Sign up for the Blank Horizons mailing list here.
Header image taken from here.
How do we test consciousness?
This problem has stumped scholars for generations because consciousness is notoriously untestable. My conscious experience seems intrinsically internal to me. If so, then it is impossible for someone else to verify with certainty the content of my experiences, or whether I am conscious at all. This claim gives rise to the notion of philosophical zombies (or p-zombies), philosopher David Chalmer’s thought experiment of an entity that behaves exactly the same as a conscious human being but does not in fact have the gift of awareness. In other words, a p-zombie is someone who reacts to pain, laughs, and enjoys delicious food in precisely the same way that a conscious human would, but does not actually feel any of the corresponding sensations. Importantly, a p-zombie can report on all of its purported experiences – that is, it can say that it has been hurt by a sharp needle or that it finds a particular joke to be funny. Hence, a p-zombie could, hypothetically, pass the Turing test, which aims to determine whether a machine is intelligent based on its responses in a natural conversation with a human. The p-zombie would be able to deceive a real human into thinking that it is conscious by convincingly answering any questions about its “experiences.” Given the problem of p-zombies, how do we design an effective Turing test – a test that is truly able to ascertain whether or not someone is conscious?
The philosophy of consciousness
The “problem of p-zombies” rests on the premise that conscious awareness is inherently private, accessible only to the “I” of the beholder. Hence, the problem presupposes a dualist ontology, in which there is an irreconcilable gap rather than a unity or complementarity between consciousness and the outside world. As I’ve written elsewhere, I don’t find dualism appealing and instead prefer an ontology called ontic structural realism, which claims that reality is composed of interactions or relations rather than separate, independent phenomena. When combined with a monist or non-dual metaphysics, ontic structural realism would imply that there is no fundamental separation between consciousness and the world. Rather, they are defined by the way in which they interact with each other.
Indeed, after all, I would argue that consciousness is an intrinsically relational phenomenon because, broadly speaking, consciousness is the expression of the way that the self relates to the world. For instance, the experience of the color red is determined by a relationship between a pattern of brain activity and the wavelengths of light reflecting from a visual stimulus. The experience is not equivalent to the neuronal activity itself, and therefore does not reside solely within the brain of the individual. That is, if one were to stimulate the same neurons that are responsible for color perception in someone who was born blind, the experimental subject would not experience red. The neurons have to be trained to activate in response to wavelengths of red light. Thus, the interaction between the neurons and the surrounding environment dictates the experience.
However, this relational notion of consciousness does not seem to offer any hope for a more effective method of testing consciousness, since it ostensibly does not resolve the issue that subjective experience cannot be transmitted from one person to another. Even if consciousness is the interaction between the self and the environment, it nonetheless seems to be an interaction that involves only one particular individual. No one can experience the interaction aside from this single person.
Yet I think that a relational ontology does suggest that consciousness is directly transmissible from one person to another. When two people are consciously aware of each other, the ontology implies that each person experiences not only the way in which he relates to the other, but also the way in which the other relates to him. Furthermore, when these two relations are identical, they will be able to share their experiences with each other in a literal sense. In other words, they wouldn’t merely be able to communicate indirectly about their experiences to each other, i.e. via language, but they could actually relay the felt sensations of their perceived reality (their “qualia”) to each other. They could have exactly the same experience of red or even of more subjective sensations like pain, greed, joy, and so on.
Qualia sharing: an anecdote
This phenomenon of sharing consciousness is not purely theoretical; it has occurred in real life, though, as far as I am aware, the evidence consists mostly of isolated, unverified anecdotes. One anecdote that I recently learned about was recounted by Ram Dass (part of this passage also appeared in an earlier blogpost):
Years ago in India I was sitting in the courtyard of the little temple in the Himalayan foothills. Thirty or forty of us were there around my guru, Maharaji. This old man wrapped in a plaid blanket was sitting on a plank bed, and for a brief uncommon interval everyone had fallen silent. It was a meditative quiet, like an open field on a windless day or a deep clear lake without a ripple. Waves of love radiated toward me, washing over me like a gentle surf on a tropical shore, immersing me, rocking me, caressing my soul, infinitely accepting and open.
