psych 421
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Chapter8.2_Fodoronthemodularityofmind-revisedfor3rdedition.pptxChapter 8.2: Fodor on the modularity of mind
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Overview
• explore motivation for Fodor’s ideas about the modularity of mind
• introduce tension between Fodor’s conception of central processing and the thinking behind the language of thought hypothesis
Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Two general approaches
• Horizontal organization – mind organized in terms of general cognitive abilities/capacities
Perception
Memory
Attention
• Vertical organization – mind organized in specialized peripheral systems + central systems in the middle
Perceptual systems
Central processing
Motor systems
Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Theoretical issues
What is the relation between information-processing in perception and cognition?
Horizontal: No real boundary between perceptual processes and central cognition
Vertical: Fundamental differences between perceptual systems and central processing
Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Blurring the boundaries
Cognitivist approaches to perception [e.g. Gregory, Bruner] stress the intelligence of perception
• Perception involves unconscious inference
• Brings into play general knowledge of the world, expectations etc.
The distinction is between perceptual processing and reflexes/innate releasing mechanisms - perception does more than simply trigger behavior
Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Innate releasing mechanisms
E.g. herring gull pecking response/feeding response exploited in brood parasitism
• Always triggered by specific stimuli
• Always take the same form
• Occur in all species members
• Independent of creature’s history
• Can’t be varied once launched
Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Perceptual processing
Two possibilities
(1) Perceptual processing involves computational information-processing
(2) Information-processing in perception draws upon centrally stored information
• Cognitivist approaches accept (1) and (2)
• Fodorean modularity accepts (1) w/out (2)
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
The arguments
Supported by poverty of the stimulus arguments
• show that information arriving at the retina does not determine the content of perception
• somehow retinal information must be (algorithmically) transformed
(2) Supported by visual illusions showing that perceptual systems are not cognitively penetrable
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Illusions and processing
Illusions reveal some of the mechanisms used to impose order on the highly variable retinal stimulus
Shape constancy illusions – Shepard illusion
Size constancy illusions – Ponzo illusion
But none of these illusions can be affected by our beliefs cognitively impenetrable
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Shepard illusion
The original citation is Shepard R. N. (1981). Psychological complementarity. In M. Kubovy M. & J. R. Pomerantz (eds.) Perceptual organization (pp. 279–342). Hillsdale, NJ: Lawrence Erlbaum Associates.
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Fodor modules
Dedicated processing systems that are
domain-specific
cognitively impenetrable
fast
mandatory
Possibly have
fixed neural architecture
specific breakdown patterns
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Examples
• Color perception
• Shape and size analysis
• Face recognition
• Voice recognition
• Syntactic parsing of heard utterances
Fodor’s basic idea is that these peripheral modules serve as inputs into central processing
There are corresponding output modules
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Modularity and innateness
• Modularity claims have often been accompanied by claims about innateness
• e.g. Chomsky’s “language organ”
• Poverty of the stimulus arguments can be used to support both types of claim
• But this is not required
• Some evidence that specialized neural circuitry takes time to develop
• Semantic processing in infancy
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Central processing
• The basic representations in central processing are personal level states – propositional attitudes and perceptions
• This goes together with central processing behaving in ways that modular systems don’t
Quinean (sensitivity to global properties of system)
isotropic (informational unencapsulation)
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Cognitive Science José Luis Bermúdez / Cambridge University Press 2020
Central processing and LOTH
• Possibilities for transforming and manipulating symbols structures in LOT are determined solely by syntactic properties
• Syntactic properties are intrinsic properties, holding independently of relations between that symbol structure and others
• Representations in central processing behave in ways constrained by global properties of coherence and consistency
• Algorithmic processing of symbol structures cannot take these global properties into account
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