Saturday, April 25, 2015

Radio 1: Consciousness as a Streaming Information Service

The benchmark of modern theories of consciousness, by Bernard Baars, 1986: "A cognitive theory of consciousness."

One of the more contentious and mysterious areas in science is consciousness. Its existence was long denied by behaviorist psychology, yet long-standing schools of (idealistic) philosophy have held that it is the only thing that exists at all- that all else is an illusion, or at least subsidiary to the great reality which is consciousness. The universe itself is conscious!

Well, that is absurd, but it indicates the trickiness of a subject that attempts to explain our ability to think about subjects. One quickly gets into philosophical, if not logical, thickets. But it is pretty clear that inanimate matter doesn't think, while we and our fellow animals have, after billions of years of painful evolution, graded abilities to think about things, including ourselves, which arise from that organ behind our eyes ... the brain.

The study of consciousness is now a hot academic field, but that happened only in the last couple of decades, after the long hiatus of behaviorism. Bernard Baars's book from 1986 is a watershed in the field, presenting a functional theory of consciousness which has little to say about its physiological basis, but has profound things to say about its phenomenology, internal logic, and purpose. Its model (consciousness as global workspace) remains the basis for current work in the field.

In some respects, consciousness is extremely small, not to mention slow. We can barely attend to one thing at a time and remember maybe five to seven things in short term memory. Anything we do consciously must be done at a snail's pace, and only once learned becomes faster as it also becomes automatized, and sinks into the unconscious. The unconscious is, in contrast, endlessly vast, taking care of physiological functions all over the body, analyzing speech as we hear it, translating our thoughts into speech as we speak it, and on and on. It is a parallel, not serial, fleet of processors, some of which are very fast. Any action we take is made up wholly of unconscious mechanisms. All we are conscious of is maybe the goal of reaching for a cup, (or typing a letter on a keyboard), and all the calculation and activations in between are taken care of, like magic. A practiced typist won't even think about reaching for individual letters anymore, but will fluently type by the word, or more.

Yet consciousness does one thing that none of these other, learned, unconscious processes do, which is broadcast information extremely widely over a vast population of other (unconscious) processors. When reading some text- consciously, and only consciously- it is judged by a variety of processes that operate outside of immediate consciousness. Is the syntax correct? Is the style fashionable? Is the content interesting? Is the spelling correct? Is the meaning connected to the last sentence? The fact that these issues and many others can only be analyzed when one is "paying attention" has great meaning for the nature and role of consciousness.

I used to think that consciousness was the caboose on the train of thought. The classic experiments of Libet showed that for any action, even so-called voluntary action, electrodes can pick up activating signals well before one is conscious of a choice being made. And it is obvious with the slowness and high-level nature of consciousness that anything that enters it has gone through a great deal of prior processing at other levels of the system. But that doesn't mean that consciousness is only a spectator. No other process provides the integrating, broad reach across virtually every process in the brain, at a high level. Bringing something into consciousness means testing it for coherence at many levels, from spelling to consonance with our model of the world and hierarchy of goals.

Thus consciousness is an active function, specially tasked with broadcasting novel data far and wide over the multifarious pool of unconscious processes, which can each in turn comment on what they see. Is an object moving in the distance? Such an event exites special visual processors and calls to attention what may have not been there before. Conscious attention then allows us to consult our full cognitive battery of memory, world model, goals, etc. to decide what that object might be, in relation to our needs.

This leads to Baars to consider the stream of consciousness phenomenon. Why is it so tenuous and fluid? The fact is that we are virtually unable to attend to unchanging stimuli. Even loud noises, if repeated endlessly, fade out of awareness. The hedonistic treadmill is notorious for habituating us to any pleasure or good forture we may experience, which is soon taken for granted and cast aside in a search for the *next great thing. Consciousness concerns itself with information, in the formal computational sense. Whenever some activity starts to pall or become routine, it fades from consciousness. When learning new skills, this is a good thing, as sufficient repetition causes the whole process to go automatic and unconscious, like touch typing. Good or bad, the phenomenon seems to be universal as well as clearly adaptive. We are constantly on the hunt for novelty and information. Whatever is been-there-done-that is relegated to the dustbin of memory, or obliviousness.

It should also be obvious at this point why conciousness is so narrow and singular. If some data is supposed to be broadcast and commented on by many, indeed all available, other processes for integrated evaluation of an ambiguous or novel situation, there can only be one such item at a time. Consciousness is a radio station we listen to one story at a time. It is, and must be, a serial processor. Baars marvels at the then-trendy studies in biofeedback, which demonstrated that with enough training, virtually every part of the body and mind can be manipulated consciously. Individual muscles can be trained, blood pressure changed, etc. This phenomenon is coming into clinical use for various prosthetic appliances, which can be controlled by all sorts of muscles or thought patterns that wouldn't at first glance be candidates for actuators of voluntary action.

