Chapter Three of Green:

Intro to Cogsci Spring 2005

Review: Boxes and Flows

• Needed with Crane• Flow Charts: Used to express procedure and

algorithms; boxes represent operations or decisions and arrows represent flow of control. “How to do it”

• Box/arrow diagram: boxes represent cognitive processes and arrows represent flow of information. “How it happens”

Flow charts

• How to do it

• Example: Recipe

Is oven on to350?

NO

Yes

Turn on to 350

Open Package

Box/arrows

• How it is done, from input to output

Proximal Stimuli

Perception of distal stimuli

Review: Attractions of Turing

• Non-mental explanation of mental: a Turing machine does not have to understand meanings in order to perform its basic operations.

• Retains compositionality, systematicity and so productivity• Compositionality of X: meaning of X determined by parts

and rules of compostion.– Examples: Grass is green. Blood is red.

• Compositionality seems to give us sytematicity: can understand same rules, same elements combined differently.– Example: Grass is red. Blood is green.

• Productivity: potential infinite number of X’s can be understood.

Architecture and modularity

• What is cognitive architecture and how does it differ from the brain’s architecture?

Features of a Module

1. Domain specificity2. Information encapsulation3. Mandatory4. Speedy (because of first three)5. Shallow output representations6. Same ontogency across species7. Characteristic and isolatable breakdowns8. Associated with a fixed and sometimes localized neural

architectureNote: 6-8 & innately prespecified

Modularity in practice

• SAQ 3.1

• 3.2

• 3.3

• 3.4

Other Issues re modularity of lang system

• Domain specificity– McGurk effect (p. 66)

• Encapsulation– Parsing– Word recognition

Parsing

• “When you are happy, visiting relatives…” [people, activity]– When you are happy, visiting relatives will enjoy your

home.– When you are happy, visiting relatives can be a good idea.

• Two views compatible with Fodorean modularity:– All interpretations present and then selected– Done in fixed order with no contextual influence on order

• Why is contextual influence important?• According to Green, evidence favors encapsulation

Word Recognition:

• A possible problem for Fodorean modularity:

• Example: The player went to the coach.• Responding quicker = primed• Priming: Process faster/easier because of

earlier process.• Fodor: this is dumb association, not

informationally informed.

The Frame Problem

• What is it?

• Why is it concerned with “central systems”

• Humans just do update their beliefs reasonably successfully.

• See Crane on relevance and Dreyfus

How modular should the mind be?

• Marr and the principle of modular design

• Fodorean arguments for modularity:– We need some systems to be fast, automatic,

etc

• Fodor’s teleological argument for non-modularity: is it evolutionarily sensible?

Piaget

• Epigenetic constructivism

• Self-organizing system structured and shaped by its environment

• 3 basic operations and interactions with the environment explain adult cognition

Karmiloff-Smith

• Innate dispositions to attend to particular stimuli and some innate skeletal knowledge structures.

• Thinks information encapsulation is acquired, not inborn

• Questions poverty of stimulus argument: environments are more structured than we thought.

• Infant mind is very plastic.

Connectionism: Advantages??

• Neurally more realistic?

• Learns in a way that allows generalizing – e.g., pattern learning/voice recognition

• Graceful degredation: unlike Turing machines

Pattern associators

• Learning rule

• Activation function

• Which is the Hebb rule?

• Instead of “a little learning is a dangerous thing,” we can have “a lot of learning is a dangerous thing.”

Delta Rule

• Two advantages over Hebb Rule.

• What are they?1. How they operate

2. What they operate on

• Why the Perceptron?

All or nothing rule

What have you Learned?