Archive for the ‘computers’ Category

030708 – Computer consciousness

Tuesday, July 8th, 2003

030708 – Computer consciousness

I begin to understand the temptation to write papers that takes the form of diatribes against another academic’s position.  I just found the abstract of the paper written by someone named Maurizio Tirassa in 1994.  In the abstract he states, “I take it for granted that computational systems cannot be conscious.”

Oh dear.  I just read a 1995 response to Tirassa’s paper by someone in the department of philosophy and the department of computer science at Rensselaer Polytechnic Institute who says we must remain agnostic toward dualism.  Note to myself: stay away from this kind of argument; it will just make me crazy.

For the record: I take it for granted that computational systems can be conscious.  I do not believe in dualism.  There is no Cartesian observer.

I do like what Rick Grush has to say in his 2002 article “An introduction to the main principles of emulation: motor control, imagery, and perception”.  He posits the existence of internal models that can be disconnected from effectors and used as predictors.

Grush distinguishes between simulation and emulation.  He states that, “The difference is that emulation theory claims that mere operation of the motor centers is not enough, that to produce imagery they must be driving an emulator of the body (the musculoskeletal system and relevant sensors).”  He contrasts what he calls a “motor plan” with “motor imagery”.  “Motor imagery is a sequence of faux proprioception.  The only way to get … [motor imagery] is to run the motor plans through something that maps motor plans to proprioception and the two candidates here are a) the body (which yields real proprioception), and b) a body emulator (yielding faux proprioception).”

What’s nice about this kind of approach is that its construction is evolutionarily plausible.  That is, the internal model is used both for the production of actual behavior and for the production of predictions of behavior.  Evolution seems to like repurpose systems so long as the systems are reasonably modular.

Grush distinguishes between what he calls “modal” and “amodal” models.  “Modal” models are specific to a sensory modality (e.g., vision, audition, proprioception) and “amodal” models (although he writes as if there were only one) model the organism in the universe.  I do not much care for the terminology because I think it assumes facts not in evidence, to wit: that the principal distinguishing characteristic is the presence or absence of specificity to a sensory modality.  I also think it misleads in that it presumes (linguistically at least) to be an exhaustive categorization of model types.

That said, the most interesting thing in Grush for me is the observation that the same internal model can be used both to guide actual behavior and to provide imagery for “off-line” planning of behavior.  I had been thinking about the “on-line” and “off-line” uses of the language generation system.  When the system is “on-line”, physical speech is produced.  When the system is “off-line”, its outputs can be used to “talk to oneself” or to write.  Either way, it’s the same system.  It doesn’t make any sense for there to be more than one.

When a predator is crouched, waiting to spring as soon as the prey it has spotted comes into range, arguably it has determined how close the prey has to come for a pounce to be effective.  The action plan is primed, it’s a question of waiting for the triggering conditions (cognitively established by some internal mental model) to be satisfied.

It is at least plausible to suggest that if evolution developed modeling and used it to advantage in some circumstances; modeling will be used in other circumstances where it turns out to be beneficial.  I suppose this is a variant of Grush’s Kalman filters argument which says that Kalman filters turn out to be a good solution to a problem that organisms have and it would not be surprising to discover that evolution has hit upon a variant of Kalman filters to assist in dealing with that problem.

It’s clear (I hope, and if not, I’ll make an argument as to why) that a mobile organism gains something by having some kind of model (however rudimentary) of its external environment.  In “higher” organisms, that model extends beyond the range of that which is immediately accessible to its senses.  It’s handy to have a rough idea of what is behind one without having to look around to find out.  It’s also handy to know where one lives when one goes for a walk out of sight of one’s home.

Okay, so we need an organism-centric model of the universe, that is, one that references things outside the organism to the organism itself.  But more interestingly, does this model include a model of the organism itself?

Certain models cannot be inborn (or at least the details cannot be).  What starts to be fun is when the things modeled have a mind of their own (so to speak).  It’s not just useful to humans to be able to model animals and other humans (to varying degrees of specificity and with varying degrees of success).  It would seem to be useful to lots of animals to be able to model animals and other conspecifics.

