Simulating Developmental Patterns in the Cross-linguistic Acquisition of Inflectional Morphology

We present a connectionist model of a general system for producing inflected words. The Multiple Inflection Generator (MIG) combines elements of several previous models (e.g., multiple inflections for a grammatical class: Hoeffner & McClelland, 1993; lexical-semantic input: Joanisse & Seidenberg, 1999; multiple grammatical classes: Plunkett & Juola, 1999). MIG assumes that the goal of this component of the language system is to output a phonological form appropriate to the grammatical context in which the word appears. We show that this model captures developmental patterns in the acquisition of morphology in two different languages: one with a simple morphological system (English), and one characterized by rich morphology and absence of default forms (Modern Greek). When MIG is trained under conditions of atypical computational constraints, it reproduces developmental patterns symptomatic of Specific Language Impairment particular to each language.