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Unlocking Minds: Introduction to Cognitive Science

Explore the interdisciplinary realm of cognitive science focusing on the mind's information processing mechanisms and its relevance to AI and IT. Discover the history, computational models, and multi-level explanations in this field.

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Unlocking Minds: Introduction to Cognitive Science

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  1. COGN1001Introduction to Cognitive Science Sept 2006 :: Lecture #1 :: Joe Lau :: Philosophy HKU

  2. Please write this downhttp://philosophy.hku.hk/courses/200607/cogn1001

  3. Topics • About this course • What is cognitive science? • The computer model of the mind

  4. About this course

  5. About this course • Course coordinator • Other teachers • Course tutor • Assessment • 60% 2-hour final exam. • 25% 5 problem sets; one for each topic. • 10% tutorial participation. • 5% tutorial attendance.

  6. What iscognitive science? Longuet-Higgins, H.C. (1973) Comments on the Lighthill report. Artificial Intelligence - A Paper Symposium. London: Science Research Council. By 1960 it was clear that something interdisciplinary was happening. At Harvard we called it cognitive studies, at Carnegie-Mellon they called in information-processing psychology, and at La Jolla they called it cognitive science. – George Miller.

  7. How is it differentfrom psychology? What is cognitive science? Cognitive science is the science of mind and behavior.

  8. “Cognitive” • Of or pertaining to cognition, or to the action or process of knowing (OED) • Understanding knowledge acquisition and use is the key to understanding the mind. Colorless green ideas sleep furiously.

  9. So what is cognitive science? • Cognitive science is a scientific study of the mind with special emphasis on the use and acquisition of knowledge and information. • Implications • An inter-disciplinary approach – Many scientific disciplines contribute to cognitive science. • A computational approach – Explain information processing in terms of neural computations.

  10. Information processing everywhere • Perception • acquiring real-time information about the surrounding environment. • Language use • making use of information about syntax, semantics and phonology. • Reasoning • combining different sources of information, deriving new information, testing consistency of information, etc. • Action • making use of information in action planning and guidance. • Memory • storing and retrieving information This is one reason why cognitive science is inter-disciplinary.

  11. Explaining information processing • What is the best explanation of why a system is capable of complex information processing? • Answer: The system is a computer.

  12. Why there was no cognitive science • They didn’t think that knowledge is the key. • Perhaps it is a special substance? (Dualism) • Perhaps it is stimulus-response? (Behaviorism) • They didn’t know about computers. • Small stupid steps combine to do difficult things. A useful short history: http://ls.berkeley.edu/ugis/cogsci/major/about.php

  13. VIP #1Cognitive science is about how the mind processes information.

  14. What is special about cognitive science? • Focuses on knowledge and information as the key to understanding the mind. • Interdisciplinary • Computational approach • Special relevance to IT and AI • Individualistic • Multi-level explanations

  15. Psychology Cognitive science Social psychology Educational psychology

  16. More on the computer model of the mind

  17. Quiz: What is a computer? (a) A person (b) A machine

  18. 17x11=? 170 17 187 What is computation? • Rule-based manipulation of symbols. S = str_replace( “cat” , ”c” , ”h” ) Philosophy  哲學

  19. A program is like a cooking recipe Ingredients recipe

  20. Is-in-love Is-happy Computational explanation of information processing in the mind • Thinking that P = activating a set of symbols in the brain which mean P. boring! Is-in-love Peter Is-happy

  21. Symbols in the mind =mental / neural representation Topographical representation of visual stimulus in visual area V1

  22. VP VP NP V NP PP V discuss N PP discuss N P NP violence P NP violence on TV on TV Representations explain lots of things • Example: Syntactic Disambiguation • “We shall discuss violence on TV.” • Two interpretations :

  23. Two methodological consequences of the computer model • Computer models can be built to test theories of mental processes. • There are different levels of analysis for a complex information processing system.

  24. Three Levels of Description (David Marr) • A complete understanding of a computational system has to involve three (kinds of) levels : • Computational theory • What is computed and why. • What the system is capable of doing. • Representation and algorithm (software) • What program is used. • What are the symbols and how are they processed. • Hardware • Where in the brain? • What kind of neurons and how are they connected?

  25. Example • Task: Multiplication.Input numbers x and y. Output x times y. • Algorithm: Given inputs x and y, look up number z on row x and column y. Output z. • Implementation: human being and paper.

  26. Alternative algorithm • How to calculate x times y: • If x =1, then answer is y. • If x>1, add y to itself (x-1) number of times.The result is the answer. • Example: 3x5 = 5+5+5 = 15 • Implementation:

  27. Two points • The same task can be performed with different algorithms. • Two different systems can do the same task in very different ways. • The same algorithm can be implemented with different hardware.

  28. How to study cognitive science • A computational theory of X should explain X at three levels. • What is computed? Visual motion • How? Correlate changes in luminance at different places. • Hardware? Comparator circuitshttp://www.psypress.co.uk/mather/resources/swf/Demo11_1.swf

  29. Demohttp://www.psypress.co.uk/mather/resources/swf/Demo11_1.swfDemohttp://www.psypress.co.uk/mather/resources/swf/Demo11_1.swf

  30. VP NP PP V discuss N P NP violence on TV Application: linguistic understanding • Task • Identify syntax and meaning corresponding to speech sounds. • Algorithm • What kind of computation and mental representations? • Implementation • Which part of the brain?

  31. INTERDISCIPLINARY approach • Division of labour • Psychology – cognitive psychology, developmental psychology … • Linguistics – syntax, semantics, phonology … • Neuroscience – brain structures, localization … • Computer science – AI, computer models … • Philosophy – theoretical foundations …

  32. How to think about cognitive science

  33. If you get lost • Which mental process? • Language, reasoning, emotions, … • Which level? • Task, algorithm, neural implementation

  34. Summary • Cognitive science is an inter-disciplinary science of mind and behavior. • The computational approach : using computations and representations to explain mental processes. • Three levels of descriptions. • Coming up next: language as an example.

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