What is the intersection of “modeling” with “learning” and “meaning”?  How does “learning” (a sort of mental sum of experience) interact with ongoing sensations?  “Learning” takes place with respect to sensible (that is capable of being sensed) events involving the organism, including things going on inside the organism that are sensible.  Without letting the concept get out of hand, I have said in other contexts that humans are voracious pattern-extractors.  “Pattern” in this context means a model of how things work.  That is, once a pattern is “identified” (established, learned), it tends to assert its conclusions.

This is not quite correct.  I seem to be using “pattern” in several different ways.  Let’s take it apart.  The kicker in just about every analysis of “self” and “consciousness” is the internal state of the organism.  Any analysis that fails to take into account the internal state of the organism at the time a stimulus is presented is not, in general, going to do well in predicting the organism’s response.  At the same time, I am perfectly willing to assert that the organism’s response—any organism’s response—is uniquely determined by the stimulus (broadly construed) and the organism’s state (also broadly construed).  Uniquely determined.  Goodbye free will.  [For the time being, I am going to leave it to philosophers to ponder the implications of this fact.  I am sorry to say that I don’t have a lot of faith that many of them will get them right, but some will.  This is just one of many red herrings that make it difficult to think about “self” and “consciousness”.]

Anyway, when I think about the process, I think of waves of data washing over and into the sensorium (a wonderfully content-free word).  In the sensorium are lots of brain elements (I’m not restricting this to neurons because there are at least ten times as many glia listening in and adding or subtracting their two cents) that have been immersed in this stream of information since they became active.  They have “seen” a lot of things.  There have been spatio-temporal-modal patterns in the stream, and post hoc ergo propter hoc many of these patterns have been “grooved”.  So, when data in the stream exhibit characteristics approximating some portion of a “grooved” pattern, other brain elements in the groove are activated to some extent, the extent depending on all sorts of things, like the “depth” of the “groove”, the “extent” of the match, etc.

In order to think about this more easily, remember that the sensorium does not work on just a single instantaneous set of data.  It takes some time for data to travel from neural element to neural element.  Data from “right now” enter the sensorium and begin their travel “right now”, hot on the heels of data from just before “right now”, and cool on the heels of data from a bit before “right now” and so on.  Who knows how long data that are already in the sensorium “right now” have been there.  [The question is, of course, rhetorical.  All the data that ever came into the sensorium are still there to the extent that they caused alterations in the characteristics of the neural elements there.  Presumably, they are not there in their original form, and more of some are there than of others.]  The point is that the sensorium “naturally” turns sequential data streams into simultaneous data snapshots.  In effect, the sensorium deals with pictures of history.

Now back to patterns.  A pattern may thus be static (as we commonly think of a pattern), and at the same time represent a temporal sequence.  In that sense, a pattern is a model of how things have happened in the past.  Now note that in this massively parallel sensorium, there is every reason to believe that at any instant many many patterns have been or are being activated to a greater or lesser extent and the superposition (I don’t know what else to call it) of these patterns gives rise to behavior in the following way.

Some patterns are effector patterns.  They are activated (“primed” is another term used here, meaning activated somewhat, but not enough to be “triggered”) by internal homeostatic requirements.  I’m not sure I am willing to state unequivocally that I believe all patterns have an effector component, but I’m at least willing to consider it.  Maybe not.  Maybe what I think is that data flows from sensors to effectors and the patterns I am referring to shape and redirect the data (which are ultimately brain element activity) into orders that are sent to effectors.

That’s existence.  That’s life.  I don’t know what in this process gives rise to a sense of self, but I think the description is fundamentally correct.  Maybe the next iteration through the process will provide some clues.  Or the next.  Or the next.

Hunger might act in the following way.  Brain elements determine biochemically and biorhythmically that it’s time to replenish the energy resources.  So data begin to flow associated with the need to replenish the energy resources.  That primes patterns associated with prior success replenishing the energy resources.  A little at first.  Maybe enough so if you see a meal you will eat it.  Not a lot can be hard-wired (built-in) in this process.  Maybe as a baby there’s a mechanism (a built-in pattern) that causes fretting in response to these data.  But basically, what are primed are patterns the organism has learned that ended up with food being consumed.  By adulthood, these patterns extend to patterns as complex as going to the store, buying food, preparing it, and finally consuming it.

