Innateness and Emergentism

1
Innateness and Emergentism

• Semmere Asfaw
• CS 6795

2
Nature-Nurture Controversy

• In this controversy, we ask if the behavior of
  people is due to their Nature (or genetics) or to
  their Nurture (or environment).
• Lack of a precise testable theory of the process
  by which genes and the environment interact.

3
Arguments for Innateness

• 1- Domain Specificity
• The outcome is so specific to a domain that it
  must be innate.
• 2-Species Specificity
• we are the only species that does this so it
  must be in the human genome
• 3-Localization
• the outcome is mediated by a particular part of
  the brain, so the outcome must be innate.
• 4-Learnability
• we cannot figure out how the outcome could be
  learned so the outcome must be innate.

4
Theories to explain interaction

• Interactionism
• Black white Grey
• Emergent theory
• Black white Green (something unrelated to the
  inputs
• Unpredictable
• Logic, knowledge and grammar are not given in
• the world, but neither are they given in the
  genes.
• environment as the ultimate cause of development

5
Innateness in an emergent view

• innateness is complex outcome from information
  contributed by the genes.
• However genes do not act independently, and they
  can be turned on and off by environmental signals
  throughout the lifetime of the organism.

6
3-Level Claims of Innateness

• Representational constraints
• Direct innate structuring for what makes up
  knowledge, possibly at the cortical level.
  (Synaptic connectivity at the cortical level)
• Hard to prove on the mathematical level
• 1014 synaptic connections in the human brain
  could be controlled by a genome with
  approximately 106 genes, particularly when
  20-30 of these genes at most go into the
  construction of a nervous system, and when we
  know that each synaptic connection can take
  multiple values.
• human brain contains more potential states of
  connectivity than there are particles in the
  universe!
• Current research shows that Instead, brain
  development in higher vertebrates appears to
  involve massive overproduction of elements early
  in life (neurons, axons and synapses), followed
  by a competitive process through which successful
  elements are kept and those that fail are
  eliminated (Edelman, 1987).

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Architectural constraints

• Architectural constraints
• innate structuring of the information-processing
  system that must acquire and/or contain these
  representations.
• There is good evidence for innate archItecures
  and innate variations in timing. This includes
  evidence that neurons know where they are
  supposed to go during cell migration (Rakic,
  1988), and evidence that axons prefer particular
  targets during their long voyage from one region
  to another (Niederer, Maimon, Finlay, 1995)
• Could this be the basis for a Universal Grammar?
• There is not enough coding power for something as
  specific and detailed as grammatical knowledge.
• The rules of growth at this level appear across
  species.
• evidence for lawful axon growth in the brain of
  the adult rat, from cortical transplants taken
  from fetal pigs.

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Chronotopic constraints

• Number of cell divisions, and innate constraints
  on the timing of developmental events, including
  spatio-temporal interactions.
• Differences among vision, audition
• Differences in the adaptive learning rates
• Learning
• Nativist views about language or social
  reasoning, assume representational nativism,
  because it is the only level with the coding
  power for implementing knowledge independent of
  experience.
• Chomskys view that a general learning
  theory....seems to me dubious, unargued, and
  without any empirical support(1980a, p. 110)
• This requires a structure would reside in the
  microcircuitry of the brain, which makes sense
  but has been impossible to prove

9
Innateness of Domain Specificity

• Language as an example
• Behavioral Specificity
• The innateness claim is that language is so
  peculiar (mapping a hyperdimensional meaning
  space to a low-dimensional channel) that it can
  only be learned by a domain specific system
• Should have resemblance to similar cognitive
  systems, but it does not. Instead languages are
  similar to other languages.
• Reason is the species share experiences that
  shape the meaning space.
• The reason why domain specificity of language is
  used to infer innateness is because
  domain-specific behaviours have emerged as a
  result of the mapping problem. However, the
  reason can also have emerged on an emergentist
  theory.

10
Innateness of Domain Specificity

• Representational Specificity
• innateness claims if a person is able to solve
  a domain-specific problem, then they must have a
  set of representations that support the behavior.
  representation is somehow distinguishable from
  other aspects of knowledge.
• This generalization is true for learned
  representations as well.

11
Innateness of Domain Specificity

• Genetic Specificity
• If a form of language impairment is associated
  with a genetically transmitted disorder. Example
  Specific Language Impairment eg an London
  Family example of SLI that affects grammatical
  morphemes.
• Walk walked
• Givegave
• Family had other deficits within and outside
  language
• Specific language impairments correlate with a
  range of subtle deficits..like mental imagery,
  detection of rapid sequence sounds.
• Only true if we can show that genetic defects
  affects language in isolation.

12
Innateness of Species Specificity

• It must be innate because only we humans do it or
  only humans do it very well.
• no body has what we have so we must have been
  created with it
• No neural structure unique to humans
• Neuronal type---neurotransmitter---cortical
  layering.

13
Innateness and Localization

• The argument for innateness
• if we could show that the brain handles regular
  and irregular grammatical morphemes differently
  would that be evidence enough for two innately
  specialized, domain specific processors?
• If we experience two stimuli in the same way,
  then we dont know that they are different.
• every new piece of learning changes the
  structure of the brain in some fashion however
  minor no end game organ
• Innateness presuppose a physical base for the
  genes.

14
Innateness and Learnability

• X is so peculiar, that it cannot be learned by
  any general learning mechanisms.
• example Golds Theorem grammars of a
  particular class cannot be induced from a finite
  base of positive evidence (sentences in the
  language) in the absence of negative evidence
  (like sentences not in the language)
• This is true only if we make assumptions about
  the learning device that are unlike any known
  nervous system.
• No work is done to find out whether grammars of a
  different kind are learnable or is another
  learning device could acquire such a grammar.

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Questions

• Does a peculiar outcome make it innate?
• ?
• Does an outcome specific to a particular species
  make it innate to that species?
• ?
• Does ascociation of an outcome with a particular
  part of the brain make it innate?
• ?
• Does lack of knowledge of how an outcome was
  learnt make it innate?
• ?