A dialogue concerning the two chief mind systems

Siri and Varuni are two keen students of philosophy chatting away one lazy afternoon, discussing the fascinating problem of the evolution of sentience1. Tea and biscuits have just been served, and Siri warms to the topic.

Siri: Say Varuni, you know what? I think I’ve figured out the biggie. There is no big deal to our minds. I believe that the subjective conscious experiences that we call “sentience” evolved as a direct result of a sort of “speech meme2” working in combination with natural selection3.

Varuni: A speech meme? Go on Siri, with biscuits like these, I’ve got all afternoon. What’s all this about…  how does speaking make us conscious? Does this mean that any creature that cannot speak, like a congenital deaf-mute or a pet dog, is unconscious and not self-aware? Explain yourself.

Siri: Ok my friend, that’s just what I’ll do. But please be patient… this is a subtle metaphysical point, and demands careful attention from both the presenter of the idea (myself) and the listener (you). I’ll begin by outlining a quick caricature of my hypothesis, for the sake of easy understanding. You could throw in your questions and allow me to fill the gaps thereafter, if I could. Would you be okay with this approach?

Varuni: Of course I would, go on… [Varuni sits back in her chair and sinks her teeth into a biscuit]

Siri: Okay. Well, It’s like this. I believe hominids4 that lived as recently as one hundred thousand years ago were complete automata5. They did not experience the subjective sensations that folks like you and I claim to have. It’s not clear exactly when or how, but some early humans began to vocalize complex signals to each other, perhaps extending a relatively narrow range of monkey-like auditory signals, signals for danger for example, to a more sophisticated speech that resulted in teamwork between two or more creatures. Like for example, the sound “woo waa” might have meant “predator approaches, back me up in defense” as an extension to “woo” which meant “predator approaches, run”. The societies of early humans who had such extended vocal signaling gained an obvious group-survival advantage over those who didn’t6, 7. Moreover, they began to propagate their signaling strategies amongst their offspring, simply because the offspring saw and imitated their parents behavior. The offspring in turn adopted and extended their repertoire of verbal signals, giving birth to the phenomenon we call Language. Four important characteristics of this process of language evolution are:

  1. Protocol Recognition: A hominid hunter-gather group arrives at a common understanding that a particular throaty noise (or combination of noises) symbolizes a new group survival behavior (e.g. fight back, run, help me etc).
  2. A Group Survival Advantage: The new word or phrase that becomes kosher amongst the group gives them a Darwinian survival advantage, causing less numbers to die prior to reproduction and childbirth, as compared with other groups or individual humans.
  3. Meme Propagation: Children living in these primitive societies picked up their vocabulary through imitation, and extend it.
  4. Evolutionary Bootstrapping: The survivors of this process are those who were able to grasp the usefulness of the new verbal signals, and imitate them. Therefore their brains and their vocal apparatus got selected in Darwinian fashion. Rather like conventional evolution bootstrapped by the language phenomenon, or speech memes. The major area that got bootstrapped would have been the brain’s ability to perform as a learning machine8.

Now comes the illusive part of my idea. Somewhere in this evolutionary process, a phenomenon emerged9 that gave the speakers the viewpoint of their speech. It is this strange viewpoint that we call consciousness. It has everything to do with verbal communication, and nothing whatsoever to do with a gradual evolution over hundreds of millions of years of a more fundamental phenomenon commonly called qualia10. An example for this erroneous notion of the existence of qualia would be the belief that a dinosaur experienced taste (as we do) simply because it had taste buds and evolved neural circuitry to home in on nutritious food.

Varuni: Gosh Siri, dinosaurs had taste buds? [Varuni Laughs]

Siri: Hey now, Its only a caricature useful for my argument, I’m not at all sure dinosaurs had taste buds…

Varuni: [still laughing] Yes I get it. The interesting point you are trying to make here is that it’s the evolution of this protolanguage11 that first gave rise to subjective experience like color or pain. The human brain, which had already evolved as an advanced learning machine (for every conceivable evolutionary advantage other than subjective experience), suddenly acquired the capacity to “signal” one’s unconsciously processed environmental input into a social strategy, by voicing it. The learned reflex of throwing-up a social strategy signal to accompany many unconscious bodily reflexes is what makes us “feel things”. What we feel is our inner voice, at a stage prior to reaching the motor centers of our larynx. There still remains the big problem of how exactly the responsible neural circuits that express the social strategy cause us to “hear” it, which I’d like you to elaborate about. But for now suffice to say that all the private notions that we have, such as the sky being blue, the wife being pretty, the pinprick being painful, the memory of bin-laden’s face or the feeling that Hillary Clinton’s foreign policies are “driving us crazy” are all unspoken speech12. These feelings are all arising out of our brains being environmentally reprogrammed for sophisticated verbal communication. For example, the sensation of “purple” is simply “I see this particular wavelength of light reflected on to me, the one we all agree to call purple”. Correct?

