System
1
|
System
2
|
Unconscious
reasoning
|
Conscious
reasoning
|
Judgments
based on intuition
|
Judgments
based on critical examination
|
Processes
information quickly
|
Processes
information slowly
|
Hypothetical
reasoning
|
Logical
reasoning
|
Large
capacity
|
Small
capacity
|
Prominent
in animals and humans
|
Prominent
only in humans
|
Unrelated
to working memory
|
Related
to working memory
|
Operates
effortlessly and automatically
|
Operates
with effort and control
|
Unintentional
thinking
|
Intentional
thinking
|
Influenced
by experiences, emotions, and memories
|
Influenced
by facts, logic, and evidence
|
Can
be overridden by System 2
|
Used
when System 1 fails to form a logical/acceptable conclusion
|
Prominent
since human origins
|
Developed
over time
|
Includes recognition, perception,
orientation, etc.
|
Includes
rule following, comparisons, weighing of options, etc.
|
Friday, June 19, 2015
Why Would an AI System Need Phenomenal Consciousness?
In my last post on Jesse Prinz, we learned about the
distinction between immediate, phenomenal awareness in consciousness in
contrast to our more deliberative consciousness that operates with the contents
of short term and longer term memory. From
moment to moment in our experience, there are mental contents in our
awareness. Not all of those contents
make it into the global workspace and become available to reflective,
deliberative thought, memory, or other cognitive functions. That is, there are contents in phenomenal
awareness that are experienced, and then they are just lost. They cease to be anything to you, or part of
the continuous narrative of experience that you reconstruct in later moments
because they never make it to the neural processes that would capture them and
make them available to you at later times.
We also know that these contents of phenomenal consciousness
are also most closely associated with the qualitative feels from our sensory
periphery. That is, phenomenal awareness
is filled with the smells, tastes, colors, feels, and sounds of our sensory
inputs. Phenomenal awareness is filled
with what some philosophers call qualia.
Let me add to this account and see what progress we can make
on the question of building a conscious AI system.
Daniel Kahneman and Amos Tversky got the Nobel Prize for their
work uncovering what they call Dual Process Theory in the human mind. We possess a set of quick, sloppy cognitive
functions called System 1, and a more careful, slower more deliberative set of
functions called System 2.
In short, System 1 makes gains in speed for what it
sacrifices in accuracy, and System 2 gives up speed for a reduction in
errors.
The evolutionary influences that led to this bifurcation are
fairly widely agreed upon. System 1 gets
us out of difficulties when action has to be taken immediately so we don’t get
crushed by a falling boulder, fall from the edge of a precipice, eaten by a
charging predator, or smacked in the head by a flying object. But when time and circumstance allows for
rational deliberation, we can think things through, make longer term plans,
strategize, problem solve, and so on.
An AI system, depending on its purpose, need not be
similarly constrained. An AI system may
not need to have both sets of functions.
And the medium of construction of an AI system may not require tradeoffs
to such an extent. Transmission time for
conduction across neural cells is about 150 meters per second. By the time the information about the
baseball that is flying at you gets through your optic nerve, through the V1
visual cortex, and up to the pre-frontal lobe for serious contemplation, the
ball has already hit you in the head. Transmission
time for silicon circuitry is effectively the speed of light. We may not have to give up accuracy for speed
to such an extent. Evolution favored
false positives over false negatives in the construction of many systems. It’s better to mistake a boulder for a bear,
as they say, than a bear for a boulder.
A better safe than sorry strategy is more favorable to your contribution
to the gene pool for the species in many cases.
We need not give up accuracy for speed with AI systems, and we need not construct
them to make the systematic errors we do.
The neural processes that are monitoring the multitude of
inputs from my sensory periphery are hidden from the view of my conscious
awareness. The motor neurons that fire,
the sodium ions that traverse the cell membranes, the neurotransmitters that
cross the synaptic gaps when I move my arm are not events that I can see, or
detect in any fashion as neural events.
I experience them as the sensation
of my arm moving. From my perspective,
moving my arm feels one way. But the
neural chemical events that are physically responsible are not available to me
as neural chemical events. A particular
amalgam of neural-chemical events from my perspective tastes like sweetness, or
hurts like a pin prick, or looks like magenta.
