turn to cognitive perspective brief history inspiration from other fields inspiration from within...
TRANSCRIPT
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