Spelling suggestions: "subject:"psychophysiology"" "subject:"psychophysiologiques""
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How brain rhythms form memoriesKöster, Moritz 27 September 2018 (has links)
The wake human brain constantly samples perceptual information from the environment and integrates them into existing neuronal networks. Neuronal oscillations have been ascribed a key role in the formation of novel memories. The theta rhythm (3-8 Hz) reflects a central executive mechanism, which integrates novel information, reflected in theta-coupled gamma oscillations (> 30 Hz). Alpha oscillations (8-14 Hz) reflect an attentional gating mechanism, which inhibit task irrelevant neuronal processes. In my dissertation I further scrutinized the oscillatory dynamics of memory formation. Study 1 demonstrated that theta-gamma coupling reflects a specific mechanism for associative memory formation. In study 2, I experimentally entrained memory encoding by visual evoked theta-gamma coupling processes, to underline its functional relevance. In two developmental studies, I found that the theta rhythm indexes explicit learning processes in adults and young children (study 3), and that visually entrained theta oscillations are sensitive to the encoding of novel, unexpected events, already in the first year of life (study 4). Throughout these studies alpha oscillations were not sensitive to memory formation processes, but indicated perceptual (study 1) and semantic (study 3) processes. I propose an integrative framework, suggesting that the alpha rhythm reflects activated semantic representations in the neocortex, while theta-gamma coupling reflects an explicit mnemonic control mechanism, which selects, elaborates and integrates activated representations. Specifically, by squeezing real time events onto a faster, neuronal time scale, theta-gamma coding facilitates neuronal plasticity in medio-temporal networks and advances neuronal processes ahead of real time to emulate and guide future behavior.
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Médecine et politique dans l'oeuvre de Pierre-Jean-Georges Cabanis / Medicine and politics : the work of Pierre-Jean-Georges CabanisMrozovski, Robert 29 March 2013 (has links)
Pierre-Jean-Georges Cabanis médecin et homme politique français. Considérant l'ensemble des opus réédités par les soins de C. Lehec et J. Cazenave en 1956 sous l'intitulé Oeuvres philosophiques de Cabanis, et bien que l'auteur n'ait jamais indiqué qu'il avait construit là un système intégrant la science, la politique et la religion, il nous a paru qu'il était possible de faire dériver, directement ou indirectement, un ensemble de recommandations pratiques, d'ordre politique et moral, de sa théorie psychophysiologique, théorie présentée dans son maître ouvrage les Rapports du physique et du moral de l'homme. Travaux dont nous avons cherché à montrer les liens plus ou moins étroits avec la pensée de prédécesseurs et de contemporains : philosophes, moralistes, politiques, économistes, médecins et naturalistes. Ces recommandations concourant à notre sens à un seul et même objectif éthique, faire que dans le cadre de la société un nombre d'hommes toujours plus grand puisse trouver le bonheur. Autrement dit c'était de la part de cet auteur oeuvrer à la paix et la prospérité sociale, c'était in fine oeuvrer à la fin de la Révolution. / Pierre Jean Georges Cabanis doctor and French politician. Considering all the opuses republished with the aid of C. Lehec and J. Cazenave in 1956 under the title Philosophic Works of Cabanis, and although the author never indicated that he had built a system there integrating the science, the politics and the religion, it seemed to us that it was possible to make derive, directly or indirectly, a set of practical recommendations, of political and moral order, of its psychophysiological theory presented in its master (teacher) decorates the Reports of the physical appearance and the morale of the man. Works the more or less narrow links of which we tried to show with the thought of predecessors and contemporaries : philosophers, moralists, politics, economics, doctors and naturalists. These recommendations contributing to our sense in the same ethical objective, to make that within the framework of the society a number of people always bigger can find the happiness. In other words it was on behalf of this author to work in the peace and the social prosperity; it was in fine to work at the end of the Revolution.
