Intro to Cog Sci
COGST 1101

[guest lecture; Tuesday, 3/25]

WOULD YOU DO MATH FOR FOOD?

WOULD YOU DO MATH FOR FOOD?

WOULD YOU DO MATH FOR FOOD?

computing = the mind


Computing is what minds do.

Computing is what minds are.

To see that, let's look at some foundational ideas from COGNITIVE PSYCHOLOGY.

cognitive psychology is about...


COGNITIVE psychology is about how the mind works.

So, how does the mind work?

so, how does the mind work?


We need a real explanation.
But what would a real explanation look like?

from metaphors to the truth

from metaphors to the truth

the truth about the brain: it is a kind of computer


How come the brain is a kind of computer?

from incidentals to the essential: what defines a cash register?


It cannot be about what it IS MADE OF.

It must be about what it DOES.

from incidentals to the essential: what defines a mind?


It cannot be about what it IS MADE OF.

It must be about what it DOES.

To understand what it does, and why,
we must consider the problems that it has evolved to solve.

minds consist of computations: example #1 (perception)


the lightness perception problem

minds consist of computations: example #2 (thinking)


the supermarket queuing problem

minds consist of computations: example #3 (action)


the motor control problem

minds consist of computations: example #3 (action)


the motor control problem

minds consist of computations: example #3 (action)


the motor control problem


"At Cornell University, for instance, researchers have been investigating how flies recover when their flight is momentarily disturbed.
Among their conclusions: a small group of fly neurons is solving calculus problems, or what for humans are calculus problems."

the computer metaphor revisited


the computer metaphor is NOT a metaphor:

minds literally consist of computations!


[The CtM challenge]

computation, representation, and forethought


A mind is a computational system that represents [certain aspects] of the universe and is capable of some forethought.

defining a mind: an explanatory move in three parts


  • Part I: putting computation to work —
    • Clarifying the relationship between computation and cognition
    • Putting natural computation to work
    • Introducing a revolutionary innovation: symbols and representation
  • Part II: representation —
    • What and how should a system represent, so as to sustain cognition
    • Kinds of representations
    • Representation and causality
    • Kinds of minds
    • Forethought and its role in cognition
  • Part III: how the environment and evolution make minds possible —
    • Three things everyone should know about the way the universe works
    • Implications for evolving minds

part I: putting computation to work


By saying cognition = computation, do I mean that every piece of chalk is doing something cognitive?

— No.

Computation has to do with cognition if it is USED by some coherent entity (system) to further its goals, the foremost of which is to stay coherent.

The goals, of course, need not be explicit or "conscious" in any sense.

putting computation to work

Ballistic missile control in castle defense.

A REVOLUTION in putting computation to work: internal representation

Ballistic missile control in castle defense.

A REVOLUTION in putting computation to work: internal representation


"If the organism carries a small-scale model of external reality and of its own possible actions within its head, it is able to try out various alternatives, conclude which is the best of them, react to future situations before they arise, utilize the knowledge of past events in dealing with the present and the future, and in every way react in a much fuller, safer, and more competent manner to the emergencies which face it."

— from The Nature of Explanation, by Kenneth Craik (1943)

defining a mind


  • Part I: computation and representation —
    • Clarifying the relationship between computation and cognition
    • Putting natural computation to work
    • Introducing a revolutionary innovation: symbols and representation
  • Part II: representation —
    • What and how should a system represent, so as to sustain cognition
    • Kinds of representations
    • Representation and causality
    • Kinds of minds
    • Forethought and its role in cognition
  • Part III: how the environment and evolution make minds possible —
    • Three things everyone should know about the way the universe works
    • Implications for evolving minds

part II: how representations work

The orderly procession of the planets across the sky is reflected in the causal structure of the armillary mechanism (or, in a more modern example, the planetarium projector).

As a consequence, setting it to any target date — past, present or future — reveals the expected positions of the represented celestial bodies on that date:

date Jan. 2014 Feb. 2014 Mar. 2014 Apr. 2014
positions of planets [...] [...] [...] [...]


  • Representation always relies on ANALOGY between structures (here, armillary / solar system).
  • In natural autonomous cognitive systems, the analogy is emplaced by evolution and enforced by physical law.

representation by analogy: [implementing/simulating] a computation

  • What does it mean for two systems to implement analogous computations?
  • Two system implement analogous computations if the causal structure of one mirrors the causal structure of the other, so that the parallels between the two hold consistently over time.
an inductor-capacitor circuita mass on a spring

defining a mind


  • Part I: computation and representation —
    • Clarifying the relationship between computation and cognition
    • Putting natural computation to work
    • Introducing a revolutionary innovation: symbols and representation
  • Part II: representation —
    • What and how should a system represent, so as to sustain cognition
    • Kinds of representations
    • Representation and causality
    • Kinds of minds
    • Forethought and its role in cognition
  • Part III: how the environment and evolution make minds possible —
    • Three things everyone should know about the way the universe works
    • Implications for evolving minds

part III: three things everyone should know about the way the universe works


  • Time is directional: you can't go back and undo things done wrong (although sometimes there may be a chance to redo them).
  • Life is fragile: for most species, most of the time, the margin of error that the animal can afford to escape death (or extinction) is very small (think of the chickadee).
  • The universe has "inertia": the future is similar to the past (always mostly often enough to make survival feasible, if you are smart enough).

the universe has inertia


how the nature of the environment and evolution make minds possible


  1. Time is directional
  2. Life is fragile
  3. The universe has inertia

Corollary: foresight/forethought —

  • can be advantageous (because of 1 and 2);
  • is possible (because of 3)

summary: what a mind is


  • Time is directional
  • Life is fragile
  • The universe has inertia

Corollary: foresight/forethought —

  • can be advantageous (because of 1 and 2);
  • is possible (because of 3)

A mind is a computational system that represents [certain aspects] of the universe and is capable of some forethought.

the happiness of pursuit


Note: the background reading material for today was from The Happiness of Pursuit (Basic Books, February 2012). A Kirkus starred selection and Must-Read in new nonfiction. Available also in Italian.