Supplementary Material for: “Measuring the Effects                     through Time of the Influence of Visuomotor and Visuotactile Synchronous                     Stimulation on a Virtual Body Ownership Illusion”

Over the last 20 years, virtual reality (VR) has been widely used to promote mental health in populations presenting different clinical conditions. Mental health does not refer only to the absence of psychiatric disorders but to the absence of a wide range of clinical conditions that influence people’s general and social well-being such as chronic pain, neurological disorders that lead to motor o perceptual impairments, psychological disorders that alter behaviour and social cognition, or physical conditions like eating disorders or present in amputees. It is known that an accurate perception of oneself and of the surrounding environment are both key elements to enjoy mental health and well-being, and that both can be distorted in patients suffering from the clinical conditions mentioned above. In the past few years, multiple studies have shown the effectiveness of VR to modulate such perceptual distortions of oneself and of the surrounding environment through virtual body ownership illusions. This narrative review aims to review clinical studies that have explored the manipulation of embodied virtual bodies in VR for improving mental health, and to discuss the current state of the art and the challenges for future research in the context of clinical care.

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

Trials ◽

10.1186/s13063-019-3591-1 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 3

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.

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The “embreathment” illusion highlights the role of breathing in corporeal awareness

Journal of Neurophysiology ◽

10.1152/jn.00617.2019 ◽

2020 ◽

Vol 123 (1) ◽

pp. 420-427 ◽

Cited By ~ 5

Author(s):

Alessandro Monti ◽

Giuseppina Porciello ◽

Gaetano Tieri ◽

Salvatore M. Aglioti

Keyword(s):

Virtual Reality ◽

Body Ownership ◽

Immersive Virtual Reality ◽

Visual Appearance ◽

Body Location ◽

Specific Position ◽

Embodied Agent ◽

Corporeal Awareness ◽

Virtual Body

Recent theories posit that physiological signals contribute to corporeal awareness, the basic feeling that one has a body (body ownership) that acts according to one’s will (body agency) and occupies a specific position (body location). Combining physiological recordings with immersive virtual reality, we found that an ecological mapping of real respiratory patterns onto a virtual body illusorily changes corporeal awareness. This new way of inducing a respiratory bodily illusion, called “embreathment,” revealed that breathing is almost as important as visual appearance for inducing body ownership and more important than any other cue for body agency. These effects were moderated by individual levels of interoception, as assessed through a standard heartbeat-counting task and a new “pneumoception” task. By showing that respiratory, visual, and spatial signals exert a specific and weighted influence on the fundamental feeling that one is an embodied agent, we pave the way for a comprehensive hierarchical model of corporeal awareness. NEW & NOTEWORTHY Our body is the only object we sense from the inside; however, it is unclear how much inner physiology contributes to the global sensation of having a body and controlling it. We combine respiration recordings with immersive virtual reality and find that making a virtual body breathe like the real body gives an illusory sense of ownership and agency over the avatar, elucidating the role of a key physiological process like breathing in corporeal awareness.

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The body fades away: investigating the effects of transparency of an embodied virtual body on pain threshold and body ownership

Scientific Reports ◽

10.1038/srep13948 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 25

Author(s):

Matteo Martini ◽

Konstantina Kilteni ◽

Antonella Maselli ◽

Maria V. Sanchez-Vives

Keyword(s):

Pain Threshold ◽

The Body ◽

Body Ownership ◽

Virtual Body

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Virtual body ownership and its consequences for implicit racial bias are dependent on social context

Royal Society Open Science ◽

10.1098/rsos.201848 ◽

2020 ◽

Vol 7 (12) ◽

pp. 201848

Author(s):

Domna Banakou ◽

Alejandro Beacco ◽

Solène Neyret ◽

Marta Blasco-Oliver ◽

Sofia Seinfeld ◽

...