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Perception olfactive et régulation émotionnelle : Approches psychophysique, psychophysiologique et par imagerie cérébrale / Olfactory perception and émotion régulation : Psychophysical, psychopgysiological and fMRI approacheBillot, Pierre-Edouard 04 December 2014 (has links)
Ces travaux ont pour but d'étudier des mécanismes centraux de l'olfaction, et la manière dont ils sont intégrés dans les processus de régulationémotionnelle. Les stratégies de distraction et de réévaluation ont fait l'objet de deux expériences distinctes en IRMf, dans lesquelles les sujets devaientdiminuer l'intensité d'émotions suscitées par des odeurs. Dans une troisième expérience, des données psychophysiques et psychophysiologiques ont étécollectées pour évaluer la capacité d'une odeur agréable à réguler un sentiment négatif préalablement induit par uneimage désagréable.Les résultats montrent que la régulation d'émotions induites par des odeurs mobilise des aires cérébrales décrites dans les études utilisant du matérielvisuel (cortex préfrontal, lobule pariétal inférieur, gyrus temporal moyen) mais aussi d'autres plus spécifiques à cette modalité sensorielle (insula, gyrusfusiforme, gyrus lingual). De plus, le cortex préfrontal semble moduler certaines aires du cortex olfactif comme le cortex piriforme et le cortexorbitofrontal lorsque les sujets utilisent une stratégie de distraction. Les données issues de la troisième expérience révèlent également qu'une odeuragréable permet de diminuer l'impact d'un affect négatif préalablement induit, tant au niveau subjectif que psychophysiologique.Par conséquent, il semble exister chez l'Homme une réelle capacité à la régulation des émotions induites par des odeurs. Ce processus met enjeu desrégions habituellement décrites pour la régulation d'émotions induites par des stimuli visuels, mais également d'autres aires plus spécifques.De plus, les odeurs elles-mêmes sont capables de réguler une émotion négative. / The research presentee in this thesis aimed to study neural mechanisms of olfaction, and the way they are integrated in emotion regulation processes. Distraction and reappraisal strategies were studied using fMRI in two separate experiments in which subjects had to decrease the intensity of emotions induced by odors. In a third experiment, psychophysical and psychophysiological data were collected to assess the ability of pleasant odors to down-regulate negative feelings induced by unpleasant pictures. The results show that the regulation of odor-triggered emotions recruits brain areas that are usually described in studies based on Visual stimulations (prefrontal cortex, inferior parietal lobule, middle temporal gyrus) but also others more specic to this sensory modality (insular cortex, fusiform gyrus, lingual gyrus). Moreover, the prefrontal cortex seems to modulate the activity within olfactory areas, such as the piriform and the orbitofrontal cortex when subjects use distraction. The data from the third experiment also reveal that a pleasant odor is able to decrease negative aects that have been previously induced by unpleasant pictures, both at subjective and psychophysiological level.Therefore, it appears that odor-triggered emotions can be down-regulated by both distraction and reappraisal strategies. This processinvolves brain regions usually recruited by the regulation of visual-triggered emotions, but also other areas more specic to theregulation of emotions elicited by odors. Moreover, odors themselves can regulate negative feelings.
