Chapter 9-Conceptual Knowledge Pt. 1

Question 1

Conceptual knowledge

Answer 1

Knowledge that enables us to recognize objects and events and to make inferences about their properties

Question 2

Concept

Answer 2

Mental representation used for a variety of cognitive functions

Question 3

Categorization

Answer 3

Process by which things are placed into groups called categories

-categories are all possible examples of a particular concept

Question 4

Why categories are useful

Answer 4

Helps us understand individual cases not previously encountered

“Pointers to knowledge”

• provide general info about an item
• allow us to identify the special characteristics of a particular item

Question 5

Definition approach to categorization

Answer 5

• determines category membership based on whether the object meets the definition of the category
• does not work well
• not all members of everyday categories have the same defining features

Question 6

Family resemblance

Answer 6

• proposed to deal with the problem of definition

- things in a category resemble one another in a number of ways

Question 7

Determining categories by similarity

Answer 7

-compare object to a standard

Prototype approach: the standard is determined by averaging category members

Exemplar approach: the standard is created by considering all of the examples you’ve seen before

Both approaches belong to family of resemblance

Question 8

Prototype Approach

Answer 8

Prototype=typical

An average representation of the “typical” member of a category

Characteristic features that describe what members of that concept are like

An average of category members encountered in the past

Question 9

Coglab: prototype

Answer 9

Each trial you are shown a dot pattern and asked to classify it as belonging to category A or category B
-each dot pattern was a variation of one of two fixed prototype random dot patterns

In test phase, a new set of dot patterns was presented

• the dot patterns in the testing phase were of four types
• one was the prototype that corresponds to the A category
• another was the prototype that corresponds to the B category
• the other two patterns were new variations of these prototypes

Question 10

Coglab: prototype result

Answer 10

Reaction time for the unseen prototypes was faster than the reaction time for the unseen variations of the prototypes

Supports idea that people do develop some average of the random pairs

Question 11

Posner and Keele experiment

Answer 11

They had three different prototypes

Participants see four distortions of each prototype, which are changed until they can discriminate them

Learn to categorize patterns with feedback

Question 12

Posner and Keele results

Answer 12

Test on:

Old distortions=easy

New distortion=hard

New far distortion=hardest

Prototype=easy

Result: prototypes are explicitly extracted from examples, and serve as representation for category

Question 13

High prototypicality

Answer 13

Category member closely resembles category prototype

Question 14

Low prototypicality

Answer 14

Category member does not closely resemble category prototype

Question 15

Rosch-The Prototype Approach

Answer 15

• Participants judged objects on a scale of 1 (good example of a category) to 7 (poor example)
• rated birds and furniture

Creates an index of high and low prototypicality

Gives us an independent variable that we can use in other experiments

Question 16

Strong ______ resemblance between prototypicality and family resemblance

Answer 16

Positive

When items have a large amount of overlap with characteristics of other items in the category, the family resemblance of these items is high

Low overlap=low family resemblance

Question 17

How to measure family resemblance

Answer 17

Rosch and Mervis

List the characteristics of the following items
-chair, sofa, mirror, telephone

Chair and sofa share a lot of common characteristics (mirror and telephone do not)

High family resemblance corresponds to high prototypicality (chair)

Low family resemblance corresponding to low prototypicality (telephone)

Question 18

Typicality effect

Answer 18

Prototypical objects are processed preferentially

• high prototypical objects have faster RT
• sentence verification technique (apple/pomegranate)

Question 19

Mervis et al

Answer 19

Prototypical objects are named first

E.g. Please list as many birds are you know

Question 20

Rosch priming task

Answer 20

Prototypical category members are more affected by a priming stimulus

Hearing “green” primes a highly prototypical “green” which has the fastest RT

Question 21

Table 9.1

Answer 21

Review in lecture notes

Question 22

The exemplar approach

Answer 22

“Standard”=exemplar (which are examples of actual category members a person has encountered before)

• explain typicality effect
• easily takes into account atypical cases
• easily deals with variable categories

Question 23

How is the exemplar approach similar to prototype view

Answer 23

Representing a category and do not define it

Question 24

How is the exemplar approach different to prototype view

Answer 24

Representation is not abstract

Descriptions of specific examples (the more similar a specific exemplar is to a known category member, the faster it will be categorized)

Question 25

Posner and Keele and the exemplar approach

Answer 25

- They had participants learn distortions from four prototypes with 1bit/dot distortion and 5bit/dot distortions - tested using 7.7bits/dot distortion - during test, those who got training with 5bits/dot distortion did better than 1 bit/dot distortion If only doing prototype 1 and 5, they should have the same results if taking average which wasn’t true

Question 26

Prototypes or exemplars

Answer 26

Early in learning people are bad at taking into account “exceptions” but later exemplars for the exceptions would be added to the category Exemplars may work best for small categories Prototypes may work best for larger categories

Question 27

Hierarchical organization

Answer 27

Kind of organization in which larger, more general categories are divided into smaller, more specific categories to create a number of levels of categories Global (superordinate) e.g. furniture Basic e.g. table Specific (subordinate) e.g. kitchen table

Question 28

Basic level as “privileged”

Answer 28

- more common features given by participants for basic level category - quicker to identify basic level category member as a category member Listening properties of furniture, table, and kitchen table From global to basic results in increase in info From basic to specific results in little gain in info

Question 29

More evidence that basic level is special

Answer 29

- people almost exclusively use basic level names in free naming tasks (think of demo) - children learn basic level concepts sooner than other levels - basic level is much more common in adult discourse than names for superordinate categories - different cultures tend to use the same basic level categories

Question 30

To fully understand how people categorize objects, one must consider

Answer 30

- properties of objects | - learning and experience of perceivers

Question 31

Results of Tanaka and Taylor’s expert experiment

Answer 31

Experts used more specific categories to name birds whereas non experts used more basic categories

Question 32

Semantic networks

Answer 32

- concepts are arranged in networks that represent the way concepts are organized in the mind - Collins and Quillian Node=category/concept Concepts are linked Model for how concepts and properties are associated in the mind

Question 33

Cognitive economy

Answer 33

Shared properties are only stored at higher level nodes (in semantic networks) Exceptions are stored at lower nodes Inheritance: lower level items share properties of higher level items