods should be promoted through third-person (video) images to weaken the reward associated with their simulated consumption, especially amongst overweight people. It appears however that, as such, manipulating visual perspective fails to enhance the perception of healthy foods. Their promotion thus requires complementary solutions
The poxviral scrapin MV-LAP requires a myxoma viral infection context to efficiently downregulate MHC-I molecules
AbstractDownregulation of MHC class I molecules is a strategy developed by some viruses to escape cellular immune responses. Myxoma virus (MV), a poxvirus causing rabbit myxomatosis, encodes MV-LAP that is known to increase MHC-I endocytosis and degradation through a C4HC3 motif critical for an E3 ubiquitin ligase activity. Here, we performed a functional mapping of MV-LAP and showed that not only the C4HC3 motif is necessary for a marked downregulation of MHC-I but also a conserved region in the C-terminal part of the protein. We also showed that the putative transmembrane domains are responsible for a specific subcellular localization of the protein: they retain MV-LAP in the ER in transfected cells and in the endolysosomal compartments in infected cells. We observed that a specific MV infection context is necessary for a fully efficient downregulation of MHC-I. Our data suggest that the functionality of viral LAP factors, inherited by herpes- and poxviruses from mammalian cells, is more complex than anticipated
Encephalopathy induced by Alzheimer brain inoculation in a non-human primate.
Alzheimer's disease is characterized by cognitive alterations, cerebral atrophy and neuropathological lesions including neuronal loss, accumulation of misfolded and aggregated β-amyloid peptides (Aβ) and tau proteins. Iatrogenic induction of Aβ is suspected in patients exposed to pituitary-derived hormones, dural grafts, or surgical instruments, presumably contaminated with Aβ. Induction of Aβ and tau lesions has been demonstrated in transgenic mice after contamination with Alzheimer's disease brain homogenates, with very limited functional consequences. Unlike rodents, primates naturally express Aβ or tau under normal conditions and attempts to transmit Alzheimer pathology to primates have been made for decades. However, none of earlier studies performed any detailed functional assessments. For the first time we demonstrate long term memory and learning impairments in a non-human primate (Microcebus murinus) following intracerebral injections with Alzheimer human brain extracts. Animals inoculated with Alzheimer brain homogenates displayed progressive cognitive impairments (clinical tests assessing cognitive and motor functions), modifications of neuronal activity (detected by electroencephalography), widespread and progressive cerebral atrophy (in vivo MRI assessing cerebral volume loss using automated voxel-based analysis), neuronal loss in the hippocampus and entorhinal cortex (post mortem stereology). They displayed parenchymal and vascular Aβ depositions and tau lesions for some of them, in regions close to the inoculation sites. Although these lesions were sparse, they were never detected in control animals. Tau-positive animals had the lowest performances in a memory task and displayed the greatest neuronal loss. Our study is timely and important as it is the first one to highlight neuronal and clinical dysfunction following inoculation of Alzheimer's disease brain homogenates in a primate. Clinical signs in a chronic disease such as Alzheimer take a long time to be detectable. Documentation of clinical deterioration and/or dysfunction following intracerebral inoculations with Alzheimer human brain extracts could lead to important new insights about Alzheimer initiation processes
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