Siri: Yep. But hominid brains were both environmentally reprogrammed through speech and subject to natural selection, to be more precise. Okay, let me address your seemingly “big problem” of the exact root-cause of the subjective sensations that we report. I’m going to dismiss it as a non-issue. As a student of philosophy, you would be aware that some phenomena that we experience “emerge” from given ground-conditions: for example there is no such thing as “explaining” the phenomenon of liquidity. The philosopher John Serl describes this phenomenon of emergence rather well13. What I’d like to say is, the so-called 1st person viewpoint (inner voice) might be an emergent phenomenon of the whole group communication setup. There need not even be a special neural circuit or massively parallel neural network that evolved in language speakers to explicitly “generate” subjective experience as an intermediate step between environmental input and speech. I doubt the existence of such an “inner voice” generation circuit, or functional program. Its just a reported phenomenon in the given social communication setup.

I’ll conclude my initial argument by saying that there is some vague evidence for the fact that subjective experience suddenly arose amongst early language speakers – for example the sculptures and drawings describing daemons, gods etc. might have all been as a result of suddenly experiencing an inner voice or 1st person perspective. Somewhat along the lines of what the congenitally deaf-blind Helen Keller experienced, when she first learned to communicate14, 15.

Varuni: [Clapping playfully] Nifty little hypothesis Siri, in which I’m about to poke several large holes. But before I do that, I’d like to hear your opinion about free will16. Within your hypothesis is there any room for free will?

Siri: Poking holes eh? Okay, I’ll give you my take on free will. Whatever “smart processing” we do in our brains based on environmental stimuli is strictly unconscious.  The other day I was at the grocery checkout, with a rather massive pile of items in the cart. I stared at it, and pulled out two 1000-rupee bills. The total came up to LKR 1995. Did I consciously “think through” the approximations and calculation? No. My brain did the computation unconsciously. When we are “thinking”, what we are doing is frame shifting between unconscious processing and conscious speaking (usually a silent “draft” speech). Decision-making is also done similarly. As Benjamin Libet’s experiment17 amply demonstrates, there is always a brain event recorded through electrodes immediately prior to us knowing our stand on a decision. We only become aware of this decision in the process of “announcing it” to society. So I believe we experience free will, but we function according to strictly deterministic laws18 from an external perspective.

[Both Siri and Varuni stretch their limbs, top up their teacups and sit down again]

Varuni: Alrightee! Lets see if your views can stand my onslaught. First a few “totally dumb questions” just to see if you are standing on steady ground. The answers you give would help me to narrow down my attack. Is there evidence to confirm that people who are blind from birth can only experience auditory dreams at best? I want to confirm that the qualia we report are strictly based on what our sense organs have picked up, and that we don’t have some “inherited inner capacity” to picture the external world.

Siri: Yes. The congenitally blind don’t dream visually19.  [Siri IM’s Varuni a link through his iPad]

Varuni: Okay, next dumb Q: what about animals?

Siri: What about them?

Varuni: My friend, don’t you realize that animals exhibit behaviors of awareness20, danger, anxiety, anguish and other inner mental states, exactly as we humans do? Are you saying that when your cat becomes alert to danger, or smells the fish cooking and sits down in the kitchen anticipating its meal, she has absolutely no subjective experience of this? Not even a rudimentary sense of pain or pleasure?

Siri: [Siri grins] Let me give that question the answer it deserves. Philosophical zombies are commonplace in the natural world. Here is the most outlandish example; did you know that a brain-dead cadaver could exhibit symptoms of sexual pleasure21? Check this link. [Siri IM’s the link to Varuni, whilst Varuni looks a bit aghast] Are we to suppose that the brain-dead cadaver feels pleasure? Are we to assume that an animal displaying behavior of apparent subjective experience should actually have that experience like we do?

Varuni: Okay perhaps not, but can you point to any research that clearly shows that the apparently complex emotional behavior of (say) a dog is strictly reflexive and unconscious?

Siri: I have to admit I cannot, but did you know that dogs fail the classic “mirror test22”, which at least suggests they lack a strong “body image” like grown humans do? Even infant humans below one and a half years fail a version of this test (the rouge test23), possibly because they cannot speak and don’t have a concept of “me”. Our own mirror neurons might trigger our speech pathways for the empathy reaction, and we would feel for our dogs when they appear cute. Not necessarily the other way about. Their apparent empathy might lack any subjective experience.

