Overview
General Sensory memory Short term / working memory Long term memory Memory for general knowledge
Review
Collins & Quillian (1969): Hierarchical semantic network model
Cognitive economy: To minimize redundancy, properties and facts are stored at the highest level possible in a hierarchy Semantic Network: Series of nodes which are connected by pointers or links
Review
Collins & Loftus (1975): Spreading activation theory
No hierarchy Concepts are represented in a web-like fashion A concept is represented by a node Spreading activation: Activation spreads between related concepts
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Memory for General Knowledge
Schemata & Scripts
Schema
The knowledge of what is involved in an experience Goldstein a large unit of organization used for representing concepts, situations, events, and actions in memory Galotti Assumed to exist at all levels of abstraction
Memory for General Knowledge
Schemata & Scripts
Script
Is a type of schema Specifically, it is a sequence of actions that describe an activity Schank & Ableson (1977)
Peoples accounts of going to a restaurant are very similar thus people share scripts
Bower et al. (1979)
When information from a story is given in scrambled order, people recall in a scripted order Scripts help memory performance
Memory for General Knowledge
Schemata & Scripts
Key point:
Knowledge influences memory
Useful for:
Behave appropriately in various situations Make inferences Help memory (organize recall)
Drawbacks:
False recall Memory distortions
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Concepts & Categorization
Text: Chapter 7
Definitions
Concept:
A mental representation that is used for a variety of cognitive functions, including memory, reasoning, and using and understanding language Goldstein A mental representation of some object, event, or pattern that has stored in it much of the knowledge typically thought relevant to that object, event or pattern Galotti
Definitions
Categorization:
process by which things are placed into groups called categories Goldstein
Category:
a class or a group of similar things (objects or entities)
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Functions of Categorization
Understand individual cases you have not seen before & make inferences about them reduces complexity of environment requires less learning/memorization guide to appropriate action order and relate classes (hierarchy)
Concepts: Overview
The Classical View The Prototype View The Exemplar View The Schemata View The Knowledge-Based View
Classical View of Categories
Category membership determined by a set of defining (necessary and sufficient) properties.
Bachelor: unmarried, human, adult, male Triangle: three-sided, planar, geometric figure Prime number: integer divisible by two numbers: itself and 1
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Classical View of Categories
Assumes
Concepts are not representations of specific examples but a list of characteristics in Membership a category is clear-cut: either in or out!
Problems with Classical View
No defining features for many natural-kind categories
e.g., Wittgensteins game
Consider for example the proceedings we call games. I mean boardgames, card-games, ball-games, Olympic games, and so on. For if you look at them you will not see anything in common at all, but similarities, relationships, and a whole series of them at that.
-- (Wittgenstein, 1953)
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Problems with Classical View
Typicality (graded membership)
Rosch and colleagues People judge members of a category as differing in goodness
E.g., Tiny Planet Pluto May Be Kicked Out of Solar System -- Los Angeles Times, Thursday, January 21, 1999
Typicality Rankings
Concepts: Overview
The Classical View The Prototype View The Exemplar View The Schemata View The Knowledge-Based View
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The Prototype View
Prototype:
An idealized representation of a class of objects Include features that are characteristic (i.e., typical) rather than necessary or sufficient Formed by averaging the category members we have encountered in the past Members within a category differ in terms of prototypicality
High-prototypicality Low-prototypicality
Determinants of Typicality
Rosch & Mervis (1975): Family resemblance.
[ABX, CDX, FGX, HJX...]
defining common features
[ABC, BCD, CDA, DAB...]
family resemblance (overlapping features)
Family resemblance as feature overlap
Fruit
apple: red, sweet, crunchy, round orange: juicy, sweet, round, soft coconut: hard, brown, white inside, tropical
Furniture
chair: sit on, legs, armrests, upholstery sofa: cushions, sit on, upholstery, armrests rug: stand on, woven, soft, flat
Overlapping features predicts...