Abstract Background Extended reality (XR), encompassing virtual reality, augmented reality (AR), and mixed reality, is increasingly being used in neurorehabilitation to provide multisensory feedback and promote neural plasticity in sensorimotor networks. Objective This scoping review aimed to (1) examine how XR technologies are applied in motor neurorehabilitation, (2) explore how body representation and somatic embodiment are addressed, and (3) analyze the methodological designs of XR-based interventions. Methods This review was conducted in accordance with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines, with a comprehensive search across PubMed, Embase, Scopus, and Web of Science from inception to December 2023. Eligible studies included original research involving XR-based interventions explicitly targeting neurorehabilitation. Studies related to somatic embodiment and reporting data on implementation and user outcomes were considered without date restriction. Three independent reviewers conducted screening in Covidence. The following variables were extracted: study design, participant characteristics, XR devices and software, experimentation details, treatment approaches, and evaluation methods. Methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale and the Murad Scale. Findings have been presented in tabular and narrative formats. Results Twenty-six studies met the inclusion criteria, and these were mainly clinical trials involving patients with neurological conditions, particularly poststroke status (n=6) and spinal cord injury (n=2). Several studies provided physiological data, including electroencephalography (n=12), electromyography (n=2), magnetic resonance imaging (n=1), galvanic skin response (n=1), electrodermal activity (n=1), and motor-evoked potential data (n=1). Two studies used noninvasive brain stimulation, and another two used eye tracking. Most studies (n=17) used built-in motion sensors; however, some (n=8) analyzed the data quantitatively. Unity 3D was the most frequently used development platform (n=8). First-person (n=20) and third-person (n=2) perspectives were used, and 4 studies combined both perspectives. Interventions mainly targeted sensorimotor deficits, with improvements in motor and cognitive performance. Sixteen studies addressed body perception, focusing on limb embodiment. Questionnaires were the most frequently used evaluation tools (n=18), and 3 studies used standardized tests. Some studies (n=7) investigated body ownership under visuomotor inconsistencies with or without visuotactile stimulation. XR was primarily applied to enhance sensorimotor recovery and assess device feasibility. Few studies directly measured embodiment (n=4), ownership (n=2), or self-location (n=2). The ability of XR platforms to deliver multisensory feedback appears to facilitate sensorimotor learning and support a more accurate body schema. Conclusions Evidence from the studies supports the usefulness of XR in enhancing reinforcement learning and facilitating recovery in neurorehabilitation. Tailored XR approaches, which are grounded in embodiment principles and patient-specific needs, show promise for improving outcomes in neurological rehabilitation programs. The AR paradigm, which could offer several advantages, was not explored in depth, perhaps due to its difficult implementation during the period considered.

Conscious awareness refers to the subjective experience of perceiving, thinking, and feeling and the ability to report these experiences. These perceptions and thoughts are experienced as bound to an individual self. A fundamental aspect of this self-consciousness is the sense of bodily self-the experience of one's physical presence distinct from the external world, serving as the spatial reference point for conscious perceptions. A key component of the bodily self is body ownership, the experience of the body as one's own. Research shows this sense involves integrating signals from different sensory modalities, including vision, touch, and proprioception, into a coherent multisensory percept. However, the relationship between body ownership and conscious awareness remains unclear. To investigate this, we developed a psychophysical paradigm to objectively quantify multisensory integration, conscious awareness, and their relationships within a bodily illusion manipulating body ownership perception. Using signal-detection analysis, metacognitive computational modeling, and drift-diffusion modeling, we found conscious awareness reports closely matched objective discrimination of body ownership. This relationship remained consistent across different levels of multisensory integration and evidence accumulation. A visuotactile control experiment revealed that this strong conscious access is specific to body ownership, not general to multisensory integration. These findings suggest that conscious awareness has continuous and prioritized access to body ownership, implying that the self-related form of multisensory integration supporting body ownership is largely implemented at the level of conscious processing. This provides theoretical insight into how conscious awareness and the bodily self are intertwined, with wide-reaching implications for consciousness and body representation research.