Varuni: Right. Luckily, those questions I asked were to see where you stand. Now I’m going to confront you head on. So you have pushed the subjective experiences of consciousness into a very special corner no doubt, based on some dubious experiments.  According to you, subjective experience exists in modern humans only, is a direct result of the rather recent development of a spoken language, and was brought about by evolution of the brain in conjunction with the social evolution of speech. The qualia we experience are like an inner voice expressing our next move in a social context. It might be some sort of fancy “emergent phenomena” – a 1st person viewpoint for speech that just comes about as a result of the entire social setup combined with the brain function associated with speech. Here is where I’m going to hammer you dead. You do conjecture that we experience this “thoughts” phenomenon, and dogs don’t experience it – correct?

Siri: Errr… well possibly yes. What of it?

Varuni: So what’s different between the structure and function of dogs and humans?

Siri: Dog’s don’t speak!

Varuni: But they bark violently in anger, and howl pathetically to their social pack-mates when in pain. That’s at least two different words isn’t it? Two words that on observation seem to be understood by other dogs. These two words have a survival advantage, and could bring about a rudimentary 1st person perspective to the world, in the context of a dog society. What level of communicational complexity is missing in a dog (or a meerkat or hyena), that makes it lack a primitive “inner voice”? Perhaps they experience pain and anger?

Siri: Maybe dog-speech has not evolved enough to bring about a self-image. Maybe it has. I’m just saying it’s all brought about through communication within a group.

Varuni: Ahhh… now you have a big hole in your hypothesis. See, if dogs have a rudimentary sentience brought about as a result of communication within their society (and their brains evolving conjointly with their barks and howls), then there must exist in some animals a subjective experience that is most rudimentary, like a building block of experience. In other words, there must be a reproducible ground-condition for a given subjective experience like pain. It could be a combination of macro conditions like the existence of a network of survival machines24 using a common communication protocol etc and micro conditions like the functional states of their nervous systems (a particular program running, in software terminology). These ground-conditions would represent a formula to artificially reproduce a subjective experience, like we can reproduce the liquid state of matter across a host of elements and compounds.

Siri: But would we ever be able to ascertain animal sentience, especially for an animal like a dog? We don’t have a universally accepted test for separating a sentient machine from a philosophical zombie25, right? Even if we were talking about a sort of intelligence test or test for imitation, it would not be practical to perform a Turing Test26 on a dog.

Varuni: Siri, I think you are digressing conceptually. Let me explain. If as I believe there is a certain set of humanly comprehensible physical ground-conditions that make it possible for a biological system to be conscious (experience a 1st person conversational viewpoint, to use your jargon), then there opens up a whole new universe of extensions to our life experience, ranging from manufacturing artificial friends to extending our experienced life-spans through machines.

More importantly, don’t you see that nature harnessed the first mutation that was capable of “experiencing”, in a Darwinian sense? Did or didn’t this “sentience” improve the procreation of the species concerned? If you consider the entire population of reptiles, mammals and birds, there probably are more chickens than there are humans on planet earth27. But that’s due to artificial breeding. Otherwise, no single species count of a cat or a cobra comes anywhere close to the count of 7 billion Homo sapiens. Clearly, this sentience business has massive Darwinian survival utility, and it is not absurd to suppose that there was an initial mutation that produced a rudimentary sentience, which was selected down the generations, whether bootstrapped by communication or not.

I don’t have a problem with the co-evolution of language and the brains that facilitate it (your meme + evolution hypothesis), but I do have a problem with dismissing the subjective phenomenon of sentience as an accident of no consequence in a Darwinian sense. It’s not one big spandrel28, as S.J. Gould might have put it if he were alive today. And if sentience evolved from a rudimentary form, irrespective of whether it was first experienced by early humans or jellyfish 500 million years ago29, 30, it gives us humans the hope (in theory at least) that the phenomenon can be understood and harnessed, like we harnessed the electromagnetic force or like we hope to harness artificial photosynthesis31 someday.

If you are proposing that sentience happened one day to a human a few thousand years ago, while he was talking unconsciously, and that he suddenly became “conscious” because of all his previous jabbering (a sort of “reprogramming of the brain”), then I’d like you to emulate this remarkable feat. Pick you favorite chimpanzee or dolphin or elephant and train it, until you are satisfied it communicates exactly like you. Remember, no 200-word limit like Panzee32… it must be able to talk philosophy like you. [Varuni grins] However, if you only succeeded partially (as I suspect you would), and the creature ended up with a vocabulary of a couple of hundred words and no complex grammar, then it might be a result in my favor. The word limit could be due to inherited limitations in the learning capacity of its brain. And we could conclude that it took at least several million years of evolution of hominids to develop the neural circuitry to have our kind of rich subjective experience. Perhaps much longer, with early fish “feeling” the sting of a jellyfish.

After all, what’s special about the medium of sound with respect to developing a group-communication protocol? One could establish a social communication strategy that bootstraps evolution through vibrations in water, by visual signaling or by mere physical contact. Humpback whales are likely to experience a variety of subjective emotions, if the complexity in their songs represents a language33.

