scholarly journals Top-down recognition leads to a reduced sense of body ownership in individuals with depersonalization tendencies: A focus on full body illusion

2021 ◽  
Author(s):  
Kazuki Yamamoto ◽  
Takashi Nakao
Keyword(s):  
Japanese Version ◽  
The Body ◽  
Body Ownership ◽  
Top Down ◽  
Instruction Condition ◽  
Person Perspective ◽  
Tactile Stimuli ◽  
Self Association ◽  
Third Person Perspective ◽  
Full Body

Sense of body ownership, i.e., the feeling that “my body belongs to me,” has been examined by both the rubber hand illusion (RHI) and full body illusion (FBI). In a study that examined the relationship between RHI and depersonalization, a symptom in which people experience a lower sense of body ownership, the degree of illusion was higher in people with a high depersonalization tendency. However, other reports have suggested that people with depersonalization disorder have difficulty feeling the sense of body ownership. Examination of depersonalization suggests that the negative body recognition in people with depersonalization may make them less likely to feel a sense of body ownership, but this has not yet been examined. In this study, by manipulating top-down recognition (e.g., instructing participants to recognize a fake body as theirs), we clarified the cause of the reduced sense of body ownership in people with a high depersonalization tendency. The FBI procedure was conducted in a virtual reality environment using an avatar as a fake body. The avatar was presented from a third-person perspective, and visual-tactile stimuli were presented to create an illusion. To examine the degree of illusion, we measured the skin conductance responses to the fear stimulus presented after the visual-tactile stimuli presentation. The degree of depersonalization was measured using the Japanese version of the Cambridge Depersonalization Scale. To manipulate the top-down recognition to the avatar, we provided self-association instructions before the presentation of the visual-tactile stimuli. The results showed that participants with a high depersonalization tendency had a lower degree of illusion (rho = -.589, p < .01) in the self-association condition, and a higher one (rho = .552, p < .01) in the non-association instruction condition. This indicates that although people with a high depersonalization tendency are more likely to feel a sense of body ownership through the integration of visual-tactile stimuli, top-down recognition of the body as one’s own leads to a decrease in the sense of body ownership.

scholarly journals Experiential ownership and body ownership are different phenomena

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caleb Liang ◽  
Wen-Hsiang Lin ◽  
Tai-Yuan Chang ◽  
Chi-Hong Chen ◽  
Chen-Wei Wu ◽  
...  
Keyword(s):  
Conscious Experience ◽  
Distinct Type ◽  
Body Part ◽  
The Body ◽  
Body Ownership ◽  
Rubber Hand ◽  
Person Perspective ◽  
The One ◽  
First Time ◽  
Full Body

AbstractBody ownership concerns what it is like to feel a body part or a full body as mine, and has become a prominent area of study. We propose that there is a closely related type of bodily self-consciousness largely neglected by researchers—experiential ownership. It refers to the sense that I am the one who is having a conscious experience. Are body ownership and experiential ownership actually the same phenomenon or are they genuinely different? In our experiments, the participant watched a rubber hand or someone else’s body from the first-person perspective and was touched either synchronously or asynchronously. The main findings: (1) The sense of body ownership was hindered in the asynchronous conditions of both the body-part and the full-body experiments. However, a strong sense of experiential ownership was observed in those conditions. (2) We found the opposite when the participants’ responses were measured after tactile stimulations had ceased for 5 s. In the synchronous conditions of another set of body-part and full-body experiments, only experiential ownership was blocked but not body ownership. These results demonstrate for the first time the double dissociation between body ownership and experiential ownership. Experiential ownership is indeed a distinct type of bodily self-consciousness.

scholarly journals Empathy or Ownership? Evidence from Corticospinal Excitability Modulation during Pain Observation

2016 ◽  
Vol 28 (11) ◽  
pp. 1760-1771 ◽  
Author(s):  
Giulia Bucchioni ◽  
Carlotta Fossataro ◽  
Andrea Cavallo ◽  
Harold Mouras ◽  
Marco Neppi-Modona ◽  
...  
Keyword(s):  
The Body ◽  
First Person ◽  
Body Ownership ◽  
Physiological Basis ◽  
Hand Model ◽  
Person Perspective ◽  
Third Person ◽  
First Person Perspective ◽  
Third Person Perspective ◽  
The One