This is not to say that the chain of determinism imposes rigid behaviors.  Indeed, what is triggered deterministically is a chain of opportunism.  Speaking of which, I have to go to the store to get fixings for dinner.  Bye.

030615 – (Heterophenomnological) Consciousness

Sunday, June 15th, 2003

030615 – (Heterophenomenological) Consciousness

It’s dreary and raining and that may make people a bit depressed.  That, in turn, may make it harder for people to find a satisfactory solution to their problems.   Realizing that, I feel a bit better.  It is sometimes useful to bring something into consciousness so one can look at it.

Although we may not have access to the underlying stimulus events (constellations) that directly determine our feelings, we can learn about ourselves just as we learn about other things and other people.  We can then shine the spotlight of consciousness on our inner state and try to glean what clues we can by carefully attention.

When I say we can learn about ourselves, that is to say that we can create an internal model of ourselves and use the predictions of that model to feed back into our decision-making process.  Such feedback has the result of modifying our behavior (as a feedback system does).

The interesting thing about the internal model is that it not only models external behavior, but also models internal state.

Interesting aside: consciousness can be switched on and off.  We can be awake or asleep.  We can be “unconscious”.

What are the design criteria for human beings such that consciousness is an appropriate engineering solution?

Goals:

  • Exist in world.
  • Basic provisioning.  Homeostasis. Obtain fuel.
  • Reproduction.  Mate.  Ensure survival of offspring.

Capabilities Required to Attain Goals:

  • Locomotion.
  • Navigation.
  • Manipulation.

Functions Required to Implement Required Capabilities

  • Identification of things relevant to implementation of goals.
  • Acquisition of skills relevant to implementation of goals (note that skills may be physical or cognitive).

Capabilities Required to Support Required Functions

  • Observation.  Primary exterosensors.
  • Memory.
  • Ability to manipulate things mentally (saves energy).  This includes the ability to manipulate the self mentally.
  • Ability to reduce power consumption during times when it is diseconomic to be active (e.g., sleep at night).

Damasio (1999, p.260) says:

“Homeostatic regulation, which includes emotion, requires periods of wakefulness (for energy gathering); periods of sleep (presumably for restoration of depleted chemicals necessary for neuronal activity); attention (for proper interaction with the environment); and consciousness (so that a high level of planning or responses concerned with the individual organism can eventually take place). The body-relatedness of all these functions and the anatomical intimacy of the nuclei subserving them are quite apparent.”

Well, I have an alternative theory of the utility of sleep, but Damasio’s is certainly plausible and has been around for a while in the form of the “cleanup” hypothesis: that there is something that is generated or exhausted over a period of wakefulness that needs to be cleaned up or replenished and sleep is when that gets done.  It raises the question of whether sleep is an essential part of consciousness and self-awareness or is it a consequence of the physical characteristics of the equipment in which consciousness and self-awareness are implemented.

One talks to oneself by inhibiting (or is it failing to activate) the effectors that would turn ready-to-speak utterances into actual utterances.  In talking to oneself, ready-to-speak utterances are fed back into the speech understanding system.  This is only a slight variation of the process of careful (e.g., public speaking) speech or the process used in writing.  In writing, the speech utterance effectors are not activated and the ready-to-speak stuff is fed into the writing system.

But does it always pass through the speech understanding system?  IOW is it possible to speak without knowing what you are going to say?  Possibly.  Specific evidence: on occasion one thinks one has said one thing and has in fact said something else.  Sometimes one catches it oneself.  Sometimes somebody says you said X, don’t you mean Y and you say oh, did I say X, I meant Y.

Nonetheless, I don’t think it’s necessary to talk to oneself to be conscious.  There are times when the internal voice is silent.  OTOH language is the primary i/o system for humans.  One might argue that language enhances consciousness.  As an aside, people who are deaf probably have an internal “voice” that “talks” to them.  Does talking to yourself help you to work things out?  Does the “voice” “speak” in unexpressed signs?  When a deaf person does something dumb, does he/she sign “dumb” to him/herself?

Is there something in the way pattern matching takes place that is critical to the emergence of consciousness?  The more I think about consciousness, the less certain I am that I know what I am talking about.  I don’t think that is bad.  It means that I am recognizing facets of the concept that I had not recognized before.  That seems to be what happened to Dennett and to Damasio.  They each had to invent terminology to express differences they had discovered.