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La pédagogie de la vision : usages de la photographie dans la recherche artistique entre 1917 et 1933 / The pedagogy of vision : photographic uses in the artistic research between 1911 and 1933Gerosa, Alice 18 November 2016 (has links)
La thèse propose d'examiner le rôle de la photographie dans la compréhension de l'œuvre d'art en tant qu'expérience de la perception : cet idéal, poussé dans! 'entre-deux-guerres par un élan internationaliste, repose sur la prétendue universalité du modèle psychophysiologique que les arts modernes empruntent aux sciences. Au cours des années vingt, les pédagogies artistiques se définissent alors comme une tentative de rationaliser la gamme des moyens/effets à utiliser dans la construction des travaux. Les photographies des volumes réalisés en cours se révèlent des dispositifs pour prolonger ces enjeux: s'il est impossible d'établir si elles sont de la documentation ou des manifestations en soi d'une intention formelle exercée à travers la photographie, c'est qu'il faut précisément résister à toute tentative de réduction. La thèse propose de considérer cette indistinction inhérente à la compréhension de la photographie au sein de la recherche artistique. La première partie, à travers l'analyse de l'école du Bauhaus, retrace le substrat et la mise en œuvre de la méthode psychophysiologique; c'est sur l'institutionnalisation de celle-ci, que s'attache la deuxième partie à travers l'analyse des écoles Vhutemas et de ! 'institut de Léningrad dirigé par Malevitch. Dès 1925 les élèves manipulent de plus en plus des petits appareils et la dimension poïétique de l'œuvre sur la quelle insiste toute la pédagogie est déplacée dans la prise ou dans les agencements scénographiques et éditoriaux. Si la photographie continue d'être comprise par les artistes comme un procédé de mise en jeu de la perception, au début des années trente les discours la réduisant à un outil de transparence connaissent une large diffusion. / The thesis proposes to examine the role of photography in the understanding of the work of art as an experience of perception : driven in the interwar period by an intemationalist impulse, this ideal stand on the supposed universality of psychophysiological mode! that modem arts borrow from science. During the twenties, artistic pedagogy is then defined as an attempt to rationalize the range of means / effects to use in constructing the work. The photographs of the volumes achieved in classes turn out to be a device for extending these issues: as far as it is impossible to establish if they arc a documentation or a demonstration in itsclf of a formai intention through photography, we must resist any attempt to reduction. The thesis proposes to consider this Jack of distinction as inherent to the understanding of photography in artistic rescarch. The first part, through the analysis of the Bauhaus school, retraces the substratc and the implementation of psycho-physiological method; the second part deal with its institutionalization through the analysis of Vhutemas schools and the Institute of Leningrad led by Malevich. ln 1925 the students manipulate more and more small camera and the poetic dimension of the work, so important to ail the artistic pedagogy, is moved in the shooting or in the display and editorial layout. If photography continues to be understood by artists as a way of bringing perception into play, in the early thirtics, its reduction as an objective tool became more commun.
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Peripheral and central mechanisms involved in post-traumatic stress disorder and its treatment by eye-movement desensitization & reprocessing / Mécanismes périphériques et centraux impliqués dans le stress post-traumatique & son traitementEl-Khoury, Myriam 28 March 2011 (has links)
Bien que la plupart des personnes soient exposées à un traumatisme au cours de leur vie, toutes ne développent pas de stress-post traumatique (PTSD). La prévalence de vie du PTSD est en effet estimée à 10%. Il peut survenir à la suite d’un événement traumatique tel un accident, agression, deuil, viol ou incendie, mais aussi un désastre naturel (inondation, tremblement de terre…) ou humain (guerre, terrorisme…). En raison de l’augmentation contemporaine des sources traumatiques, les rapports récents de l'Organisation Mondiale de la Santé décrivent le PTSD comme un problème de santé mondiale croissant, en raison de sa fréquence, sévérité, comorbidité et de son coût élevé. Un corpus de recherche enquête sur divers aspects du PTSD concernés par les pensées intrusives, l'hypervigilance, les déficits émotionnels, les troubles cognitifs et les problèmes de mémoire.Comme d'autres problèmes de santé mentale, le PTSD est à ce jour assez méconnu. Comme d'autres troubles anxieux, il est surtout marqué par une peur excessive. Il n'est donc pas surprenant que l'hypothèse la plus répandue dans le PTSD soit celle d'un déficit du traitement de la peur. S’il est vrai que la conceptualisation du PTSD comme un trouble de la peur parait phénoménologiquement étroite, elle a été néanmoins pragmatique en permettant l’approfondissement de la recherche translationnelle de l'animal à l’humain, en passant par la paillasse. Les études