By Zixuan Pan
The problem of “who I am” in the virtual reality environment (VRE) has been a hot philosophical issue in recent years (Metzinger 103). Some experiments found that when some participants are embodied in a virtual body, they regard themselves more correlated to the virtual identity than the physical identity (Hasler, Spanlang, and Slater 12). The reasons behind the alternation of self-identification in VRE may be that the process of mirror neurons creating “Pavlovian association[s]” is accelerated (Hickok 16). So far, experiments have found that some neurons in the premotor cortex are discharged when the alternation of self-identification happens. A prominent finding in this area of the brain is called “mirror neuron,” which is related to human’s understanding of action (Rizzolatti 419). The probable mechanism of how the mirror neuron understands action is that it generates “pure Pavlovian association[s],”[1] which means correlating an action with individual sensory perceptions (Hickok 16). The first-person perspective and synchronization of the virtual and physical bodies in VRE may accelerate the process of making the Pavlovian association and lead to the change in self-identification. Though it sounds novel that VR users’ self-identification may be changed in VRE, some potential detriment on users’ health may arise.
Virtual reality is a computer technology that creates an immersive artificial world by giving sensory information and feedback to its user. Studies so far have manifested that VR can create illusory perceptions toward virtual body attributes like size or shape (Banakou, Groten, and Slater 12846). Several experiments have been carried out to find out how participants are accustomed to their virtual body, and two of them demonstrated some striking results. In one case, some adult participants were put into child-sized virtual bodies, and they tended to overestimate object size. They also responded faster to child images in their virtual body, which is linked to childlike behavior (Banakou, Groten, and Slater 12848–12849). In another case, when several white participants were embodied in black virtual bodies, they had the inclination to categorize them into racial groups according to their virtual race, which indicated acceptance toward their virtual bodies to some extent (Hasler, Spanlang, and Slater 12). These results substantialized some changes in self-identification in VRE.
Before delving into the probable explanation for this kind of phenomenon, it needs to be clarified that it is not caused by personal experiences but by some intrinsic properties of humans.[2] If one’s personal experiences are the leading cause, participants should have gone through such cases that are similar to owning the virtual body. It may be arguable that in the “adult in a child body” experiment, the specific environment recalled their reminiscence of childhood. But in the “white person in a black body” experiment, the participants cannot have experienced living with a black body. After they felt themselves with the black body in only a few minutes, however, they tended to join the different racial group. Therefore, the change of self-identity may not derive from some similar experiences. Meanwhile, in some VR games, users are propelled to act as a role in the imaginary world without a corresponding real-world experience (Beat Games). Thus, the reason for it may be more correlated to some of human’s intrinsic ability. Focusing on the field of neural science, whose goal is to “understand the biological mechanisms that account for mental activity,” can be a direction to find the reason for it (Albright, Jessell, Kandel, and Posner 1).
Neural scientists have shown keen interest in finding the mechanism for how someone feels there is a “real me” that is related to the experience he/she is undergoing (Blanke 556). The method they have applied to achieve this goal is to carry out certain experiments and analyze “bodily signals” (Blanke 556). Previous experiments have proved that synchronous visual and tactile stimuli can affect the self-identification of the virtual body (Botvinick and Cohen qtd. In Blanke 559). Blanke concluded that the synchronization and “multisensory integration” are the key factors for us to create ownership of the virtual body (559). Neuroscientists also tried to find the brain mechanisms for self-identification. With an electroencephalography experiment, Lenggenhager and others associated self-identification of a virtual body in VRE with “activity in bilateral medial sensorimotor cortices and medial [premotor cortex (PMC)]” (qtd. in Blanke 559).
However, Lenggenhager and others only found the brain areas that were activated when the change of self-identification happened without elucidating the whole mechanism. Rizzolatti named a kind of neuron with specific ability in PMC as “mirror neuron” (419). He claimed that mirror neurons were discharged when someone performed an action or he/she saw another person performing an action (419). The possible function of mirror neurons is to help humans imitate and understand actions (Rizzolatti and Craigheor qtd. in Rizzolatti 419). With a hypothesis based on the mirror neuron, the possible mechanism of self-identification alternation in VRE can be raised.
