Turn to Cognitive Perspective

Brief history

Inspiration from other fields

Inspiration from within psychology

A framework: we’re talking about scientific method

Observe

TheorizeTest

Example: what’s this?

1. Fool with it.

2. Develop a hypothesis

3. Try it to see if you’re right

Pot trammel, used to position cooking pots higher or lower over a fire.

1. Fool with it.

2. Develop a hypothesis

3. Try it to see if you’re right

Observe

TheorizeTest

Philosophy (prior to mid 18th)

Observe

TheorizeTest

Introspectionism

• First attempt to apply scientific method to thought (1880s).

• Wilhelm Wundt. Edward Titchener

• Goal: description of the contents of consciousness; find irreducible “elements of consciousness.

• Method: introspection.

Introspectionism

Observe

TheorizeTest

Only use introspection to test

Introspection

• Only covers conscious processing

• Poor reliability between subjects

• Watching a mental process changes it

• Not making much progress

Turn to behaviorism

• Focus on observables only

• Theory must be parsimonious

• Break behavior down into irreducible concepts

Focus on observables

Note that psychology became a science not of the mind, not of

thought, but of behavior.

Parsimony

Shared with all sciences; this was lacking in introspectionism, and was really emphasized in behaviorism.

E.g., all of behavior boiled down to a few simple laws of learning: operant, and classically conditioned response

Irreducible concepts

Again, all sciences have this as their goal; introspectionism had it as a goal as well, but couldn’t come up with good irreducible concepts. Behaviorism had good candidates: free operant and the conditioned response.

What was lacking in this perspective, and where are we now?

Observe

TheorizeTest

“Observables only” in theory development was too restrictive

Overview of changes

• Inability to account for all animal behavior indicated something might be wrong.

• Inability to go from animal models to human behavior indicated it was incomplete

• Posing abstract constructs suggested as what was needed to solve these problems.

• Inspiration from other fields to use abstract constructs.

Inability to account for all animal behavior

Work from ethology--1

Critical period: A time when the animal is able to learn particular information rapidly and with little exposure; if the time window is missed, the animal learns with greater effort or not at all.

Critical period--example

Some birds (e.g., ducks, geese) follow the first large thing that they see when they are hatched--usually first large thing is mom.

The tendency to follow first large thing has a critical period.

What happens if first large thing is not mom?

Lorenz as mom

Lorenz as mom

Critical period in humans?

Johnson and Newport (1989)A case for the critical period Subjects       46 native Chinese or Korean learners of English       In the US for at least 5 years       Age of arrival: 3-39 years old Method       Grammaticality Judgment Task

Results       Accuracy on grammaticality test correlated with age of arrival for subjects who arrived in US before puberty       Accuracy on grammaticality NOT correlated with age of arrival for subjects who arrived in US after puberty

Other work from ethology

Fixed action pattern--this is a complex behavior that emerges, full-blown, with little opportunity for practice or reward.

Fixed action pattern--stickleback

Fixed action pattern in humans?

Eyebrow flick

Fixed action pattern--coy

• Catch eye

• Look down, smiling

• Catch eye, smile,cover mouth

Fixed action pattern

Overview of changes

• Inability to account for all animal behavior

• Inability to go from animal models to human behavior

• Apparent need to pose abstract constructs.

• Inspiration from other fields to use abstract constructs.

Going from animals to humans

Language

Skinner, 1957

Chomsky, 1959

Language is generative

Skinner, 1957

The behaviorist account of language:

Child utters sounds at random; is reinforced for utterances that are close to appropriate. Language is shaped.

Behaviorist accounts ignore that language is generative. This means that virtually everything you say and hear is novel. It can’t be the case that you understand it because of reinforcement in the past, because you’ve never heard it before.

Chomsky, 1959

Behaviorist account is wrong

Need for abstract constructsGenerativity seems to call for rules, similar to y = mx +b

Thoughts about baby

trying to hug self

Translation rules

“That is so cute!”

Thoughts about baby

Translation rules

“That is so cute!”

“How many handsdid Aristotle have?”

Speech Interpretation

Interpretation ofquestion

Find answerin memory

Make decision:answer or not?

Phrase theanswer

Create motorcommands to

lips, tongue, etc

“Two”

In memory research, data seemed to call for some discussion of subjects’ strategies.

Need for abstract constructs

E.g., subjects hear a mixed list, but report it back in categories. When asked, they say that they are doing so because it helps them to remember.

Abstract constructs

A theoretical set of processes and representations (e.g., a rule for

language, or a strategy in memory)

E.g., why do people forget phone numbers after 30 seconds?You could propose that there is a short term memory, which holds information for 30 seconds or so. Short term memory has representations (e.g. of the number “8”and processes (e.g., refresh). It’s like a mini-theory.

Abstract constructs

This drove behaviorist nuts, because it violated one of their tenets.Which one?

Abstract constructs

This drove behaviorist nuts, because it violated one of their tenets.

Which one?

Deal only with observables.

“Where is this short term memory?I can’t see it.” (uttered in snide voice)

Abstract constructs--other fields

Computer science (artificial intelligence research) was crucial. Their whole field was based on abstract constructs, with no loss of rigor.

In the 1950’s, AI had progressed beyond “glorified adding machines.”

Newell & Simon’s Logic Theorist (1956)

• Discovered proofs in symbolic logic, of the kind originally presented in Whitehead & Russell’s Principia Mathematica

• Program contains a list of axioms, a list of previously proven theorems, and a manner in which axioms may be combined

• Program given new statement which it must prove.

• Successfully proved 38 of the first 52 theorems in Principia Mathematica (usually in less than 5 minutes each).

• Not just a cool program--they claimed that people really solve problems this way.

• Other programs were simply cool.

Greater usefulness of brain data

What’s wrong with this patient?

“What happened to you?”Speech

InterpretationInterpretation of

question

Find answerin memory

Make decision:answer or not?

Phrase theanswer

Create motorcommands to

lips, tongue, etc

“bus”

Abstract constructs--recap

1. It appeared that certain phenomena could only be accounted for by using abstract constructs, not behaviorist principles.

2. Abstract constructs were forbidden in behaviorist thinking--they were rejected as “mystical,” “unscientific”

3. Other fields (artificial intelligence, neurology) used abstract constructs with no apparent loss of rigor.

What replaced behaviorism?

We’ve just been listing problems with behaviorism--question:

What could replace behaviorism?

Observablestimuli

Observableresponses

Observablestimuli

Observableresponses

Abstract constructs (mind)

Huge question

How can you discover abstract constructs?

Example

Sternberg task: given a “set,” e.g., A, K, Y, W:size of the set varies.

Stimulus appears, K,and you must say “yes” or “no” if it is in the set.

Encode Search Decide Respond

K AKYW

K

AKYWHit “yes” button

How does the search work?

• Serial, exhaustive

• Serial, self-terminating

• Parallel

Serial, exhaustive

Serial, self-terminating

Parallel

Sternberg’s data

Yes=filledNo=open

Key features of cognitive strategy

• Develop alternate models of processing

• Derive signature predictions of each model

• Obtain data that allow comparison