Keyword(s):

Virtual Reality ◽

Black People ◽

Racial Bias ◽

Implicit Bias ◽

Short Exposure ◽

White Female ◽

Body Ownership ◽

Implicit Racial Bias ◽

Two Factors ◽

Virtual Body

When people hold implicit biases against a group they typically engage in discriminatory behaviour against group members. In the context of the implicit racial bias of ‘White' against ‘Black' people, it has been shown several times that implicit bias is reduced after a short exposure of embodiment in a dark-skinned body in virtual reality. Embodiment usually leads to the illusion of ownership over the virtual body, irrespective of its skin colour. Previous studies have been carried out in virtual scenarios that are affectively neutral or positive. Here, we show that when the scenario is affectively negative the illusion of body ownership of White participants over a White body is lessened, and implicit bias is higher for White participants in a Black virtual body. The study was carried out with 92 White female participants, in a between-groups design with two factors: BodyType (their virtual body was White or Black) and a surrounding Crowd was Negative, Neutral or Positive towards the participant. We argue that negative affect prevents the formation of new positive associations with Black and distress leads to disownership of the virtual body. Although virtual reality is often thought of as an ‘empathy machine' our results suggest caution, that this may not be universally the case.

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

10.21203/rs.2.9339/v1 ◽

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.

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

10.21203/rs.2.9339/v2 ◽

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, UMIN000019832. Registered on 25st September 2018.

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The Golden Rule as a Paradigm for Fostering Prosocial Behavior With Virtual Reality

Current Directions in Psychological Science ◽

10.1177/09637214211046954 ◽

2021 ◽

pp. 096372142110469

Author(s):

Mel Slater ◽

Domna Banakou

Keyword(s):

Virtual Reality ◽

Prosocial Behavior ◽

Implicit Attitudes ◽

Golden Rule ◽

Helping Behavior ◽

Ethical Principle ◽

Body Ownership ◽

Positive Form ◽

Negative Form ◽

Virtual Body

The Golden Rule of ethics in its negative form states that you should not do to others what you would not want others to do to you, and in its positive form states that you should do to others as you would want them to do to you. The Golden Rule is an ethical principle, but in virtual reality (VR), it can also be thought of as a paradigm for the promotion of prosocial behavior. This is because in VR, you can directly experience harm that you inflicted or were complicit in inflicting from the embodied perspective of the victim. This use of what we refer to as the Golden Rule Embodiment Paradigm (GREP) relies on participants in VR having the illusion of body ownership over a virtual body. In this article, we introduce virtual embodiment and the consequent illusion of ownership over the virtual body, and describe how this phenomenon has been utilized to influence implicit attitudes. We then introduce the GREP and give examples of studies in which it enhanced helping behavior.

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Impact of visuomotor feedback on the embodiment of virtual hands detached from the body

Scientific Reports ◽

10.1038/s41598-020-79255-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Sofia Seinfeld ◽

Jörg Müller

Keyword(s):

Motor Performance ◽

The Body ◽

Body Ownership ◽

Motor Tasks ◽

Person Perspective ◽

Skin Conductance Responses ◽

Contradictory Evidence ◽

The Impact ◽

Physiological Reactions ◽

Virtual Body

AbstractIt has been shown that mere observation of body discontinuity leads to diminished body ownership. However, the impact of body discontinuity has mainly been investigated in conditions where participants observe a collocated static virtual body from a first-person perspective. This study explores the influence of body discountinuity on the sense of embodiment, when rich visuomotor correlations between a real and an artificial virtual body are established. In two experiments, we evaluated body ownership and motor performance, when participants interacted in virtual reality either using virtual hands connected or disconnected from a body. We found that even under the presence of congruent visuomotor feedback, mere observation of body discontinuity resulted in diminished embodiment. Contradictory evidence was found in relation to motor performance, where further research is needed to understand the role of visual body discontinuity in motor tasks. Preliminary findings on physiological reactions to a threat were also assessed, indicating that body visual discontinuity does not differently impact threat-related skin conductance responses. The present results are in accordance with past evidence showing that body discontinuity negatively impacts embodiment. However, further research is needed to understand the influence of visuomotor feedback and body morphological congruency on motor performance and threat-related physiological reactions.

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