Two-Dimensional Rubber-Hand Illusion: The Dorian Gray Hand Illusion

The rubber-hand illusion provides a window into body representation and consciousness. It has been found that body-ownership extended to numerous hand-like objects. Interestingly, the vast majority of these objects were three-dimensional. We adopted this paradigm by using hand drawings to investigate whether rubber-hand illusion could be extended to two-dimensional hand samples, and we measured skin conductance responses and behavioural variables. The fact that this illusion extended to two-dimensional stimuli reveals the dominant role of top–down information on visual perception for body representation and consciousness.

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The Emotional Glue of the Senses: Affective Certainty and Congruency in the Rubber Hand Illusion

10.1101/401422 ◽

2018 ◽

Author(s):

Maria Laura Filippetti ◽

Louise P. Kirsch ◽

Laura Crucianelli ◽

Aikaterini Fotopoulou

Keyword(s):

Multisensory Integration ◽

Sensory Stimulation ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Top Down ◽

Rubber Hand ◽

Spatial Properties ◽

Affective Quality ◽

Temporal And Spatial

AbstractOur sense of body ownership relies on integrating different sensations according to their temporal and spatial congruency. Nevertheless, there is ongoing controversy about the role of affective congruency during multisensory integration, i.e. whether the stimuli to be perceived by the different sensory channels are congruent or incongruent in terms of their affective quality. In the present study, we applied a widely used multisensory integration paradigm, the Rubber Hand Illusion, to investigate the role of affective, top-down aspects of sensory congruency between visual and tactile modalities in the sense of body ownership. In Experiment 1 (N = 36), we touched participants with either soft or rough fabrics in their unseen hand, while they watched a rubber hand been touched synchronously with the same fabric or with a ‘hidden’ fabric of ‘uncertain roughness’. In Experiment 2 (N = 50), we used the same paradigm as in Experiment 1, but replaced the ‘uncertainty’ condition with an ‘incongruent’ one, in which participants saw the rubber hand being touched with a fabric of incongruent roughness and hence opposite valence. We found that certainty (Experiment 1) and congruency (Experiment 2) between the felt and vicariously perceived tactile affectivity led to higher subjective embodiment compared to uncertainty and incongruency, respectively, irrespective of any valence effect. Our results suggest that congruency in the affective top-down aspects of sensory stimulation is important to the multisensory integration process leading to embodiment, over and above temporal and spatial properties.

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The supernumerary rubber hand illusion revisited: perceived duplication of limbs and visuotactile events

10.31234/osf.io/eskr8 ◽

2020 ◽

Cited By ~ 1

Author(s):

Chenggui Fan ◽

H. Henrik Ehrsson

Keyword(s):

Cognitive Neuroscience ◽

Body Representation ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Rubber Hand ◽

Real Right ◽

The Real ◽

Skin Conductance Responses ◽

Supernumerary Limbs ◽

Real Hand

A controversial and unresolved issue in cognitive neuroscience is whether humans can experience supernumerary limbs as part of their own body. Some previous experiments have claimed that it is possible to elicit supernumerary hand illusions based on modified versions of the rubber hand illusion. However, other studies have provided conflicting results that suggest that only one rubber hand can be perceived as one’s own. To address this issue, we developed a supernumerary hand illusion paradigm that allowed us to disambiguate ownership of individual rubber hands from simultaneous ownership of two fake hands. In our setup, the participant’s real right hand was hidden under a platform, while two identical right rubber hands were placed in parallel on top of the platform in direct view of the participant. We applied synchronous strokes to both rubber hands and the real hand (SS), synchronous strokes to one rubber hand and the real hand and asynchronous strokes to the other model hand (AS and SA) or asynchronous strokes to both fake hands in relation to the real hand (AA). Our results demonstrate that a genuine illusion of owning two rubber hands can be elicited and that such a supernumerary hand illusion can be isolated from the sense of ownership of a single rubber hand both in terms of questionnaire ratings and threat-evoked skin conductance responses (SCRs). These findings advance our knowledge about the dynamic flexibility and fundamental constraints of body representation and emphasize the importance of correlated afferent signals for causal inference in body ownership.

