Overview and HistoryOverview and History ofof Cognitive Science Cognitive Science

How do minds work?How do minds work?

What would an answer to this question What would an answer to this question look like?look like? What is a mind?What is a mind? What is intelligence?What is intelligence? How do brains work? How do brains work?

NeuronsNeurons

Brain structureBrain structure What’s the difference between the brain and What’s the difference between the brain and

the mind?the mind?

CognitionCognitionCognition – from Latin base cognitio – Cognition – from Latin base cognitio – “know together”“know together”

The collection of mental processes and The collection of mental processes and activities used in perceiving, learning, activities used in perceiving, learning, remembering, thinkingremembering, thinking, , and understandingand understanding and the act of using those processesand the act of using those processes

Ways of thinking about learningWays of thinking about learning

Who learns?Who learns? brain vs. genomebrain vs. genome individual vs. groupindividual vs. group

What is learned?What is learned? facts vs. skills vs. rules vs. ..facts vs. skills vs. rules vs. ..   information vs. physiologyinformation vs. physiology

Where does knowledge come from?Where does knowledge come from? experience vs. reason vs. analogy vs. chanceexperience vs. reason vs. analogy vs. chance

How does learning work?How does learning work?

Cognitive Processes Cognitive Processes

Learning and MemoryLearning and MemoryThinking and Reasoning (Planning, Decision Thinking and Reasoning (Planning, Decision Making, Problem Solving ...)Making, Problem Solving ...)Analogy and metaphorAnalogy and metaphorLanguageLanguageVision-PerceptionVision-PerceptionSocial CognitionSocial CognitionEmotionsEmotionsDreaming and Consciousness Dreaming and Consciousness

So So What IS Cognitive Science?What IS Cognitive Science?

Some possible definitions:Some possible definitions: ““The interdisciplinary study of mind and intelligenceThe interdisciplinary study of mind and intelligence”” ““Study of cognitive processes involved in the Study of cognitive processes involved in the

acquisition, representation and use of human acquisition, representation and use of human knowledgeknowledge””

““Scientific study of the mind, the brain, and intelligent Scientific study of the mind, the brain, and intelligent behaviour, whether in humans, animals, machines or behaviour, whether in humans, animals, machines or the abstractthe abstract””

Disciplines in Cognitive ScienceDisciplines in Cognitive Science

Computer Science- Artificial Computer Science- Artificial Intelligence Intelligence NeuroscienceNeurosciencePsychology – Cognitive PsychologyPsychology – Cognitive PsychologyPhilosophyPhilosophyLinguisticsLinguisticsAnthropology, EducationAnthropology, Education

Methods of Cognitive ScienceMethods of Cognitive Science

Computational Modeling (artificial intelligence, Computational Modeling (artificial intelligence, computational neuroscience)computational neuroscience)

Experimentation (psychology, linguistics, Experimentation (psychology, linguistics, neuroscience)neuroscience)

Introspection, Argumentation, Formal Logic and Introspection, Argumentation, Formal Logic and Mathematical Modeling (philosophy, linguistics)Mathematical Modeling (philosophy, linguistics)

Ethnography (cognitive anthropology) Ethnography (cognitive anthropology)

Paradigms of Cognitive ScienceParadigms of Cognitive Science

Computational Representational Computational Representational Understanding of MindUnderstanding of Mind Mind = mental representation + computational Mind = mental representation + computational

processesprocesses Computational Theory of MindComputational Theory of Mind

Duplicating mind by implementing the right Duplicating mind by implementing the right programprogram

Cognitivism, FunctionalismCognitivism, Functionalism

Symbolicism – Connectionism- Symbolicism – Connectionism- Dynamicism - Hybrid approaches Dynamicism - Hybrid approaches

Intelligence vs. Cognition Intelligence vs. Cognition

The goal of cognitive scienceThe goal of cognitive science develop a theory of Intelligent Systemsdevelop a theory of Intelligent Systems??

The goal of artificial intelligenceThe goal of artificial intelligence Creation of intelligent artifacts?Creation of intelligent artifacts?