A systematic review and meta-analysis on the neural correlates of bodily self-consciousness.

Shaping bodily self-awareness through thermosensory signals.

Juggling with rubber hands, leaping with rubber feet: Sensorimotor reuse during verb comprehension.

Does the peak-end rule apply to judgments of body ownership in virtual reality?

The neural representation of the body is highly flexible and can be altered by integrating multisensory signals in the brain. The rubber hand illusion (RHI) is a widely used paradigm to investigate this phenomenon; participants experience ownership of a rubber hand and perceive their real hand as shifting toward the rubber hand's location, a phenomenon known as proprioceptive drift. Although individual differences in the extent of this drift are well documented, it remains unclear whether such differences are related to specific aspects of motor function. In this study, we examined the relationship between the magnitude of proprioceptive drift during the RHI and the ability of individuals to imitate and reproduce elbow movements. Our results revealed a significant correlation between the magnitude of proprioceptive drift and the accuracy of action reproduction but not imitation. These findings suggest that altered body representation may selectively influence the motor processes involved in action reproduction, highlighting the interplay between body ownership and motor control.

Behavioral and neural effects of virtual embodiment in individuals with Body Integrity Dysphoria.

Most studies in bodily self-consciousness were limited to the case of a single body. We performed VR experiments to test the hypothesis that it is possible for healthy subjects to experience the Double Body Effect-the experiential combination of double body ownership and double body-location. Under proprioceptive-vestibular and visual manipulations, participants wobbled involuntarily while watching two identical avatars doing exactly the same. The results showed that, in both the 1PP and 3PP conditions, it was indeed possible for healthy subjects to experience the Double Body Effect. This reveals that body ownership and body location are more flexible than most studies have considered so far. It also suggests that self-location and body-location are not the same experiences, and that the relation between self and body is more complicated than both traditional dualism and contemporary reductionism. Finally, our findings can serve as a preliminary model for understanding the perplexing phenomenology of heautoscopy.

Shifting the body midline: The impact of visuomotor modulations in virtual reality on peripheral autonomic activity.

Pain-a complex, highly subjective experience-is shaped by interoceptive signals, especially the systolic and diastolic phases of cardiac rhythmicity. While body ownership illusions (BOI, the perceptual attribution of artificial limbs to one's own body) are modulated by interoceptive signals, their influence on pain processing remains controversial, with conflicting findings in the literature. Critically, it remains unclear whether cardiac-phase-specific pain modulation occurs independently of BOI. To resolve this, we examined: (1) the effects of cardiac cycles, (2) the influence of BOI, and (3) their potential interactions on pain processing. In the present study, we used a virtual reality rubber hand illusion (VR-RHI) paradigm to induce BOI. In the control condition (object, OBJ condition), participants viewed a VR scenario with an inanimate object (cardboard) instead of a rubber hand, which does not induce BOI. Pain stimulation was administered under four experimental conditions: RHI-systole, RHI-diastole, OBJ-systole, and OBJ-diastole. We assessed pain perception-thresholds, intensity and unpleasantness ratings, and somatosensory evoked potentials (SEPs)-while delivering painful electrical stimuli timed to systolic or diastolic phases under BOI and control VR conditions. Results demonstrated that compared to the systolic phase, the diastolic phase was associated with significantly lower pain intensity and unpleasantness ratings, along with reduced SEP amplitudes. However, neither BOI nor its interaction with cardiac cycle exerted significant effects on these measures. Our findings suggest that while cardiac cycle modulates pain perception, this effect operates independently of BOI.

