16 research outputs found
Neuroimaging - Clinical Applications
Modern neuroimaging tools allow unprecedented opportunities for understanding brain neuroanatomy and function in health and disease. Each available technique carries with it a particular balance of strengths and limitations, such that converging evidence based on multiple methods provides the most powerful approach for advancing our knowledge in the fields of clinical and cognitive neuroscience. The scope of this book is not to provide a comprehensive overview of methods and their clinical applications but to provide a "snapshot" of current approaches using well established and newly emerging techniques
Mécanismes cérébraux de la régulation de la douleur : perception de la douleur et hypoalgésie induite psychologiquement
Objectif : Cette thèse a pour but de préciser les mécanismes neuropsychologiques de
la douleur, de la régulation endogène de la douleur et de l'hypoalgésie induite
psychologiquement (HIP) par la synthèse de près de trente ans de recherche imagerie cérébrale
fonctionnelle. Méthodologie : Étant donné l'abondance des études sur le sujet et le manque
d'intégration de leurs résultats, la technique de métaanalyse quantitative basée sur les
coordonnées d'activation cérébrale fut privilégiée dans cette thèse, telle qu’implémentée dans
l'algorithme ALE (Activation Likelyhood Estimate). Une force supplémentaire de cette thèse
repose sur la rigueur du processus de sélection des articles. En effet, les études incluses dans
les métaanalyses devaient satisfaire des critères stricts d'inclusion, ceci dans le but de favoriser
la prĂ©cision et la validitĂ© des conclusions subsĂ©quentes. Étude 1 : Le premier article visait Ă
identifier les aires cérébrales impliquées dans la réduction de la douleur par des méthodes
psychologiques d'interventions. Les articles retenus portent sur une variété de méthodes
d'intervention, telles que le placebo, l'hypnose, la méditation, la perception de contrôle sur la
stimulation douloureuse et l'induction d'émotions. Les résultats indiquent que l'HIP implique
un vaste réseau d'activation qui comprend le cortex cingulaire antérieur, l'insula antérieure, les
zones orbitofrontale et préfrontale latérale, ainsi que les régions pariétale, temporale et souscorticales.
Ces activations reflèteraient l'implication des mécanismes neuropsychologiques
cognitifs et émotionnels sous-tendent les interventions psychologiques ciblées par ces études,
incluant la conscience de soi et la motivation. De plus, les divergences de patron d'activation
entre les approches ont été explorées, notamment pour le placebo et la distraction. Étude 2 :
Le deuxième article a identifié des patrons d'activations préférentiellement associés à la
perception de la douleur, à l'HIP, ainsi que des activations communément associées à la
douleur et l'HIP. Les rĂ©sultats indiquent que 1) la perception de la douleur est associĂ©e Ă
l'activation d'aires somatosensorielles et motrices, ce qui pourrait ĂŞtre le reflet de la
préparation d'une action adaptative, 2) l'HIP est liée à l'engagement de régions préfrontales
antéromédianes et orbitales, possiblement en lien avec des processus motivationnels et
émotionnels, et 3) la douleur et l'HIP sont associés à l'activation d'aires préfrontales
dorsolatérales, de l'insula antérieure et du cortex cingulaire moyen, ce qui pourrait refléter
l'engagement spontané pendant la douleur de mécanismes endogènes de régulation
descendante. Conclusion : Par ces études, cette thèse fait le point sur les mécanismes
cérébraux impliqués différentiellement dans la perception de la douleur, dans sa régulation
endogène et dans l'hypoalgésie induite psychologiquement.Objective: This thesis aims to clarify the neuropsychological mechanisms of pain,
of the endogenous regulation of pain and of psychologically induced hypoalgesia (PIH),
through the synthesis of almost thirty years of functional brain imaging
research. Methodology: Given the abundance of studies in this domain and the lack of
integration of their results, we used the quantitative meta-analysis technique based on brain
activation using the ALE (Activation likelihood Estimate) statistic. The strength of this thesis
lies in the globalized perspective of the litterature, and in the rigor of the article selection
process from which results were extracted. Indeed, the studies included in the meta-analyses
needed to meet strict inclusion criteria in order to strengthen the accuracy and the validity of
subsequent conclusions. Study 1: The first article is aimed at identifying brain areas involved
in pain reduction through psychological methods of intervention. Chosen articles that covered
a variety of approaches, such as placebo, hypnosis, meditation, perception of control over the
stimulation, and induction of emotions. Analysis across these various studies indicated that
PIH involves a broad network of activation that includes the anterior cingulate cortex,
anterior insulae, orbital and lateral prefrontal and frontal areas, as well as parietal, temporal
and subcortical regions. This activation network may reflect the involvement of diverse
neuropsychological mechanisms in the various affective, self-awareness, cognitive and
motivational processes underlying the psychological interventions targeted by these studies. In
addition, we explored some specific patterns of brain activity related to placebo and
distraction, in comparison to other approaches. We propose several hypotheses regarding the
distinctive neuropsychological processes underlying these approaches. Study 2: The second
article aimed at investigating patterns of brain activity preferentially associated with pain
perception or with PIH. First we assessed patterns of increased and decreased activity during
experimental pain in healthy volunteers. Second we determined the brain regions
preferentially activated during pain perception or during PIH with subtraction analyses. Using
a conjunction analysis, we also determined a set of brain regions possibly involved in
regulatory processes activated spontaneously during acute of pain. Our results indicate that 1)
somatosensory and motor areas are preferentially related to pain perception, which may reflect
the preparation of a motor response, 2) dorsolateral prefrontal areas, anterior insula and the
anterior midcingulate cortex were associated with both pain and PIH and may reflect the
spontaneous activation of top-down regulation mechanisms during pain, and 3) antero-medial
and orbital prefrontal regions were preferentially associated with PIH, which may indicate
motivational and emotional processes associated with the engagement of an externally driven
hypoalgesic procedure
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This monograph describes the largest unethical medical experiment in human history: the implementation and operation of non-ionizing non-visible EMF radiation (hereafter called wireless radiation) infrastructure for communications, surveillance, weaponry, and other applications. It is unethical because it violates the key ethical medical experiment requirement for “informed consent” by the overwhelming majority of the participants.
The monograph provides background on unethical medical research/experimentation, and frames the implementation of wireless radiation within that context. The monograph then identifies a wide spectrum of adverse effects of wireless radiation as reported in the premier biomedical literature for over seven decades. Even though many of these reported adverse effects are extremely severe, the true extent of their severity has been grossly underestimated.
Most of the reported laboratory experiments that produced these effects are not reflective of the real-life environment in which wireless radiation operates. Many experiments do not include pulsing and modulation of the carrier signal, and most do not account for synergistic effects of other toxic stimuli acting in concert with the wireless radiation. These two additions greatly exacerbate the severity of the adverse effects from wireless radiation, and their neglect in current (and past) experimentation results in substantial under-estimation of the breadth and severity of adverse effects to be expected in a real-life situation. This lack of credible safety testing, combined with depriving the public of the opportunity to provide informed consent, contextualizes the wireless radiation infrastructure operation as an unethical medical experiment