It would appear that evolution stumbled upon this sort of condensed, shorthand
monitoring system to make fast work of categorizing certain classes of
phenomenal experience for quick reference and response. If the physical system in humans is capable
of producing qualia that are experiencable from the subject’s point of view (It’s
important to note that whether qualia are even real things is a hotly debated
question
then presumably a physical AI system could be built that
generates them too. Not even the
fiercest epiphenomenalist, or modern property dualist denies mind/brain
dependence. But a legitimate question
is, do we want or need to build an AI system with them? What would be the purpose, aside from
intellectual curiosity, of building qualia into an AI system? If AI systems can be better designed than the
systems that evolution built, and if AI systems need not be constrained by the
tradeoffs, processing speed limitations, or other compromises that led to the
particular character of human consciousness, then why put them in there?
Monday, June 8, 2015
Artificial Intelligence and Conscious Attention--Jesse Prinz's AIR theory of Consciousness
Jesse Prinz has argued for that consciousness is best
understood as mid-level attention.
Consciousness, Prinz argues, is best understood as mid-level attention.
Low level representers in the brain are neurons that perform
simple discrimination tasks such as edge or color detection. They are activated early on in the process of
stimuli from the sensory periphery.
(a poorly taken, copyright violating picture from Michael Gazzaniga's Cognitive Neuroscience textbook.)
The activation of a horizontal edge detector, by itself, doesn’t
constitute organized awareness of the object, or even the edge.
Neuron complexes in human brains are also capable of very
high level, abstract representation. In
a famous study, “Invariant visual representation by single neurons in the humanbrain,” Quiroga, Reddy, Kreiman, Kock, and Fried, they discovered the so-called
Halle Berry neuron with some sensitive detectors inserted into different
regions of the brains of some test subjects.
This neuron’s activity was correlated with activation patterns for a
wide range of Halle Berry images.
What’s really interesting here is that this neuron became
active with quite varied photos and line drawings of Halle Berry, from
different angles, in different lighting, in a Cat Woman costume, and even,
remarkably, in response to the text “Halle Berry.” That
is, this neuron plays a role in the firing patterns for a highly abstract
concept of Halle Berry.
Prinz is interested in consciousness conceived as mid-level
representational attention that lies somewhere between these two extremes. “Consciousness is intermediate level
representation. Consciousness represents
whole objects, rich with surface details, located in depth, and presented from
a particular point of view.” During the
real time moments of phenomenal awareness, various representations come to take
up our attention in the visual field. Prinz
argues that, “Consciousness arises when we attend, and attention makes
information available to working memory. Consciousness does not depend on
storage in working memory, and, indeed, the states we are conscious of cannot
be adequately stored.”
When you look at a Necker cure, you can first be aware of
the lower left square as the leading face.
Then you can switch your
awareness to seeing the upper right square as the leading face. So you attention has shifted from one
representation to another.
That is the level at which Prinz is located the mercurial
notion of consciousness, and trying to develop a predictive theory based on the
empirical evidence. And Prinz goes to
some lengths to argue that consciousness in this sense is not what’s moved into
working memory, it’s not the contents necessarily that have become available to
the global workspace such as when they are stored for later access. These contents may or may not be accessible
later for recall. But at the moment they
are the contents of mind, part of the flow and movement of attention.
Here I’m not interested in the question of whether Prinz
provides us with the best theory of human consciousness, but I am interested in
what light his view can shed on the AI project.
I’m particularly interesting in Prinz here because it’s arguable that we
already have artificial systems that are capable, more or less, of doing the
low level and the high level representations described above. Edge detection, color detection, simple
feature detection in a “visual” field are relatively simple tasks for
machines. And processing at a high level
of conceptual abstraction has been accomplished in some cases. IBM’s Jeopardy playing system Watson
successfully answered clues such as, “To push one of these paper products is to
stretch established limits,” answer:
envelope. “Tickets aren’t needed
for this “event,” a black hole’s boundary from which matter can’t escape,”
answer: event horizon. “A thief, or the bent part of an arm,”
answer: crook. Even Google search algorithms do a remarkable
job of divining the intentions behind our searches, excluding thousands of
possible interpretations of our search strings that would be accurate to the
letters, but have nothing to do with what we are interested in.