Modeling for Study of CognitionModeling for Study of Cognition

Strong AI (duplicating a mind by implementing Strong AI (duplicating a mind by implementing the right program) vs Weak AI (machines that the right program) vs Weak AI (machines that act as if they are intelligent)act as if they are intelligent)AIAI as as the study of human the study of human intelligenceintelligence using using computer as a tool vs Acomputer as a tool vs AII as as the study of machine the study of machine intelligence as intelligence as artificial artificial intelligenceintelligenceArtificial Intelligence and Cognitive Science: a Artificial Intelligence and Cognitive Science: a history of interactionhistory of interaction

AI and Cognitive ScienceAI and Cognitive Science

"AI can have two purposes. One is to "AI can have two purposes. One is to use the power of computers to use the power of computers to augment human thinking, just as we augment human thinking, just as we use motors to augment human or use motors to augment human or horse power. Robotics and expert horse power. Robotics and expert systems are major branches of that. systems are major branches of that. The other is to use a computer's The other is to use a computer's artificial intelligence to understand artificial intelligence to understand how humans think. In a humanoid how humans think. In a humanoid way. If you test your programs not way. If you test your programs not merely by what they can accomplish, merely by what they can accomplish, but how they accomplish it, they but how they accomplish it, they you're really doing cognitive science; you're really doing cognitive science; you're using AI to understand the you're using AI to understand the human mind." human mind."

Advantages of Computational Advantages of Computational ModelingModeling

Push predictive aspects of a theory: more Push predictive aspects of a theory: more formal, precise and abstract specificationsformal, precise and abstract specifications

Computer programs are good Computer programs are good experimental participantsexperimental participants

Unify several different classes of facts as Unify several different classes of facts as compared to hypothesis testingcompared to hypothesis testing

Representation and ComputationRepresentation and Computation

Central hypothesis of cognitive scienceCentral hypothesis of cognitive science thinking can best be understood in terms of thinking can best be understood in terms of

representational structures in the mind and representational structures in the mind and computational procedures that operate on computational procedures that operate on those structures. those structures.

much disagreement about the nature of the much disagreement about the nature of the representations and computations that representations and computations that constitute thinkingconstitute thinking

The The IInformation-nformation-PProcessing rocessing MMetaphoretaphor

Mind has mental representations analogous to computer Mind has mental representations analogous to computer data structures, and computational procedures similar to data structures, and computational procedures similar to computational algorithms. computational algorithms. Symbolic View: mind contains such mental Symbolic View: mind contains such mental representations as logical propositions, rules, concepts, representations as logical propositions, rules, concepts, images, and analogies, and that it uses mental images, and analogies, and that it uses mental procedures such as deduction, search, matching, procedures such as deduction, search, matching, rotating, and retrieval. rotating, and retrieval. Connectionist View: mental representations use neurons Connectionist View: mental representations use neurons and their connections as mechanisms for data and their connections as mechanisms for data structures, and neuron firing and spreading activation as structures, and neuron firing and spreading activation as the algorithms – i.e., cognition can be explained by using the algorithms – i.e., cognition can be explained by using artificial neural networks artificial neural networks

Is cognition information Is cognition information processing? processing?

Church-Turing ThesisChurch-Turing Thesis

Universal Turing MachineUniversal Turing Machine

The information-processing metaphor: The information-processing metaphor: data+ algorithmsdata+ algorithms

From Marr (1982): “What does it mean, to see? The plain man’s answer (and Aristotle’s too) would be, to know what is where by looking. In other words, visionis the process of discovering from images what is present in the world,and where it is.

“Vision is therefore, first and foremost, an information-processing task,But we cannot think of it just as a process. For if we are capably of knowing what is where in the world, our brains must somehow be capableof representing this information – in…. The study of vision must therefore include not only the study of how to extract from images the variousaspects of the world that are useful to us, but also an inquiry into the nature of the internal representations by which we capture this information ….”

Levels of Analysis: Background

[ -- Continuing Marr (1982)]: “This duality – the representation and the processing of information – lies at the heart of most information-processing tasks and will profoundly shape Our investigation of the particular problems posed by vision.”

- If one accepts the information-processing approach, how does one move forward in understanding a complex information-processing system (e.g. some aspect of cognition, such as vision)?