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EXPRESS: Vicarious Pain is an Outcome of Atypical Body Ownership: Evidence from the Rubber Hand Illusion and Enfacement Illusion

Quarterly Journal of Experimental Psychology ◽

10.1177/17470218211024822 ◽

2021 ◽

pp. 174702182110248

Author(s):

V. Botan ◽

Abigail Salisbury ◽

H.D. Critchley ◽

Jamie Ward

Keyword(s):

Sensory Information ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Multiple Sources ◽

Top Down ◽

Rubber Hand ◽

Single Body ◽

Sensory Evidence ◽

Different Response ◽

Bodily Illusion

Some people report localised pain on their body when seeing other people in pain (sensory-localised vicarious pain responders). In this study we assess whether this is related to atypical computations of body ownership which, in paradigms such as the Rubber Hand Illusion (RHI), can be conceptualised as a Bayesian inference as to whether multiple sources of sensory information (visual, somatosensory) belong together on a single body (one’s own) or are distributed across several bodies (vision=other, somatosensory=self). According to this model, computations of body ownership depend on the degree (and precision) of sensory evidence, rather than synchrony per se. Sensory-localised vicarious pain responders exhibit the RHI following synchronous stroking and – unusually – also after asynchronous stroking. Importantly, this occurs only in asynchronous conditions in which the stroking is predictable (alternating) rather than unpredictable (random). There was no evidence that their bottom-up proprioceptive signals are less precise, suggesting individual differences in the top-down weighting of sensory evidence. Finally, the Enfacement illusion (EI) was also employed as a conceptually-related bodily illusion paradigm that involves a completely different response judgment (based on vision rather than proprioception). Sensory-localised responders show a comparable pattern on this task after synchronous and asynchronous stroking. This is consistent with the idea that they have top-down (prior) differences in the way body ownership is inferred that transcends the exact judgment being made (visual or proprioceptive).

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What do participants expect to experience in the rubber hand illusion?

10.31234/osf.io/d8x9y ◽

2021 ◽

Author(s):

Arran T Reader

Keyword(s):

Subjective Experience ◽

The Body ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Rubber Hand ◽

Demand Characteristics ◽

Open Questions ◽

Synchronous Condition ◽

Subjective Reports

The sense of body ownership (the feeling that the body belongs to the self) is commonly believed to arise through multisensory integration. This is famously shown in the rubber hand illusion (RHI), where touches applied synchronously to a false hand and to the participant’s real hand (which is hidden from view) can induce a sensation of ownership over the fake one. Asynchronous touches weaken the illusion, and are typically used as a control condition. Subjective experience during the illusion is measured using a questionnaire, with some statements designed to capture illusory sensation and others designed as controls. However, recent work by Lush (2020, Collabra: Psychology) claimed that participants may have different levels of expectation for questionnaire items in the synchronous condition compared to the asynchronous condition, and for the illusion-related items compared to the control items. This may mean that the classic RHI questionnaire is poorly controlled for demand characteristics. As such, Lush (2020) suggested that subjective reports in the RHI may reflect compliance or even the generation of experience to meet expectations (‘phenomenological control’), rather than multisensory processes underlying the sense of body ownership. In the current work a conceptual replication of Lush (2020) was performed with an improved experimental design. Participants were presented with a video of the RHI procedure and reported the sensations they would expect to experience, both in open questions and by rating questionnaire items. In keeping with Lush (2020), participants had greater expectations for illusion statements in the synchronous condition compared to the asynchronous condition, and for illusion statements compared to control statements. However, there was also evidence that some expectations may be driven by exposure to the questionnaire items rather than exposure to the illusion procedure. The role of pre-illusion expectations and expectations driven by questionnaire exposure in the RHI require further examination.

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The rubber hand illusion in children with autism spectrum disorders: delayed influence of combined tactile and visual input on proprioception

Autism ◽

10.1177/1362361311430404 ◽

2012 ◽

Vol 16 (4) ◽

pp. 406-419 ◽

Cited By ~ 88

Author(s):

Carissa J. Cascio ◽

Jennifer H. Foss-Feig ◽

Courtney P. Burnette ◽

Jessica L. Heacock ◽

Akua A. Cosby

Keyword(s):

Autism Spectrum Disorders ◽

Temporal Integration ◽

Body Representation ◽

Autism Spectrum ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Self Awareness ◽