Previous findings revealed that social ostracism reduces people's sense of agency and body ownership, and vicarious ostracism reduces agency. Given theoretical claims that other's and own behavior may be cognitively represented similarly, we compared the impact of first-hand and vicarious social ostracism on agency and ownership, using both explicit and implicit measures. Participants were separated into target group and observer group, to experience first-hand or vicarious ostracism or inclusion. We used a virtual Cyberball game to induce social ostracism or inclusion; and virtual hand illusion, where participants could freely control a virtual hand by moving their real hands, for agency and ownership measurements. Findings show that, both first-hand and vicarious ostracism reduced agency and ownership in both explicit and implicit measures. While the implicit measures were affected by first-hand and vicarious experience equally, the explicit measures showed a stronger reduction of agency and ownership for first-hand than for vicarious experience.

This study addresses the challenge of sustaining motivation and engagement in long-term lower-limb training, particularly during home-based recovery. Lower-limb motor dysfunction, often due to neurological conditions, hinders daily activities, making effective training essential. Traditional methods struggle to maintain engagement during the transition from facility-based to home-based training. We developed a VR-based Seated knee extension exercise system integrated with a rehabilitation robot, testing three redirection strategies: pre-offset, scale offset, and rear offset. Results showed all strategies improved task performance and engagement, with the rear offset strategy uniquely preserving body ownership and spatial awareness. In contrast, pre-offset and scale offset strategies enhanced performance but slightly reduced spatial coherence. The study highlights the importance of choosing suitable redirection strategies to optimize training outcomes and supports VR-integrated rehabilitation robots for improved home-based recovery.

SummaryThe way we perceive our body and its dimensions depends on how our brain combines multisensory information. As the human sensory system declines with age, we hypothesize that body perception may change during aging. We investigated this hypothesis by comparing body ownership (BO) and upper limb perceived dimensions (mBR) in young and older individuals (>65 years). We used computational and psychophysical methods to quantify alterations in mBR and BO, and modeled their relationship with sensorimotor and cognitive factors. Results revealed altered body perception in healthy older adults, with significant underestimation in arm dimensions and increased feeling of ownership over an incongruent virtual hand, incorporating it into their motor plans. Reduced abilities in localizing one’s own body in space (i.e., proprioception) emerged as a common factor influencing both BO and mBR. These findings pave the way for stimulation strategies to maintain or restore body perception in aging.

The sense of body ownership, a core aspect of self-recognition, has been studied using illusions such as the full-body illusion. Although the premotor cortex is considered central to body ownership in first-person full-body illusions, the occipitotemporal cortex-including the temporoparietal junction (TPJ) and the extrastriate body area (EBA)-also plays a critical role in third-person full-body illusions. However, their distinct contributions to the full-body illusion remain unclear, partly due to the challenges of applying neuroimaging in such experiments. This study employed functional near-infrared spectroscopy to investigate brain activity during a third-person full-body illusion in virtual reality. Eighteen healthy human adult males participated in the study. The experiment consisted of two sessions. In Session 1, participants observed an avatar's back receiving either synchronous or asynchronous visual-tactile stimulation. In Session 2, visual stimuli alone were presented to participants after they experienced the full-body illusion to induce visuotactile discrepancies. In the synchronous condition of Session 1, we found significant deactivation in the superior and middle temporal gyri (partially including the TPJ), followed by higher activity than in the asynchronous condition in the left middle occipital gyrus (likely EBA). The left premotor cortex also showed significant activation (uncorrected), although this did not survive multiple-comparison adjustment. In Session 2, the visuotactile discrepancy induced significant left premotor activation only in the synchronous condition (FDR-corrected). These findings suggest that the occipitotemporal cortex supports receptivity to third-person full-body illusions, whereas the premotor cortex contributes to maintaining illusory body ownership by reconciling multisensory conflicts.

Visibility manipulations affect the functional connectivity related to illusory body ownership.

