Lyle Ungar, University of Pennsylvania Kinds of Minds Beyond Turing: Intentionality and its...
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Transcript of Lyle Ungar, University of Pennsylvania Kinds of Minds Beyond Turing: Intentionality and its...
Lyle Ungar, University of Pennsylvania
Kinds ofKinds ofMindsMinds
Beyond Turing: Intentionality
and its alternatives
2Lyle H Ungar, University of Pennsylvania
Our GoalOur GoalOur GoalOur Goal
Scientific models of minds Must make predictions about something
which is observable “the mind parallels the brain, but has no
connection to it” “the mind is that in us which thinks” “the mind is the part of God within each
of us” Implies falsifiability
Karl Popper
3Lyle H Ungar, University of Pennsylvania
Philosophy questions Philosophy questions Philosophy questions Philosophy questions
What kinds of minds are there? ontology Yeast, amoeba, cockroach, sparrow, lion,
person?
How can we know? epistemology
If a lion could talk, we could not understand him
- Ludwig Wittgenstein
4Lyle H Ungar, University of Pennsylvania
Models are at different levelsModels are at different levelsModels are at different levelsModels are at different levels
What is done What goes in, what comes out
What algorithm is used E.g. stores information in a tree
How it is physically implemented E.g. with neurons, silicon, …
Why it is done
5Lyle H Ungar, University of Pennsylvania
FunctionalismFunctionalismFunctionalismFunctionalism
Functionalism The function matters, not how it is carried out “a clock is something that can be used to tell
time”
Machine Functionalism The mind is to the brain as
the program is to the computer
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The brain as transducerThe brain as transducerThe brain as transducerThe brain as transducer
Input signal -> brain -> output signal
light -> brain -> blink The myth of double transduction
light -> neurons -> consciousness -> neurons -> blink
7Lyle H Ungar, University of Pennsylvania
The Intentional StanceThe Intentional StanceThe Intentional StanceThe Intentional Stance
Interpret the behavior of an entity as if it were making choices based on its beliefs and desires
Allows one to make predictions Without knowing how the entity works
Contrast with the physical stance design stance
Intentional systems are entities whose behavior is predictable from the intentional stance.
- Dennett
8Lyle H Ungar, University of Pennsylvania
IntentionalityIntentionalityIntentionalityIntentionality
Aboutness, representation “aimed at something” Lock and key Receptor and endorphin Thermometer “represents” temperature Thermostat controls temperature Frog gulps at a fly
Not “intentional” vs. “accidental”
9Lyle H Ungar, University of Pennsylvania
IntenIntenttional is not Intenional is not IntenssionalionalIntenIntenttional is not Intenional is not Intenssionalional
Intensional vs. extensional Meaning/definition vs. listing “books in my room” vs. {“kinds of minds,”
“freedom evolves”, …} Referential transparency
“a rose by any other name is just as sweet”
Intentional A representation of the world
(which may be wrong) I think you’re Bob You think that is the north star
10Lyle H Ungar, University of Pennsylvania
The Intentional StanceThe Intentional StanceThe Intentional StanceThe Intentional Stance
Predict what an entity will do by modeling it (its mind) as if it had beliefs and desires
Beliefs The entity’s model of the world
Desires A utility function Or perhaps a ranked set of goals
11Lyle H Ungar, University of Pennsylvania
The Intentional StanceThe Intentional StanceThe Intentional StanceThe Intentional Stance
Sunflowers intentionally follow the sun
Dogs intentionally get food by begging
Students intentionally get good grades by studying
12Lyle H Ungar, University of Pennsylvania
Beliefs and DesiresBeliefs and DesiresBeliefs and DesiresBeliefs and Desires
Beliefs and desires can be More or less complex More or less explicit
13Lyle H Ungar, University of Pennsylvania
How does a sunflower’s How does a sunflower’s mind work?mind work?How does a sunflower’s How does a sunflower’s mind work?mind work?
“There goes the sun; let me point a bit more to the west.”
“Its brighter in that direction; let me point towards the light.”
“#$*#&$ b)(*&(*&# ^*^&%@#*()”
Is the sunflower’s behavior
“intentional”?
14Lyle H Ungar, University of Pennsylvania
How does a dog’s mind workHow does a dog’s mind workHow does a dog’s mind workHow does a dog’s mind work “Lyle’s a sucker; if I beg I’ll get a handout!” “When I hear those sounds and see those
colors, if a make this sound, food shows up.!”
“lkajkj asdfpwoeiru asfoiu asdfpuoi!!!”
If a lion could talk, we could not understand him
- Ludwig Wittgenstein
If a lion could talk, we could not understand him
- Ludwig Wittgenstein
15Lyle H Ungar, University of Pennsylvania
How does a student’s How does a student’s mind work?mind work?How does a student’s How does a student’s mind work?mind work? Do you know how your pancreas
works? Do you know how your mind works? Is “knowing” one different from
knowing the other?
