Acquisition of a natural versus an unnatural stress system
This dissertation investigates the role of Universal Grammar (UG) in the adult second language acquisition of phonological stress. Specifically, it examines whether universal linguistic phonological principles can be accessed by learners to aid them in acquiring the stress pattern of an artificial language.
I address the question of adult accessibility to UG by investigating whether a specific phonological principle of UG that does not exist in the subjects' native language is accessible to adult learners. To do this, I compare the acquisition of a stress system that follows this phonological principle (a "natural" system) with one that does not (an "unnatural" system). If second language learners have access to innate universal linguistic principles they should be better able to learn the natural rule over the unnatural one.
Using an artificial language learning methodology, two sets of natural/unnatural rule pairings were designed, one set based on vowel height and the other on syllable weight. The natural rule for the vowel height experiment was: Stress the leftmost low vowel, else stress the leftmost vowel; while the unnatural rule was the opposite: Stress the leftmost high vowel, else stress the leftmost vowel. The syllable weight experiments followed the natural/unnatural rules: Stress the leftmost heavy syllable, else leftmost, or, stress the leftmost light syllable, else leftmost. The same experiments were conducted with native speakers of American English and native speakers of Quebec French.
The results show that in the case of the vowel height experiments, both English and French speakers learned the natural rule better than the unnatural one. The results were not as clear in the syllable weight experiments.
An analysis is given within Optimality Theory of second language learning as the process of changing from the constraint ranking of the native language to that of the target language. Further, a comparison is made of the differences in learning a variable stress system by native speakers of a fixed stress language and native speakers of a variable stress language.