The development of lexical competition in heritage speakers

Kutlu, Ethan, Gainesville FL

Investigators

Abstract

This award was provided as part of NSF's Social, Behavioral and Economic Sciences Postdoctoral Research Fellowships (SPRF) program. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research. NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields. Under the sponsorship of Dr. Bob McMurray at the University of Iowa, this postdoctoral fellowship award supports an early career scientist examining language development in heritage speaker children. In the current geographical, political, and global climate, immigrant populations are expected to continue increasing around the world. A critical barrier faced by the children of these immigrants is language, as they may not have the same opportunities as monolingual children do to develop the majority language of their new home (Valdés, 2005). Thus, a challenge is posed for understanding the language development of heritage speaker children, as their first language (the heritage language) becomes their less dominant language as they age (often when schooling begins), and their second language (the majority language) eventually becomes dominant, despite a delayed start (Polinsky, 2011). This often relegates them to special English Language Learner classrooms or leaves them with insufficient support. Currently, how heritage speakers develop their dominancy in the majority language and what type of neural changes happen when this language dominancy shift occurs is not well-studied. The proposed research study aims to understand spoken word recognition, a bottleneck process of early language development (Perfetti, 2007; Verhoeven, Reitsma, & Siegel, 2011), in monolingual and heritage speakers at Grade 1, Grade 4, and in adulthood by using eye-tracking, EEGs, and machine learning. Here, lexical processing—a critical hub in the language system—is being targeted as a model system in which to ask how heritage speakers become more automatic language processors in the majority language and maintain this in their heritage language. Assessing heritage speaker children’s linguistic backgrounds presents a unique challenge in that their exposure to English is not similar to their monolingual peers, and their age and manner of acquisition as well as their proficiency in the majority and the heritage language do not follow previously assessed bilingual norms. Therefore, typical language background questionnaires may not adequately capture heritage speaker children’s experience. Instead, a more holistic approach, including an innovative recording tool (i.e., the LENA system) and network science to quantify the exposure in both languages are employed. Finally, the proposed study aims to not only understand the impact of delayed exposure to the majority language in childhood but also its prolonged impact on heritage speaker adults’ language representation, and to separate the contributions of semantic and auditory differences using electrophysiological and machine learning techniques. Findings here expand on both language acquisition and the cognitive neuroscience of language processing in various bilingual populations (i.e., heritage speakers). Crucially, heritage speakers provide insight to help answer theoretically challenging questions in lexical processing which cannot be otherwise addressed. Overall, this study aims to broaden the participation of heritage speakers in language development research as well as find and create more sustainable language and educational programs for heritage speakers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.