So think about this. Simple
feature detection isn’t a problem. And we
are on our way to some different kinds of high level conceptual abstraction. Long term storage for further analysis also
isn’t a problem for machines. That’s one
of the things that machines already do better than us. But what Prinz has put his finger on is the
ephemeral movement of attention from moment to moment in awareness. During the course of writing this piece, I’ve
been multi-tasking, which I shouldn’t have.
I’ve been answering emails, sorting out calendar scheduling, making
plans to get kids from school, and so on.
And now I’m trying to recall what all I’ve been thinking about over the
last hour. Lots of it is available to me
to now. But there were, no doubt, a lot
of mental contents, a lot of random thoughts, that came and went without leaving much of a trace. I say, “no doubt,” because if they didn’t
go into memory, if they didn’t become targets of substantial focus, then even
though I had them then I won’t be able to bring them back now. And I say, “no doubt,” because when I am
attending to my conscious experience now, from moment to moment, and I’m really
concentrating on just this point, I realize that I’m aware of the feeling of
the clicking keyboard keys under my fingers, then I notice the music I’ve got
playing in the background, then I glance at my email tab, and so on. That is, my moments are filled with
miscellaneous contents. I’ve mode those
particular ones into a bigger deal in my brain because I just wrote about them
in a blog post. But lots of our
conscious lives, maybe most, those
contents come and go, like hummingbirds flitting in and out of the scene. And once they are gone, they are gone.
Now we can ask the questions: Do we want an AI to have that? Do we need an AI to have that? Would it serve any purpose?
Bottom Up Attention
That capacity in us served an evolutionary purpose. At any given time, there are countless zombie
agents, low level neuronal complexes, that are doing discriminatory work on
information from the sensory periphery and from other neural structures. The outputs of those discriminators may or
may not end up being the subject of conscious attention. In many cases, those contents become the
focus of attention from the bottom up.
So lower level system deems the content important enough to call your
attention to it, as it were. So when
your car doesn’t sound right when it’s starting up, or when a friend’s face
reveals that he’s emotionally troubled it jumps to our attention. Your brain is adept at scanning your
environment for causes for alarm and then thrusting them into the spotlight of
attention for action.
Top Down Attention
But we are able to
direct the spotlight as well. We can
focus our attention, sustain mental awareness on a task or some phenomena, to
suss out details, make extended plans, anticipate problems, and model out
possible future scenarios and so on. You can go to work finding Waldo:
gives a more detailed account of the evolutionary functions
of consciousness.
Given what we saw above about the difference in Prinz
between conscious attention and short and long term memory, we can see conscious
attention can be seen as a sort of screening process. A lot of ordinary phenomenal consciousness is
the result of low level monitoring systems crossing a minimal threshold of
concern. This, right here is important enough to take a closer look at.
Part of the reason that the window of our conscious
attention is temporally brief and spatially finite is that resources are
limited. Resources were limited when
evolution was building the system. It’s
kludged up from parts and systems that we re-adapted from other functions. There was no long view, or deliberate
planning on the process. Just the slow
pruning of mutation branches on the evolutionary tree. And it modifies the gene pool according to
the rates at which organisms, equipped as they are, manage to meet survival
challenges.
Kludge: Consider to
different ways to work on a car. You
could take it apart, analyze the systems, plan, make modifications, build new
parts, and then reassemble the car. While
the car is taken apart and while you are building new parts, it doesn’t
function. It’s just a pile of parts on
the shop floor.
But imagine that the car is in a race, and there’s a bin of
simple replacement parts on board, some only slightly different than the ones
currently in the car, and modifications to the car must be made while the car
is racing around the track with the other cars.
The car has to keep going at all times, or it’s out of the race for
good. Furthermore, no one gets to choose
which parts get pulled out of the bin and put into the car. That’s a kludge.
Resources are also limited because evolution built a system
that does triage. The cognitive systems
just have to be good enough to keep the organism alive long enough to bear its
young, and possibly make a positive contribution toward their survival. The monitoring systems that are keeping track
of its environment just need to catch the deadly threats, and catch them only
far enough in advance to save its ass.
It’s not allowed the luxury of long term, substantial contemplation of
one topic or many to the exclusion of all others. Furthermore, calories are limited. Only so many can be scrounged up during the
course of the day. So only so many can
be dedicated to the relatively costly expenditure of billions of active neural
cells.