What gets access to consciousness? Again, unconscious processes lead the way. A big driver is our internal hierarchy of goals, one of the major unconscious functions that interacts with conciousness. Do we want a sandwich? A walk? A newspaper? Money? Survival? Life is complicated that way, as needs come up all the time at all levels. When a super-high level goal comes under fire, we are rivetted. Earthshaking experiences change conciousness itself, by re-arranging the unconscious contexts that underly it- it is not the earth that shakes, at least most of the time. Hallucinogens like LSD can have this kind of deep, long-lasting effect. On the other hand, if information comes along that violates a high-level model of reality particularly egregiously, we may also block it out rather than take on the problem of breaking down our painstakingly developed models of reality, (contexts, in Baars's teminology). Thus we fight cognitive dissonance to save them by rationalization, confirmation bias, denial, etc. Bears makes a point of the coherence that conscious contents must have to be useful, which rests on the cooperation of the many unconscious processes / contexts that join to create conscious contents. If these sub-processes conflict rather than cooperate, the result may not be conscious novelty, but rather indecision at lower levels and lack of consciousness on that topic.

Dreams naturally arrive on this train of thought as well, though Baars leaves that topic as an exercise for the reader. Baars does note that consciousness is heavily visual, with much less vivid access to abstractions than to scenes in front of our eyes. He speculates that this may indicate the evolutionary history of consciousness began in straight sensation, and only later attracted goal evaluation, retrospection, planning, inner speech, and all the other aspects that so enrich consciousness for us. During sleep we are released from the immediate layers of the goal system, so one might hypothesize that the consciousness apparatus turns towards free experimentation, using imagery to explore the deeper levels of our unconscious contexts- the goal, memory and prediction systems, which are susceptible to many complexities and internal contradictions. Dramatic role-playing, which is such staple of waking entertainment as a way into the mysteries of the human condition, are here personally staged for our continuing development.

Indeed, the theater is a leading metaphor for consciousness itself:
One can compare the mind of a man to a theater of indefinite depth whose apron is very narrow but whose stage becomes larger away from the apron. On this lighted apron [i.e. front of the stage] there is room for one actor only. He enters, gestures for a moment, and leaves; another arrives, then another, and so on ... Among the scenery and on the far-off stage ... . unknown evolutions take place incessantly among this crowd of actors of every kind, to furnish the stars who pass before our eyes one by one, as in a magic lantern.
-Hyppolite Taine, 1871

Lastly, one must wonder at how this is instantiated physically. The fact, and it does seem to be a fact, that consciousness involves wide broadcast of its narrow content, with far-flung systems both understanding what they are receiving and sending back ongoing commentary, requires a lingua franca of the mind. One aspect of this is clearly the gamma oscillation, which co-occurs with attentive consciousness and fits the model of something that unites broad but temporary coalitions of brain areas. But what is the code? What is the wave carrying? Is mere coordinated activation from one specialized area to another enough to form useful communication? That is hard to believe, but as yet, our tools are too narrow, or too crude in time or space resolution to figure out what this code might be.

Baars speculates that all goals and abstractions seem to have fleeting imagery in consciousness, again harkening back to the perceptual bias of consciousness. Our use of metaphor in language is naturally tied up with this phenomenon. Thus it may be imagery that is in some functional sense the lingua franca of the system, thought that still does not say how so many parts of the brain could recognize this language, especially the many humble parts that really do not seem to deal in imagery at all, like syntax checking, posture, "aha"- type solution verification, etc. Perhaps imagery forms a high-level language of aspirations, fears, planning, etc., without being needed for low level processes. This would tie in with the Jungian conception of the unconscious, with its core of archetypal images, our experience of them in dreams, and our need to develop and express them in art.

  • Cognitive nature and nurture in Scrabble.
  • But is the presidential campaign "news" enough to enter consciousness?
  • People do have their own facts.
  • On anger, and its cheap dismissal.
  • Myths of the mythically-minded.
  • A big key to poverty- violence, lawlessness, corruption.
  • Like in Qatar.
  • Best case scenario from the WSJ: wages are awful, peaked in 1972.
  • The labor market won't do it alone ... we need better policy towards redistribution.
  • Do we need "low cost, low wage" economies anywhere in the US? Where public assistance makes up the difference? No is the short answer.
  • IBM luvs Louisiana.
  • Reason prevails, barely, in Comcast merger.
  • Props to the Hubble.
  • Neonicotinoids even worse than thought.
  • Islam: "But it also brought together peoples who’d never had a common worldview, or shared humanity, before." And.. "And there can be no freedom if we are stuck believing in people, like Hirsi Ali and her ilk." ... who had to move to the US due to Islamist threats on her life. The author is scattershot in his apologetics, but well-intentioned.
  • Please don't use bar graphs for complex data.
  • A little mesmerizing cymbalon.
The WSJ agrees- wages have been stagnant for a very long time in the US, clearly not related to productivity growth.

No comments:

Post a Comment