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

2021 ◽  
Author(s):  
Arran T Reader

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.

2014 ◽  
Vol 26 (4) ◽  
pp. 712-721 ◽  
Author(s):  
Mirta Fiorio ◽  
Caterina Mariotti ◽  
Marta Panzeri ◽  
Emanuele Antonello ◽  
Joseph Classen ◽  
...  

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.


2018 ◽  
Vol 31 (6) ◽  
pp. 537-555 ◽  
Author(s):  
Jennifer L. Campos ◽  
Graziella El-Khechen Richandi ◽  
Babak Taati ◽  
Behrang Keshavarz

Percepts about our body’s position in space and about body ownership are informed by multisensory feedback from visual, proprioceptive, and tactile inputs. The Rubber Hand Illusion (RHI) is a multisensory illusion that is induced when an observer sees a rubber hand being stroked while they feel their own, spatially displaced, and obstructed hand being stroked. When temporally synchronous, the visual–tactile interactions can create the illusion that the rubber hand belongs to the observer and that the observer’s real hand is shifted in position towards the rubber hand. Importantly, little is understood about whether these multisensory perceptions of the body change with older age. Thus, in this study we implemented a classic RHI protocol (synchronous versus asynchronous stroking) with healthy younger (18–35) and older (65+) adults and measured the magnitude of proprioceptive drift and the subjective experience of body ownership. As an adjunctive objective measure, skin temperature was recorded to evaluate whether decreases in skin temperature were associated with illusory percepts, as has been shown previously. The RHI was observed for both age groups with respect to increased drift and higher ratings of ownership following synchronous compared to asynchronous stroking. Importantly, no effects of age and no interactions between age and condition were observed for either of these outcome measures. No effects were observed for skin temperature. Overall, these results contribute to an emerging field of research investigating the conditions under which age-related differences in multisensory integration are observed by providing insights into the role of visual, proprioceptive, and tactile inputs on bodily percepts.


2018 ◽  
Author(s):  
Maria Laura Filippetti ◽  
Louise P. Kirsch ◽  
Laura Crucianelli ◽  
Aikaterini Fotopoulou

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.


2017 ◽  
Vol 30 (7-8) ◽  
pp. 615-637 ◽  
Author(s):  
Olga Perepelkina ◽  
Maria Boboleva ◽  
Galina Arina ◽  
Valentina Nikolaeva

The aim of the study was to investigate how emotion information processing factors, such as alexithymia and emotional intelligence, modulate body ownership and influence multisensory integration during the ‘rubber hand illusion’ (RHI) task. It was previously shown that alexithymia correlates with RHI, and we suggested that emotional intelligence should also be a top-down factor of body ownership, since it was not shown in previous experiments. We elaborated the study of Grynberg and Pollatos [Front. Hum. Neurosci.9(2015) 357] with an additional measure of emotional intelligence, and propose an explanation for the interrelation of emotion and body ownership processing. Eighty subjects took part in the RHI experiment and completed the Toronto Alexithymia Scale and the Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT). Only MSCEIT was detected to be a significant predictor of the subjective measure of the RHI. There were no significant correlations between alexithymia scores and the test statements of the RHI or the proprioceptive drift, thus we did not replicate the results of Grynberg and Pollatos. However, alexithymia correlated with the control statements of subjective reports of the illusion, which might be explained as a disruption of the ability to discriminate and describe bodily experience. Therefore, (1) alexithymia seems to be connected with difficulties in conscious or verbal processing of body-related information, and (2) higher emotional intelligence might improve multisensory integration of body-related signals and reflect better predictive models of self-processing.


2021 ◽  
Author(s):  
Peter Lush

Seeing a fake hand brushed in synchrony with brushstrokes to a participant’s hand (the rubber hand illusion; RHI) prompts reports of referred touch, illusory ownership and that the real hand has drifted toward the fake hand (proprioceptive drift). According to one theory, RHI effects are attributable to multisensory integration mechanisms, but they may alternatively (or additionally) reflect the generation of experience to meet expectancies arising from demand characteristics (phenomenological control). Multisensory integration accounts are supported by contrasting synchronous and asynchronous brush stroking conditions, typically presented in counter-balanced order. This contrast is known to be confounded by demand characteristics, but to date there has been no exploration of the role of demand characteristics relating to condition-order. In an exploratory study, existing data from a rubber hand study (n = 124) were analysed to test order effects. Synchronous condition illusion report and the difference between synchronous and asynchronous conditions in both report and proprioceptive drift were greater when the asynchronous condition was performed first (and therefore participants were exposed to the questionnaire materials). These order effects have implications for interpretation of reports of ownership experience: in particular, there was no mean ownership agreement in the synchronous-first group. These data support the theory that reports of ownership of a rubber hand are at least partially attributable to phenomenological control in response to demand characteristics.


