Two of our graduate students have successfully defended their dissertations during the first half of May, and can now deservedly call themselves "doctor"! We congratulate both Harim Kwon and Tridha Chatterjee on this achievement, and wish them well as they start out on the next phase of their academic careers. The title and abstracts of their dissertations are given below.

Harim Kwon: "Cue Primacy and Spontaneous Imitation: Is Imitation Phonetic or Phonological?"
(Advisors: Pam Beddor and Andries Coetzee)

Previous research on spontaneous imitation examines how speaker-listeners’ own production changes after hearing a few minutes of model speech, and suggests that speech perception and production are closely related. This dissertation asks how cue primacy influences imitation by separately manipulating two co-varying cues differing in their primacy for one phonological category. By examining how similarly or differently primary and non-primary cues operate in spontaneous imitation, this dissertation investigates the nature of the cognitive representations that are responsible for imitation.

In order to examine whether the cognitive representations that are involved in speech imitation are abstract phonological categories or individual phonetic properties, this study tests spontaneous imitation of aspirated stops by Seoul Korean speakers. In Seoul Korean, at least two distinct acoustic properties, stop voice onset time (VOT) and post-stop fundamental frequency (f0), differentiate aspirated stops from stops of different phonation types, with post-stop f0 being the primary cue for aspirated stops. Seoul Korean participants heard and shadowed (i.e., immediately repeated what they heard without being told to imitate) target model speech, including aspirated /th/ with either extended VOT or raised post-stop f0. The realization of these properties in their own /th/, /t/, and /t*/ productions were compared before, during, and after exposure.

The results show that enhancements of both primary and non-primary cues trigger imitative changes, and that exposure to an enhanced non-primary cue (long VOT) influences the production not only of that cue but also of the primary cue for aspirated stops (post-stop f0). However, an enhanced primary cue (high f0) does not have similar effects on the non-primary cue. Moreover, the imitative changes are generalized to maximize the relevant phonological contrast, as evidenced by lowering of f0 after lax /t/ and sonorants. These findings suggest that imitation is not strictly tied to individual phonetic properties but it is rather phonological in that abstract categories are involved in the process of imitation. This dissertation provides a new insight on the role of phonology in spontaneous imitation.

Tridha Chatterjee: "Bilingualism, language contact and change: The case of Bengali and English in India"
(Advisors: Marlyse Baptista and Acrisio Pires)

This dissertation examines the nature of bidirectional influences in Bengali and English in the understudied bi/multilingual setting of West Bengal, India. Close contact between the languages has resulted in extensive bilingualism including code-switching between the languages in a section of the population. In order to get a better understanding of language change and development in this community, the following research questions are investigated i) What types of contact effects are observable in Bengali today? ii) What are the grammatical features in bilingual Bengali-English speech that have changed under contact and what are those resulting from language-internal developments? iii) How can we ascertain that new properties found in bilingual Bengali-English are contact-induced? iv) What are the grammatical differences between monolingual and bilingual Bengali? v) What is the direction of change in contact? These questions are addressed from both diachronic and synchronic standpoints and following the methodology of Thomason (2001), two current monolingual and bilingual Bengali corpora (collected and compiled through fieldwork) are compared with nineteenth-century Bengali plays for a set of linguistic features. Further, a corpus of English speech data from Bengali-English bilinguals is investigated to evaluate what types of changes occurred in English. This investigation has also been complemented with a quantitative analysis of the distribution of linguistic features in the corpora following the variationist methodology discussed in Poplack & Levey (2010). The findings are as follows: English influence has led to heavy lexical borrowing in Bengali, as well as code-switching and morphosyntactic changes in the domain of bilingual Bengali-English verbs comprising English ‘nouns’ or ‘verbs’ alongside ‘do’ verbs from Bengali. Change has also occurred in Bengali equational sentences where the new meaning and position of the ‘be’ verb hocche, unattested in nineteenth-century Bengali, seems to emerge from multiple causation. The English data reveals slight divergences in the use determiners and progressive tenses, which have resulted only partially from interference from Bengali, but mostly conditioned by speakers’ different proficiency levels in English. These findings provide evidence for overall stability in the grammar of both languages (specifically for this subject pool) despite the presence of extensive bilingualism in the community.