To summarize my view, I believe we can:

  1. Drag this business of the emergence of sentience much further back in evolutionary time than the emergence of early human tribes and
  2. If your ideas about “evolution bootstrapped by social interaction” is true, we can then make a genuine attempt to understand sentience from the perspective of a network of learning, communicating machines setup against a backdrop of environmental challenges. Note my emphasis on the four words network, learning, communicating and environmental challenges. They would be factors critical to simulating the macro-picture of the evolution of sentience.

I believe there is hope for the development of artificial consciousness34 (not to be confused with AI) within a virtual software-based environment. However the key to setting up a successful social network of learning machines is to study how the brain is architected as such an enormously plastic learning machine in the first place, and thereafter figure out how to transfer these design principles into silicon and code. Empirical study of the brain is crucial, indulging in philosophy or conceptual models alone won’t help much further.

Siri: Wow… provocative ideas. By the way, the theory about why the smart chimp Panzee35 is so smart is in my favor, read this account. [Siri IM’s the link] But you just might have a valid point about keeping the study of sentience wide open, in the context of reproducing the phenomenon. I think I’ve reached the limits of my knowledge though, Varuni. And, by the looks of things, we’ve run out of biscuits!

Varuni: [Standing up to leave and shaking Siri’s hand warmly] I wish I was Jane and had met Tarzan, completely isolated from human society and fresh out of the woods. Could have easily figured out if he was a zombie, amongst other things… [Laughs all around]

Useful References:

  1. About sentience: http://en.wikipedia.org/wiki/Sentience
  2. About memes: http://en.wikipedia.org/wiki/Meme
  3. About natural selection: http://en.wikipedia.org/wiki/Natural_selection
  4. About hominids: http://en.wikipedia.org/wiki/Hominidae
  5. About evolved automata: http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life
  6. About the evolution of language: http://library.thinkquest.org/C004367/la1.shtml
  7. More about the origin of language: http://en.wikipedia.org/wiki/Origin_of_language
  8. About machine learning: http://en.wikipedia.org/wiki/Machine_learning
  9. About emergence: http://en.wikipedia.org/wiki/Emergence
  10. About qualia: http://en.wikipedia.org/wiki/Qualia
  11. About proto-human language: http://en.wikipedia.org/wiki/Proto-Human_language
  12. Consciousness explained: http://en.wikipedia.org/wiki/Consciousness_Explained
  13. Serl on Emergence (a video): http://www.youtube.com/watch?v=giwXG3QYWQA
  14. About Helen Keller: http://en.wikipedia.org/wiki/Helen_Keller
  15. More about Helen Keller: http://www.percepp.com/keller.htm
  16. About free will: http://en.wikipedia.org/wiki/Free_will
  17. Libet’s experiment: http://en.wikipedia.org/wiki/Benjamin_Libet
  18. About determinism: http://en.wikipedia.org/wiki/Determinism
  19. About the blind dreaming: http://www2.ucsc.edu/dreams/Library/kerr_2004.html
  20. Awareness in animals: http://www.science20.com/gerhard_adam/selfawareness_animals
  21. Talk about cadaver orgasm http://www.youtube.com/watch?v=7jx0dTYUO5E
  22. About the Mirror Test: http://en.wikipedia.org/wiki/Mirror_test
  23. About the rouge test: http://en.wikipedia.org/wiki/Rouge_test
  24. About Survival Machines: http://en.wikipedia.org/wiki/The_Selfish_Gene
  25. About a Philosophical Zombie: http://en.wikipedia.org/wiki/Philosophical_zombie
  26. About the Turing Test: Turing Test: http://en.wikipedia.org/wiki/Turing_test
  27. About the population of chickens: http://answers.yahoo.com/question/index?qid=20071028132443AAZJ6KU
  28. About Spandrels: http://en.wikipedia.org/wiki/Spandrel_%28biology%29
  29. Pain in invertebrates: http://www.abolitionist.com/darwinian-life/invertebrate-pain.html
  30. Nervous systems in jellyfish: http://www.sciencedaily.com/releases/2011/05/110517132644.htm
  31. Artificial photosynthesis: http://en.wikipedia.org/wiki/Artificial_photosynthesis
  32. Smart chimp Panzee: http://news.discovery.com/animals/chimpanzee-human-speech-111031.html
  33. Whale songs represent a language: http://www.newscientist.com/article/dn8886-whale-song-reveals-sophisticated-language-skills.html
  34. About artificial consciousness: http://en.wikipedia.org/wiki/Artificial_consciousness
  35. Speech perception in chimps: http://www.physorg.com/news/2011-10-chimpanzee-speech-perception-uniquely-human.html

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