Recent studies show that motor responses similar to those present in one's own pain (freezing effect) occur as a result of observation of pain in others. This finding has been interpreted as the physiological basis of empathy. Alternatively, it can represent the physiological counterpart of an embodiment phenomenon related to the sense of body ownership. We compared the empathy and the ownership hypotheses by manipulating the perspective of the observed hand model receiving pain so that it could be a first-person perspective, the one in which embodiment occurs, or a third-person perspective, the one in which we usually perceive the others. Motor-evoked potentials (MEPs) by TMS over M1 were recorded from first dorsal interosseous muscle, whereas participants observed video clips showing (a) a needle penetrating or (b) a Q-tip touching a hand model, presented either in first-person or in third-person perspective. We found that a pain-specific inhibition of MEP amplitude (a significantly greater MEP reduction in the “pain” compared with the “touch” conditions) only pertains to the first-person perspective, and it is related to the strength of the self-reported embodiment. We interpreted this corticospinal modulation according to an “affective” conception of body ownership, suggesting that the body I feel as my own is the body I care more about.

scholarly journals The Redundant Signals Effect and the Full Body Illusion: not Multisensory, but Unisensory Tactile Stimuli Are Affected by the Illusion

2021 ◽  
pp. 1-33
Author(s):  
Lieke M. J. Swinkels ◽  
Harm Veling ◽  
Hein T. van Schie
Keyword(s):  
Multisensory Integration ◽  
Objective Measure ◽  
Race Model ◽  
Detection Task ◽  
Head Mounted Display ◽  
Person Perspective ◽  
Tactile Stimuli ◽  
Third Person Perspective ◽  
Full Body ◽  
Virtual Body

Abstract During a full body illusion (FBI), participants experience a change in self-location towards a body that they see in front of them from a third-person perspective and experience touch to originate from this body. Multisensory integration is thought to underlie this illusion. In the present study we tested the redundant signals effect (RSE) as a new objective measure of the illusion that was designed to directly tap into the multisensory integration underlying the illusion. The illusion was induced by an experimenter who stroked and tapped the participant’s shoulder and underarm, while participants perceived the touch on the virtual body in front of them via a head-mounted display. Participants performed a speeded detection task, responding to visual stimuli on the virtual body, to tactile stimuli on the real body and to combined (multisensory) visual and tactile stimuli. Analysis of the RSE with a race model inequality test indicated that multisensory integration took place in both the synchronous and the asynchronous condition. This surprising finding suggests that simultaneous bodily stimuli from different (visual and tactile) modalities will be transiently integrated into a multisensory representation even when no illusion is induced. Furthermore, this finding suggests that the RSE is not a suitable objective measure of body illusions. Interestingly however, responses to the unisensory tactile stimuli in the speeded detection task were found to be slower and had a larger variance in the asynchronous condition than in the synchronous condition. The implications of this finding for the literature on body representations are discussed.

scholarly journals Duplication of the bodily self: a perceptual illusion of dual full-body ownership and dual self-location

2020 ◽  
Vol 7 (12) ◽  
pp. 201911
Author(s):  
Arvid Guterstam ◽  
Dennis E. O. Larsson ◽  
Joanna Szczotka ◽  
H. Henrik Ehrsson
Keyword(s):  
Tactile Stimulation ◽  
Sense Of Self ◽  
Body Ownership ◽  
Healthy Human ◽  
Perceptual Illusion ◽  
Person Perspective ◽  
Human Participants ◽  
Third Person Perspective ◽  
Stimulation Of ◽  
Full Body

