56 research outputs found

    Understanding and Extending Incremental Determinization for 2QBF

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    Incremental determinization is a recently proposed algorithm for solving quantified Boolean formulas with one quantifier alternation. In this paper, we formalize incremental determinization as a set of inference rules to help understand the design space of similar algorithms. We then present additional inference rules that extend incremental determinization in two ways. The first extension integrates the popular CEGAR principle and the second extension allows us to analyze different cases in isolation. The experimental evaluation demonstrates that the extensions significantly improve the performance

    Causal hierarchy within the thalamo-cortical network in spike and wave discharges

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    Background: Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. Methodology and Principal Findings: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1. Conclusion: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy. © 2009 Vaudano et al

    Hypnosis Antenatal Training for Childbirth (HATCh): a randomised controlled trial [NCT00282204]

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    BACKGROUND: Although medical interventions play an important role in preserving lives and maternal comfort they have become increasingly routine in normal childbirth. This may increase the risk of associated complications and a less satisfactory birth experience. Antenatal hypnosis is associated with a reduced need for pharmacological interventions during childbirth. This trial seeks to determine the efficacy or otherwise of antenatal group hypnosis preparation for childbirth in late pregnancy. METHODS/DESIGN: A single centre, randomised controlled trial using a 3 arm parallel group design in the largest tertiary maternity unit in South Australia. Group 1 participants receive antenatal hypnosis training in preparation for childbirth administered by a qualified hypnotherapist with the use of an audio compact disc on hypnosis for re-enforcement; Group 2 consists of antenatal hypnosis training in preparation for childbirth using an audio compact disc on hypnosis administered by a nurse with no training in hypnotherapy; Group 3 participants continue with their usual preparation for childbirth with no additional intervention. Women > 34 and < 39 weeks gestation, planning a vaginal birth, not in active labour, with a singleton, viable fetus of vertex presentation, are eligible to participate. Allocation concealment is achieved using telephone randomisation. Participants assigned to hypnosis groups commence hypnosis training as near as possible to 37 weeks gestation. Treatment allocations are concealed from treating obstetricians, anaesthetists, midwives and those personnel collecting and analysing data. Our sample size of 135 women/group gives the study 80% power to detect a clinically relevant fall of 20% in the number of women requiring pharmacological analgesia – the primary endpoint. We estimate that approximately 5–10% of women will deliver prior to receiving their allocated intervention. We plan to recruit 150 women/group and perform sequential interim analyses when 150 and 300 participants have been recruited. All participant data will be analysed, by a researcher blinded to treatment allocation, according to the "Intention to treat" principle with comprehensive pre-planned cost- benefit and subgroup analyses. DISCUSSION: If effective, hypnosis would be a simple, inexpensive way to improve the childbirth experience, reduce complications associated with pharmacological interventions, yield cost savings in maternity care, and this trial will provide evidence to guide clinical practice

    Psychedelics and hypnosis: Commonalities and therapeutic implications

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    Background Recent research on psychedelics and hypnosis demonstrates the value of both methods in the treatment of a range of psychopathologies with overlapping applications and neurophenomenological features. The potential of harnessing the power of suggestion to influence the phenomenological response to psychedelics toward more therapeutic action has remained unexplored in recent research and thereby warrants empirical attention. Aims Here we aim to elucidate the phenomenological and neurophysiological similarities and dissimilarities between psychedelic states and hypnosis in order to revisit how contemporary knowledge may inform their conjunct usage in psychotherapy. Methods We review recent advances in phenomenological and neurophysiological research on psychedelics and hypnosis and we summarize early investigations on the coupling of psychedelics and hypnosis in scientific and therapeutic contexts. Results/Outcomes We highlight commonalities and differences between psychedelics and hypnosis that point to the potential efficacy of combining the two in psychotherapy. We propose multiple research paths for coupling these two phenomena at different stages in the preparation, acute phase, and follow-up of psychedelic-assisted psychotherapy in order to prepare, guide, and integrate the psychedelic experience with the aim of enhancing therapeutic outcomes. Conclusions/Interpretation Harnessing the power of suggestion to modulate response to psychedelics could enhance their therapeutic efficacy by helping to increase the likelihood of positive responses, including mystical type experiences

