Bodily-self consciousness and virtual reality
Will virtual reality affect our bodily-consciousness?
|BY DANA CORINNE HALLANDER
Let’s start with the heart of the matter: consciousness
Truthfully, it’s still an unanswered question, a centuries-old debate kept alive by the curiosity of philosophers, artists, and scientists. Neuroscientists are especially keen to unlock this pandoras box.
What is consciousness? (What do you think?) Consciousness is difficult to define because it comes in many forms. The most commonly triggered associations with consciousness are “awakeness” or free-will. Consciousness is often defined as “awareness”. It is also both the ally and traitor of our notion of humans’ darling free-will. Determinists and metaphysical libertarians cannot agree: do we control our decisions, or are they determined? The most egotistical organism on the planet (us) is continually bewitched by this question.
Ironically, people are “less conscious” of bodily consciousness as one of many forms of consciousness.
What is bodily consciousness?
In simple terms, it is the awareness of your body, the feeling of the ‘real me’ that resides in ‘my’ body. It is the awareness of “I” who perceives and thinks.
There are three aspects of bodily-consciousness in natural reality:
- Self-ownership
- Self-location
- First-person perspective
Self-Ownership
This describes the feeling of owning a body. As you write a birthday card to your mother, your brain is conscious that the hand writing “Happy Birthday Mom! Love you!” is your hand — and not someone else’s. Your brain is visually perceiving your hand writing and simultaneously receiving proprioceptive and tactile feedback inputs from your skin and muscles confirming that the hand you are visually, tactilely, and proprioceptively experiencing are the same hand: your hand.
Though several regions are implicated in bodily consciousness, the temporoparietal cortex region is partially responsible for bodily ownership. When this region is lesioned in one hemisphere, one can experience loss of ownership to the contralesional hand. This condition is called somatoparaphrenia.
Can you imagine perceiving a foreign arm attached to your body? Imagine experiencing an arm, or a foot attached to you/following you everywhere you go all day, from your bed, to the bathroom, to the bar, yet remaining convinced that it is not yours? Strange, isn’t it? Patients with somatoparaphrenia suffer from this denial of limbs.
Likewise, some patients with somatoparaphrenia wrongly attribute the limbs of others as their own when presented in their contralesional hemispace (the visual field of the contralateral brain hemisphere). In fact, even healthy people can experience bodily ownership of other limbs in experimental conditions.
This is called the rubber hand illusion.
Viewing a fake hand being stroked by a paint-brush in synchrony with strokes applied to one’s own corresponding (but occluded) hand can induce the illusion that the touch applied to the fake hand is felt. Furthermore, in these conditions people perceive their hand at a position displaced towards the fake hand. In other words, their brains process corresponding visual and tactile inputs but conflicting proprioceptive and visual inputs.
The result?
Our visual inputs override the proprioceptive inputs, resulting in the brain identifying with the fake rubber hand as opposed to the real hand.
Luckily, the brain isn’t always so gullible. When experimenters brush the fake hand out of synchrony with ones real hand OR if the fake rubber hand is unaligned with or placed far from the patient’s real hand, then patients are less likely to misidentify the fake hand.
How does the brain process ownership — and misidentify limbs?
The brain receives multiple inputs from multiple avenues and tries to fit them together into one reality. Trimodal neurons (neurons which respond to signals from three perpetual domains) in the premotor cortex, insula, and sensorimotor cortex integrate tactile, visual, and proprioceptive signals into one conscious experience.
In other words, you visually experience your hand in visual space. You also experience tactile perception of your hand — the feeling of your fingers grasped around your pen, your hand resting atop the table. Finally, your brain receives proprioceptive signals regarding your hand’s position in corporeal space. Your brain takes these three different types of inputs and creates one output: your conscious experience.
However, not all inputs are created equal. Our brain’s visual system has the powerful ability to alter our conscious experience so that it fits with reality (hence the plethora of optical illusions).
