PHIL/PSYCH 256, Week 1

Class 1a, Introduction

What is Cognitive Science

Cognitive science is the interdisciplinary study of mind and intelligence: psychology + philosophy + artificial intelligence + neuroscience + linguistics + anthropology

Cognitive science links.

Why Cognitive Science?

Understanding the human mind requires numerous methods and theories.

Psychological experiments, computational models, brain scans, etc.

My own history: philosophy -> philosophy of science -> psychology -> computational models -> neuroscience.

Aims of Cognitive Science

Theoretical: explain how thinking works

Applied: e.g. robotics, education, design, management, mental illnes.

Structure of this course:

Impossible to review everything in all 6 fields. Instead, I am focussing on a central topic in all these fields: 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.


Readings, 3 exams, essay. See syllabus.

Lecture notes will be updated on Web site weekly.

Mental representations:

e.g. pictures, "horses have tails", "horses have lungs"


We are going to look at various representational schemes that have been proposed and debated. We will also consider the more philosophical question of whether cognitive science is a mistake: consciousness, emotions, knowledge without representation.

Example: What do you know about the university?

How do you decide what classes to take?

Rules: e.g. avoid 8 a.m. classes.

Concepts: e.g. "gut"

Images: e.g. route from one part of campus to another

Cases: e.g. particularly good or bad classes.

History of cognitive science

Fundamental philosophical questions since Plato

1. What is the nature of mind? Metaphysics and nature of reality.

2. What is the nature of knowledge? Epistemology and nature of knowledge.

3. How do we think?

Psychology, 1890s. Behaviorism: can't study what is in the mind.

1950's. Miller, etc.: mind has structure.

Artificial intelligence, 1956. Minsky, Newell, Simon, McCarthy.

Linguistics 1956: Chomsky versus behaviorist view of language. Innateness.

Anthropology: social, cultural aspects of knowledge

Neuroscience: how does the brain make a mind?

Key question:

How can all these fields, with different histories and methodologies, cooperate to produce an understanding of mind?


Class 1b

What is cognitive science?

Central hypothesis:

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.

Analogy between computation and thinking

data structures mental representations

+ algorithms +procedures

= running programs =thinking

Methodological consequence: study the mind by developing computer simulations of thinking.

Talk to a computer, Alice

Google robotic car

Different methodologies for studying mind:


1. Deduction

e.g. Descartes, I am a thing that thinks

2. Thought experiment

e.g. imagine brain transfer

3. General theorizing

e.g. develop theory of mind

dualism, materialism, functionalism

4. Case studies in history and philosophy of science.


1. Experiments:

e.g. mental rotation, analogy, concepts

2. Theorizing: postulate structures and processes

Computer science: AI

1. Write programs aiming to be intelligent.

evaluation can either be cognitive or engineering

e.g. SOAR: see what it can do, and see whether it can do it like people.

Psychologists and philosophers now also use this methodology.

2. Theoretical analyses, e.g. computational complexity.


1. Experiments, but biological, not cognitive.

e.g. record cell firing, PET and MRI scans, lesions

2. Also theoretical

3. Also computational: build computer models of mind, e.g. neural networks


1. Judgments of grammaticality: syntax

2. Semantics, pragmatics: data, theory

3. Computional models


Ethnography, but pay attention to how people think. Like psychology, but less experimental, more cross cultural.

Psychologists are also doing cross-cultural studies.


Everyone is theorizing, but there are different methods of empirical evaluation:

Each of these has limitations, but all can contribute toward evaluating theories of mind.

Evaluating approaches to mental representation

See Mind, p. 15, Box. 1.1.

Will increases in computer speed lead to computer intelligence surpassing human intelligence?


Key points in H. Simon, "What is an explanation of behavior?"

Herbert Simon is one of the founders of artificial intelligence and cognitive science.

Phil/Psych 256

Computational Epistemology Laboratory.

Paul Thagard

This page updated Sept. 10, 2012