Previous research has shown that it is possible to use multisensory stimulation to induce the perceptual illusion of owning supernumerary limbs, such as two right arms. However, it remains unclear whether the coherent feeling of owning a full-body may be duplicated in the same manner and whether such a dual full-body illusion could be used to split the unitary sense of self-location into two. Here, we examined whether healthy human participants can experience simultaneous ownership of two full-bodies, located either close in parallel or in two separate spatial locations. A previously described full-body illusion, based on visuo-tactile stimulation of an artificial body viewed from the first-person perspective (1PP) via head-mounted displays, was adapted to a dual-body setting and quantified in five experiments using questionnaires, a behavioural self-location task and threat-evoked skin conductance responses. The results of experiments 1–3 showed that synchronous visuo-tactile stimulation of two bodies viewed from the 1PP lying in parallel next to each other induced a significant illusion of dual full-body ownership. In experiment 4, we failed to find support for our working hypothesis that splitting the visual scene into two, so that each of the two illusory bodies was placed in distinct spatial environments, would lead to dual self-location. In a final exploratory experiment (no. 5), we found preliminary support for an illusion of dual self-location and dual body ownership by using dynamic changes between the 1PPs of two artificial bodies and/or a common third-person perspective in the ceiling of the testing room. These findings suggest that healthy people, under certain conditions of multisensory perceptual ambiguity, may experience dual body ownership and dual self-location. These findings suggest that the coherent sense of the bodily self located at a single place in space is the result of an active and dynamic perceptual integration process.

scholarly journals Contributions of Body-Orientation to Mental Ball Dropping Task During Out-of-Body Experiences

2022 ◽  
Vol 15 ◽  
Author(s):  
Ege Tekgün ◽  
Burak Erdeniz
Keyword(s):  
Body Position ◽  
Body Orientation ◽  
First Person ◽  
Body Ownership ◽  
Person Perspective ◽  
Body Experiences ◽  
Significant Difference ◽  
Third Person Perspective ◽  
Full Body ◽  
Virtual Avatar

Out-of-body experiences (OBEs) provide fascinating insights into our understanding of bodily self-consciousness and the workings of the brain. Studies that examined individuals with brain lesions reported that OBEs are generally characterized by participants experiencing themselves outside their physical body (i.e., disembodied feeling) (Blanke and Arzy, 2005). Based on such a characterization, it has been shown that it is possible to create virtual OBEs in immersive virtual environments (Ehrsson, 2007; Ionta et al., 2011b; Bourdin et al., 2017). However, the extent to which body-orientation influences virtual OBEs is not well-understood. Thus, in the present study, 30 participants (within group design) experienced a full-body ownership illusion (synchronous visuo-tactile stimulation only) induced with a gender-matched full-body virtual avatar seen from the first-person perspective (1PP). At the beginning of the experiment, participants performed a mental ball dropping (MBD) task, seen from the location of their virtual avatar, to provide a baseline measurement. After this, a full-body ownership illusion (embodiment phase) was induced in all participants. This was followed by the virtual OBE illusion phase of the experiment (disembodiment phase) in which the first-person viewpoint was switched to a third-person perspective (3PP), and participants' disembodied viewpoint was gradually raised to 14 m above the virtual avatar, from which altitude they repeated the MBD task. During the experiment, this procedure was conducted twice, and the participants were allocated first to the supine or the standing body position at random. Results of the MBD task showed that the participants experienced increased MBD durations during the supine condition compared to the standing condition. Furthermore, although the findings from the subjective reports confirmed the previous findings of virtual OBEs, no significant difference between the two postures was found for body ownership. Taken together, the findings of the current study make further contributions to our understanding of both the vestibular system and time perception during OBEs.

Using Body Ownership to Modulate the Motor System in Stroke Patients

2021 ◽  
pp. 095679762097577
Author(s):  
Riccardo Tambone ◽  
Alberto Giachero ◽  
Melanie Calati ◽  
Maria Teresa Molo ◽  
Dalila Burin ◽  
...  
Keyword(s):  
Motor System ◽  
Motor Recovery ◽  
The Body ◽  
Motor Deficits ◽  
Body Ownership ◽  
Stroke Patients ◽  
Motor Functioning ◽  
Person Perspective ◽  
Third Person ◽  
Third Person Perspective

Recent findings suggest that body ownership can activate the motor system in the absence of movement execution. Here, we investigated whether such a process promotes motor recovery in stroke patients. A group of patients with left-hemisphere damage ( N = 12) and chronic motor deficits completed an immersive virtual reality training (three sessions of 15 min each week for 11 weeks). Patients sat still and either experienced (first-person perspective) or did not experience (third-person perspective) illusory ownership over the body of a standing virtual avatar. After the training, in which the avatar walked around a virtual environment, only patients who experienced the illusion improved gait and balance. We argue that representing the virtual body as their own allowed patients to access motor functioning and promoted motor recovery. This procedure might be integrated with rehabilitative approaches centered on motor execution. These findings also have an impact on the knowledge of the motor system in general.