Ultimately, we need an operational definition of whatever it is that I’m talking about here.  That is the case because at the level I am trying to construct a theory, there is no such thing as consciousness.  If there were, we’d just be back in the Cartesian theatre.  Is the question: How does it happen that human beings behave as if they have a sense of self?  I’m arriving at Dennett’s heterophenomenology.  (1991, p.96) “You are not authoritative about what is happening in you, but only about what seems to be happening in you….”

To approach the question of how heterophenomenological consciousness emerges, it is essential to think “massively parallel”.  What is the calculus of the brain.  A + B = ?  A & B ?  A | B ?  A followed by B?  Thinking massive parallelism, the answer could be: All of the above.  It must be the case that serial inputs are cumulatively deserialized.  There’s an ongoing accumulation of history at successively higher levels of abstraction (well, that’s one story, or one way of putting it).  Understanding language seems to work by a process of successive refinement.  Instinctively it’s like A & B in a Venn diagram, but that feels too sharp.

The system doesn’t take “red cow” to mean the intersection of red things with cow things.  The modifier adds specificity to an otherwise unspecified (default) attribute.  So the combination of activation of “red” and the activation of “cow” in “red cow”  leads to a new constellation of activation which is itself available for further modification (generalization or restriction or whatever).  This probably goes on all the time in non-linguistic processing as well.  A pattern that is activated at one point gets modified (refined) as additional information becomes available.  Sounds like a description of the process of perception.

Massively parallel, always evolving.  It doesn’t help to start an analysis when the organism wakes up, because the wake-up state is derived from (is an evolution of) the organism’s previous life.  Learning seems to be closely tied to consciousness.  Is it the case that the “degree” of consciousness of an organism is a function of the “amount of learning” previously accumulated by the organism?

We know how to design an entity that responds to its environment.  An example is called a PC (Personal Computer).

There’s learning (accumulation of information) and there’s self-programming (modification of processing algorithms).  Are these distinguishable in “higher” biological entities?  Does learning in say mammals, necessarily involve self-programming?  Is a distinction between learning and self-programming just a conceptual convenience for dealing with Von Neuman computers?

There’s “association” and “analysis”

There is learning and there’s self programming.  Lots of things happen automatically.  Association and analysis.  Segmentation is important: chunking is a common mechanism.  Chunking is a way of parallelizing the processing of serial inputs.  Outputs of parallel processors may move along as chunks.  Given that there’s no Cartesian observer, every input is being processed for its output consequences.  And every input is being shadow processed to model its consequences and the model consequences are fed back or fed along.  Associations are also fed back or fed along.  In effect there is an ongoing assessment of what Don Norman called “affordances”, e.g., what can be done in the current context?  The model projects alternate futures.  The alternate futures coexist with the current inputs.  The alternate futures are tagged with valences.  Are these Dennett’s “multiple drafts”?  I still don’t like his terminology.  Are the alternate futures available to consciousness?  Clearly sometimes.  What does that mean?  It is certainly possible for a system to do load balancing and prioritization.  If there is additional processing power available or if processing power can be reassigned to a particular problem.  Somehow, I don’t think it works that way.  Maybe some analyses are dropped or, more likely, details are dropped as a large freight train comes roaring through.  Tracking details isn’t much of a problem because of the constant stream of new inputs coming in.  Lost details are indeed lost, but most of the time, so what?

Language output requires serialization as do certain motor skills.  The trick is to string together a series of sayings that are themselves composed of ordered (or at least coordinated) series of sayings.  Coordination is a generalization of serialization because it entails multiple parallel processors.  Certainly, serial behavior is a challenge for a parallel organism, but so are all types of coordinated behavior.  Actions can be overlaid (to a certain extent, for example: walk and chew gum; ride a horse and shoot; drive and talk; etc.) Week can program computers in a way that evolution cannot hardwire organisms.  On the other hand, evolution has made the human organism programmable (and even self programmable).  Not only that, we are programmable in languages that we learn and we are programmable in perceptual motor skills that we practice and learn.  Is there some (any) reason to think that language is not a perceptual motor skill (possibly writ large)?