    Editorial

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    Hypnose et conscience

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    L’hypnotisme et les techniques de l’hypnose sont connus depuis l’Antiquité. Mesmer était le premier à avoir entrepris une étude expérimentale de la relation psychothérapeutique jusqu’alors noyée dans les pratiques magiques. Il proposait une théorie qu’il croyait physiologique, rationaliste, et posait l’existence d’un fluide, aussi réel et matériel que l’action exercée par l’aimant. Une lutte opposa d’abord les « fluidistes » et les « animistes » dans la première moitié du XIXe siècle. Ensuite, elle prit la forme d’une opposition entre les partisans de l’explication physiologique et ceux de l’explication psychologique. L’école de la Salpetrière, avec Charcot, voyait dans l’hypnose un état pathologique, une névrose hystérique artificielle. A l’opposé, l’école de Nancy, représentée par Bernheim, Liébault et Liégeois, soutenait que c’était un phénomène psychologique normal. La lutte entre les deux écoles fut très âpre. D’autres théories inspirées d’abord par l’école pavlovienne virent le jour, celle-ci fut remplacée par celle inspirée de la psychologie expérimentale et une troisième d’inspiration psychanalytique prit le relais. Une objectivation de l’état hypnotique permettrait de sortir des querelles qui s’éternisent sur la réalité et la non-réalité de l’état hypnotique. Cette tentative d’objectivation a été conduite entre autres à partir des techniques de neuroimagerie fonctionnelle révolutionnant actuellement notre connaissance sur le fonctionnement cérébral et les recherches dans le domaine des neurosciences cognitives permettent d’aborder les questions sur la conscience et son substrat neurobiologique. La recherche sur l’hypnose nécessite de faire des distinctions entre « l’état de conscience » et « contenu conscient ». Différentes études en neuro-imagerie fonctionnelle sont rapportées explorant le domaine de la « neurophénoménologie » du processus hypnotique.Hypnotic-like behavior has been reported from the dawn of history. The early origins are shrouded in mystery and magic; but Franz Anton Mesmer, an Austrian physician, conducted his therapeutic sessions under the name of ‘‘animal magnestism’’. He proposed a theory that the ‘‘magnetic’’ influence could be transfered by iron bars. However a committee of leading scientists of the day showed that the ‘‘magnetic’’ influence could be transfered as well by wooden rods as by iron bars and that influence upon the patient was a result of imagination. Mesmer was obviously wrong in his theory, but he was the first attempting to use modern physical science to replace some of the superstition of his day. This in turn became opposition between supporters of physiological theories and those of psychological theories. Salpetriere, with Charcot, saw a pathological state in hypnosis, an artificial hysterical neurosis. On the other hand, the Nancy school of thought, represented by Bernheim, Liebault and Liegeois, suggested that it was a normal psychological phenomenon. The fight between the two schools was very bitter. Other theories initially inspired by the Pavlov school of thought came to light; these were replaced by those inspired by experimental psychology and a third psychoanalytic theory became predominant. A description of the hypnotic state revealed the reality and non-reality of the hypnotic state. This was the outcome of functional neuro-imaging techniques that are currently revolutionising our knowledge of cerebral functioning and research in the area of cognitive neuroscience allows questions about consciousness and its neurobiological substrate to be asked. Research into hypnosis requires a distinction to be made between ‘‘the state of consciousness’’ and ‘‘conscious content’’. Various functional neuro-imaging studies are reported investigating the area of ‘‘neurophenomenology’’ in the hypnotic process

    Pain Processing and Modulation in the Cingulate Gyrus

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    Cingulate cortex occupies a large part of the medial surface of the brain and has become an important region of interest in acute and chronic pain studies. Although it is among the most frequently activated regions in human functional imaging research, no part of the cingulate gyrus can be referred to as a \u201cpain center\u201d because none has been shown to have mainly pain processing functions. For example, the midcingulate region, which is usually activated during acute noxious stimulation, has primarily skeletomotor functions through the two cingulate motor areas and has been activated in numerous tasks that do not involve noxious stimuli. These include the Stroop and Flanker interference, complex movement, and word generation tasks. The logic of studying pain processing in this context requires a clear statement of the functions of each cingulate region in general brain function followed by an assessment of how these functions are redirected to resolve problems of anticipated or actual pain experiences. Here we consider the structural, connection and functional organization of the cingulate gyrus, its top-down role in anticipation of pain and the application of hypnosis to engage cingulate mediated processing for hypnosedation
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