Lexically Specific Constraints: Gradience, Learnability, and Perception

Lexically specific constraints are indexed versions of constraints that apply only when a morpheme that bears that index is evaluated by the grammar. They have been used in Optimality Theory to deal with exceptions (e.g. Hammond 1995, Kraska-Szlenk 1997, Pater 2000), and have also been applied to the lexical strata of Japanese and other languages (Fukuzawa 1999, Itô and Mester 1999, 2001, Gelbart 2005). In this paper, we propose a further application of lexically specific constraints: to the analysis of gradient phonotactics (cf. Frisch, Pierrehumbert and Broe 2004). Markedness constraints are ranked according to the degree to which they are obeyed across the words of the language, with lexically specific constraints interspersed between them. We then show that rankings of this type can be learned with a relatively minor elaboration of the Biased Constraint Demotion Algorithm (Prince and Tesar 2004). Finally, we provide experimental evidence from lexical decision tasks and acceptability judgments that language users are aware of such lexical patterns.