scholarly journals The developing bodily self: How posture constrains body representation in childhood

2018 ◽  
Author(s):  
Janna M. Gottwald ◽  
Laura Bird ◽  
Samantha Keenaghan ◽  
Clare Diamond ◽  
Eliana Zampieri ◽  
...  

Adults’ body representation is constrained by multisensory information and knowledge of the body such as its possible postures. This study (N = 180) tested for similar constraints in children. Using the rubber hand illusion with adults and 6- to 7-year-olds, we measured proprioceptive drift (an index of hand localisation) and ratings of felt hand ownership. The fake hand was either congruent or incongruent with the participant’s own. Across ages, congruency of posture and visual-tactile congruency yielded greater drift towards the fake hand. Ownership ratings were higher with congruent visual-tactile information, but unaffected by posture. Posture constrains body representation similarly in children and adults, suggesting that children have sensitive, robust mechanisms for maintaining a sense of bodily self.

2021 ◽  
Author(s):  
Janna M. Gottwald ◽  
Laura Bird ◽  
Andrew J. Bremner ◽  
Dorothy Cowie

Children’s and adults’ body representation is constrained by bottom-up multisensory information and by top-down knowledge on possible postures. Using the rubber hand illusion paradigm, this study (N = 229) investigates whether different fake hand sizes (60%, 80%, 100%, 120% or 140% of typical hand size) constrain embodiment in three age groups (6- to 7-year-olds, 12- to 13-year-olds, and adults). Embodiment was measured by questionnaire, proprioceptive drift, and affordance judgements. In line with previous work, we found robust effects of age and synchrony, with higher responses at younger ages and under conditions of visual-tactile synchrony. There were no significant effects of hand size on proprioceptive drift or self-rated hand ownership; nor did participants verbally report that their hand had changed size. Participants of all ages therefore embodied a differently-sized fake hand, without being explicitly aware of the size change. However, manual judgments of own-hand size were significantly influenced by the size of the previously seen fake hand. Therefore, participants did implicitly incorporate a size change into their body schema. In sum, embodiment of differently-sized hands reveals substantial plasticity in body representation, modulated strongly by multisensory information and age. Further, the embodiment of a differently-sized hand specifically affects action-oriented representations of the body.


2020 ◽  
Vol 13 (3) ◽  
pp. 31-45
Author(s):  
V.P. Vorobeva ◽  
O.S. Perepelkina ◽  
G.A. Arina

Computer technologies implementation into the body illusions research is increasing because they allow to controllably model complex processes that cannot be realised in ordinary life. It was previously demonstrated that the rubber hand illusion may be reconstructed in the virtual setting and cause similar changes in the somatoperception when the virtual hand begins to feel like your own. This result suggests that the phenomenological experience obtained in the classical illusion and in its virtual reality version has much in common. However, a direct experimental comparison of the two illusion variants has not been made, therefore, in this research we studied the equivalence of the rubber and virtual hand illusions (RHI and VHI). The sample consisted of 16 subjects (18—25 years). As registration methods we used a subjective sense of ownership of an artificial limb and the proprioceptive drift of the real hand towards the illusory hand. The analysis has proved the equivalence of illusions.


i-Perception ◽  
2017 ◽  
Vol 8 (3) ◽  
pp. 204166951770652 ◽  
Author(s):  
Kenri Kodaka ◽  
Ayaka Kanazawa

The paradigm of the rubber hand illusion was applied to a shadow to determine whether the body-shadow is a good candidate for the alternative belonging to our body. Three kinds of shadows, a physical hand, a hand-shaped cloth, and a rectangle cloth, were tested for this purpose. The questionnaire results showed that both anatomical similarity and visuo-proprioception correlation were effective in enhancing illusory ownership of the shadow. According to the proprioceptive drift measurement, whether the shadow purely originated from the physical body was a critical factor in yielding the significantly positive drift. Thus, results demonstrated that the shadow can distort illusory ownership with the rubber hand illusion paradigm, but the proprioception was clearly distorted only when the body-shadow was purely applied. This implies the presence of special cognitive processing to discriminate the self-body shadow from the others.


