The Role of Similarity in Hungarian Vowel Harmony: a Connectionist Account

Abstract

Over the last 10 years, the assimilation process referred to as vowel harmony has served as a test case for a number of proposals in phonological theory. Current autosegmental approaches successfully capture the intuition that vowel harmony is a dynamic process involving the interaction of a sequence of vowels; still, no theoretical analysis has offered a non-stipulative account of the inconsistent behavior of the so-called ‘transparent’, or disharmonic, segments. This paper proposes a connectionist processing account of the vowel harmony phenomenon, using data from Hungarian. The strength of this account is that it demonstrates that the same general principle of assimilation which underlies the behavior of the ‘harmonic’ forms accounts as well for the apparently exceptional ‘transparent’ cases, without stipulation. The account proceeds in three steps. After presenting the data and current theoretical analyses, the paper describes the model of sequential processing introduced by Jordan (1986), and motivates this as a model of assimilation processes in phonology. The paper then presents the results of a series of parametric studies that were run with this model, using arbitrary bit patterns as stimuli. These results establish certain conditions on assimilation in a network of this type. Finally, these findings are related to the Hungarian data, where the same conditions are shown to predict the correct pattern of behavior for both harmonic and transparent vowels.

I am grateful to Jeff Elman for his assistance and encouragement through all stages of this project, and to Steve Poteet, David Corina, Sanford Schane, Gary Cottrell, Ann Thyme, Robert Port, and an anonymous reviewer for useful comments and discussion. I am especially indebted to Rob Kluender for invaluable assistance on an earlier draft, to Kathy Carey for her contribution to the introduction, and to Errapel Mejias-Bikandi for a series of illuminating e-mail messages. This research was supported in part by contract No. DAAB07-87-C-H027 from Army Avionics, Ft. Monmouth, to the Center for Research in Language.