~ Marr’s suggestion – Three Levels of Understanding

Levels of Analysis: Background

Levels of analysis (Levels of analysis (MarrMarr):):Three kinds of questionsThree kinds of questionscomputationcomputation what is the problem?what is the problem?

inputs, outputsinputs, outputswhat is being computed or maximized?what is being computed or maximized?

algorithmalgorithm what are the methods?what are the methods?

Data representation, “process”Data representation, “process”

implementationimplementation what are the mechanisms?what are the mechanisms?

springs or neurons springs or neurons

Three Levels (from Marr, 1982):

History of Cognitive ScienceHistory of Cognitive ScienceThe study of mind remained the province of The study of mind remained the province of philosophy until the 19th century, when philosophy until the 19th century, when experimental psychology developed. experimental psychology developed.

Philosophy: rationalism (Plato, Descartes, Kant) vs empiricism Philosophy: rationalism (Plato, Descartes, Kant) vs empiricism (Aristotle, Locke, Hume, Mill)(Aristotle, Locke, Hume, Mill)

Cartesian Dualism Cartesian Dualism – the mind-body problem– the mind-body problem

experimental psychology became dominated by experimental psychology became dominated by behaviorism (e.g., J. B. Watson)behaviorism (e.g., J. B. Watson) psychology should restrict itself to examining the psychology should restrict itself to examining the

relation between observable stimuli and observable relation between observable stimuli and observable behavioral responsesbehavioral responses

denied the existence of consciousness and mental denied the existence of consciousness and mental representations representations

Behaviourism and Cognitive Behaviourism and Cognitive ScienceScience

History of Cognitive ScienceHistory of Cognitive ScienceGeorge Miller (1950’s)George Miller (1950’s) showed that the capacity of human thinking is showed that the capacity of human thinking is

limited, with short-term memory, for example, limited, with short-term memory, for example, limited to around seven itemslimited to around seven items

proposed that memory limitations can be proposed that memory limitations can be overcome by recoding information into overcome by recoding information into chunks, mental representations that require chunks, mental representations that require mental procedures for encoding and decoding mental procedures for encoding and decoding the information. the information.

History of Cognitive ScienceHistory of Cognitive ScienceCognitive PsychologyCognitive Psychology First textbook by Neisser in 1967First textbook by Neisser in 1967 Advances in memory models (60s)Advances in memory models (60s)

Artificial IntelligenceArtificial Intelligence Alan Turing – Turing machines, Turing TestAlan Turing – Turing machines, Turing Test Newell and Simon – Logic Theorist, GPSNewell and Simon – Logic Theorist, GPS McCarthy – McCarthy – FFrame problemrame problem MinskyMinsky –– The Chinese room The Chinese room

History of Cognitive ScienceHistory of Cognitive ScienceNeuroscience: Neuroscience:

Brain structure and function Brain structure and function related related (Gall, (Gall, Spurzheim)Spurzheim)Localization of function: Wernicke, BrocaLocalization of function: Wernicke, BrocaMeasurement of rates of electrical nMeasurement of rates of electrical neural eural impulseimpulsess: Helmholtz: HelmholtzComplexity of the human cortex: Lashley, Complexity of the human cortex: Lashley, PenfieldPenfieldNeural Network Modeling in 1950s: Pitts and Neural Network Modeling in 1950s: Pitts and McCulloch, Hebb, RosenblattMcCulloch, Hebb, Rosenblatt

History of Cognitive ScienceHistory of Cognitive ScienceLinguistics: Linguistics: Saussure- late 19Saussure- late 19thth century, on structure of century, on structure of

languagelanguage Chomsky: language as a generative systemChomsky: language as a generative system

rejected behaviorist assumptions about language rejected behaviorist assumptions about language as a learned habit and proposed instead to explain as a learned habit and proposed instead to explain language comprehension in terms of mental language comprehension in terms of mental grammars consisting of rules. grammars consisting of rules.

History of Cognitive ScienceHistory of Cognitive ScienceBirth date: Symposium on Information Birth date: Symposium on Information Theory at MIT in 1956-Participants: Theory at MIT in 1956-Participants: Chomsky, Newell, Simon, Miller...Chomsky, Newell, Simon, Miller...Cognitive Science journal in 1977Cognitive Science journal in 1977Cognitive Science society in 1980Cognitive Science society in 1980