Dolor crónico y modificaciones de la conciencia corporal

This review article addresses the relationship between chronic pain and body awareness. Chronic pain refers to an ensemble of pain conditions whose common characteristic is the fact that peripheral lesions cannot explain the duration and intensity of the pain. The lack of explanation in terms of peripheral damage has led researchers to assume that the central nervous system plays a crucial role in these conditions. In particular, one suggestion about how such central factors might operate is by influencing patients? body awareness. In the first part of this article I present evidence showing a bidirectional relationship between chronic pain and what might be called "exteroceptive" body awareness, as well as the related hypothesis that pain results from a disruption in the mechanisms underlying exteroceptive body awareness. Next, I discuss some issues that this hypothesis fails to explain, and I consider the relationship between chronic pain and the autonomic nervous system. Finally, I relate this latter relationship to the notion of "interoceptive" body awareness, and explore the idea that understanding the mechanisms that relate exteroceptive and interoceptive aspects of body awareness might shed light on the nature and development of chronic pain.Este artículo aborda la relación entre el dolor crónico y la conciencia corporal. El dolor crónico se refiere a un conjunto de patologías que se caracterizan por la presencia constante de dolor, cuya intensidad y duración no pueden ser explicadas en términos de lesiones del sistema nervioso periférico. La falta de explicación en términos de daño periférico ha llevado a los investigadores a suponer que el sistema nervioso central desempeña un papel crucial en estos síndromes. En particular, se ha propuesto que la cronicidad del dolor causada posiblemente por una perturbación de los mecanismos involucrados en lo que podría llamar-se la conciencia corporal 'exteroceptiva'. En la primera parte de este artículo presento estudios que muestran una relación bi-direccional entre el dolor crónico y la conciencia corporal exteroceptiva, así como la hipótesis que el este dolor resulta de la perturbación de los mecanismos subyacentes a este tipo de conciencia corporal. A continuación, presento algunos problemas que esta hipótesis no logra explicar, y considero la relación entre el dolor crónico y el sistema nervioso autónomo. Por último, considero esta última relación a la luz de la noción de conciencia corporal 'interoceptiva', y sugiero que la comprensión de los mecanismos que relacionan los aspectos exteroceptivos e interoceptivos de la conciencia corporal, podrían contribuir a la comprensión de la natura-leza y el desarrollo de dolor crónico

Exploring the subjective experience of the "rubber hand" illusion

International audienceDespite the fact that the rubber hand illusion (RHI) is an experimental paradigm that has been widely used in the last 14 years to investigate different aspects of the sense of bodily self, very few studies have sought to investigate the subjective nature of the experience that the RHI evokes. The present study investigates the phenomenology of the RHI through a specific elicitation method. More particularly, this study aims at assessing whether the conditions usually used as control in the RHI have an impact in the sense of body ownership and at determining whether there are different stages in the emergence of the illusion. The results indicate that far from being "all or nothing," the illusion induced by the RHI protocol involves nuances in the type of perceptual changes that it creates. These perceptual changes affect not only the participants' perception of the rubber hand but also the perception of their real hand. In addition, perceptual effects may vary greatly between participants and, importantly, they evolve over time

Body, space, and pain

status: publishe

Body, space and pain

There is growing interest in understanding how the perception of pain (and touch) is influenced by the way we represent our body and the space surrounding it. Recent views argue that pain can only be understood in a larger framework of body perception and action. This attention is driven by accumulating research in experimental and clinical domains, indicating that pain perception depends largely on cognitive factors and multisensory integration. The interest is also boosted by studies on chronic pain conditions suggesting a tight link between body perception and the maintenance of pain. Many aspects remain yet to be elucidated. We welcomed submissions from researchers in cognitive neuroscience and pain to increase our understanding of the interplay among body, space, pain, touch and movement. We aimed to gather insights from different theoretical frameworks and encouraged investigators using a broad range of methods including (but not limited to) behavioural and neuropsychological approaches, imaging techniques, electrophysiology, psychophysiology and TMS to present their results in this Research Topic. In the attempt to go from bench- to bedside we also strongly encouraged submissions from clinicians and physiotherapist whose contribution may help rising some future key questions. Qualitative and phenomenological approaches were also welcome

Bilateral Alternating Auditory Stimulations Facilitate Fear Extinction and Retrieval

International audienceDisruption of fear conditioning, its extinction and its retrieval are at the core of posttraumatic stress disorder (PTSD). Such deficits, especially fear extinction delay, disappear after alternating bilateral stimulations (BLS) during eye movement desensitization and reprocessing (EMDR) therapy. An animal model of fear recovery, based on auditory cued fear conditioning and extinction learning, recently showed that BLS facilitate fear extinction and fear extinction retrieval. Our goal was to determine if these previous results found in animals can be reproduced in humans. Twenty-two healthy participants took part in a classical fear conditioning, extinction, and extinction recall paradigm. Behavioral responses (fear expectations) as well as psychophysiological measures (skin conductance responses, SCRs) were recorded. The results showed a significant fear expectation decrease during fear extinction with BLS. Additionally, SCR for fear extinction retrieval were significantly lower with BLS. Our results demonstrate the importance of BLS to reduce negative emotions, and provide a successful model to further explore the neural mechanisms underlying the sole BLS effect in the EMDR