Computational and Evolutionary Aspects of Language

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Computational and Evolutionary Aspects of
Language

• Written by Martin Nowak, Natalia Komarova, and
  Partha Niyogi
• Presentation by Amerika Adams, Isaac Huang, and
  Margaret Kuwata

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Purpose

• Attempt to formulate a synthesis of three
  theories.
• Addresses the importance of human language.
• Addresses the following questions
• 1. What is language?
• 2. What is grammar?
• 3. What is learning?
• 4. How does a child learn language?
• 5. How formal language theory and
  learning theory can be extended to study language
  as a biological phenomenon and as a product of
  evolution.

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Formal Language Theory

• It is a mode of communication
• It is a crucial part of human behavior
• It is the sequencing of small units into bigger
  structures.
• There are rules for word grouping.

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What is language?

• The alphabet is a set of symbols
• Sentences are strings of symbols
• Language is a set of sentences
• Example Binary Language

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What is grammar?

• It is a finite set of rules specifying a
  language.
• Expressed in terms of rewrite rules

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Languages, Grammars, and Machines.

• Correspondence between languages, grammars, and
  machines.
• Regular Languages are generated by finite-state
  grammars which is equal to finite-state automata.
  
• Finite-state automata have a start, a finite
  number of intermediate states, and a finish.
• A particular run from start to finish produces a
  sentence.

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Learning Theory

• Learning is the ability to generalize beyond
  ones own experience to new circumstances.
• Learning theory describes the mathematics of
  learning with the aim of outlining conditions for
  successful generalization.
• Theory of Universal Grammar (UG)

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What is special about language acquisition?

• We learn the grammar of generative systems.
• The process occurs without being instructed about
  rules.
• The set of all computable languages is learnable
  by an algorithm that memorizes the rules.

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Evolutionary Language Theory

• The evolution of language occurred in several
  incremental steps that were guided by natural
  selection.
• The theory states that by taking a population of
  individuals and with each individual using a
  particular language, the successful ones are able
  to communicate which results in a pay-off that
  attributes to fitness.
• Languages change overtime because the
  transmission from one generation to the next is
  not perfect.

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Agreements

• 1. Language is a crucial part of human identity
  and behavior.
• 2. Language has evolved through Darwinian
  dynamics of natural selection.
• 3. That learning is the ability to generalize
  beyond ones own experience. Not just modeling
  others.

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Disagreements

• 1. The set of all computable languages is
  learnable by an algorithm that memorizes rules.
  (?)
• That children have a restricted set of innate
  languages they could learn correctly.