Interestingly, under repeated conditions of the fake hand illusion, one not only misidentifies the fake hand as ones own, but the visual receptive fields of neurons in the premotor cortex and insula shift to encode the position of the fake hand.
Self-ownership and first perspective
Slightly different than the conscious ownership of different limbs, self-location consciousness refers to the experience of one’s self as an entire being. First perspective refers to the perception reality from one’s self. Self-location and first-person perspective coincide since changes in ones location affect one’s first-person perspective.
Occasionally, people experience autoscopic phenomena, like out-of-body experiences or hallucinations of one’s body outside one’s self (heautoscopy), in which subjects perceive themselves from a third-person perspective. Weird, right?
Even weirder: this illusory self-identification can be induced through virtual reality.
Subjects viewing their bodies in virtual reality can self-identify with their virtual bodies despite the fact that their actual bodies and virtual bodies exist in different locations in corporeal space. When subjects’ virtual bodies and actual bodies are brushed synchronously with a stick, visual representation of their bodies override the proprioceptive experience of their bodies.
As with the rubber hand illusion, this illusory self-identification depends on corresponding visual and tactile input. In the right conditions, this mis-identification with virtual bodies can have powerful, psychological effects. For instance, pain thresholds increased during states of illusory self-identification. In other words, people experienced pain to non-noxious stimuli to their virtual bodies. Conversely, identical stimuli applied in natural reality do not illicit pain.
Currently, fMRI, EEG and BOLD imaging (blood-oxygen-level-dependent-contrast) tests show activation in several regions like the sensorimotor cortex, ventral premotor cortex, and intraparietal sulcus. However, these results don’t reveal changes occurring on a structural level. They don’t show how neural networks change, only that they are activated. After repeated submersion in virtual reality, will neural networks change?
Conscious submersion in virtual reality
What does it mean to be immersed in virtual reality?
It means one is physically present in a reality different than the ‘reality’ surrounding one’s body. It could be a fantasy world, or a world similar to this planet. Either way, virtual reality will give our brains the illusion that we are present in a totally different environment. In virtual reality, our brains will receive sensory inputs from a virtual world and process them into conscious experiences.
My big question:
How will bodily consciousness adapt to submersion in virtual reality?
The brain is a plastic organ.
What does plastic, or plasticity, mean?
Plasticity allows the brain to learn or adapt by making structural changes to neural networks. These changes can include manufacturing more neurotransmitter receptors at synaptic sites, increasing the number of synaptic spines on the dendrites of a neuronal cell bodies, thickening synaptic buttons (causing an increase in speed of neural transmission), and increasing the storage of neurotransmitter at the cell membrane of a firing neuron, and more. Synaptic connections can be strengthened or pruned according to how often our brain utilizes those connections.
What does plasticity have to do with virtual reality?
Good question. Well,
Our ability to learn depends on the plastic nature of the brain. Also, our experiences shape our learning. Virtual realities will give our brains novel experiences and perhaps new ways of perceiving “realities”. Our brain will adapt to new experiences (as with any input).
The more one consciously lives in a virtual reality, the more ones brain will adapt to that reality. We will become increasingly conscious of our virtual bodies in a virtual world. Our brains will structurally adapt to accommodate sensory inputs from our virtual bodies.
Crazy questions for the future
of virtual reality and neuroscience
- As our brains adapt to perceptions of virtual bodies will our virtual and physical bodies battle for consciousness?
- To what extent can perceptions from our virtual bodies override perceptions from our real bodies, like hunger, height, or pain?
- How will our brains adapt to virtual realities with different, governing nature laws?
- Will people confuse virtual and natural realities?
- Will virtual reality help us better understand consciousness (or will this be a perpetual disagreement that men/women stubbornly obsess over forever, even in the face of smarter robots telling us “the answers”)
- If we are capable of self-identifying with virtual bodies and feeling tactile stimulation to our virtual skin — what else is our brain capable of in the virtual world?
