General Knowledge

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General Knowledge

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

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Semantic Memory

• General Conceptual Knowledge
• Lexical Knowledge (e.g., apple and )
• Organized - (e.g., pencil related to pen
  think of apple ---- banana
• Categories and Concepts
• Category - a class of objects that belong
  together (e.g., variety of objects fruits or
  apple)
• Concept - mental representation of a category

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• Concepts allow us to make inferences when we
  encounter new instances (e.g. read chair)
• Natural concepts vs. Artifacts
• Questions
• Organization and Structure?
• Storage?
• Inferences?
• Cognitive Economy?
• Relatedness and Similarity?

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Feature Comparison Models

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

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Feature Comparison Model
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The Sentence Verification Technique

• For each of the items below, answer as quickly
  as possible either true or false.
• 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.

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Comparison Decision in Feature Comparison Model
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Prototype Approach

• Classical View vs. Protoype
• Rosch
• Idealized version of category (example)
• Graded membership - not all memebers

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Bachelor Unmarried, male

• But which of the following are really bachelors?
• My 32-year old cousin, John, who works at a bank
  in Chicago
• My 6 month old son Tim
• An elderly Catholic Priest

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Characteristics of Prototypes

• 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 sentence.
• Prototypes share common attributes in a family
  resemblance category.
• No one attribute shared by all members
• In / out phenomenon

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Mervis, Catlin, Rosch (1976)

• Group 1 generated examples for 8 different
  categories
• Birds? robin, sparrow
• Fruits?
• Sports?
• Etc.
• Group 2 provided prototype ratings (low to high)
  for each example
• e.g., sparrow 7 - high
• penguin 2 - low
• Strong correlation between frequency and rating
• Typicality Effect

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Demonstration 7.2 Prototypes as Reference Points
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Lexical Decision Task
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
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What Is a Priming Effect?
Lexical Decision Task
doctor
Y/N
450 ms
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Prototype Priming Effect
Robin
Penguin
550 ms.
670 ms.
Bird
Bird
Robin 480 ms.
Penguin 660 ms.
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Demo 7.3 Substituting Prototypes Nonprototypes
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• Group 1 Prototype Ratings
• e.g., vehicles car, truck, tractor, sled
• vegetable carrots, beets, eggplant
• clothing shirt, sweater, vest
• Group 2 List attributes possessed by each
  item
• e.g., car wheels, steering wheel, doors,
  etc.
• Score What proportion of an items attributes
  were shared by other category members
• Strong correlation between score and prototype
  rating.

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Prototype Ratings for Words in Three Categories
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Levels of Categorization

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

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Carrot
Vegetable
Same / Different
Same / Different
Priming Effect
No Priming Effect
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(No Transcript)
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Exemplar Approach

• Store specific instances or examples (exemplars)
• Decision process comparison of new item to
  stored exemplars.
• Comparison to prototype approach

• Absence of features -- (characteristic vs.
  defining)

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Picture of Dog
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Exemplar Approach

• 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!

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Network Models

• Semantic networks
• (concepts and connections ---- nodes and links)
• Collins Loftus
• Node concept
• Link relation or connection
• Spreading activation
• Sentence verification ---- intersections
• Explaining Typicality Effect
• Andersons ACT Theory

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Example of a network structure
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Portion of Semantic Net
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Activation Spread
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Hierarchical Network Structure
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Levels Effect
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Anderson

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

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Susan gave a white cat to
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.
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Propositional Network for Susan Gave
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Partial Representation of a Cat in Memory
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Schemas

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

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

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

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Trafimow Wyer (1993)

• 4 different scripts
• Photocopying a piece of paper
• 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)

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Demo 7.5 Nature of Scripts
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Picture of Room
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Schemas and Memory Selection

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

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Schemas and Boundary Extension
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Schemas and Memory Abstraction

• Abstraction
• Verbatim vs. Gist
• Constructive Approach
• Bransford Franks (1971)
• Holmes Colleagues (1998)
• Pragmatic Approach
• Murphy Shapiro (1994)
• Attention Allocation / Control
• C P compatible

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Demo 7.7 Contructive Memory
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Constructive Memory part 2
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Murphy Shapiro (1994)
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Schemas and Inferences in Memory

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

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Schemas and Integration in Memory

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