IntroductionAutoscopic Phenomena (APs) are rare perceptual experiences where individuals perceive a visual double or duplicate of their own body. It has been recognized since ancient times, but gained significant attention in the 19th century, both through its depiction in romantic literature and in neuropsychiatric studies; in the literature, their association with epilepsy and schizophrenia is very extensively documented. Recent research brought new insights into the neurobiology of these phenomena.ObjectivesIn this article, we aim to review the phenomenology and psycopathology of APs.MethodsNarrative literature review.ResultsFrom a phenomenological perspective, three main conditions can be identified. In Autoscopy, the person sees a double, but does not feel a connection with it, meaning that they can distinguish between themselves and the double. In Out-of-body Experience (OBE), the individual feels as though they have left their body and observe themselves from an external perspective. In Heautoscopy, the boundary between the self and the double is blurred, causing uncertainty about where one’s “self” is located, representing a middle ground between autoscopy and OBE.Current research suggests that APs are linked to dysfunctions in the normal integration of body ownership, self-location, and perspective-taking, caused by lesions in regions responsible for integrating multisensory inputs (visual, proprioceptive and vestibular). All types of APs have in common a dysfunction specifically in the temporo-parietal junction (TPJ), a brain area involved in processing self-location and integrating sensory inputs to create a unified sense of self; other common areas include the insula and cingulate cortex.Regarding to the different networks of APs, Autoscopy primarily involves abnormalities in the visual processing regions (as the occipital and parietal lobes), causing a visual perception of double; OBEs are caused by dysfunctions in areas responsible for self-location and vestibular processing (such as the medial prefrontal cortex), leading to a sensation of floating outside one’s body; lastly, Heautoscopy engages more widespread brain dysfunctions, including the regions involved in self-representation and embodiment, leading to ambiguity in self-location.ConclusionsAPs challenge our understanding of the bodily self and how identity is constructed, raising questions about how the brain creates a unified sense of being in a body and how this can break down under certain pathological conditions. Although much is unknown, one thing is for sure: these phenomena demonstrate that the sense of self is not fixed, and the study of its disruption, by exploring its phenomenology and psychopatology, may contribute to reveal the underlying processes involved in bodily self-consciousness.Disclosure of InterestNone Declared

This article discusses about Senandung tak Bertahta exhibition which departs from the situation and conditions of Balinese society in the frame of socialist realism Pramoedya Ananta Toer. Balinese society is still struggling to meet their living needs behind the glittering tourism sector. Take for example the Kerobokan area of Bali which is always under pressure with the rate of growth, between struggling, surviving, actually giving up, especially on the issue of land which is squeezed and lured by investors' enticements. The data source was obtained through a qualitative approach using a descriptive analysis method by utilizing library media. The Senandung tak Bertahta exhibition is a representative to voice the phenomenon, through three works that represent the voices of the buried community, the context of body ownership and the issue of fake identity. The Senandung tak bertahta exhibition will be studied using the theory of Socialist Realism which is in line with Pramoedya's thoughts and the works will be studied using theories by Adorno, Foucault and Julia Kristeva which describe the problem of the helplessness of society which is in line with the context of socialist realism. By studying symbolic elements, visual composition, and social context, this exhibition shows how contemporary art is still relevant as a medium for the struggle of lower-class discourse, as proposed in Pramoedya's literature.

Body ownership and vicarious Agency: Behavioural consequences in a virtual reality rock concert.

Human experimental psychology seems inextricably bound up with a notion of self, or individual mental life. The link between self and body has always been acknowledged, but psychologists have few ways to investigate, analyze, or understand this link. As 2025 marks the 50th birthday of the Journal of Experimental Psychology: Human Perception and Performance and 20 years since the publication of our "Re-Visiting the Rubber Hand Illusion" article in the journal, we take this opportunity to reflect on the impact, reach, and major developments that followed its publication. In particular, we focus on how the methods and theoretical constructs from our article have extended the concepts of bodily self-awareness toward other fields beyond experimental psychology. Our article helped to develop experimental approaches to understanding the role of the body in self-awareness, and mental life more generally. The combination of rigorous experimental methods and a clear theoretical model has allowed psychologists to have a clearer view of the relation between body and self. (PsycInfo Database Record (c) 2025 APA, all rights reserved).