Suppose we believe that learning involves modifications of synaptic behavior.  What do we make of the dozen or so neurotransmitters?  Is there a hormonal biasing system that influences which transmitters are most active?  Is that what changes mode beyond just neural activity in homeostatic systems?  Otherwise, does the nature of neuronal responses change depending on the transmitter mix, and can information about that mix be communicated across the synaptic gap?  These are really not questions that need to be answered in order to create a model of consciousness (even though they are interesting questions) but they do serve as a reminder that the system on which consciousness is based is only weakly understood and probably much more complicated even than we think (and we think it’s pretty complicated).

I seem to have an image — well, a paradigm– in mind involving constraints and feature slots, but I don’t quite see how to describe it as an algorithm.  This is a pipelined architecture, but with literally millions of pipelines that interact locally and globally.  The answer to “what’s there?” or “what’s happening?” is not a list, but a coruscating array of facets.  It is not necessary to extract “the meaning” or even “a meaning” to appreciate what is going on.  A lot of the time, nothing is “going on”; things are what they are and are not changing rapidly.

Awareness and attention seem to be part of consciousness.  One can be aware of something and not pay attention to it.  Attention seems central — the ability to select or emphasize certain input (and/or output) streams.  What is “now”?  It seems possible to recirculate the current state of things.  Or just let them pass by.  Problem: possible how?  What “lets” things pass by?  The Cartesian observer is so seductive.  We think we exist and watch our own private movie, but it cannot happen that way.  What is it that creates the impression of “me”?  Yes, it’s all stimulus-response, and but the hyphen is where all the state information is stored.  What might give the impression of “me”?  I keep thinking it has something to do with the Watslawyck et al. [(1969(?) The Pragmatics of Human Communication] idea of multiple models.  This is the way I see you. This is the way I see you seeing me.  This is the way I see you seeing me seeing you.  And then nothing.  Embedding works easily once: “The girl the squirrel bit cried.”  But “The girl the squirrel the boy saw bit cried” is pathological.

As a practical matter, if we want to create an artificial mind, we probably want to have some sort of analog to the homunculus map in order to avoid the problem of having to infer absolutely everything from experience.  That is, being able to refer stimuli to an organism centric and gravity aware coordinate system, goes a long way towards establishing a lot of basic concepts: up-down, above-below, top-bottom, towards-away, left-right, front-back.  Add an organism/world boundary and you get inside-outside.  I see that towards-away actually cheats in that it implies motion.  Not a problem because motion is change of position over time and with multiple temporal snapshots (naturally produced as responses to stimuli propagate through neural fields), motion can be pretty easily identified.  So that gets things like fast-slow, into-out of, before-after.  We can even get to “around” once the organism has a finite extent to get around.

What would we expect of an artificial mind?  We would like its heterophenomenology to be recognizably human.  What does that mean?  Consider the Turing test.  Much is made of the fact that certain programs have fooled human examiners over some period of time.  Is it then the case that the Turing test is somehow inadequate in principle?  Probably not.  At least I’m not convinced yet that it’s not adequate.  I think the problem may be that we are in the process of learning what aspects of human behavior can be (relatively) easily simulated.  People have believed that it is easy to detect machines by attempting to engage them in conversation about abstract things.  But it seems that things like learning and visualization are essential to the human mind.  Has anyone tried things like: imagine a capital a.  Now in your imagination remove the horizontal stroke and turn the resulting shape upside down.  What letter does it look like?

Learning still remains intransigent problem.  We don’t know how it takes place.  Recall is equally dicey.  We really don’t seem to know any more about learning skills that we do about learning information.  We’re not even very clear about memorizing nonsense syllables for all the thousands of psychological experiments involving them.  Is learning essential to mind?  Well, maybe not.  Henry can’t learn any conscious facts, and he clearly has a mind (no one I know of has suggested otherwise).  Okay, so there could be a steady state of learning.  The ability to learn facts of the kind Henry Molaison couldn’t learn isn’t necessary for a mind to exist.  We don’t know whether the capacity for perceptual motor learning is necessary for a mind to exist.  Does a baby have a mind?  Is this a sensical question?  If not, when does it get one?  If so when did it develop?  How?

