Gk

Gk - Transcript

General Knowledge General


Structure of Semantic Memory
Background Feature Comparison Model Prototype Approach Exemplar Approach Network Models Background Recall of Scripts Schemas Memory Selection Schemas Boundary Extension Schemas Memory Abstraction Schemas Memory Inferences Schemas Integration in Memory Conclusions



Schemas Scripts


Semantic Memory Semantic


General Conceptual Knowledge Lexical Knowledge e g apple and of apple banana of

Organized e g pencil related to pen think Organized



Categories and Concepts
Category a class of objects that belong together e g variety of objects fruits or apple variety Concept mental representation of a category



Concepts allow us to make inferences when we Concepts encounter new instances e g read chair encounter Natural concepts vs Artifacts Artifacts
apple dog tree table pen chair





Questions
Organization and Structure Storage Inferences Cognitive Economy Relatedness and Similarity

Feature Comparison Models Feature






Concepts list of features or attributes e g Smith Concepts Shoben and Rips 1974 Shoben Defining vs Characteristic Features Characteristic Decision Process 2 Stages Stage 1 global comparison Stage 2 compare defining features Research Research Typicality Effect Category Size Effect faster RTs for membership in Category small category NOT explained small Other Problems

The Sentence Verification Technique The
For each of the items below answer as quickly For as possible either true or false as
1 2 3 4 5 6 7 8

A poodle is a dog A squirrel is an animal A flower is a rock A carrot is a vegetable A mango is a fruit A petunia is a tree A robin is a bird A rutabaga is a vegetable

Prototype Approach Prototype


Classical View vs Protoype Rosch Idealized version of category example Graded membership not all memebers

Bachelor Unmarried male Bachelor
But which of the following are really bachelors
1 My 32 year old cousin John who works at a My bank in Chicago bank 2 My 6 month old son Tim 3 An elderly Catholic Priest

Characteristics of Prototypes Characteristics
1 2 3 4 5

Prototypes are supplied as examples of a category Prototypes serve as reference points Prototypes are judged more quickly after priming Prototypes can substitute for a category name in a Prototypes sentence sentence Prototypes share common attributes in a family Prototypes resemblance category resemblance
No one attribute shared by all members In out phenomenon

Mervis Catlin Rosch 1976 Mervis


Group 1 generated examples for 8 different categories
Birds robin sparrow Fruits Sports Etc



Group 2 provided prototype ratings low to high for each provided ratings example example
e g sparrow 7 high penguin 2 low



Strong correlation between frequency and rating Typicality Effect

Lexical Decision Task Lexical
The following items Decide whether each item is a word yes or not a word no Respond by pressing the yes button or the no button
apple table tadjld mountain pudor

What Is a Priming Effect Priming
Lexical Decision Task doctor hospital doctor Y N 450 ms 400 ms 450 ms automobile doctor Y N

Y N

Robin

Penguin

550 ms Bird Robin 480 ms

670 ms Bird Penguin 660 ms

Group 1 Prototype Ratings Group
e g vehicles car truck tractor sled vegetable carrots beets eggplant vegetable clothing shirt sweater vest clothing

Group 2 List attributes possessed by each item
e g car wheels steering wheel doors e g etc

Score What proportion of an item s attributes were shared by other category member s shared Strong correlation between score and prototype Strong rating rating

Levels of Categorization 1 Levels


Superordinate Level
furniture animals tools



Basic Level
chair cat screwdriver



Subordinate Level
desk chair persian cat phillips screwdriver

Levels of Categorization 2 Levels
Superordinate level Basic level Subordinate level
1 2

Basic level names are used to identify objects Members of basic level categories have more Members attributes in common attributes Basic level names produce the priming effect Experts use subordinate categories differently

3 4

Carrot

Vegetable

Same Different Priming Effect

Same Different No Priming Effect

Expert Superordinate

Novice

Basic

10

11

Subordinate

10

6

Exemplar Approach Exemplar


Store specific instances or examples exemplars Store instances Decision process comparison of new item to Decision stored exemplars exemplars Comparison to prototype approach Comparison
Stored Representation Prototype Approach Exemplar

Typical or idealized representation

Stored representation Specific members instances

Absence of features characteristic vs defining

Exemplar Approach Exemplar


No abstraction no summary representation Storage requirements May be more suitable for smaller categories Evidence from Social Psychology stereotypes Individual differences Co existence prototypes and exemplars Strategic differences Explaining concept learning Explaining concept

Network Models Network






Semantic networks concepts and connections nodes and concepts links links Collins Loftus Node concept Link relation or connection Link Spreading activation Sentence verification intersections Explaining Typicality Effect Anderson s ACT Theory

Activation Spread Activation
Does a robin breathe

Anderson Anderson


ACT Adaptive Control of Thought Declarative vs Procedural Knowledge Propositional Networks Proposition the smallest unit of knowledge with a truth value truth Proposition node link Working Memory active part of Long Term Working Memory Memory



Susan gave a white cat to Maria who is the president of the club

1 Susan gave a cat to Maria 2 The cat was white 3 Maria is the president of the club

Schemas Schemas
1 2 3 4 5 6

Larger cognitive units Packages of interrelated units Used to interpret encode understand and Used remember new instances remember Provide expectations about what should occur Provide expectations top down top Default values parts filled in when schema Default activated activated Sometimes errors

When Lisa was on her way back from When the store with the balloon she fell and the balloon floated away the

Scripts Scripts






Simple well structured sequence of events Simple associated with a highly familiar activity associated Schema vs script Recall of scripts Different from conceptual categories Barsalow Different Sewell 1985 Sewell Script Identification early vs late Trafimow Script and Wyer 1993 and Appreciating the similarity of scripts

Trafimow Wyer 1993 Trafimow


4 different scripts
Photocopying a piece of paper Photocopying Cashing a check Making tea Taking the subway



Irrelevant details added e g taking candy out of pocket Script identification information presented first or last Filler Recall of script related events 23 vs 10 script identified first script identified last

Schemas and Memory Selection Schemas


Remember best info consistent with schema Remember consistent or inconsistent inconsistent Brewer Treyons 1981 Rojahn Pettigrew 1992 Incidental vs Intentional learning



Schemas and Boundary Extension Schemas

Schemas and Memory Abstraction Schemas
Abstraction Abstraction Verbatim vs Gist Constructive Approach


Bransford Franks 1971 Holmes Colleagues 1998


Pragmatic Approach
Murphy Shapiro 1994 Attention Allocation Control



C P compatible

Schemas and Inferences in Memory Schemas


Bartlett 1932 Ebb vs Bartlett Interaction of prior knowledge and experience and Interaction formation of new memories formation War of the Ghosts story Initial vs Delayed Recall Bransford et al 1972 Implications e g advertising Implications



Schemas and Integration in Memory Schemas


Final process in memory formation Result of selection abstraction and inference Result selection inference Important Integration and Delayed Recall Integration and Limited Memory Capacity