scholarly journals Virtual training leads to real acute physical, cognitive, and neural benefits on healthy adults: study protocol for a randomized controlled trial

Trials ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Dalila Burin ◽  
Noriki Yamaya ◽  
Rie Ogitsu ◽  
Ryuta Kawashima
Keyword(s):  
Heart Rate ◽  
Randomized Controlled Trial ◽  
Executive Functions ◽  
Controlled Trial ◽  
The Body ◽  
Body Ownership ◽  
Functional Near Infrared Spectroscopy ◽  
Randomized Controlled ◽  
Person Perspective ◽  
Virtual Body

Abstract Background Keeping a certain level of physical activity has beneficial effects on the body itself but also, surprisingly, on cognition: specifically, physical high-intensity intermittent aerobic exercise (HIE) can show improvement on cognitive executive functions. Although, in some cases performing strength or aerobic training is problematic or not feasible. Immersive virtual reality (IVR) can induce the illusory feeling of ownership and agency over a moving virtual body, therefore showing comparable physiological reactions: for example, if an individual is sitting on a chair but his virtual body climbs a hill, the individual’s heart rate increases coherently, as if he is actually walking. In this study, we investigate whether this same illusion can show beneficial consequences on the body as well as on executive functions (using the color-word matching Stroop task) and on its neural substrates (using functional near-infrared spectroscopy [fNIRS]). Methods In a cross-over randomized controlled trial, 30 healthy young adults will experience HIE training in IVR (i.e. the virtual body will perform eight sets of 30 s of running followed by 30 s of slow walking, while the participant is completely still) according to two random-ordered conditions: during the experimental condition, the virtual body is displayed in first-person perspective (1PP), while in the control condition, the virtual body is displayed in third-person perspective (3PP). To confirm that individuals have the illusion of ownership and agency over the virtual body in 1PP (and not in 3PP), we will record the heart rate, in addition to subjective questionnaires. Before and after every IVR sessions (one week apart), we will measure cortical hemodynamic changes in the participants’ prefrontal cortex using the fNIRS device during the Stroop task’s execution. Discussion From a theoretical perspective, we could prove that the sense of body ownership and agency can modulate physical and cognitive parameters, even in the absence of actual movements; from a clinical perspective, these results could be useful to train cognition and body simultaneously, in a completely safe environment. Trial registration University Hospital Medical Information Network Clinical Trial Registry, UMIN000034255. Registered on 1 October 2018.

scholarly journals Challenging the boundaries of the physical self: purely distal cues in the environment impact body ownership

2019 ◽  
Author(s):  
Klaudia Grechuta ◽  
Javier De La Torre ◽  
Belén Rubio Ballester ◽  
Paul F.M.J. Verschure
Keyword(s):  
The Body ◽  
Body Ownership ◽  
Environment Impact ◽  
Rubber Hand ◽  
Sensory Stimuli ◽  
Sensory Signals ◽  
Surrounding Environment ◽  
Tactile Stimuli ◽  
Multisensory Cues ◽  
Multisensory Information

AbstractThe unique ability to identify one’s own body and experience it as one’s own is fundamental in goal-oriented behavior and survival. However, the mechanisms underlying the so-called body ownership are yet not fully understood. The plasticity of body ownership has been studied using two experimental methods or their variations. Specifically, the Rubber Hand Illusion (RHI), where the tactile stimuli are externally generated, or the moving RHI which implies self-initiated movements. Grounded in these paradigms, evidence has demonstrated that body ownership is a product of bottom-up reception of self- and externally-generated multisensory information and top-down comparison between the predicted and the actual sensory stimuli. Crucially, provided the design of the current paradigms, where one of the manipulated cues always involves the processing of a proximal modality sensing the body or its surface (e.g., touch), the contribution of sensory signals which pertain to the environment remain elusive. Here we propose that, as any robust percept, body ownership depends on the integration and prediction of all the sensory stimuli, and therefore it will depend on the consistency of purely distal sensory signals pertaining to the environment. To test our hypothesis, we create an embodied goal-oriented task and manipulate the predictability of the surrounding environment by changing the congruency of purely distal multisensory cues while preserving bodily and action-driven signals entirely predictable. Our results empirically reveal that the way we represent our body is contingent upon all the sensory stimuli including purely distal and action-independent signals which pertain to the environment.