It begins to feel like the problem it is to figure out what the question should be.  “Consciousness” seems not to be enough.  “Mind” seems ill-defined.  “Self awareness” has some appeal, though I struggle to pin down what it denotes: clearly “awareness” of one’s “self” but then what’s a “self” and what does “awareness” mean?  Surely self-awareness means 1)  there is something that is “aware” (whatever “aware” means”), 2) that thing has a “self” (whatever “self” means), and that thing can be and is “aware” of its “self”.  A person could go crazy.

Is this a linguistic question — or rather a meta linguistic question: what does “I” mean?  What is “me”?  In languages that distinguish a “first person” it would appear that these questions can be asked.  And by the way, what difference does it make if the language doesn’t have appropriate pronouns and resorts to things like “this miserable wretch begs forgiveness”?  Who’s doing the begging?  No.  That’s not the question.  What’s doing the begging. heterophenomenologically, it doesn’t matter if I say it referring to myself or referring to another person.  Except that it has for me a special meaning when it refers to “my self” and that special meeting is appreciated, that is, understood, by others hearing “me” say it.

I don’t know anything about children learning what “I” and “me” refer to.  I remember reading something about an (autistic I think) child who referred to himself in the third person, for example: “he’s thirsty”

Consciousness seems to require inputs.  That is, one cannot just “be conscious” rather one must “be conscious of” things.  That sounds a bit forced, but not if it is precisely the inputs that give rise to consciousness.  No inputs, no consciousness.  Something in the processing of inputs gives rise to the heterophenomenological feeling of being conscious.

Does self-awareness have to do with internal models?  Does the organism have an internal model of the universe in which exists?  Does that model include among the entities modeled, the organism itself?  And is it necessary that the model of the organism include a model of the internal model of the universe and its component model of the organism?  It may not be an infinite series.  In fact it can’t be.  The brain (or any physical computer) has finite capacity.

But doesn’t a model imply someone or something that makes use of the model?  We keep coming back to metaphors that encourage the Cartesian fallacy.

Let’s think computer systems design.  Hell, let’s go all the way, let’s think robot design.  The robot exists in a universe.  The robot’s program receives inputs from its exteroceptors about the state of the universe and its inputs, suitably processed, are abstracted into a set of signals representing the inputs — in fact representing the inputs over a period of time.  The same thing is happening with samples representing the interoceptors monitoring the robot’s internal mechanical state: position of limbs, orientation, inertial state (falling, turning, whatever), battery/power level, structural integrity.

On the goals side, based on the internal state, the robot has certain not action triggers, but propensity triggers.  For example: When the internal power level or the internal power reserves fall below a particular threshold, the goal of increasing power reserves is given increased priority.  But we do not assume that the robot has a program that specifies exactly what to do in this state.  The state should trigger increased salience (whatever that means) and attention to things in the current environment that are (or have been in the learned past) associated with successful replenishing of power reserves.

At all times, the important question is: “what do I do now?”  The answer to this question helps determine what needs “attention” and what doesn’t need “attention”.  As a first approximation, things not “associated” with current priority goals are not attended to.  Well, it’s not quite a simple as that.  Things that don’t need attention, even though associated with an ongoing task (like walking or driving) don’t get attention processing.  Attention is the assignment of additional processing power to something.  Additional processing power can boost the signal level to above the consciousness threshold and can reduce the decay rate of attended signals.

No one has succeeded in explaining why heterophenomenological evidence indicates that people feel “conscious” sometimes and when they don’t feel “conscious” they don’t “feel” anything and they shift back and forth.  It’s a processing thing.  If I close my eyes and lie quietly, I’m not asleep.  I still hear things.  I can still think about things.  So consciousness can be turned on and off in the normal organism.  What’s going on here?  Understanding the neural connections won’t do it.  We would need to know what the connections “do”; how they “work”.

Sleep.  In effect, the organism can “power down” into a standby state (for whatever evolutionary reason).  If the threshold for external events is set high, most of them won’t make an impact (have an effect).  It’s like a stabilized image on the retina.  It disappears — well, it fades.  No change equals no signal.  If there’s nothing to react to, the organism, well, doesn’t react.

If outside inputs are suppressed, where do daydream inputs come from?  Not a critical question, but an interesting one.  Somebody pointed out that so-called “dream paralysis” is a good thing in that it keeps us from harming ourselves or others in reaction to dream threats or situations.