The History and Methods of Cognitive Psychology

• Why look at the history of psychology?– Science as a process, not a set of answers– Borrowing and reinventing old ideas

• Movements in the psychology of cognition– Structuralists: 1870-1920– Behaviorists: 1920-1960– Cognitive psychology: 1956-present

Structuralism/Introspectionism

• Methods– Anectdotes– Describe sensory experience

• Avoid “stimulus error”

– Stream of consciousness– Test self

• Ebbinghaus as a cross-over to scientific psychology

• Problems– Different people get different results– Cannot introspect on all processes– Introspections can be wrong

IntrospectionismWilhelm Wundt

Ebbinghaus: Tested self, but experimentally

Introspections can be wrong• Unconscious influences on judgments

– Right-side preference

• Change-blindness: difficulty detecting obvious changesfrom one scene to another– And “Change-blindness blindness” - people don’t think that

they would have a hard time detecting obvious changes

Behaviorism• Only care about behavior

– Don’t hypothesize internal events

• Stimulus-response (S-R) psychology• Align psychology with science• Empiricist

– Tabula rasa = blank slate– Empirical = uses experimental research methods

• Problems with behaviorism– Animals are not infinitely malleable, nor tabula rasas– Not just learning S-R combinations

• Tolman’s maze experiments• Learning by observing - don’t need reward

– Language

Acquired taste aversion is very strongTaste-to-stomache-ache associations are easily built

Not all associations are equally learnable

Learnlights->shocktaste->stomache ache

Don’t learnlights->stomache achetaste -> shock

There’s more toassociation than simplyreinforcement history

Tolman’s cognitive maps

Food

Rat learns more than just the response (route)necessary to get reward

Learning is possible even if not personally reinforced

Learning by observing (Thorndike, 1911)

Noam Chomsky: Languagecannot be learned solely bylearning stimulus-responseassociations.

Cognitive Psychology• Mental processes exist and can be studied• Need to give abstract, functional descriptions of behavior• Use rigorous empirical methods• Active processing

– Not just passive response to stimulus

• Understanding minds through decomposition– Flow charts

• Information processing and representation– Transformation of information– Representation = symbol that stands for something the real world– Computer metaphor

Developing Functional Descriptions

ABCDEF

Input

ABCDEFF

Mirror

Duplicate?

Duplicate?

Add one?

Add flipped shape to left side?

Add flipped version of rightmost shape to left side?

Flowcharts for breaking down cognition into pieces

Abstract description of the stages necessary for cognition,and how the stages are ordered and transfer information

Response times for analyzing information processing