CONNECTIONIST MODELLING

CAT

Has fur purrs Likes tuna

CONNECTIONIST MODELLING

CAT

Has fur purrs Likes tuna

Amphibians Fish Mammals Birds Reptiles

Vertebrates

ANIMALS

Notion of Cognitive Economy

Animal

Vertebrate

Birds Mammals

Robin Penguin Cat

alive sleeps reproduces

eats

has a spine

fly lay eggs feathered

have milk live young have hair

Evidence FOR• Sentence verification speed:

- quicker to verify across fewer levels of hierarchy (Schwartz & Reisberg, 1991)

Evidence AGAINST• Prototypicality effect – a robin is a bird; a penguin is a bird

• Familiarity effect – a cat is an animal; a cat is a mammal

Notion of Cognitive Economy

Animal

Vertebrate

Birds Mammals

Robin Penguin Cat

alive sleeps reproduces

eats

has a spine

fly lay eggs feathered

have milk live young have hair

Resolution: The Development of Connectionist

Models (Collins & Loftus, 1973)

• Abandon hierarchy

• Introduce concept of strong and weak links

Strong = familiarity/prototypical exemplars

Weak = unfamiliar/non-prototypical exemplars

Bruce and Young (1986): Information Processing Model

Expression Analysis

View-Centred Descriptions

Expression-Independent Descriptions

Structural Encoding

Face Recognition Units

Person-Identity Nodes

Name Generation

Facial Speech Analysis

Directed Visual Processing

“Cognitive System”

Burton, Bruce & Johnston, (1991): Interactive Activation and Competition Model

FRUs

‘tony’

‘paul’ ‘john’

‘bill’

NAMES

Bill Clinton

John Lennon Tony Blair

Paul McCartney

SIUs

Singer politician British American Dead Alive President PM ‘Beetle’

Burton, Bruce & Johnston, (1991): Interactive Activation and Competition Model

FRUs

‘tony’

‘paul’ ‘john’

‘bill’

NAMES

Bill Clinton

John Lennon Tony Blair

Paul McCartney

SIUs

Singer politician British American Dead Alive President PM ‘Beetle’

+

+

+

+++++

+++

+

Burton, Bruce & Johnston, (1991): Interactive Activation and Competition Model

‘tony’

‘paul’ ‘john’

‘bill’

NAMES

Bill Clinton

John Lennon Tony Blair

Paul McCartney

SIUs

Singer politician British American Dead Alive President PM ‘Beetle’

+

+

+

+++++

+++

+

PROSOPAGNOSIA

ANOMIA

SUMMARY: The Value of the Connectionist Approach

• It offers a very powerful model of memory

• It possesses cognitive economy

• It possesses biological plausibility

• It can model both intact memory and impaired memory

• It can model simple semantic memory and more complex real-world memory

• It provides a model of how information is stored and how it is retrieved.