The evolutionary functions of consciousness for us give us
some insight into whether it might be useful or dangerous in an AI. First, AIs can be better planned, better
designed than evolution’s brains. An AI
need not be confined to triage functions, although we can imagine modeling
human brains to some extent and using them to keep watch on bigger, more
complex systems where more can go wrong than human operators could keep track
of. An AI might run an airport better,
or a subway system, or a power grid, where hundreds or thousands or more
subsystems need to be monitored for problems.
The success of self-driving Google cars already suggest what could be
possible with wide spread implementation on the street and highway
systems. So bottom up indicated
monitoring could clearly be useful in an AI system.
Top down, executive directed control of the spotlight of
attention, and the deliberate investment of processing resources into a
representational complex with longer term planning and goal directed activity
driving the attention could clearly be useful for an AI system too. “Hal, we want you to find a cure for
cancer. Here are several hundred
thousand journal articles.”
The looming question, of course, is what about
the dangers of building mid-level attention into an AI? Bostrom’s Superintelligence has been looming
in the back of my mind through this whole post.
It’s a big topic. I’ll save that
for a future post, or 3 or 10 or 25.
Friday, June 5, 2015
Evil Demonology and Artificial Intelligence
Eliminativists eliminate.
In history, the concepts and theories that we build about the world form
a scaffold for our inquiries. As the
investigation into some phenomena proceeds, we often find that the terms, the
concepts, the equations, or even whole theories have gotten far enough out of
synch with our observations to require consignment to the dustbin of
history. Demonology was once an active
field of inquiry in our attempts to understand disease. The humour theory of disease was another
attempt to understand what was happening to Plague victims in the 14th
century. Medieval healers were trying to
explain a bacterial infection with yersenia pestis 600 years before the
microbe, the real cause, had even been identified. Explanations of the disease symptoms in terms
of imbalances of yellow bile, blood, black bile, and phlegm produced worthless
and ineffective treatments. So we
eliminate humour theory of disease, demonology, the elan vital theory of life, God, Creationism, and so on as science
marches on.
Eliminativism has taken on the status of a dirty word among
some philosophers, a bit like people who are quick to insist that they believe
women are equal and all that, but they aren’t “feminists” because that’s too
harsh or strident.
But we can and should take an important lesson from EM, even
if we don’t want to be card carrying members.
Theory changes can be ontologically conservative or ontologically
radical depending on the extent to which they preserve the entities, concepts,
or theoretical structures of the old account.
That is, we can be conservative; we can hold onto the old
terms, the old framework, the old theory, and revise the details in light of
the new things we learn.
Here’s how the Churchlands explains the process.
We begin our inquiry into what appears to be several related
phenomena, calling it “fire.”
Ultimately, when a robust scientific theory about the nature of the
phenomena is in place, we learn that some of the things, like fireflies and
comets, that we originally thought were related to burning wood, are actually
fundamentally different. And we learn
that “fire” itself is not at all what we originally thought it was. We have to start with some sort of conceptual
scaffolding, but we rebuild it along the way, jettison some parts, and
radically overhaul parts of it.
My point then, is that we must take a vital lesson from the
eliminativists about the AI project. At
the outset of our inquiry, it seems like terms such as “thinking,”
“consciousness,” “self-awareness,” “thoughts,” “belief,” and so on identify
real phenomena in the world. These terms
seem to break nature at the joints, as they say. But we should be prepared, we should be eager
even, to scrap the term, overhaul the definition, toss the theory, or otherwise
regroup in the light of important new information. We are rapidly moving into the golden age of
brain science, cognitive science, and artificial intelligence research. We should expect that to produce upheaval in
the story we’ve been telling for the last several hundred years of thinking
about thinking. Let’s get ahead of the
curve on that.
With that in mind, I’ll use these terms in what follows with
a great big asterisk: * this is a sloppy term that is poorly defined
and quite possibly misleading, but we’ve gotta start somewhere.
Folk psychological terms that I’m prepared to kick to the
curb: belief, idea, concept, mind,
consciousness, thought, will, desire, freedom, and so on. That is, as we go about theorizing about and trying
to build an AI, and someone raises a concern of the form, “But what about
X? Can it do X? Oh, robots will never be able to do X….” I am going to treat it as an open question
whether X is even a real thing that needs to be taken into account.
