27. The Turing Machine 28. The Brain as a Computing Device 29. Universal Computation 30. Computatio

1
  27.  The Turing Machine  28. The Brain as a
Computing Device  29.  Universal Computation 
30.  Computation and Cognitivism  31.  The
Machine Brain  32.  Functionalist Separation of
Mind from Brain  33.  The Physical Symbol
Systems Hypothesis  34.  A Theory of Intelligent
Action  35.  Could a Machine Really Think?  36.
 The Turing Test  37.  The Loebner Prize  38.
 Problems with the Turing Test  39.  Inside the
Machine Searles Chinese Room
Introducing Artificial Intelligence by Henry
Brighton and Howard SelinaSECTION C.
. Chuck Selden

• Name Chuck Selden
• Profession Health Scientist Administrator
• Affiliation NIH-OD-OER-OEP-ESTO
• Relation (to the subject matter) My
  Intelligence, unfortunately, is not artificial
• Question (that you would like to explore in the
  dialogue)
• What is minimal number, speed, and level of
  complexity for a system of cells/nodes/reactive
  memory units needed for a machine to reach AI?

2
The Turing Machine

• Imaginary Machine
• Contains a Finite Control that defines all
  states in which machine can exist
• Machine states reached by what is read off an
  infinite tape inscribed with symbols
• Turing Machine predated all modern computers
• Exemplar of the theory of computation

3
The Brain as a Computing Device

• Warren McCulloch and Walter Pitts in 1943 A
  Logical Calculus of the ideas Immanent in Nervous
  Activity
• The neuron as a computing device
• Configurations of neurons as logic gates can
  perform any calculation computable by a Turing
  Machine

4
Universal Computation

• All computers are restricted to perform
  calculations as would a Turing Machine
• All other machines and the human brain can also
  be reduced to Turing Machines
• NOTE The human brain, and other animal brains,
  have the ability to initiate thoughts and actions
  without relying on a list of instructive symbols
  (inputs) ie. spontaneous activity
• Thus, the brain is much more than a Turing
  Machine

5
Computation and Cognitivism

• Turing Machines and computers work in various
  ways
• TM reads an infinite tape of symbols
• Desktop computer uses random access memory to
  carry out computations
• The Brain uses a vast network of neurons

• But how does the mind compute?

6
The Machine Brain

• Brain function has been explained historically as
  using the most complex machinery of the period
• Renaissance - clockwork
• Industrial age - steam engine
• Present day - computer
• Brain as hardware, mind as software
• Mind has no mass, no material
• Operates on the hardware

7
Functionalist Separation of Mind from Brain

• Operations matter, not the physical process
• Functionalism means many different ways to do
  something
• Example a spreadsheet will run on many different
  kinds of operating systems
• Cognition, then, is platform-independent
• Machines could be cognitive just like a brain is.

8
The Physical Symbol Systems Hypothesis (PSSH)

• The mind relies on syntactic manipulation of
  symbols
• Cognition relies on manipulation of symbolic
  representations of things in the world
• The platform carrying out the manipulations is
  irrelevant (neurons, silicon, tin cans and
  string, clockworks, steam engines)
• A physical symbol system has the necessary and
  sufficient means for intelligent action.

9
A Theory of Intelligent Action

• Newall and Simon wanted to tell what operations
  were needed for intelligent action
• The science of AI is to test PSSH
• Acording to PSSH, the right program is all that
  is required for a theory of intelligent action
• NOTE
• Do computers really use a physical symbol system?
  THIS IS THE KEY TO AI
• NO, Computers use numerical representations of
  symbols, thus, computers cannot become (act)
  intelligent.

10
Could a Machine Really Think

• Is there a decisive argument that proves machines
  cannot think?
• Alan Turing in 1950 asked Can Machines think?
  but thought the question was ill-defined and
  meaningless
• Can a computer win the imitation game?
• The test can a person on a computer, linked to
  another computer in another room, tell if the
  other computer is responding to questions or a
  conversation unaided by a human, or not?

11
The Turing Test

• Interrogator asks any question
• On basis of the response(s), which do not have to
  be truthful, the interrogator decides if is
  corresponding with a human or a machine.
• Machine passes test if interrogator thinks it is
  a human.
• Example
• Add 34957 to 70764
• Answer 105621

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Correct Answer 105721

• Did the wrong answer make you think a human was
  in the other room, answering via computer?

13
But what is thought?

• Is there thinking involved?
• Is it just processing?
• Example, from Noam Chomsky, using the word Swim
• Does a submarine swim?

14
The Loebner Prize

• In 1990, start of an annual competition for
  100,000 and a gold medal
• To be won by first person who designs a computer
  program that passes the Turing Test
• Some cash and bronze medals have been awardednot
  the gold.
• The authors suggest that no one will win for some
  time.

15
Problems with the Turing Test

• Test ignores linguistics and how the machine
  operates
• Goal for developing AI is not to win a prize or
  fool a person, but to make an intelligent
  machine, a machine with a mind.
• Turing test could be passed by a computer that
  memorizes all questions and responses to all
  questions ever asked, and, given that any new
  question will be like an old one, will give
  reasonable answers every time.
• It would still not be intelligent.

16
Inside the Machine Searles Chinese Room

• In 1980s, John Searle tried to knock out AI
  claimants with this argument
• A man in a room with a rule book for using
  Chinese symbols would get questions in Chinese
  and provide answers in Chinese.
• But couldnt read any Chinese.
• Did he understand the exchanges?
• NO Even though he might provide the right
  answers and so pass the Turing Test.
• Similarly, the computer might compute, but will
  not, cannot, understand what it is doing...it has
  no cognition.