Llorens Roberto, Borrego Adrián, Palomo Priscila, Cebolla Ausiàs, Noé Enrique, I Badia Sergi Bermúdez, Baños Rosa
Neurorehabilitation and Brain Research Group, Instituto de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; Servicio de Neurorrehabilitación y Daño Cerebral de los Hospitales NISA, Fundación Hospitales NISA, Río Tajo 1, 46011 Valencia, Spain.
Neurorehabilitation and Brain Research Group, Instituto de Investigación e Innovación en Bioingeniería, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Neuropsychologia. 2017 Feb;96:61-69. doi: 10.1016/j.neuropsychologia.2017.01.007. Epub 2017 Jan 8.
Stroke can lead to motor impairments that can affect the body structure and restraint mobility. We hypothesize that brain lesions and their motor sequelae can distort the body schema, a sensorimotor map of body parts and elements in the peripersonal space through which human beings embody the reachable space and ready the body for forthcoming movements. Two main constructs have been identified in the embodiment mechanism: body-ownership, the sense that the body that one inhabits is his/her own, and agency, the sense that one can move and control his/her body. To test this, the present study simultaneously investigated different embodiment subcomponents (body-ownership, localization, and agency) and different neurophysiological measures (galvanic skin response, skin temperature, and surface electromyographic activity), and the interaction between them, in clinically-controlled hemiparetic individuals with stroke and in healthy subjects after the rubber hand illusion. Individuals with stroke reported significantly stronger body-ownership and agency and reduced increase of galvanic skin response, skin temperature, and muscular activity in the stimulated hand. We suggest that differences in embodiment could have been motivated by increased plasticity of the body schema and pathological predominance of the visual input over proprioception. We also suggest that differences in neurophysiological responses could have been promoted by a suppression of the reflex activity of the sympathetic nervous system and by the involvement of the premotor cortex in the reconfiguration of the body schema. These results could evidence a body schema plasticity promoted by the brain lesion and a main role of the premotor cortex in this mechanism.
中风可导致运动障碍，进而影响身体结构并限制活动能力。我们假设脑损伤及其运动后遗症会扭曲身体图式，身体图式是身体各部分及个人周边空间元素的感觉运动图谱，通过它人类能够体现可触及空间并为即将到来的动作做好身体准备。在具身机制中已确定两个主要概念：身体所有权，即感觉自己所居住的身体是自己的；能动性，即感觉自己能够移动和控制自己的身体。为验证这一点，本研究同时调查了临床对照的中风偏瘫个体以及经历橡皮手错觉后的健康受试者中不同的具身子成分（身体所有权、定位和能动性）和不同的神经生理学指标（皮肤电反应、皮肤温度和表面肌电活动），以及它们之间的相互作用。中风患者报告称，在受刺激的手中，身体所有权和能动性显著增强，而皮肤电反应、皮肤温度和肌肉活动的增加则有所减少。我们认为，具身差异可能是由身体图式可塑性增加以及视觉输入相对于本体感觉的病理优势所导致的。我们还认为，神经生理反应的差异可能是由交感神经系统反射活动的抑制以及运动前皮质参与身体图式的重新配置所促成的。这些结果可能证明了脑损伤促进了身体图式可塑性，以及运动前皮质在这一机制中的主要作用。