Imagine we time traveled a medieval healer from 14th
century France to the Harvard school of medicine. We show him around, we show him all the
modern fancy tools we have for curing disease, we show him all the different
departments where we address different kinds of disease, and we show him lots
of cured patients. He’s suitably
impressed and takes it all in. But then
he says, “This is all very impressive and I am amazed by the sights and things
going on here. But you call yourselves
healers? What you are doing here is interesting, but where are your demonologists?
In 700 years, have you not made any progress at all addressing the real
source of human suffering which is demon possession? Where is your department of demonology? Those are the modern experts who I’d really like
to talk to.”
We don’t want to end
up being that guy.
We should expect, given the lessons of history, that some of
the folk psychological terms that we’ve been using are going to turn out to not
identify anything real, some of them will turn out to not be what we thought
they’d be at all, and we’re going to end up filling in the details about minds
in ways that we didn’t imagine at the outset.
Let’s not be curmudgeonly theorists, digging in our heels and refusing
to innovate our conceptual structures. But
on the other hand, let’s also not be too ready to jump onto to every new
theoretical bandwagon that comes along.
Wednesday, June 3, 2015
Turing and Machine Minds
In 1950, mathematician Alan M. Turing proposed a test for
machine consciousness. If a human
interrogator could not distinguish between the responses of a real human being
and a machine built to hold conversations, then we would have no reason, other
than prejudice, for not admitting that the machine was in fact conscious and
thinking. http://orium.pw/paper/turingai.pdf
I won’t debate the merits or sufficiency of the Turing Test
here. But I will use it to introduce
some clarifications into the AI discussion.
Turing thought that if a machine could do some of the things we do, like
have conversations, that would be an adequate indicator of the presence of a
mind. But we need to get clear on the
goal in building an artificial intelligence.
Human minds are what we have to work with as a model, but not everything
about them is worth replicating or modeling.
For example, we are highly prone to confirmation bias, we have loss
aversion, and we can only hold about 7-10 digits (a phone number) in short term
working memory. Being able to
participate in a conversation would be an impressive feat, give the subtleties
and vagaries of natural language. But it’s
a rather organic, idiosyncratic, and anthropocentric task. And we might invest substantial effort and
resources into replicating contingent, philosophically pointless attributes of
the human mind instead of fully exploring some of the possibilities of a new,
artificial mind of a different sort. Japanese
researchers, for example, have invested enormous amounts of money and effort
into replicating subtle human facial expressions on robots. Interesting for parties maybe, but we
shouldn’t get lost up side tributaries as we move up the river to the source of
mind.
One of the standard objections to Turing’s thesis is
this: But a Turing machine/Artificial
intelligence system can’t/doesn’t have _______________, where we insert one of
the following:
a. make mistakes. (Trivial to build in, but inessential and
unimportant.)
b. have emotions (Inessential,
and philosophically and practically uninteresting.)
c. fall in love
(Yawn.)
d. care/want (Maybe
this is important. Perhaps having goals
is essential/interesting. It remains to
be seen if this cannot be built into such a system. More on goals later.)
e. freedom (Depends
on what you mean by freedom. Short
answer: there don’t appear to be any
substantial reasons a priori why an artificial system cannot be built that has “freedom”
in the sense that’s meaningful and interesting in humans. See Hume on freewill. http://www.iep.utm.edu/freewill/
f. produce original ideas.
( What does original mean? A new
synthesis of old concepts, contents, forms, styles? That’s easy.
Watson, IBM’s jeopardy dominating system is being used to make new
recipes, and lots of innovate, original solutions to problems.)
g. creativity (What
does this mean? produce original new
ideas? See above. Complex systems, such as Watson, have
emergent properties. They are able to
lots of new things that their creators/programmers did not foresee.)
h. do anything that it’s not programmed to do. (“Programmed” is outdated talk here. More later on connectionist systems. Can sophisticated AI programs do
unpredictable things now? Yes. Can they now do things that the designers
didn’t anticipate? Yes. Will they do more in the future as the
technology advances? Yes.)
