摘要
In two artificial grammar learning experiments, we tested the learnability of tonal phonotactics forbidding non-domain-final rising tones (*NonFinalR) against the phonotactics banning non-domain-final high-level tones (*NonFinalH). We propose that a firm phonetic ground drives a presumably innate inductive bias favoring *NonFinalR and against *NonFinalH. In Exp. I, we trained two groups of participants with an artificial language conforming to either *NonFinalR or *NonFinalH and tested them with the same set of novel items violating either tonal constraint in an acceptability judgment task. In two separate test sessions, *NonFinalR learners demonstrated a significantly higher consistency in making correct judgments than *NonFinalH learners. In Exp. II, learners participated in the same acceptability judgment task without being exposed to inputs in an a priori training session; participants had to learn from the immediate explicit feedback given to their judgments on every test item. Results suggest that only *NonFinalR learners demonstrated signs of converging on the target tonal phonotactics. In addition, both experiments found that *NonFinalR learners, but not *NonFinalH learners, acquired the tonal phonotactics and a baseline segmental phonotactics prohibiting retroflex consonants similarly. Altogether, the experimental results support the hypothesis of an inductive learning bias toward *NonFinalR and against *NonFinalH.