I was nearly overcome, on the verge of tears, so grateful and so full of joy it was hard to believe it was happening. Opening my eyes, I looked around, and I could feel that everyone else around me was experiencing the same thing. I looked over at my guru. He was just sitting here, looking around, not doing anything. It was just his being, shining like the sun equally on everyone. It wasn’t directed at anyone in particular. For him it was nothing special, just his own nature.
This passage neglects to mention an important fact, namely that Maharaji was loved very deeply by everyone whom he met. As Ram Dass says in Be Here Now, yogis would burst into tears when they traveled to see Maharaji, and many of the local townsfolk would be willing to give away their most valuable possessions to him. Maharaji also felt unconditional love; however, this love was not directed towards anyone in particular, but rather towards all sentient beings. In the passage above, Maharaji related to his audience by transmitting “just his own nature,” and I suspect that the audience related to Maharaji with profound love. Since Maharaji’s nature is filled with boundless, unconditional love, I imagine that Maharaji related to the audience in exactly the same way that they related to him, giving rise to a mutual, shared experience of infinite compassion and extraordinary bliss. Maharaji’s conscious awareness resonated, literally, with the feelings of compassion that his audience had already been experiencing, and hence he was able to transmit qualia of unlimited, oceanic love to those around him.
There are other, more familiar examples of consciousness sharing. When we say that we are able to “feel someone’s vibes,” we are essentially receiving the qualia that he or she is transmitting. For instance, when people give off fear, we begin to relate to them with fear as well. Some people are exceptionally skilled at “vibe detection”; they can immediately and effortlessly sense the “collective qualia” of a room. But, to some degree, almost everyone is capable of tuning into the emotional qualia of other people. This ability is not unique to humans; dogs and other animals can pick up on anxious energy.
A test of consciousness
If consciousness can indeed be shared, then we can test whether an entity is conscious by determining whether it is capable of experiencing qualia transmitted by other conscious beings.
The exact details of the test depend on the underlying mechanisms of qualia sharing, which remain unknown. I hypothesize that the phenomenon results from some kind of resonance between the brains of the individuals who are relaying their experiences. Recently, neuroscientists have shown that interpersonal neural synchronization (a form of resonance) can blur the boundaries between self and other, such that the “positive thoughts of the self” blend into “the thoughts of the other.” The Qualia Research Institute (QRI) has also argued that the emotional valence of a conscious experience is determined by consonance (another type of resonance) between brain harmonics; thus, when two brains are consonant with each other, then both individuals may be able to experience a shared sensation of bliss. (Indeed, QRI is the organization that inspired me to think about consciousness as a resonant phenomenon.)
Once we have discovered the physical substrate of consciousness (PSC), we can decompose it into its resonant modes, following techniques developed by Selen Atasoy and discussed by QRI. We can then test consciousness by inducing resonance between the PSCs of two individuals, one of whom is already known to be conscious, and discovering whether the second one is able to experience the qualia of the first. For instance, if Integrated Information Theory is correct in claiming that consciousness is a cause-effect structure specified by the PSC, then we can identify the conditions in which two PSCs resonate with each other by performing harmonic decomposition on the graph formed by the constituent points of the structure. (For more details, see Technical Appendix 1 or my upcoming blogpost, “Integrated Information Theory, Part I”). We can then map these harmonics back onto the PSC and apply some form of brain stimulation or perhaps even spiritual practice (advanced meditation, yoga, etc.) to lock two people into resonant PSCs. We then present a perceptual stimulus only to the test subject who is known to be conscious, and we ask the other subject whether he or she subsequently experiences the same qualia. 