scholarly journals Virtual training leads to real acute physical, cognitive and neural benefits on healthy adults: study protocol for a randomized-controlled trial

2019 ◽  
Author(s):  
Dalila Burin ◽  
Noriki Yamaya ◽  
Rie Ogitsu ◽  
Ryuta Kawashima
Keyword(s):  
Heart Rate ◽  
Randomized Controlled Trial ◽  
Executive Functions ◽  
Controlled Trial ◽  
The Body ◽  
Body Ownership ◽  
Functional Near Infrared Spectroscopy ◽  
Randomized Controlled ◽  
Person Perspective ◽  
Virtual Body

Abstract BACKGROUND Keeping a certain level of physical activity has beneficial effects on the body itself but also, surprisingly, on cognition: specifically, physical high-intensity intermittent aerobic exercise (HIE) can show improvement on cognitive executive functions. Although, in some cases performing strength or aerobic training is problematic or not feasible. Immersive virtual reality (IVR) can induce the illusory feeling of ownership and agency over a moving virtual body, showing therefore comparable physiological reactions: for example, if a subject is sitting on a chair but the own virtual body climbs a hill, the subject’s heart rate increases coherently, as if he’s actually walking. In this study, we want to investigate whether this same illusion can show beneficial consequences on the body but also on executive functions (using the colour-word matching Stroop task) and on its neural substrates (using the functional near infrared spectroscopy, fNIRS). METHODS In a cross-over randomized controlled trial, 30 healthy young adults will experience a HIE training in IVR (i.e., the virtual body will perform eight sets of 30 seconds of running followed by 30 seconds of slow walking, while the subject is completely still) according to two random-ordered conditions: during the experimental condition, the virtual body is displayed in the first-person perspective (1PP), while in the control condition, the virtual body is displayed in third-person perspective (3PP). To confirm that in 1PP (and not in 3PP) subjects have the illusion of ownership and agency over the virtual body, we will record the heart rate, in addition to subjective questionnaires. Before and after every IVR sessions (one week apart), we will measure cortical hemodynamic changes in the participants’ prefrontal cortex (PFC) using the fNIRS device during the Stroop task’s execution. DISCUSSION From a theoretical perspective, we could prove that the sense of body ownership and agency can modulate physical and cognitive parameters, even in absence of actual movements; from a clinical perspective, these results could be useful to train cognition and body simultaneously, in a completely safe environment. Trial registration University Hospital Medical Information Network Clinical Trial Registry, UMIN000034255. Registered on 1st October 2018.

scholarly journals First person experience of threat modulates cortical network encoding human peripersonal space

2018 ◽  
Author(s):  
A.W. de Borst ◽  
M.V. Sanchez-Vives ◽  
M. Slater ◽  
B. de Gelder
Keyword(s):  
Brain Activity ◽  
Peripersonal Space ◽  
Brain Network ◽  
The Body ◽  
First Person ◽  
Threat Detection ◽  
Person Perspective ◽  
Third Person ◽  
First Person Perspective ◽  
Third Person Perspective

AbstractPeripersonal space is the area directly surrounding the body, which supports object manipulation and social interaction, but is also critical for threat detection. In the monkey, ventral premotor and intraparietal cortex support initiation of defensive behavior. However, the brain network that underlies threat detection in human peripersonal space still awaits investigation. We combined fMRI measurements with a preceding virtual reality training from either first or third person perspective to manipulate whether approaching human threat was perceived as directed to oneself or another. We found that first person perspective increased body ownership and identification with the virtual victim. When threat was perceived as directed towards oneself, synchronization of brain activity in the human peripersonal brain network was enhanced and connectivity increased from premotor and intraparietal cortex towards superior parietal lobe. When this threat was nearby, synchronization also occurred in emotion-processing regions. Priming with third person perspective reduced synchronization of brain activity in the peripersonal space network and increased top-down modulation of visual areas. In conclusion, our results showed that after first person perspective training peripersonal space is remapped to the virtual victim, thereby causing the fronto-parietal network to predict intrusive actions towards the body and emotion-processing regions to signal nearby threat.

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