Rubber Hand ◽

Children With Asd ◽

Spectrum Disorders

In the rubber hand illusion, perceived hand ownership can be transferred to a rubber hand after synchronous visual and tactile stimulation. Perceived body ownership and self–other relation are foundational for development of self-awareness, imitation, and empathy, which are all affected in autism spectrum disorders (ASD). We examined the rubber hand illusion in children with and without ASD. Children with ASD were initially less susceptible to the illusion than the comparison group, yet showed the effects of the illusion after 6 minutes. Delayed susceptibility to the illusion may result from atypical multisensory temporal integration and/or an unusually strong reliance on proprioception. Children with ASD who displayed less empathy were significantly less likely to experience the illusion than those with more intact ability to express empathy. A better understanding of body representation in ASD may elucidate neural underpinnings of social deficits, thus informing future intervention approaches.

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The development of the bodily self: Children’s responses to the Rubber Hand Illusion

Seeing and Perceiving ◽

10.1163/187847612x647063 ◽

2012 ◽

Vol 25 (0) ◽

pp. 87

Author(s):

Dorothy A. Cowie

Keyword(s):

Sense Of Self ◽

Body Representation ◽

Rubber Hand Illusion ◽

Hand Position ◽

Proprioceptive Information ◽

Body Ownership ◽

Rubber Hand ◽

Multisensory Information ◽

Tactile Integration ◽

Process Controlling

The bodily self is constructed from multisensory information. However, little is known of the relationship between multisensory development and the emerging sense of self. We investigated how multisensory processes underpin the developing sense of bodily self by measuring the strength of the ‘Rubber Hand Illusion’ in young children (4 to 9 years old) and adults. Stroking mode (synchronous vs asynchronous) was varied between subjects. Following this visuotactile stimulation, we measured processes of body localisation using intermanual pointing, and feelings of body ownership using questionnaire responses. Intermanual pointing showed that children were as sensitive as adults to visual-tactile synchrony cues for hand position. Similarly, explicit feelings of embodiment, measured by questionnaire items, were sensitive to visual-tactile integration independent of age. These converging results indicate a visual-tactile pathway to the bodily self which matures by at least 4 years of age. However, regardless of synchrony cues, children’s pointing was more captured by the fake hand than adults, indicating a second, later-maturing process based on visual-proprioceptive information. These findings demonstrate two dissociable processes underlying body representation in early life: an early-maturing visual tactile process controlling hand localisation and ownership, and a later-developing visual-proprioceptive process controlling localisation only. The findings further suggest that hand localisation and ownership may not always be so intimately bound together as adult data would suggest, and therefore call for a reassessment of the systems involved in adult own-body perception.

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The rubber hand illusion does not influence basic movement

10.31219/osf.io/6dyzq ◽

2020 ◽

Author(s):

Arran T Reader ◽

Victoria S Trifonova ◽

H. Henrik Ehrsson

Keyword(s):

Body Representation ◽

Position Sense ◽

Convincing Evidence ◽

Rubber Hand Illusion ◽

Hand Position ◽

Body Ownership ◽

Rubber Hand ◽

Sense Of Ownership ◽

Basic Movement ◽

Proprioceptive Drift

Body ownership refers to the distinct sensation that our observed body belongs to us, which is believed to stem from multisensory integration. The rubber hand illusion (RHI) provides the most well-known evidence for this proposal: synchronous (but not asynchronous) stroking of a fake hand and a participant’s real hidden hand can induce a sense of ownership over the false limb. Whilst the RHI may interfere with object-directed action and alter motor cortical activity, it is not yet clear whether a sense of ownership over an artificial hand has functional consequences for movement production per se. As such, we performed two motion-tracking experiments (n=117) to examine the effects of the RHI on the reaction time, acceleration, and velocity of rapid index finger abduction. We also examined whether subjective components of the illusion and the associated changes in hand position sense (proprioceptive drift) were correlated with changes in the kinematic variables. We observed convincing evidence that the induction of the RHI did not alter any kinematic variables. Moreover, the subjective sensations of rubber hand ownership, referral of touch, and agency did not convincingly correlate with kinematic variables, and nor did proprioceptive drift, suggesting that changes in body representation elicited by the RHI may not influence basic movement. Whilst experiment 1 suggested that individuals reporting a greater sensation of the real hand disappearing performed movements with smaller acceleration and velocity following illusion induction, we did not replicate this effect in a second experiment, suggesting that these effects may be small or not particularly robust.

