A connectionist word production tool for Finnish nouns with a model for vowel harmony restrictions

Abstract

Vowel harmony is a pervasive feature in Finnish. It is only rarely violated in slips of the tongue or in aphasic output. Thus it is a constraint which should be successfully simulated by any model aiming to account for word production in Finnish. Only a few neural network models for Finnish language processing have been developed so far, although Finnish should be a very challenging object for modeling because of its complex morphology. Our work is the first attempt to model Finnish vowel harmony using neural networks. We have introduced a tool, FinnPro, for building interactive spreading activation models and for simulating word production processes. Our tool produces Finnish nouns in different cases and forms and simulates both normal and damaged speech. In this paper, the vowel harmony control features of FinnPro are introduced. The control structure of FinnPro maintains vowel harmony even in damaged word production. The vowel harmony adjustment process in FinnPro follows the idea that the vowel harmony process in Finnish is phonological. Our model suggests that in disturbed word productions, the vowel harmony category of the output word is triggered by the whole set of vowels activated in the production.