sur le sujet ont suggéré que les déficiences centrales et périphériques du PTSD tourneraient autour d’altérations du réseau neuronal de la peur. Ceci impliquerait un dérèglement des mécanismes qui sous-tendent le conditionnement à la peur, ainsi que le traitement des émotions et de l'attention, qui sont en effet bouleversés dans le PTSD. / Although most people encounter at least one traumatic event over their lifetime, not all of them will develop post-traumatic stress disorder (PTSD). Lifetime prevalence of full-blown PTSD, known as an anxiety disorder, is in fact around 10%. In addition to accidents, aggression, grief, rape, fires, traumatic events can be caused by natural (flooding, earthquake…) or man-made stressors (war, terrorism…). With the contemporary rise in traumatic sources the World Health Organization recent reports describe PTSD as an increasing global health issue, due to its high frequency, severity, comorbidity and cost. A body of research has thus started investigating various aspects of PTSD concerned with intrusive thoughts, hypervigilance, emotional deficits, cognitive disturbances and memory issues. Similarly to other mental health problems, much remains unknown about PTSD, and similarly to other anxiety disorders it is marked by excessive fear. It comes as no surprise that the most prevalent hypothesis in PTSD is that of a fear-processing deficit. Conceptualizing PTSD as a fear disorder can be phenomenologically quite narrow. It has been nonetheless pragmatic in allowing thorough translational research from animal to bench-side and clinical studies. Most studies have suggested that central and peripheral impairments in PTSD revolve around altered neural fear processing network. These alterations involve mechanisms implicated in fear conditioning, as well as emotional and attentional processing, all of which are altered in PTSD.
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Observations of cortical object representations in the human EEG - Problems and SolutionsHaßler, Uwe 15 July 2014 (has links)
It is a common finding that neurons synchronize their firing rates in a high frequency range above 30 Hz, the so‐called gamma band, if they are involved in the processing of the same stimuli. Furthermore, it was hypothesized that object representations are stored within the cortical networks that are formed of synchronously firing neurons. Consequently, induced gamma band responses in the electroencephalogram were utilized to investigate cortical object representations.
A more recent finding by Yuval‐Greenberg et al. questioned this common interpretation. It was shown that miniature eye movements as they occur during fixation are accompanied by small artifacts that mimic activity in the gamma band. The question arose whether induced gamma band responses in the electroencephalogram are a marker of neuronal processing or a mere artifact caused by miniature eye movements.
The present thesis aims at providing solutions for this dilemma by investigating whether evoked gamma band responses and steady state visual responses are suitable tools to examine cortical network activity in relation to object recognition. Both measurements are not affected by miniature eye movements. It was found that evoked gamma band responses are particularly qualified to study early processes of object recognition. Furthermore, steady state visual evoked potentials were sensitive to the semantic content of presented stimuli. Therefore they are feasible for studying object recognition, too. Additionally, the present thesis provides the COSTRAP algorithm, a new method to effectively identify and remove the eye movement artifacts related to miniature eye movements. The remaining induced gamma band responses are most certainly of cortical origin. They proved to be sensitive to object recognition and repetition priming. Finally, it was shown that miniature eye movements and cortical gamma band responses can be experimentally dissociated, further underpinning the different methodological importance of induced gamma band response when studying object recognition.
In summary, it was shown that the investigation of cortical networks representing object knowledge can also be addressed by evoked gamma band responses and steady state visual responses. Furthermore, it was proven that induced gamma band responses remain a powerful tool in electrophysiological research when studying the neuronal dynamics behind object recognition and other cognitive processing.
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Motivation and the brain: How do appetitive versus aversive states relate to electroencephalographic activity?Schomberg, Jessica 07 January 2016 (has links)
Approach and Avoidance motivation are two of the oldest psychological concepts of behavior. Whereas approach motivation corresponds to the strong urge to come close to an object, state or person (e.g., during states of sexual attraction), avoidance motivation corresponds to the strong urge to avoid a specific situation (e.g., evade a dangerous situation). This dissertation deals with the electroencephalographic (EEG) markers of approach and avoidance motivation, assessed using event-related-potentials and brain oscillations in a low frequency band (alpha band).
