Words-and-Rules

  • Look up past-tense - No past-tense stored? Generate form
    • Why symbolic? It uses the abstract ‘Verb
    • Rules that refer to these categories are used to guide processing
    • past tense
    • Irregular forms stored in associative memory (Declarative memory)
    • Symbolic rules produce past tense forms (procedural memory)
    • look-up is quicker than rule application
    • rule application takes more time but is always done ‘on-the-fly’
    • Time 1: Every form is memorized (irregular and regular)
    • Time 2: child notices pattern: Verb root+ed = past
    • Child creates a rule
    • Child applies rule to all forms: overgeneralization
    • Time 3: Child realizes that there are irregular and regular forms
      • creates a dual system: irregular forms are retrieved from memory, regular forms are created by a rule
      • new and novel verbs will get regular endings in past tense unless exposed to irregular past
      • the fact that children seem to learn a rule = language must be symbolic
    • Traditional U-shaped learning predicts children won’t be able to create past-tense forms for novel verbs when they are in the initial stage. This isn’t consistent with data
    • Overregularization is not common
    • Cannot account for the presence of two past forms
      • e.g. dream/dreamed-dreamt, light/lit-lighted
    • In production experiments
      • Irregulars produced faster
      • Frequent irregulars are produced faster than infrequent irregulars (Prasada et al., 1990; Albright & Hayes 2003)
      • No difference between frequent and infrequent regulars
    • Maybe because experiments always present the root form? (1) This is a girl who knows how to dance. She did the same
      • Root presentation might mask differences due to frequency in regulars
  • Challenges of Words-and-rules