i. feel pleasure or pain
(I’ll concede, for the moment, that building an artificial system that
has this capacity is a ways off technologically. And I’ll concede that it’s a very interesting
philosophical question. I won’t concede
that building this capacity in is impossible in principle. And we must also ask why is it important? Why do we need an AI to have this capacity?)
j. intelligence
k. consciousness
l. understand
m. qualitative or phenomenal states (See Tononi, Koch, and McDermott)
I think objections a-h miss the point entirely. I take it that for a-h, the denial that a
system can be built with the attribute is either simply false, will be proven
false, or the attribute isn’t interesting or important enough to warrant the
attention. i through m, however, are
interesting. And there’s a lot more to
be said about them. For each, we will
need more than a simple denial without argument. We need an argument with substantial
principled, non-prejudicial reasons for thinking that these capacities are beyond
the reach of technology. (In general,
history should have taught us to be very skeptical of grumbling naysaying the
form of “This new-fangled technology will never be able to X.” But one of the things I’m going to be doing
in the blog in the future is caching out in much more detail what the terms
intelligence, consciousness, understand, and phenomenal states should be taken
to mean in the AI project context, and working out the details of what we might
be able to build.
But more importantly, I think the list of typical objections
to Turing’s thesis raises this question:
just what do we want one of these things to do? Maybe someone wants to simulate a human mind
to a high degree of precision. I can
imagine a number of interesting reasons to do that. Maybe we want to model up the human neural
system to understand how it works. Maybe
we want to ultimately be able to replicate or even transfer a human
consciousness into a medium that doesn’t have such a short expiration
date. Maybe we want to build helper
robots that are very much like us and that understand us well. Maybe a very close approximation of a human
mind, with some suitable tweaks, could serve as a good, tireless, optimally
effective therapist. (See the early AI
experiments with a therapy program.)
But the human brain is a kludge. It’s a messy, organic amalgam of a lot of
different models and functions that evolved under one set of circumstances that
later got repurposed for doing other things.
The path that led from point A to point B, where B is the set of
cognitive capacities we have is convoluted, circuitous, full of fits and
starts, peppered with false starts, tradeoffs, unintended consequences, byproducts,
and the like.
A partial list of endemic
cognitive fuckups in humans from Kahneman and Tversky (and me): Confirmation Bias, Sunk Cost Fallacy, Asch
Effect, Availability Heuristic, Motivated Reasoning, Hyperactive Agency
Detection, Supernaturalism, Promiscuous Teleology, Faulty Causal Theorizing, Representativeness
Heuristic, Planning Fallacy, Loss Aversion, Ignoring Base Rates, Magical
Thinking, and Anchoring Effect.
So with all of that said, again, what do we want an AI to
do? I don’t want one to make any of the
mistakes on the list just above. And I think
that we shouldn’t even be talking about mistakes, emotions, falling in love,
caring or wanting, freedom, or feeling pleasure of pain. What these things show incredible promise at
doing is understanding complex, challenging problems and then devising
remarkable and valuable solutions to them. Watson, the Jeopardy dominating system built
by IBM, has been put to use devising new recipes. Chef Watson is able to interact with would be
chefs, compile a list of preferred flavors, textures, or ingredients, and then
create new recipes, some of which are creative, surprising, and quite
good. The tamarind-cabbage slaw with
crispy onions is quite good, I hear. But
within this seemingly frivolous application of some extremely sophisticated
technology, there is a more important suggestion. Imagine that Watson’s ingenuity is put to
work in a genetics lab, in a cancer research center, in an engineering firm
building a new bridge, or at the National Oceanic and Atmospheric
Administration predicting the formation and movement of hurricanes. I submit that building a system that can
grasp our biggest problems, fold in all of the essential variables, and create
solutions is the most important goal we should have. And we should be injecting huge amounts of
our resources into that pursuit.
Tuesday, June 2, 2015
Building Self-Aware Machines
The public mood toward the prospect of artificial
intelligence is dark. Increasingly,
people fear the results of creating an intelligence whose abilities will far
exceed our own, and who pursues goals that are not compatible with our
own. See Nick Bostrom’s Superintelligence: Paths, Dangers, Strategies for a good
summary of those arguments. I think resistance
is a mistake (and futile) and I think we should be actively striving toward the
construction of artificial intelligence.