2012 ◽  
Vol 25 (0) ◽  
pp. 87
Author(s):  
Dorothy A. Cowie

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.


2020 ◽  
Author(s):  
Arran T Reader ◽  
Victoria S Trifonova ◽  
H. Henrik Ehrsson

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.


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 ◽  
Author(s):  
Charlotte Rae ◽  
Dennis Larsson ◽  
Jessica Eccles ◽  
Jamie Ward ◽  
HUgo Critchley

The rubber hand illusion describes a sense of embodiment over a fake hand induced by synchronous visuo-tactile stimulation. In Tourette Syndrome, the expression of involuntary tics and preceding premonitory sensations is associated with the perturbation of subjective feelings of self-control and agency. We compared responses to induction of the Rubber Hand Illusion in 23 adults with TS and 22 matched controls. Both TS and control participants reported equivalent subjective embodiment of the artificial hand: feelings of ownership, location, and agency were greater during synchronous visuo-tactile stimulation, compared to asynchronous stimulation. However, individuals with TS did not manifest greater proprioceptive drift during synchronous relative to asynchronous stimulation, an objective marker of embodiment observed in controls. We computed an ‘embodiment prediction error’ index from the difference between subjective embodiment and objective proprioceptive drift. This embodiment prediction error correlated with severity of premonitory sensations according to the Premonitory Urge for Tics Scale (PUTS). Feelings of ownership over the artificial hand also correlated with premonitory sensation severity, and feelings of agency with tic severity (YGTSS). Together our findings suggest that the subjective strength of bodily ownership, as measured by the rubber hand illusion, contributes to susceptibility to the premonitory sensations that are a precipitating factor in tics. These results also suggest that somatosensory neural pathways underpinning visuo-tactile integration are likely altered in TS and may interact with other sensory and motor systems to engender premonitory sensations and tics.


2020 ◽  
Author(s):  
Regine Zopf

Body perception can be dramatically altered in individuals with schizophrenia resulting in experiences of undefined bodily boundaries, loss of body ownership, and size changes for parts of the body. These individuals may also be more susceptible to the rubber hand illusion (RHI: an illusion of body perception that can also be induced in neurotypical populations), but the findings are mixed. Furthermore, the perception of timing information about multisensory stimuli, which is thought to be fundamental for body perception, has been reported to be altered in schizophrenia. We tested here whether altered perception of the temporal relationship between visual and tactile signals in schizophrenia can predict self-reported perceptual aberrations and RHI susceptibility (indexed by both illusion self-ratings and a more objective proprioceptive-drift measure). We found that the sensitivity to detect temporal asynchronies is reduced in schizophrenia and this predicts bodily perceptual symptoms. In contrast, we found no evidence for a direct relationship between asynchrony detection sensitivity and RHI susceptibility. Instead, our findings suggest that experiencing more bodily perceptual symptoms increases the likelihood of endorsing unusual bodily experiences, resulting in higher RHI self-ratings but not higher proprioceptive-drift scores. Overall, our findings provide evidence for both direct and indirect links between temporal and body perception and thus new insight into the mechanisms that may underlie unusual body perceptions in schizophrenia.


2020 ◽  
Vol 82 (8) ◽  
pp. 4084-4095
Author(s):  
Roberto Erro ◽  
Angela Marotta ◽  
Mirta Fiorio

Abstract In the rubber hand illusion (RHI), simultaneous brush stroking of a subject’s hidden hand and a visible rubber hand induces a transient illusion of the latter to “feel like it’s my hand” and a proprioceptive drift of the hidden own hand toward the rubber hand. Recent accounts of the RHI have suggested that the illusion would only occur if weighting of conflicting sensory information and their subsequent integration results in a statistically plausible compromise. In three different experiments, we investigated the role of distance between the two hands as well as their proximity to the body’s midline in influencing the occurrence of the illusion. Overall, the results suggest that the illusion is abolished when placing the two hands apart, therefore increasing the mismatch between the visual and proprioceptive modality, whereas the proximity of the two hands to the body’s midline plays only a minor role on the subjective report of the illusion. This might be driven by the response properties of visuotactile bimodal cells encoding the peripersonal space around the hand.


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.


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