I can think of two objections to this approach for testing consciousness. Firstly, two people cannot actually share the same consciousness. They may have very similar or perhaps identical experiences, but they are inherently separate from each other. From an outsider’s perspective, a person’s consciousness is a black box enclosed within the brain, and so long as his brain isn’t merged with another’s (see Supplementary Links), it will be impossible to directly experience the contents of his experience. However, as stated above, consciousness is not reducible to brain activity, but is rather a correspondence or resonance between the brain and the environment. If the PSCs in the brains of two individuals resonate perfectly with each other, then they will experience each other in exactly the same way.
Secondly, when someone feels a sensation that appears to have been transmitted by someone else, he is not actually experiencing the other person’s qualia, but rather perceiving his own reaction to the other person’s emotional state. When I become anxious by observing another person’s anxiety, I am not receiving anxious qualia that he has transmitted to me. Instead, I am merely reacting to his behavioral cues: to the sweat on his brow, perhaps, or the tension in his arms. Alternatively, I could be imagining or conjecturing that the other person is nervous based on my knowledge of him (for instance, I may know that he is running late for an important meeting) and in turn becoming anxious by empathizing with him. As psychologists have recently discovered, sensing the vibes of other people merely arises from the act of processing their “chemosignals,” such as their body odor. These chemosignals are clearly not the same as the other person’s conscious experience. Furthermore, it is possible to design a robot that lacks conscious awareness but is nonetheless capable of emitting chemosignals and mimicking the facial and bodily expressions that correspond to human emotions.
To overcome this objection, we would need to find evidence of situations in which a person tunes into the qualia of other people without responding to their behavioral cues or projecting his own expectations of their emotional state onto them. Arguably, the Ram Dass anecdote is an example of directly perceiving the qualia of another person, since the love that Ram Dass had experienced was simply too profound to be the result of an inference about Maharaji’s emotional state. Maharaji did not seem to be displaying any particularly expressive cues about his state of consciousness; as Ram Dass said, Maharaji “was just sitting here, looking around, not doing anything.” But it could also be the case that Ram Dass was merely perceiving his own love for Maharaji and mistaking that for direct insight into Maharaji’s experience of boundless compassion. Would Ram Dass have had the same experience if he had no prior knowledge of Maharaji? The answer seems to be yes. In Be Here Now, Ram Dass says, “When you meet a being who is centered, you always know it,” presumably even if you are meeting this being for the first time. “You always feel a kind of calm emanation,” he writes. I have had similar experiences; once when I traveled to a Buddhist monastery called The Monastic Academy for a meditation retreat, I could immediately sense the preternatural calm of the monks as soon as I opened the front door. Granted, my experience may have been informed by my expectations; perhaps my mind anticipated that I would be meeting some very tranquil people at the monastery. But I also felt, if only for a moment, a certain flavor of clarity that I had never quite perceived before; I experienced firsthand the mental quietude that one could only achieve after years of meditation.
My time at the Monastic Academy, as well as Ram Dass’ encounters with “centered beings,” attests to the fact that we can directly experience the qualia of other people. Thus, in conclusion, we can test whether an entity is conscious by putting it in the presence of someone who is exceptionally skilled at transmitting qualia. For whatever reason, spiritually awakened people appear to be more effective at sharing their states of consciousness with others. Hence, I suspect that a highly intelligent but non-conscious robot would report that it doesn’t feel any differently when it meets Maharaji, whereas a human being would experience waves of joy and compassion.
Andrés Gomez Emilsson’s “mind-melding” approach for testing consciousness.
 As I have written before, an essential and perhaps defining feature of consciousness is binding, or the integration of many qualia into a single, coherent, unified experience. Thus, the experimental setup must ensure that the conscious experiences of the two test subjects are bound together, otherwise they will not actually be able to transmit qualia to each other. Each one would merely be predicting the other person’s experience, rather than genuinely sharing his consciousness. I have argued, very speculatively, that binding may be encoded by an invariance in the Lagrangian of consciousness. If so, then the setup would need to not only create resonance between the PSCs of the test subjects, but also equalize the corresponding Lagrangians, which is a highly nontrivial task.