The rubber hand illusion: Maintaining factors and a new perspective in rehabilitation and biomedical engineering?

Abstract

Feelings of unrealistic body parts are related to deficits in human information processing and can occur as a part of phantom sensations after amputation [8]. Experimentally induced sensoric illusions like rubber hand illusion (RHI) [1] may help to understand basic information processing and could give new ideas for treatment or the rehabilitation process. Factors that are related to modulate sensoric illusions during movement may help to develop new intervention strategies in the rehabilitation of illusory symptoms. The goal of this study was to review the factors affecting persistence of the RHI effect during movement. We selected 13 keywords and searched in the following www.dimdi.de data bases (CCTR93, CDAR94, CDSR93, DAHTA, DAHTA, EA08, ED93, EM00, EM47, HG05, KP05, KR03, ME00, ME60, PI67, PY81, TV01, TVPP). A total of 160 articles were found. Duplicates were removed and the remaining list was filtered with the objective to explore the influence of active or passive movement during experimentally induced RHI. Then we identified six articles which experimentally examined persistence of RHI during active or passive movements. Results indicate that RHI are maintained during active or passive movements due to visual and temporal congruency. During active movements the RHI is more stable or global than in passive movements or during tactile stimulation. Factores like visual and temporal congruency are related to maintain RHI and are discussed in the rehabilitation of phantom sensations regarding new innovations in the design of prosthetics IntroductionAfter an amputation, feelings of unrealistic body parts are related to deficits in human information processing and can occur as a part of phantom sensations [8]. Those phantom sensations after an amputation are able to lead to feelings of pain which may be localized in a limb that no longer exists. All of these symptoms suggest disturbances in the experience of the body image/body scheme or in general a potential harm to the body matrix concept [24]. The rubber hand illusionBotvinick and Cohen [2] showed that the body image/scheme can experimentally be manipulated in healthy volunteers. In this standard paradigm a subject sees a visibly rubber hand being brushed while the real hidden hand of the subject is also synchronously brushed. After a certain time (15 seconds to 10 minutes) this process induces the feeling of ownership of an artificial limb (the rubber hand). Studies demonstrated that on average 25% of the participants do not respond to items that indicate this kind of illusory embodiment [10,6,5,4]. The cause and stability of this effect in responding subjects is attributed to multisensory integration between visual, tactile and proprioceptive information (see Image 1).Also a proprioceptive recalibration towards the rubber hand can be measured. This proprioceptive drift is being measured after the evoking of the illusion. The subject is asked to show the position of his/her real hand. In case of a successful illusion, subjects tend to show the po...

Robotic hand illusion with tactile feedback: Unravelling the relative contribution of visuotactile and visuomotor input to the representation of body parts in space

“…Moreover, prostheses, which are perceived as belonging to the amputee’s body, are associated with lower levels of phantom limb pain [51], a common consequence of limb amputation. All these findings suggest that eliciting embodiment sensations for prostheses might not only shape body-space representation, but also have important therapeutic implications [52]. Moreover, closed-loop user control is currently seen as an important design goal in prosthetic engineering [53, 54], which is supported by the present study due to the bimodal and synchronous conditions achieving the strongest results.…”

Robotic interfaces for cognitive psychology and embodiment research: A research roadmap

“…A better understanding of the fundamental cognitive mechanisms of the bodily experience of wearable robotic devices seems to be a very promising way to improve the design of prosthetic hardware and the related bHMIs (Christ et al, 2012;Rognini & Blanke, 2016;Beckerle et al, 2017). Research on embodiment also potentially sheds light on how to design novel experimental and functional assessment protocols: prosthetics research must get out of the laboratories and dive deep into daily living activities.…”

A Human–Robot Interaction Perspective on Assistive and Rehabilitation Robotics

“…Especially whenever visual feedback is present, non-visual feedback is usually disregarded, and in extreme cases the simultaneous delivery of multiple types of information could even degrade performance (Kim and Colgate, 2012 ). Generally, appropriate feedback is the basis for successful multisensory integration that can facilitate embodiment of the device by the user (Giummarra et al, 2008 ; Christ et al, 2012a ).…”