Lecture 10 - Categorisation and Concept Formation

Question 1

Define a concept

Answer 1

Mental representation
Based sharing common properties
Items same class

Question 2

Outline concept formation

Answer 2

Induction concepts divide items into classes
According their shares properties
Categorisation

Question 3

Why are concepts not always defined by specific features

Answer 3

Sometimes do not have necessary or sufficient features define them
Polymorphous
E.g. what is a defining feature of a game

Question 4

What are the 3 types of concept

Answer 4

1. Basic level concept
2. Superordinate concept
3. Abstract concept

Question 5

Define basic level concept

Answer 5

Similarity or perceptual qualities

E.g. bird, flower

Question 6

Define superordinate concept

Answer 6

Groups basic level concepts
Not based perceptual similarity
E.g. politician, tools

Question 7

Define abstract concept

Answer 7

Not refer to individual entity
But to some property, relation or state
E.g. sameness, truth

Question 8

Outline Bhatt, Wasserman, Reynolds and Knauss 1998 study on basic level concept formation in animals

Answer 8

Pigeons chambers choice 4 response keys
Learned peck different keys for example mars of each 4 categories: flowers, cara, people, chairs
Controlled for colour by using variety coloured
Able respond correctly new exemplars never seen before

Question 9

Outline RESULTS Bhatt, Wasserman, Reynolds and Knauss 1998 study on basic level concept formation in animals

Answer 9

Birds had formed concept flowers, cars, people, chairs
Performance more accurate with training 80%
Than with novel, test stimuli 50-60%

Question 10

Outline Exemplar Theory of basic level concept formation

Answer 10

Learn about every instance independently
Classify novel examplars via similarity learned instances
Store everything you see
Always perform best at what you have seen

Question 11

Outline Prototype Theory of basic level concept formation

Answer 11

Abstract prototype corresponding to central tendency of training exemplars
Don’t actually store images what you have seen = more viable as storing everything you see takes up capacity
Hold central idea what you have seen = averaging
Could be better at something you have never seen before

Question 12

Summarise Prototype Model in helping us to Categorise

Answer 12

Category judgements made by comparing new exemplar to prototype

Question 13

Summarise Exemplar Model in helping us to Categorise

Answer 13

Judgements made by comparing new exemplar to all old exemplars of a category or to exemplar that is most appropriate

Question 14

Relate Exemplar Theory to Bhatt, Wasserman, Reynolds and Knauss 1998 study on basic level concept formation in animals

Answer 14

Animals storing info about training exemplars

Why they were more accurate at training exemplars to novel test stimuli

Question 15

Explain why Homa et al 1981 argues humans show Prototype effect

Answer 15

Categorise prototype more accurately than training stimuli

Even though never seen before

Question 16

Outline Aydin and Pearce 1994 prototype effect in pigeons

Answer 16

Artificial positive (ABC) and negative (DEF) prototypes.
Never see test stimuli in training.
Birds trained 3 element displays created by distorting prototypes
Taught 3 positive patterns always paired with food, 3 negative we’re not
Birds pecked more at positive

Question 17

Outline Aydin and Pearce 1994 RESULTS prototype effect in pigeons

Answer 17

Responded more positive prototype than any of the trained positive stimuli and less to negative prototype than negative trained stimuli
Prototype effect

Question 18

Outline Whittlesea 1987 study on prototype effects

Answer 18

Lists 1, 2 and 3 all differ from prototype by 2 letters
List 1 more similar to list 2 than list 3
Only trained on list 1. Tested on 1,2,3

Question 19

Outline PREDICTIONS Whittlesea 1987 study on prototype effects

Answer 19

Prototype predicts: list 1 = list 2 = list 3. All lists should be learnt the same

Exemplar predicts: list 1 best learnt, then list 2, finally list 3

Question 20

Outline RESULTS Whittlesea 1987 study on prototype effects

Answer 20

Humans show results consistent with Exemplar Theory

List 1 easiest

Question 21

Conclusions of Prototype Theory and Exemplar Theory

Answer 21

Humans and animals retain info about training items/exemplars
But show prototype effect
Variation Exemplar Theory explain prototype effect

Question 22

Outline Aydin and Pearce experiment on how the Exemplar Theory can explain the Prototype effect

Answer 22

Explain why birds peck more positive prototype to trained stimuli
Examine learning each component feature
Storing different parts stimulus rather thing as whole
Looking individual components we can identify something we have never seen before quicker

Question 23

Outline the combined theory of Feature Theory

Answer 23

Rather look stimulus as a whole
Look at individual components
Features associated with category membership

Question 24

Compare Feature Theory with Exemplar Theory

Answer 24

Exemplar: classifies basis similarity of whole stimulus. Take everything you have seen as a whole

Feature: classified basis sharing features stored exemplars, break down individual components.

Categories form means associative learning. Features category are associated with category label.

Question 25

Does category learning show blocking?

Answer 25

Blocking key characteristic associative learning.

Pairing only produce association between X and category if category is surprising

Question 26

Outline Shanks 1990 study of Exemplar theory and Associative Theory

Answer 26

Medical symptoms paired with disease diagnosis
Subjects must predict disease from symptoms
1 disease common - flue
1 rare - NA
1 target symptom, 2 non target symptom
Presented more cards for common disease
Asked which does headache predict more? NA or flu? Same number pairings for each disease

Question 27

Outline BLOCKING in Shanks 1990 study of Exemplar theory and Associative Theory

Answer 27

If all that matters is number of pairings then headaches should be as good as predicting flu as NA

Headache paired flu, runny nose also present = loads of experience. Headache = blocked.
Headache paired NA rash present = not sure on rash = pay attention and learn

Question 28

Outline link between Exemplar Theory and Associative Theory view of Shanks 1990 study

Answer 28

Exemplar Theory: just likely predict flu as NA

Associative Theory: more likely choose rare NA.

Question 29

Outline RESULTS Shanks 1990 study of Exemplar theory and Associative Theory

Answer 29

Proportion common disease flu diagnosis: .37

Proportion rare disease NA diagnosis: .63

Associative learning best explanation performance categorisation task in humans

Question 30

Outline superordinate categories

Answer 30

Members not necessarily physically similar but share common associate

Question 31

Outline Wasserman, De Volder and Coppage 1992 study initial training

Answer 31

Pigeons trained slides people, chairs, cars, flowers

Reinforced making pecking response 1 people and chairs, making response 2 cars and flowers = superordinate categories

Question 32

Outline Wasserman, De Volder and Coppage 1992 study secondary training

Answer 32

Taught make response 3 to people and response 4 to cars

Tested with chairs and flowers to make response 3 and 4

Question 33

Outline Wasserman, De Volder and Coppage 1992 study RESULTS

Answer 33

Response 3 to chairs and 4 to flowers correct

Animals can form superordinate categories

Question 34

What is Pearce 1997 argument on superordinate level concept formation in animals

Answer 34

Not true categorisation as seen in humans
But simply associative learning
We are more complex
But we need to specify exactly how what is more complicated so we can test

Question 35

Outline abstract concept formation in animals using match to sample technique (MTS)

Answer 35

Bird shown sample key e.g. red then given choice red or green
Peck same colour shown
Master this
But poor transferring skill to different colours
Not really learned concept
Do not learn rule

Question 36

Outline Wasserman, Hungary and Kirkpatrick-Steiger 1995 study on Match to sample technique (MTS)

Answer 36

Pigeons show complex stimulus displays, given red or green key
Trained arrays 1 set of specific icons
Rewarded for pecking red on same trials, green different trials
Perform above Chance for unfamiliar stimuli not in training stage
Evidence some generalisation of abstract concept