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The Role of the Cerebellum in Dynamic Changes of the Sense of Body Ownership: A Study in Patients with Cerebellar Degeneration

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00522 ◽

2014 ◽

Vol 26 (4) ◽

pp. 712-721 ◽

Cited By ~ 7

Author(s):

Mirta Fiorio ◽

Caterina Mariotti ◽

Marta Panzeri ◽

Emanuele Antonello ◽

Joseph Classen ◽

...

Keyword(s):

Cerebellar Ataxia ◽

Subjective Experience ◽

Premotor Cortex ◽

The Body ◽

Rubber Hand Illusion ◽

Subjective Feeling ◽

Body Ownership ◽

Rubber Hand ◽

Proprioceptive Drift

The sense of the body is deeply rooted in humans, and it can be experimentally manipulated by inducing illusions in at least two aspects: a subjective feeling of ownership and a proprioceptive sense of limb position. Previous studies mapped these different aspects onto anatomically distinct neuronal regions, with the ventral premotor cortex processing subjective experience of ownership and the inferior parietal lobule processing proprioceptive calibration. Lines of evidence suggest an involvement also of the cerebellum, but its precise role is not clear yet. To investigate the contribution of the cerebellum in the sense of body ownership, we applied the rubber-hand illusion paradigm in 28 patients affected by neurodegenerative cerebellar ataxia, selectively involving the cerebellum, and in 26 age-matched control participants. The rubber hand illusion is established by synchronous stroking of the participants' real unseen hand and a visible fake hand. Short asynchronous stroking does not bring about the illusion. We tested the subjective experience of the illusion, evaluated through a questionnaire and the proprioceptive drift of the real unseen hand toward the viewed rubber hand. In patients with cerebellar ataxia, we observed reduced sense of the subjective illusory experience specifically after synchronous stroking. In contrast, the proprioceptive drift was enhanced after synchronous and after asynchronous stimulation. These findings support the contention that the mechanisms underlying the presence of the illusion and the proprioceptive drift may be differently affected in different conditions. Impairment of the subjective sense of the illusion in cerebellar patients might hint at an involvement of cerebellar-premotor networks, whereas the proprioceptive drift typically associated with synchronous stroking appears to rely on other circuits, likely involving the cerebellum and the parietal regions.

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Psychometric properties of the embodiment scale for the rubber hand illusion and its relation with individual differences

Scientific Reports ◽

10.1038/s41598-021-84595-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daniele Romano ◽

Angelo Maravita ◽

Marco Perugini

Keyword(s):

Individual Differences ◽

Personality Traits ◽

Subjective Experience ◽

Body Representation ◽

Self Esteem ◽

Healthy People ◽

Rubber Hand Illusion ◽

Body Ownership ◽

Rubber Hand ◽

The Individual

AbstractThe Rubber Hand Illusion (RHI) opened the investigation of the sense of body ownership in healthy people. By putting in slight contrast vision touch and proprioception, healthy people embody a fake hand in one's body representation. The easiness of the procedure, typically measured with a set of questions that capture the subjective experience, favoured its blooming. However, validation studies of embodiment questionnaires are lacking, and the individual differences that contribute to the embodiment received little attention. In our study, 298 participants underwent an RHI procedure following both synchronous and asynchronous (control) visuo-tactile stimulations. The study had multiple aims: (a) to explore the psychometric structure of a 27-items questionnaire largely used in the literature; (b) to build a psychometrically efficient scale to measure embodiment-related phenomena; (c) to explore whether and how individual differences (empathy, self-esteem and mindfulness) are associated with the experience of illusion. We found a relatively simple structure consisting of three components: embodiment of the rubber hand, disembodiment of the biological hand, physical sensations experienced during the procedure. The scales designed were psychometrically reliable and theoretically meaningful, encompassing 18 of the original items. Finally, by adopting a network analysis approach, we found that the embodiment is directly related to empathy and self-esteem, while disembodiment and physical sensation are unrelated to individual personality traits. The study provides substantial evidence to use the embodiment scale as a standard questionnaire for future RHI studies. Additionally, the correlations with personality traits suggest that the embodiment induced by the RHI deeply integrates with the complexity of the individuals and their differences.

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