16Lyle H Ungar, University of Pennsylvania
Knowing one’s mind is hardKnowing one’s mind is hardKnowing one’s mind is hardKnowing one’s mind is hard
How do you know why you do things? By observing yourself and making up
stories? Stuffing envelopes for good causes Thinking computers are intelligent Subliminal cuing Brain lesion studies
17Lyle H Ungar, University of Pennsylvania
The Origins of IntentionalityThe Origins of IntentionalityThe Origins of IntentionalityThe Origins of Intentionality
Simple organisms Sense and respond to environment
Grow towards the sun Move up the chemical gradient
Animals Use circulating molecules or electrons to
send messages The pineal gland detects a decrease in
daily light, and “tells” the body to prepare for winter
18Lyle H Ungar, University of Pennsylvania
Animal sentienceAnimal sentienceAnimal sentienceAnimal sentience
Does an octopus feel pain? Does an oyster or a trout?
Does a rhesus monkey feel pain? when one of its testicles is ripped out
How would you tell? the difference between sensitivity and
sentience
19Lyle H Ungar, University of Pennsylvania
Intentional GroupsIntentional GroupsIntentional GroupsIntentional Groups
Fungus-growing ants engage in agriculture. Workers cut leaves, carry these into the nest, prepare them as a medium for growing fungus, plant fungus on them, fertilize the fungus with their own droppings, weed out competitive species by hauling them away, and finally, harvest a special part of the fungus on which they feed.
- Robert Trivers
20Lyle H Ungar, University of Pennsylvania
Leaf-cutter AntsLeaf-cutter AntsLeaf-cutter AntsLeaf-cutter Ants
21Lyle H Ungar, University of Pennsylvania
Kinds of (Learning) MindsKinds of (Learning) MindsKinds of (Learning) MindsKinds of (Learning) Minds
Darwinian Try something, if you are successful, you will have
more offspring Skinnerian
Try some things; repeat the ones that get “reinforcement”
Popperian Try something out in your mind; see if it is likely to
work Permits our hypotheses to die in our stead
Gregorian Use tools (e.g. words)
Permits learning from others
22Lyle H Ungar, University of Pennsylvania
Towards IntentionalityTowards IntentionalityTowards IntentionalityTowards Intentionality
Language was invented so that people could conceal their thoughts from each other
- Charles-Maurice de Talleyrand
Most actions don’t require thoughtAnimals flock, eat, hide, flock, flee
Self-consciousnessDeveloped to model what others think?
Models of others neededWhen one can communicate - and deceive
Most actions don’t require thoughtAnimals flock, eat, hide, flock, flee
Self-consciousnessDeveloped to model what others think?
Models of others neededWhen one can communicate - and deceive
23Lyle H Ungar, University of Pennsylvania
Levels of IntentionalityLevels of IntentionalityLevels of IntentionalityLevels of Intentionality
First-order Have beliefs and desires
Second order Have beliefs and desires about beliefs and
desires
Third order I want you to believe that I want dinner
now.
24Lyle H Ungar, University of Pennsylvania
Higher order intentionality?Higher order intentionality?Higher order intentionality?Higher order intentionality?
Distraction displays Bird expects approaching fox to discover
chicks Bird reasons “The fox could be distracted by
its desire to catch and eat me, but only if it thought that there was a reasonable chance of catching me; it would contract that belief if I gave it evidence I couldn’t fly anymore.
- Dennett
25Lyle H Ungar, University of Pennsylvania
Free will and DeterminismFree will and DeterminismFree will and DeterminismFree will and Determinism
26Lyle H Ungar, University of Pennsylvania
The Turing Test revisitedThe Turing Test revisitedThe Turing Test revisitedThe Turing Test revisited
Can you imagine a computer that …
http://cobot.research.att.com/ http://www.kurzweilai.net/
Would you say it could think? How could you tell?
27Lyle H Ungar, University of Pennsylvania
Alternate TheoriesAlternate TheoriesAlternate TheoriesAlternate Theories
Dualism Identity theory
28Lyle H Ungar, University of Pennsylvania
(Cartesian) Dualism(Cartesian) Dualism(Cartesian) Dualism(Cartesian) Dualism
The mind and brain are separate “The athletes are prepared mentally and
physically.” “There’s nothing wrong with your body; its
all in your mind.” “Your depression a biological imbalance
not a psychological disturbance.”
The problem:
29Lyle H Ungar, University of Pennsylvania
Identity TheoryIdentity TheoryIdentity TheoryIdentity Theory
The mind and the brain are the same thing Brain states are thoughts and feelings Implication
Machines or animals with different chemistry can’t have the same thoughts or feelings
Problem Do people with different brain chemistry then
not have the same thoughts or feelings? How specific must it be?
30Lyle H Ungar, University of Pennsylvania
Animal sentience (again)Animal sentience (again)Animal sentience (again)Animal sentience (again)
Does an octopus feel pain? Does an oyster or a trout?
Does a rhesus monkey feel pain? when one of its testicles is ripped out
How would you tell? the difference between sensitivity and
sentience
31Lyle H Ungar, University of Pennsylvania
SummarySummarySummarySummary
The intentional stance Describing an entity as if it has beliefs and
desires It is useful to model other entities as having
intentions It is possible (but hard) to test what models
of the world entities use Different levels of learning, intentionality
Alternatives Dualism Identity theory