Predictors of main concept production (Rivera et al., 2017)

<div><b>Purpose: </b>A conceptual framework of bilingual aphasia assessment requires an understanding of the variables that influence discourse in bilingual speakers. This study aimed to determine predictors of main concept (MC) production, a measure of discourse completeness, as well as the effect of language dominance on MCs.</div><div><b>Method: </b>The Nicholas and Brookshire (1993) picture stimuli were used to elicit English and Spanish discourse in 83 young bilinguals. Participant-reported variables (e.g., proficiency self-ratings) and measured language variables (e.g., correct information units [CIUs] in discourse) were entered into regressions to determine potential MC predictors. A repeated-measures analysis of variance evaluated MCs within and across dominance groups categorized by speaking self-ratings.</div><div><b>Results:</b> Measured language variables (number of CIUs, naming accuracy) were most predictive of MCs. The participant-reported variable most associated with MC production was self-rating of speaking proficiency. Spanish- and English-dominant groups produced more MCs in their dominant language; the balanced group produced more English MCs. Between-groups differences were observed. </div><div><b>Conclusions:</b> Two measures related to lexical retrieval (CIUs and naming) were most predictive of MC production across languages. Participant ratings of speaking proficiency were also highly correlated to MCs. They also accurately reflected dominance, though balanced bilinguals verestimated their Spanish abilities.</div><div><br></div><div><b>Supplemental Material S1. </b>List of main concepts by picture. </div><div><br></div><div>Rivera, A., Hirst, J., & Edmonds, L. A. (2017). Evaluation of language predictors of main concept production in Spanish/English bilingual discourse using Nicholas and Brookshire stimuli. <i>American Journal of Speech-Language Pathology</i>. Advance online publication.</div>