2019 ◽  
Vol 13 ◽  
pp. 117906951984990 ◽  
Author(s):  
Maria Pyasik ◽  
Tiziano Furlanetto ◽  
Lorenzo Pia

At present, most of the neurocognitive models of human sense of agency (ie, “this action is due to my own will”) have been traditionally rooted in a variety of internal efferent signals arising within the motor system. However, recent neuroscientific evidence has suggested that also the body-related afferent signals that subserve body ownership (ie, “this body is mine”) might have a key role in this process. Accordingly, in the present review paper, we briefly examined the literature investigating how and to what extent body ownership contributes to building up human motor consciousness. Evidence suggests that, if required by the context, body ownership per se can act on agency attribution (ie, independently from efferent signals). Hence, a unitary and coherent subjective experience of willed actions (ie, “this willed action is being realized by my own body”) requires both awareness of being an agent and of owning the body.


2021 ◽  
Vol 15 ◽  
Author(s):  
Letizia Della Longa ◽  
Giovanni Mento ◽  
Teresa Farroni

During childhood, the body undergoes rapid changes suggesting the need to constantly update body representation based on the integration of multisensory signals. Sensory experiences in critical periods of early development may have a significant impact on the neurobiological mechanisms underpinning the development of the sense of one’s own body. Specifically, preterm children are at risk for sensory processing difficulties, which may lead to specific vulnerability in binding together sensory information in order to modulate the representation of the bodily self. The present study aims to investigate the malleability of body ownership in preterm (N = 21) and full-term (N = 19) school-age children, as reflected by sensitivity to the Rubber Hand Illusion. The results revealed that multisensory processes underlying the ability to identify a rubber hand as being part of one’s own body are already established in childhood, as indicated by a higher subjective feeling of embodiment over the rubber hand during synchronous visual-tactile stimulation. Notably, the effect of visual-tactile synchrony was related to the suppression of the alpha band oscillations over frontal, central, and parietal scalp regions, possibly indicating a greater activation of somatosensory and associative areas underpinning the illusory body ownership. Moreover, an interaction effect between visual-tactile condition and group emerged, suggesting that preterm children showed a greater suppression of alpha oscillatory activity during the illusion. This result together with lower scores of subjective embodiment over the rubber hand reported by preterm children indicate that preterm birth may affect the development of the flexible representation of the body. These findings provide an essential contribution to better understand the processes of identification and differentiation of the bodily self from the external environment, in both full-term and preterm children, paving the way for a multisensory and embodied approach to the investigation of social and cognitive development.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Francesco della Gatta ◽  
Francesca Garbarini ◽  
Guglielmo Puglisi ◽  
Antonella Leonetti ◽  
Annamaria Berti ◽  
...  

During the rubber hand illusion (RHI), subjects experience an artificial hand as part of their own body, while the real hand is subject to a sort of 'disembodiment'. Can this altered belief about the body also affect physiological mechanisms involved in body-ownership, such as motor control? Here we ask whether the excitability of the motor pathways to the real (disembodied) hand are affected by the illusion. Our results show that the amplitude of the motor-evoked potentials recorded from the real hand is significantly reduced, with respect to baseline, when subjects in the synchronous (but not in the asynchronous) condition experience the fake hand as their own. This finding contributes to the theoretical understanding of the relationship between body-ownership and motor system, and provides the first physiological evidence that a significant drop in motor excitability in M1 hand circuits accompanies the disembodiment of the real hand during the RHI experience.


Psihologija ◽  
2022 ◽  
pp. 2-2
Author(s):  
Aitao Lu ◽  
Xuebin Wang ◽  
Xiuxiu Hong ◽  
Tianhua Song ◽  
Meifang Zhang ◽  
...  

Many studies have reported that bottom-up multisensory integration of visual, tactile, and proprioceptive information can distort our sense of body-ownership, producing rubber hand illusion (RHI). There is less evidence about when and how the body-ownership is distorted in the brain during RHI. To examine whether this illusion effect occurs preattentively at an early stage of processing, we monitored the visual mismatch negativity (vMMN) component (the index of automatic deviant detection) and N2 (the index for conflict monitoring). Participants first performed an RHI elicitation task in a synchronous or asynchronous setting and then finished a passive visual oddball task in which the deviant stimuli were unrelated to the explicit task. A significant interaction between Deviancy (deviant hand vs. standard hand) and Group (synchronous vs. asynchronous) was found. The asynchronous group showed clear mismatch effects in both vMMN and N2, while the synchronous group had such effect only in N2. The results indicate that after the elicitation of RHI bottom-up integration could be retrieved at the early stage of sensory processing before top-down processing, providing evidence for the priority of the bottom-up processes after the generation of RHI and revealing the mechanism of how the body-ownership is unconsciously distorted in the brain.


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