As Rizzolatti stated, the mirror neuron can make a copy of action, which can help us not only understand what the action is, but also why a person performs such an action (420). This “why” is critical to support this explanation. A VR user experiences the action of a virtual body, and the reason for performing the action was sent into his/her brain. After a successive series of actions, his/her thinking pattern might be fully changed. It can be associated with the result of Pavlov’s experiment about a dog. A dog previously connected its salivation with food, but later the ringing of a bell was added whenever the dog was offered the food. Finally, the dog developed a new behavior of salivating when hearing the bell after being trained for some time (Pavlov qtd. in McLeod). An interpretation for this experiment can be that the dog changed its understanding towards the ringing of a bell because it made correlations between food and the bell. Hickok proposed an assumption that “[mirror neuron] reflects pure Pavlovian association” (16). In this assumption, mirror neurons associate individual sensory perceptions with action, and the correlation helps us understand the action, which is analogous to the interpretation of the Pavlovian experiment (Mahon and Caramazza qtd. in Hickok 16). Therefore, chances are that if such a correlation can be created instantly, the understanding of the action can be changed in a short range of time.
The first-person perspective and synchronization of virtual and physical body action may act as two leading factors in the rather rapid process of creating Pavlovian associations in VRE. On the one hand, the first-person perspective makes VR users feel that the virtual visual sense is real. In an experiment comparing some VR users’ experience in the first-person perspective and third-person perspective, users in the first-person perspective have reported more like being the owner of the virtual body, instead of an agent between the virtual and physical bodies, mainly because of the change in visual senses (Petkova, Khoshnevis, and Ehrsson 33). The mechanism may be as follows. With a first-person perspective, a VR user only sees parts of a body. When he/she further makes a judgment of which body the pieces belong to, he/she is likely to regard them as the parts of their own body because the parts seem closely connected to their “eyes.” While the third-person perspective, a VR user sees the whole body. He/she may regard the body as other’s because he/she cannot see his/her own head directly with the eyes. Thus, the first-person perspective increases the feeling of reality created by virtual images.
On the other hand, the synchronization of virtual and physical body action makes that VR users feel that the virtual tactile sense is real. Virtual tactile sense only refers to virtual objects that generate the tactile sense, while the tactile sense itself exists. To be more specific, the subject of the tactile sense is the physical body of a VR user. However, when his/her visual senses are occupied with virtual objects, he/she is likely to regard the tactile senses as created by the virtual object because the visual sense misleads him/her (Botnivick and Cohen qtd. in Blanke 559).
The integration of the virtual, visual, and tactile senses can create and change some Pavlovian associations. The process can be inspired by an example in a VR game: Beat Saber (Beat Games). Beat Saber is a rhythm game, where players use a sword to cut the virtual objects to earn scores (Beat Games). When a player of the game feels himself/herself brandishing a sword in VR, his/her physical body is only waving arms with holding some weight exerted by a gamepad. When he/she is playing the game, hand movement of the virtual body and that of the physical body will be the same. Without the virtual image of the sword, the Pavlovian association is made between the user’s waving arm with waving the gamepad. However, when the user is embodied in VRE, he/she cannot see either the gamepad or his/her real arm. His/her tactile sense give signals to the brain and tell that he/she is waving his/her arm with something held in hand; his/her visual senses tell him/her that he/she is brandishing a sword. The Pavlovian association is then made between waving an arm with brandishing a sword. After a series of activities performed by the virtual body, the user’s self-identification may have changed as much as the previous action has been altered, and understanding a new action has been created. The hypothesis is similar to the one of Hickok that humans’ understanding of action is continually changing (16).
Compared to the time of training in Pavlov’s dog experiment, the process of creating Pavlovian associations is rather fast. Reasons may lie in that the association is created without a medium. In Pavlov’s experiment, food is the medium. There are two associations in the experiment, both including food: salivation with food, and the bell with food. As the latter association is not linked with the action of the dog, it may take a longer time to create such an association. While in the VRE, associations are directly made between the action of users and some virtual scenes. More detailed bodily signals flow into the brain and accelerate the process. As the process of creating Pavlovian associations is rather rapid in VRE, VR users may instantly understand their action and get used to their virtual body. Thus, their self-identification may be changed because of the fast process.