The first manuscript shows a left hemispheric processing advantage for approach-related stimuli. Specifically, we report a reduction in the alpha band (as an inverse maker for cortical activity) for erotic, but not for control pictures. Notably, we are the first to report alpha-asymmetries using an event-related design.
In the second manuscript we describe evidence (a) for separating approach motivation from the affective dimensions of valence and arousal and (b) for an enhanced attention-related early EEG amplitude (P1 component) only for approach-related but not for control pictures. Up to our knowledge, we are the first to associate the P1 component with approach motivation.
In the third manuscript we report an enlarged P1 component for increased avoidance motivation, as measured by the negative affect scale of the German Positive and Negative Affect Schedule (PANAS; Krohne, Egloff, Kohlmann, & Tausch, 1996). In more detail, state negative affect correlated positively with the P1 component, as a marker of increased selective attention. As far as we know, no study ever showed that state negative affect has an influence on attention. Therefore, we consider these findings regarding previous findings on trait negative affect, specifically on anxiety and phobia.
All findings are discussed in the context of established views and models, such as Personality Systems Interaction (PSI) theory, hypervigilance theory, wanting versus liking and are also integrated into the findings from neuroimaging studies.
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Les yeux ont des oreilles : examen de la pupillométrie en tant qu'indice psychophysiologique de la capture attentionnelle auditiveMarois, Alexandre 28 May 2019 (has links)
Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2018-2019. / La présence de sons non pertinents est reconnue pour affecter le fonctionnement cognitif. Plus précisément, la présentation d’un son qui dévie du contexte auditif a le potentiel d’affecter la performance à une tâche réalisée simultanément. Plusieurs études s’intéressant à l’impact délétère des sons déviants sur la performance à une tâche montrent qu’il découle de la réorientation de l’attention déclenchée lorsqu’un son déviant est détecté par l’organisme. Cette capture attentionnelle (ou réponse d’orientation) est également reconnue pour engendrer plusieurs réponses physiologiques associées à l’état d’alerte. Ces réponses physiologiques, sous certaines conditions, sont considérées comme des indices psychophysiologiques de la capture attentionnelle auditive permettant de démontrer l’occurrence d’une réorientation de l’attention de la tâche en cours vers le son déviant. De récentes études suggèrent qu’il existe un lien entre ces indices et la réponse pupillaire, soit l’augmentation rapide du diamètre pupillaire. Quelques études ont tenté d’évaluer si cette réponse pouvait remplir les critères d’un indice valide de la réponse d’orientation; cependant, les résultats de ces études sont parfois contradictoires ou incomplets. La présente thèse propose donc une évaluation systématique de l’utilisation de la réponse pupillaire à titre d’indice psychophysiologique de la capture attentionnelle auditive. Les résultats de la première étude montrent que la réponse pupillaire respecte les critères d’un index valide de la réponse d’orientation, supportant ainsi la validité de cet index. L’Étude 2 montre que cet indice peut être utilisé dans des contextes dans lesquels les sujets effectuent simultanément à l’écoute des sons une tâche visuelle provoquant des changements systématiques de luminosité ou des mouvements oculaires qui affectent la taille de la pupille. Ces expériences appuient ainsi l’utilisabilité de cet index. Enfin, la dernière étude permet d’établir l’utilité de ce proxy puisque ce dernier permet de distinguer l’origine de deux phénomènes de distraction auditive différents. Dans l’ensemble, les résultats de la thèse révèlent que la réponse pupillaire représente un indice psychophysiologique adéquat qui pourrait être intégré aux études sur la distraction auditive ou dans des contextes plus appliqués où les mesures de la capture attentionnelle auditive peuvent s’avérer pertinentes. / The presence of task-irrelevant sound is known to impede cognitive functioning. More precisely, presenting a sound that deviates from the auditory background has been shown to disrupt performance on an ongoing task. Several studies regarding performance disruption by deviant sounds showed that this effect originates from the reorientation of attention triggered when the organism has detected the deviant sound. Such attentional capture (or orientation response) also elicits many physiological responses related to one’s state of alertness. These physiological responses, under certain conditions, are considered as psychophysiological indices of auditory attentional