Manton Matthews Department of Computer Sc. & Engr.

1. Manton MatthewsDepartment of Computer Sc. & Engr. How computers think; but do they understand? Scholar’s Day April 5, 2008

2. What is Thinking? Merriam-Webster Definitions • Thinking- The action of using one’s mind to produce thoughts • Can a machine think? http://www.merriam-webster.com/dictionary/

3. What is Intelligence? • the ability to learn or understand or to deal with new or trying situations • the ability to apply knowledge to manipulate one's environment or to think abstractly as measured by objective criteria (as tests) http://www.merriam-webster.com/dictionary/

4. Computers Acting Intelligently • Interacting with humans • Analyzing situations and making appropriate decisions

5. Examples of Intelligence? Interact with customers in a business Worker must be able to: • Understand customer’s wishes • Address the request • Maybe handle the details of the sale

6. More Specifically a Bank Teller Teller must be able to: Understand customer’s wishes Count checks/money Give cash and receipts to the customer

7. Computer Bank Teller Teller must be able to: • Understand customer’s wishes • Count checks/money • Give cash and receipts to the customer

8. Chess Player “chess is gymnastics of the mind”

9. Evolution of Chess Playing Computers

10. Deep Blue defeats World Chess Champion "You have to be on full guard every move of the game, which means it is more exhausting. I think Deep Blue is stronger than all but a handful of top human players." - Garry Kasparov

11. Aibo .

12. .

13. Examples of Aibo’s “thinking” Waking up on back (1:14) Picking up the Aibone (= Aibo’s bone) (3:03/2:00) Aibo juggling ball (3:51/2:12) Aibo ball balancing trick (5:05/1:42) Time for rest and recharge. (1:26) Solving a maze (2:59) Following Directions Remote photographer

14. Aibo’s “maze solving” Aibo’s sensors: Solve a maze: • Walk forward till we sense an obstacle • Pan head from left to right looking for longest distance that is unobstructed • Turn that direction and repeat 1-3 Else if all directions obstructed turn 180 degrees and repeat 1-3

15. Email me a photo! x

16. Star Trek’s Doctor Why consider him here? http://en.wikipedia.org/wiki/Doctor_(Star_Trek)

17. Practical Computers Acting Intelligently Expect computers to do some things well (even better than a human): • Number crunching • Combinatorial search (chess) • … But how about tasks requiring subjective judgment? Example: Predict success of a student in a training program • 1955 Paul Meehl showed simple statistical learning algorithms out performed experts in 19 or 20 studies Since 1999 ETS has used a program to grade essay questions on the GMAT, 97% agreement with human expert graders (the same as with other human experts)

18. Alan Turing 1912 (23 June): Birth, Paddington, London1931-34: Undergraduate at King's College, Cambridge University1932-35: Quantum mechanics, probability, logic1935: Elected fellow of King's College, Cambridge1936: The Turing machine, computability, universal machine1936-38: Princeton University. Ph.D. Logic, algebra, number theory1938-39: Return to Cambridge. Introduced to German Enigma cipher machine1939-40: The Bombe, machine for Enigma decryption1939-42: Breaking of U-boat Enigma, saving battle of the Atlantic1943-45: Chief Anglo-American crypto consultant. Electronic work.1945: National Physical Laboratory, London1946: Computer and software design leading the world.1947-48: Programming, neural nets, and artificial intelligence1950: The Turing Test for machine intelligence1954: Death (suicide) by cyanide poisoning

19. Turing’s Imitation Game Version 1 • Three participants A,B and the interrogator • One of A and B is a woman, the other a man • In separate rooms, communicate only through terminal • Assuming the man tries to fool the interrogator, can he still identify the woman? Version 2 • Replace the man with a computer. Turing’s claim: If the computer can make the interrogator miss 50% of the time, then the computer has acted intelligently.

20. Loebner Prize The Loebner Prize is an annual competition that awards prizes to the Chatterbot considered by the judges to be the most humanlike

21. John Searle's Chinese room • Thought experiment By John Searle 1980 • to show that a symbol processing machine like a computer can never be properly described as understanding • Suppose a computer that behaves as if it understands Chinese so well it passes the Turing Test • Chinese characters  program  Chinese response •  means pages with the characters are slid under the door • Now suppose Searle is in the room reading a book in English that has the program instructions in it And he follows them to produce the output character

22. But can a computer understand? Circle of terms revisited • Intelligence • Think • Understand • Mind • Conscious This is the realm of philosophers!

23. Weak AI vs Strong AI Weak AI hypothesis: It is possible for a machine to act intelligently or even less objectionable “to act as if it were intelligent.” Strong AI hypothesis It is possible for a machine to actually think; to understand; to be conscious;

24. Examples of Quirkiness in Meanings Consider the definitions of two forms of locomotion: flying through the air and swimming through water. • Fly - 1 a: to move in or pass through the air with wings • So airplanes fly • Swim - 1 a: to propel oneself in water by natural means (as movements of the limbs, fins, or tail) • But boats don’t swim Norvig and Rusell: AI a Modern Approach

25. So now do we agree? Computer can act intelligently but they can’t understand.

26. The Human Mind How do humans: • think • remember • understand

27. Your Brain • 100 billion nerve cells, neurons • Interconnections • Neurons have: • Cell body • Axon • Dendrites • Synapses • Neuro-transmitters • They stimulate each other by “firing”

28. http://health.howstuffworks.com/brain1.htm

29. Neurons Firing Neurons that fire together get better at it; they form associations The Brain Fitness Program

30. Hebb’s Law Donald Hebb a Neuro-psychologist (1949) “When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased.” "Neurons that fire together wire together."

31. Organic vs Inorganic Chemistry • 1828 Wohler wrote • "I must tell you that I can make urea without the use of kidneys, either man or dog. Ammonium cyanate is urea." • “This organic synthesis dealt a severe blow to a widespread belief called ‘vitalism’ which maintained that organic chemicals could be modified by chemistry but could only be produced through the agency of a vital force present in living plants and animals.” http://www.3rd1000.com/urea/urea.htm

32. Organic vs Inorganic Minds Can we build an artificial Neuron? • Not yet certainly • But artificial hearts, … Suppose we could and further suppose that we could replace one in the brain And replace another … Did that mind lose its ability to understand when we replaced the first artificial neuron? the 2nd ? … the last

33. Moore’s Law 1965 for next 10 years The number of transistors in an Integrated Circuit is doubling approximately every two years http://en.wikipedia.org/wiki/Moore's_law