我观故我在?——从橡胶手错觉对自我身体所有权的探讨

I See,therefore I Am?——A Perspective from Rubber Hand Illusion of Self Body-ownership

橡胶手错觉是一种能将非自我的肢体感知为自我的肢体的反应。继发现橡胶手错觉现象后,研究者通过操纵自变量以及观测不同的因变量,得到了大量新的研究结果。橡胶手错觉的出现与强度受到时间、空间和手姿势的影响,其产生机制为单纯的多感觉整合或多感觉整合与身体表征共同作用的结果。未来研究侧重于被试取样、研究策略以及医学领域中患者的认知神经康复和截肢病人的假肢控制等方面。

The ‘rubber hand illusion’ is a perceptual phenomenon. In 1998 Botvinick and Cohen provided the first description of the rubber hand illusion. In the classical RHI experiment the subjects was seated with their left arm rested on the table. A standing screen was positioned beside the arm to hide it from the subject’s view while a realistic life-sized rubber hand was placed in front of the subject. The subjects’ eyes fixed on the artificial hand while experimenter used two small paintbrushes to stroke the rubber hand and the subject’s hidden hand, synchronizing timing as closely as possible. After a short period, subjects completed a two-part questionnaire and proprioceptive drift measure. （The result showed that）Subjects reported feeling a sense of ownership of the rubber hand and proprioceptive drift towards the rubber hand. Subsequent experiments have been done by researchers after the classical RHI experiment. The materials, stimuli presentation, participants selection and other aspects of the experiment have been improved in different ways. The change of the classical experiment resulted in a tremendous new findings. The mechanism of the RHI still needs more research. What we know is that there are two possible explanations on the RHI. First one involved the pure multisensory integration. Many researchers think that the rubber hand illusion reflected a three-way interaction between vision, touch, and proprioception. Second one considered the RHI is modulated by top-down influences originating from the representation of one’s own body and bottom-up processes of multisensory integration. Evidences suggested that RHI can be influenced by many factors. Firstly, the “spatial limits” is an important phenomenon in the RHI. If the distance between the rubber hand and the participant’s own hand was too larger, the strength of the rubber hand illusion was signi？cantly reduced. Secondly, the occurrence of RHI is affected by anatomical and postural constrains. If the dummy hand was placed in an anatomically implausible position, the RHI effects are abolished. The extent of the RHI depends on the alignment between the actual position of the subject’s hand and the seen position of the dummy hand. Thirdly, many studies showed that the spatiotemporal pattern of stimulation influences the RHI. The necessary condition for the inducement of the illusion is the presence of synchronized and spatially congruent visual and tactile stimulation. This illusion does not occur when the rubber hand is stroked asynchronously with respect to the participant＇s own hand. The future research should stress in the participant selection, research strategy, self explore and will probably have many important clinical applications, and for example, using a modi？ed version of the rubber hand illusion can not only promote the amputation patients to integrate artificial limb into the body schema, but also help consciousness to control and manipulate prosthetic. The rubber hand illusions will promote paralysis patients and stroke patient＇s physical and cognitive rehabilitation.