Download Lecture1

What is Cognitive Science?
• The study of mind and intelligence
–
–
–
–
–
–
Psychology
Philosophy
Artificial intelligence
Neuroscience
Linguistics
Anthropology
Why Bother?
• Right now, there are too many questions.
We can’t tackle them all with only one
approach.
• Understanding the human mind requires
numerous methods and theories.
• Psychological experiments, computational
models, brain scans, etc.
How did I get here?
• Biology
– Cognitive Psychology
• Clinical Ophthalmology
– Development
– Stroke
• Neuroscience
– Vision and movement through the world
This Course
• It’s impossible to review everything in all 6
fields.
– We will focusing on a central topic in each field.
– What mental representations does the mind use (or
can computers use) to develop thinking?
• Major focus will be on human cognition, but
we will also discuss machine intelligence.
What do you need to know in order to
graduate?
•
•
•
•
•
Where do you park/live?
How do you decide what classes to take?
Rules: avoid 8 a.m. classes.
Concepts: “Mickey Mouse“ course.
Images: Route from one part of campus to
another.
• Cases: Particularly good or bad professors.
History of Cognitive Science
• Fundamental philosophical questions since Plato
– Virtue as innate knowledge
• Epistemology - What is the nature of knowledge?
– Descartes – Rationalism
– Locke – Empiricism
Can you study the mind?
• Franciscus Donders (18181889)
– Dutch Physician
• Conducted experiments in
mental chronometry
– Measuring the time course of
cognitive processes
First Cognitive Psychologists
• Wilhelm Wundt
(1832-1920)
– Leipzig, Germany
– First Psychology Lab
– Introspective methods
Behaviorism
• John B. Watson (1878-1958)
– Problems with introspection
– 1913 paper threw the “mind” out of
psychology
– Behaviorism: Measure externals not
internals
– Successful for about 50 years
– Pavlov
– B. F. Skinner
Cognitive Science Emerges
• Noam Chomsky (1959)
Linguist
– The development of language is
not just about copying what is
heard. There is evidence of rule
formation and originality.
• New interest in exploring how
the mind works. If you ask
the right questions, you can
learn quite a lot.
History of Cognitive Science
• Anthropology: social, cultural aspects of knowledge
• Neuroscience: how does the brain make a mind?
Can we study mental Representations?
• How does the mind hold and manipulate data?
– Canaries are yellow. Canaries are birds.
– I fixed-ed my bike.
• Does our mind store images in three
dimensions?
• http://psychexps.olemiss.edu/
Questions
• How can all these fields, with different
histories and methodologies, cooperate to
produce an understanding of mind?
Computers and the Brain
• Computers are getting faster. Will they ever
achieve human intelligence?
Computers and the Brain
How far can the analogy go?
• Intelligence requires software as well as hardware.
• The software for emulating the brain would be
astonishingly complex.
• The "software" for human intelligence includes
motivation, emotion, and consciousness, which are
not part of current computer programs.
• Thinking might not be a kind of computation.
• Maybe minds are non-material souls?
What is Cognitive Science?
• Central hypothesis if CS:
• Thinking = representational structures +
procedures that operate on those structures.
• This is broad enough to encompass rules,
concepts, images, cases, and distributed
representations.
• This hypothesis may be wrong, but it is far more
powerful and successful than any competing
hypothesis to date.
The CRUM approach
• Computational-Representational Understanding of Mind
• Methodological consequence: study the mind by
developing computer simulations of thinking.
Computer
Mind
Data Structures
Mental Representations
Algorithms
Computational Procedures
DS+A=Running Programs
MR+CP= Thinking
War and Science
The Beginning of modern AI
• Is the intelligence of the computer the
same as that of the human?
• Initially, idea eagerly accepted
• 1950 Turing test: can a subject interacting
with a computer be persuaded that he/she
is communicating instead with a human?
• Chinese Room Problem
• Deep Blue vs. Kasparov
Alan Turing (1912-1954)
Computers can calculate, but can they think?
• Chat with Alice
– Assignment for
Wednesday will be
available at the
end of class.
Bringing it all Together
Philosophy
•
Deduction
– Descartes, I am a thing that thinks
•
Thought experiment
– imagine brain transfer
•
General theorizing
– develop theory of mind
– dualism, materialism, functionalism
•
Case studies in history and philosophy of
science.
Bringing it all Together
Psychology
• Experiments
Mental rotation, analogy, concepts
• 2. Theorizing
Postulate structures and processes
Bringing it all Together
Computer Science and AI
• Write programs aiming to be intelligent.
• Evaluation can either be cognitive or
engineering
– See what it can do, and see whether it can do it
like people…even if it means making mistakes.
Bringing it all Together
Neuroscience
• Experiments, but biological, not cognitive.
– record cell firing, PET and MRI scans, lesions
• Also theoretical
• Also computational
– build computer models of mind, e.g. neural
networks
Bringing it all Together
Linguistics
• Judgments of grammaticality: syntax
• Semantics, pragmatics: data, theory
• Computational models
Bringing it all Together
Anthropology
• Ethnography, but pay attention to how
people think. Like psychology, but less
experimental, more cross cultural.
• Psychologists are also doing cross-cultural
studies.
Next Class
• Throughout this course: Think about how
these disciplines can contribute to our
understanding of the mind.
• Evaluating approaches to mental
representation
• See Mind, p. 15, Box. 1.1.
Mind Reading + Chapter 2
• "What is an explanation of behavior?"
• Programs that simulate cognitive processes explain
intelligent behavior by performing the tasks whose
performance they explain.
• Neurophysiological explanation is compatible with
computational explanation, but operates at a different
level.
• At the neural level, cognitive processes are parallel, but
at the symbolic level, the brain behaves like a serial
system.
• The human mind is an adaptive system, learning to
improve its performance in accomplishing its goals.
• Herbert Simon is one of the founders of artificial
intelligence and cognitive science.