The whole process of self-identification alternation in VRE has been explained so far. Thus, a hierarchy of it can be proposed. From the perspective of neuroscience, self-identification alternation is linked with mirror neurons. Mirror neurons have a vital function, which is understanding action. The probable mechanism for the function is creating Pavlovian associations. Two criteria of VR: the first-person perspective and synchronization of virtual and physical body action may drastically accelerate the process of creating Pavlovian associations. Therefore, self-identification is likely to be changed in VRE.
As VR is so powerful in changing a person’s self-identification, potential concerns may arise. The Pavlovian association created in VRE might still be effective in reality. The process may be reversible, which means a rapid adjustment can relink an action with something else in reality, but the frequent shifting may increase the probability of falling into “heautoscopy,” a symptom of which is feeling that there is a distance between mind and body (Blanke 562). Adopting the third-person perspective instead of the first-person perspective can be a solution toward it because, in a third-person perspective, the user has the stronger feeling of being an agent but not the owner of the virtual body (Petkova, Khoshnevis, and Ehrsson 3).
In conclusion, the function of mirror neurons to understand action may play a notable role in the process of self-identification alternation. The first-person perspective and synchronization of virtual and physical body action are two important criteria of virtual reality that boost the function of mirror neurons, making the alternation more likely to happen in VRE. However, the change of self-identification could cause potential detriment to VR users’ health. Thus, awareness of VR users should be raised as a precaution against the alternation.
Works Cited
Albright, Thomas D., Thomas M. Jessell, Eric R. Kandel, and Michael I. Posner. “Neural
Science: A Century of Progress and the Mysteries that Remain.” Neuron 25.1 (2000): S1–255. Web. 18 Apr. 2020.
Banakou, Domna, Raphaela Groten, and Mel Slater. “Illusory Ownership of a Virtual Child
Body Causes Overestimation of Object Sizes and Implicit Attitude Changes.” National Academy of Sciences 31 (2013): 12846–12851. Web. 23 Apr. 2020.
Beat Saber. Windows PC version. Beat Games, 2019. https://beatsaber.com. Web. 23 Apr. 2020.
Blanke, Olaf. “Multisensory Brain Mechanisms of Bodily Self-Consciousness.” Nat Rev
Neurosci 13 (2012): 556–71. Web. 17 Apr. 2020.
Hasler, Beatrice, Bernhard Spaanlang, and Mel Slater. “Virtual Race Transformation Reverses
Racial In-Group Bias.” PLoS ONE e0174965 (2017): 12. Web. 16 Apr. 2020.
Hickok, Gregory. “Eight Problems for the Mirror Neuron Theory of Action Understanding in
Monkeys and Humans.” Journal of Cognitive Neuroscience 21.7 (2009): 1229-43. NCBI. Web. 21 Apr. 2020.
Kuhlmeier, Valerie A., Paul Bloom, and Karen Wynn. “Do 5-Month-Old Infants See Humans as
Material Objects?” Cognition 94 (2004): 95–103. Web. 22 Apr. 2020.
McLeod, Saul. “Pavlov’s Dogs.” Simply Psychology 8 Oct. 2018.
https:/www.simplypsychology.org/pavlov.html. Web. 5 Apr. 2020.
Metzinger, Thomas K. “Why Is Virtual Reality Interesting for Philosophers?” Frontiers in
Robotics and AI 2296–9144 (2018): 101. Web. 5 Apr. 2020.
Petkova, Valeria I., Mehrnoush Khoshnevis, and H. Henrik Ehrsson. “The Perspective Matters!
Multisensory Integration in Ego-Centric Reference Frames Determines Full-Body Ownership.” Frontiers in Psychology 2 (2011): 35. Web. 21 Apr. 2020.
Rizzolatti, Giacomo. “The Mirror Neuron System and Its Function in Humans.” Anat Embryol
419–421 (2005): 210. Web. 17 Apr. 2020.
[1] Hickok borrowed the idea of “Pavlovian association” from Mahon and Caramazza, but the term “Pavlovian association” was first introduced by Hickok. Thus, in this article, if only the term “Pavlovian association” is used, then the author in the in-text citation will be Hickok. If the detailed idea of it is used, the authors in the in-text citation will be Mahon and Caramazza.
[2] The intrinsic properties mean some mental abilities or somatic functions humans have in common; for example, the ability to distinguish human from immaterial objects (Kuhlmeier et al. 101).