A Local Connectionist Account of Consonant Harmony in Child Language

This study represents an attempt to sketch a processing model of phonological development in children acquiring their first language. The investigation is framed within a local connectionist network in which activation spreads between levels and inhibition within levels. Three ways are focused on in which an emergent processing system may diverge from a fully developed one—hypoactivation (too little activation due to underdeveloped links), hyperactivation (too much activation due to overloaded links) and impaired self‐inhibition. With a view to determining how children's productions relate to these three “error mechanisms,” one widespread phonological process, consonant harmony, is subjected to examination. Hypoactivation is found to capture the great majority of harmonic patterns. Hyperactivation and impaired self‐inhibition play a more marginal role and are only needed to account for exceptional cases of harmony. The feasibility of the psycholinguistic model is demonstrated with the help of computer simulations that were run with noise on both fully developed and developing networks. The model makes a number of predictions including the claim that difficult sounds are acquired in coda positions first.