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University Studies 15A: Consciousness I Animal and Machine Consciousness First things first: back to our basic question. What is consciousness? What are we talking about? Remember John Locke? “Consciousness is the perception of what passes in a man's own mind.“ This seems like a good, simple, intuitive definition. However, what did he mean by it? Sight is the perception of what comes before our eyes. Hearing is the perception of what passes before our ears. Consciousness is the perception of what passes in one’s mind. So, by this definition, how does visual consciousness differ from vision? However, people grew unhappy with this definition. “Consciousness is the perception of what passes in a man's own mind.“ Who is doing the perceiving? This image of watching what comes before the mind leads us to the homunculus: The effort to think of consciousness as something other than an inner theater has led to the popularity of Ned Block’s proposal for two distinct types of consciousness. 1. Access Consciousness: the sort of awareness of thoughts and sensations that we can report. 2. Phenomenal Consciousness: the qualitative experience. As an aside, if you google “access consciousness,” you may learn that: “Access Consciousness™ is about creating oneness, which includes everything without judgment.” Apparently popular culture has appropriated the term in a rather different manner from what Block intended. However, back to Block. Access Consciousness refers to mental states that are “(1) … poised to be used as a premise in reasoning, (2) poised for control of action, and (3) poised for rational control of speech.” That is, it’s a rainy Sunday afternoon. You’ve been studying in your room. You’ve been aware, in the back of your mind, that it is raining. Your roommate announces, “I’m bored; let’s go out and do something.” Now you look out the window, and the torrential rain enters your access consciousness: You think, “If I go out, I’ll get drenched.” (“rain” -> reasoning) You grab your (water-resistant) coat. (“rain” -> action) You say, “What’s a little rain?” (“rain” -> speech) Access consciousness is that limited-access focal attention that Baars modeled with his Global Workspace Theory. Not everything that you are phenomenally aware of enters access consciousness, only that which as the greatest saliency. What then are the features of Access Consciousness? 1. 2. 3. 4. 5. Awareness Attentiveness Specific focus Connection to possibility of analysis, action, and speech: semantic systems decision systems language Ownership: Embeddedness Specificity of this time, this place, this mind Phenomenal Consciousness: When we are running in the rain, we are aware that we are running, but the phenomenal consciousness is all that is involved in what if feels like to be running in the rain. We encountered “phenomena” earlier in the term as “that which appears before us” as possible objects of experience. Phenomenal consciousness is how we “take in” experience. Philosophers usually think in terms of the qualia of experience: the private, subjectively experienced qualities of a cloudless blue sky on a summer afternoon or drinking coffee on a cold, drizzly morning: what was that coffee like? As we discussed at the beginning of the term, qualia are very hard to convey because they go to the heart of the private, subjective character of consciousness. So, instead, we largely have focused on the general idea of phenomenal consciousness being “what it is like to be…” The phrase became famous when Thomas Nagel posed the question of whether we could understand “What it is like to be a bat?” I stressed that this is not the metaphysical question of what it would be like to have the soul of a bat. It is about what sort of consciousness a creature that inhabited a bat-body with a bat-brain would have. What then are the features of Phenomenal Consciousness? 1. 2. 3. Global Awareness “Dynamic, multisensory feature binding:” perceptual systems semantic systems decision systems Ownership: Embeddedness Specificity of this time, this place, this mind, this body If Phenomenal Consciousness is one’s on-going subjective engagement with the world, what do we mean by “subjective” We use the term all the time. What does it mean? “Of, or pertaining to the subject of experience rather than the object” Are subjective judgments: 1. Self-generated and an end in themselves? 2. Causally opaque? 3. Open to discussion, contextualization, comparison, and reflection? If we wish to claim a privilege for subjective judgments, what is that privilege and what is its basis? Animal Consciousness If we think of the question of “bat consciousness” as the subjectively engaged world (which includes the self) as experienced by a bat with its particular body, senses, and brain, and, perhaps, mind, then we are ready to turn to today’s topic, animal and machine consciousness. Once again I follow the issues as Blackmore sets them out. Once again, remember that Blackmore tries to provoke questions more than answer them. She begins by asking whether human consciousness reflects an evolutionary continuity or a big break. That is, can we expect that animals with brains similar to ours will experience consciousness in a way that is similar to how we do? Or was there a major evolutionary break such that our consciousness, like our language ability is unique? The question of language is actually quite relevant to that of consciousness. A central question in why there the primates do not reveal a seeming continuity in language development—with some species using