1. Lyle Ungar, University of Pennsylvania Kinds of Minds Beyond Turing: Intentionality and its alternatives

2. Lyle H Ungar, University of Pennsylvania 2 Our 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

3. Lyle H Ungar, University of Pennsylvania 3 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

4. Lyle H Ungar, University of Pennsylvania 4 Models 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

5. Lyle H Ungar, University of Pennsylvania 5 FunctionalismFunctionalism  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

6. Lyle H Ungar, University of Pennsylvania 6 The brain as transducer Input signal -> brain -> output signal light -> brain -> blink  The myth of double transduction light -> neurons -> consciousness -> neurons -> blink

7. Lyle H Ungar, University of Pennsylvania 7 The 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

8. Lyle H Ungar, University of Pennsylvania 8 IntentionalityIntentionality  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”

9. Lyle H Ungar, University of Pennsylvania 9 Intentional is not Intensional  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

10. Lyle H Ungar, University of Pennsylvania 10 The 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

11. Lyle H Ungar, University of Pennsylvania 11 The Intentional Stance Sunflowers intentionally follow the sun Dogs intentionally get food by begging Students intentionally get good grades by studying

12. Lyle H Ungar, University of Pennsylvania 12 Beliefs and Desires  Beliefs and desires can be More or less complex More or less explicit

13. Lyle H Ungar, University of Pennsylvania 13 How does a sunflower’s 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”?

14. Lyle H Ungar, University of Pennsylvania 14 How 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

15. Lyle H Ungar, University of Pennsylvania 15 How does a student’s mind work?  Do you know how your pancreas works?  Do you know how your mind works?  Is “knowing” one different from knowing the other?

16. Lyle H Ungar, University of Pennsylvania 16 Knowing 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

17. Lyle H Ungar, University of Pennsylvania 17 The 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

18. Lyle H Ungar, University of Pennsylvania 18 Animal 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

19. Lyle H Ungar, University of Pennsylvania 19 Intentional 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

20. Lyle H Ungar, University of Pennsylvania 20 Leaf-cutter Ants

21. Lyle H Ungar, University of Pennsylvania 21 Kinds 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

22. Lyle H Ungar, University of Pennsylvania 22 Towards Intentionality Language was invented so that people could conceal their thoughts from each other - Charles-Maurice de Talleyrand  Most actions don’t require thought  Animals flock, eat, hide, flock, flee  Self-consciousness  Developed to model what others think?  Models of others needed When one can communicate - and deceive  Most actions don’t require thought  Animals flock, eat, hide, flock, flee  Self-consciousness  Developed to model what others think?  Models of others needed When one can communicate - and deceive

23. Lyle H Ungar, University of Pennsylvania 23 Levels 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.

24. Lyle H Ungar, University of Pennsylvania 24 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

25. Lyle H Ungar, University of Pennsylvania 25 Free will and Determinism

26. Lyle H Ungar, University of Pennsylvania 26 The Turing Test revisited  Can you imagine a computer that … http://cobot.research.att.com/ http://www.kurzweilai.net/http://cobot.research.att.com/  Would you say it could think? How could you tell?

27. Lyle H Ungar, University of Pennsylvania 27 Alternate Theories  Dualism  Identity theory

28. Lyle H Ungar, University of Pennsylvania 28 (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:

29. Lyle H Ungar, University of Pennsylvania 29 Identity 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?

30. Lyle H Ungar, University of Pennsylvania 30 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

31. Lyle H Ungar, University of Pennsylvania 31 SummarySummary  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