The effects of English (L2) language proficiency on speech motor indices for bisyllabic bilabial word utterances in typical Kannada (L1)–English (L2) bilinguals

Native Language and Second Language Convergence and Second Language Instruction Shape Speech-Language Performance in Adult Learners

PURPOSE

We examined native language (L1) and second language (L2) convergence of underlying skills in adult L2 learners as well as the contribution of instructional L2 level on L2 attainment across speech motor, lexical, and narrative levels.

METHOD

Thirty-four adult Spanish L2 learners who had completed at least 1 year of college Spanish participated in this preliminary study. Learners were tested at the speech motor, lexical, and narrative levels in their L1 (English) and L2 (Spanish). L1-L2 convergence was indexed by associative links between corresponding L1 and L2 skills. In regression analyses, the level of Spanish instruction at the time of the study was also considered as a predictor of L2 attainment across speech motor, lexical, and narrative levels.

RESULTS

L1-L2 convergence was identified for some speech motor skills (distance, maximum speed) and for lexical skills but was limited for other speech motor skills (duration, spatiotemporal index) and for narrative measures. Furthermore, lexical and narrative measures, but not speech motor measures, showed improvements with Spanish (L2) instruction.

CONCLUSIONS

L1-L2 convergence and instructional level are predictors of L2 performance in adult language learners. These factors play somewhat different roles across speech motor, lexical, and narrative levels, warranting further "all-system" research across processing and proficiency levels.

Effects of utterance rate and length on the spatiotemporal index in Parkinson's disease

Purpose: To characterise labial articulatory pattern variability using the spatiotemporal index (STI) in speakers with idiopathic Parkinson's disease (PD) across different speaking rates and syllable-sentence conditions compared to age- and sex-matched healthy controls.Method: Ten speakers with mild-severe idiopathic PD and 10 controls produced "pa" and the Rainbow Passage at slow, typical and fast speech rates. Upper lip and lower lip kinematics were digitised during a motion capture system. Data were analysed using linear mixed modelling.Result: Regardless of the participant group, a high STI value was observed in the fast speech rate for the "pa" syllable condition, particularly for movements of the lower lip. As utterance rate increased, the control group showed the highest variability, followed by PD OFF and PD ON conditions. Syllable "pa" showed a greater STI value compared to both the first and second utterance of Rainbow Passage.Conclusion: PD manifests sufficient residual capacity to achieve near-normal motor compensation to preserve the consistency of lower lip movements during speech production. The lack of a significant difference in lip STI values between ON-OFF medication states suggests that dopaminergic treatment does not influence stability of speech for individuals with mild-moderate stage PD.