When we ask “Can a machine be conscious?,” I believe we often
misses several important distinctions. With
regard to the AI project, we would be better off distinguishing at least
between qualitative/phenomenal states, exterior self-modeling, interior
self-modeling, information processing, attention, sentience, executive top-down
control, self-awareness, and so on. Once
we make a number of these distinctions, it becomes clear that we have already
created systems with some of these capacities, others are not far off, and
still others present the biggest challenges to the project. Here I will focus
just on two, following Drew McDermott:
interior and exterior self-modeling.
A cognitive system has a self-model if it has the capacity
to represent, acknowledge, or take account of itself as an object in the world
with other objects. Exterior
self-modeling requires treating the self solely as a physical, spatial-temporal
object among other objects. So you can
easily spatially locate yourself in the room, you have a representation of
where you are in relation to your mother’s house, or perhaps to the Eiffel
Tower. You can also easily temporally
locate yourself. You represent Napoleon
as am 18th century French Emperor, and you are aware that the
segment of time that you occupy is after the segment of time that he
occupied. Children swinging from one bar
to another on the playground are employing an exterior self-model, as is a
ground squirrel running back to its burrow.
Exterior self-modeling is relatively easy to build into an
artificial system compared to many other tasks that face the AI project. Your phone is technologically advanced enough
to put itself in a location in space in relationship to other objects with its
GPS system. I built a CNC machine in my
garage (Computer Numeric Controlled cutting system) that I ”zero” out when I
start it up. I designate a location in a
three dimensional coordinate system as (0, 0, 0) for the X, Y, and Z axes, then
the machine keeps track of where it is in relation to that point as it cuts. When it’s finished, it returns to (0, 0,
0). The system knows where it is in
space, at least in the very small segment of space that it is capable of
representing (About 36” x 24” x 5”).
Interior self-modeling is the capacity to represent yourself
as an information processing, epistemic, representational agent. That is, a system has an interior self-model
if it represents the state of its own informational, cognitive capacities. Loosely, it is knowing what you know and
knowing what you don’t know. It is a
system that is able to locate the state of its own information about the world
within a range of possible states. When
you recognize that watching too much Fox News might be contributing to your being
negative about President Obama, you are employing an interior self-model. When you resolve to not make a decision about
which car to buy until you’ve done some more research, or when you wait until
after the debates to decide which candidate to vote for, you are exercising
your interior self-model. You have
located yourself as a thinking, believing, judging agent within a range of
possible information states. Making
decisions requires information. Making
good decisions requires being able to assess how much information you have, how
good it is, and how much more (or less) you need or how much better you need it
to be in order to decide within the tolerances of your margins of error.
So in order to endow an artificial cognitive system with an
interior self-model, we must build it to model itself as an information system
similar to how we’d build it to model itself in space and time. Hypothetically, a system can have no
information, or it can have all of the information. And the information it has can be poor
quality, with a high likelihood of being false, or it can be high quality, with
a high likelihood of being true. Those
two dimensions are like a spatial-temporal framework, and the system must be
able to locate its own information state within that range of
possibilities. Then the system, if we
want it to make good decisions, must be able to recognize the difference
between the state it is in and the minimally acceptable information state it
should be in. Then, ideally, we’d build
it with the tools to close that gap.
Imagine a doctor who is presented with a patient with an unfamiliar set
of symptoms. Recognizing that she
doesn’t have enough information to diagnosis the problem, she does a literature
search so that she can responsibly address it.
Now imagine an artificial system with reliable decisions heuristics that
recognizes the adequacy or inadequacy of its information base, and then does a
medical literature review that is far more comprehensive, consistent, and
discerning than a human doctor is capable of.
At the first level, our AI system needs to be able to compile and
process information that will produce a decision. But at the second level, our AI system must
be able to judge its own fitness for making that decision and rectify the
information state short coming if there is one.
Representing itself as an epistemic agent in this fashion strikes me as
one of the most important and interesting ways to flesh out the notion of being
“self-aware” that is often brought up when we ask the question “Can a machine
be conscious?”
McDermott, Drew.
“Artificial Intelligence and Consciousness,” The
Cambridge Handbook of Consciousness, 117-150. Zelazo, Moscovitch, and Thompson, eds. 2007.
Also here: http://www.cs.yale.edu/homes/dvm/papers/conscioushb.pdf
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