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Il ruolo della dopamina nella bizzarria cognitiva : studio sperimentale sul sogno e sulla fantasia di soggetti in terapia con farmaci pro-dopaminergici
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Hypnagogic hallucinations and sleep paralysis
No full textHypnagogic hallucinations and sleep paralysis are two associated features of narcolepsy that can also be found as isolated phenomena or within the context of other clinical conditions. Hypnagogic hallucinations are abnormal sensory perceptions experienced in the transition between wakefulness and sleep, whereas analogous hallucinations that occur upon awakening are called hypnopompic. Sleep paralysis is a transient paralysis of skeletal muscles associated with a clear waking mentation occurring in sleep–wake transitions. The two phenomena often occur together in narcoleptic subjects, provoking significant fear responses, especially when first experienced, because of the threatening and often terrifying nature of the hallucinations and the associated inability to move.
Though underlying neurobiological mechanisms are still partly unknown, hypnagogic hallucinations and sleep paralysis are usually considered dissociated manifestations of REM sleep, with the former described as dreamlike intrusions into waking cognition and the latter considered to be the persistence of typical REM muscle atonia into wakefulness. Experimental evidence seems to point to the sleep-onset REM period typically found in narcoleptic subjects as a neurophysiological substrate for these phenomena; sleep paralysis has also been found to occur upon awakening during offset REM, confirming the hypothesis of an underlying dissociation of the REM stage in the transition between wakefulness and sleep. From a neurochemical point of view, an imbalance in the monoaminergic -cholinergic modulation of transitions among states of consciousness seems to underpin hypnagogic hallucinations and sleep paralysis by shifting the brain towards cholinergically driven hallucinatory cognition and inhibition of motility. The AIM state space model appears to further explain these REM-related phenomena by interpreting them in terms of varying levels of brain activation (A) and processing of internal–external inputs (I) in addition to neurochemical modulation (M).
Though adequately structured clinical trials for evaluating the efficacy of medications for hypnagogic hallucinations and sleep paralysis are lacking, sodium oxybate and antidepressants such as clomipramine, venlafaxine and SSRIs are commonly used to alleviate the significant distress caused by these symptoms in narcoleptic subjects
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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