capture, permitting to show that attention has been reoriented from an ongoing task toward the deviant auditory stimulus. Recent work suggested a relationship between these indices and the pupillary dilation response, that is a rapid increase in the pupil size. A few studies have attempted to assess whether the pupillary dilation response could respect the criteria for an index to be considered as a proxy for attentional capture; yet, results of these studies either lack consistency or are incomplete. Hence, the current thesis proposes a systematic assessment of using the pupillary dilation response as a psychophysiological proxy for the auditory attentional capture. Results of the first study suggest that the pupillary dilation response respects criteria of a valid auditory attentional capture index, thus supporting the validity of this index. Study 2 shows that this index can be used in contexts in which participants are exposed to irrelevant deviant sound while concurrently performing a task inducing luminance changes or ocular movements, both influencing the pupil size. These experiments hence supported the usability of this index. The last study allows establishing the utility of this proxy since it can be used to dissociate the origin of two different auditory distraction phenomena. Overall, results of the current thesis reveal that the pupillary dilation response is a psychophysiological index that could be added to several auditory distraction paradigms or in applied contexts in which the occurrence of attention reorientation toward a sound may be relevant to assess.
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Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) im Erwachsenenalter: Stressreagibilität und Stressbewältigung unter Laborbedingungen und im Alltag / Attention-deficit/hyperacitvity disorder (ADHD) in adulthood: Stressreagibility and stress-related coping under laboratory conditions and in everyday lifeLackschewitz, Halina 29 October 2008 (has links)
No description available.
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Psychophysiological Effects of Respiratory Challenges before and after Breathing Training in Panic Disorder and Patients suffering from Episodic Anxiety AttacksWollburg, Eileen 13 December 2007 (has links) (PDF)
Panic Disorder (PD) has been associated with abnormalities in the respiratory system for a long time, and treatment programs aimed at reversing these abnormalities have been developed. Panicogenic effects of biological challenges have been shown to be altered after successful treatment. Furthermore, there is evidence that anxious non-PD patients show similar responses to these challenges and hence may benefit from some kind of breathing training (BT). To test these assumptions, we recruited 45 PD patients, 39 Episodic Anxiety (EA) patients who suffered from subclinical panic attacks, and 20 non-anxious controls (NAC). Patients were randomized to one of two versions of a 4-week therapy with BT, either lower or raise end-tidal pCO2, or a waiting list (WL). Before and after treatment, participants underwent in randomized order a Voluntary Hypoventilation (VHO) test and a Voluntary Hyperventilation (VHT) test in which they were asked to either lower or raise their pCO2 while psychophysiological measures were recorded. Each test consisted of 3 segments: 1 min baseline, 3 min paced breathing, and 8 min recovery. Before treatment, PD and EA patients were more anxious, distressed, tense, and worried than NAC, and felt more dizziness, chest pain, and nausea during the laboratory assessment. However, increases in psychological symptoms or physiological sensations from baseline to the paced breathing segments were not different between groups. The two tests produced similar changes except that anxiety and dizziness increased more during the VHT than VHO. We replicated baseline breathing abnormalities previously reported for PD patients, namely greater respiration rate, tidal volume instability, and number of sighs. However, analyses did not find that patients recovered slower to either challenge. After treatment, both therapies improved on the main outcome measure. Furthermore, BT affected baseline pCO2, resulting in lower levels in the hypocapnic groups and higher levels in the hypercapnic groups without affecting any other measures. We conclude that baseline respiratory abnormalities are specific to PD. However, data suggest that the manipulations might have been too weak to elicit other previously reported group differences. Breathing training was equally effective for the lower and raise BT. Hence, factors unrelated to modifying one’s pCO2 must have accounted for the symptomatic improvement. Breathing training should not be restricted to PD but be applied to all patients suffering from anxiety attacks.
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