transitional forms of communication—rather than the large gap between us and the great apes. One argument has been co-evolution: that the sorts of changes in the body (control over the mouth and larynx) and the changes in neocortical organization needed for language ability evolved together and pushed one another, leaving the other hominids behind. The changes in the neocortex have to do, in part, with the arbitrariness of the relation between sound and meaning, and in part, with the way words take their meaning from their place in a large system of words/referents The thought is that this way of making connections required a great expansion of the high-order multimodal association areas of the posterior parietal cortex, precisely the areas that are perhaps the key regions for making phenomenal consciousness possible. In any case, the question remains, “How do we assess animal consciousness to see if it resembles ours?” What can behavior tell us? If my cat looks guilty (slinking and shifty-eyed), is he feeling guilty? If your dog is looking doubtful and hesitant, is it? There is no good way to answer these questions and respond to criticism that we are just applying human attributes of mind without justification. So, once again, how can one test for animal consciousness? One thought was, “Do animals have a sense of self, since a self is necessary for consciousness?” Hence the “mirror self-recognition” (MSR) test: can an animal realize that what it sees in the mirror is its own reflection, since this would require drawing on some sort of inner self-representation? Scientists have been cheerfully inventing ways to subject a wide range of animals to the test: Chimpanzees were the first: an ethologist gave young chimpanzees mirrors to play with. Soon they were examining parts of their bodies they otherwise could not see and used the mirror to pick their teeth. The real test, though, was what would happen if the chimpanzees saw red paint on the face in the mirror: would they realize it was their own face and try to examine it by touch? It turned out, yes, they would. Variations of this experiment have been successfully repeated with dolphins, elephants, and magpies. However, what does the test tell us? These species can create forms of internal self-representation. If they are conscious, can they represent the fact of consciousness itself and use it in their engagement with the world? More particularly, can they conceive of “other minds,” of other creatures who also have inner states shaped by individuated experience? Once again, chimpanzees proved an excellent test group. Could a chimpanzee conclude that a person wearing a blindfold could not see it (and that therefor there was no point trying to get food from the person)? Apparently not. Blackmore also introduces learning through “true imitation,” which requires a theory of mind to see behind the imitated gestures. However, the results of experiments seeking to elicit imitation have been fairly murky. The more important question is, “Does one need a theory of mind to be conscious?” Can one be conscious without being aware that one is conscious (Descartes and Locke reject this) or without a concept of consciousness that one can apply to others? So, the question of animal consciousness is apparently wide open. What is at stake? Would you be more reluctant to kill and eat animals that were conscious? What level of consciousness (if there are levels of consciousness) would be the threshold to permit killing? The pragmatic Mencius concludes, “The noble man in relation to animals is such that, having seen them alive, he cannot bear to see them die; having heard their cries, he cannot bear to eat their flesh. Therefore he keeps away from the slaughterhouse and kitchen.” Machine Consciousness What can we mean by “machine consciousness?” http://www.youtube.com/watch?feature=player_detailpage&v=N-o-4txOiVE#t=13s Blackmore spends a good deal of time giving the background history of machine intelligence. But I believe I do not need to spend much time making the point that although IBM’s “Deep Blue” could beat Kasparov at chess, it is computationally powerful, but the intelligence is in its design. The more central question for machine consciousness is when do machines understand “meanings” rather than process symbols. Meaning: Machine and Human Understanding We are on difficult terrain here: much effort has been expended trying to define what we mean by “understanding meaning.” For example, what is the meaning of “water?” Or, to rephrase, how do you understand what water means? Qualia matter in our account of understanding meaning. The hard question is, “Must qualia count for any decent theory of what is required to properly understand meanings?” The argument has been that machines process symbols but do not understand meanings. The usual examples of this distinction are 1. 2. The Turing Test: can a machine make you believe it is human after a five minute interview? The Chinese Room: a person in a room uses a big book to look up proper responses to inputs in Chinese and passes these responses to a recipient. The person does not know a word of Chinese, but to the recipient, the person appears to know Chinese. This problem of understanding has led to a “new robotics” that stresses selfassembling embodied semantics and embodied cognition. These are robots that use artificial neural networks to build their perceptual, cognitive, and response systems based on a few homeostatic (self-stabilizing) rules. If they succeed, will these robots have phenomenal consciousness? Access consciousness? SkyNet, here we come.