Doctoral Dissertation Research: Using ERPs to Track the Scope of Inhibition in Bilingual Speech

With National Science Foundation support, Ms. Rhonda McClain will collect data for her doctoral dissertation under the direction of Dr. Judith Kroll and Dr. Eleonora Rossi. Speaking fluently in a second language is a notoriously difficult skill to develop as a late learner, presumably because the second language competes for selection with the native language. Current research demonstrates that bilinguals experience persistent activation of both languages even when speaking one language alone. A critical question is how bilinguals prevent speaking the more dominant or native language when trying to speak the second language. Recent studies have reported that the native language becomes inhibited, or suppressed, in order to speak in the second language. However, little is known about what type of information becomes inhibited in the native language. One possibility is that all of the words in one language are suppressed. Alternatively, a network of words that bear resemblance in meaning to each other become active or inhibited together. Another possibility is that specific words that had been spoken in the other language are inhibited. It is also unclear whether inhibition is momentary or long lasting. The planned experiments will test the scope of inhibition (what is inhibited) its time course (the duration of inhibition) by using electrophysiological measures that may provide a more sensitive index of the earliest moments of speech planning. A comparison of bilinguals and monolinguals will also determine whether the repeated requirement for bilinguals to inhibit their native or more dominant language confers expertise in the realm of inhibitory control relative to monolingual speakers.

The funded research has a number of broader implications. It will contribute important foundational knowledge about multilingualism that will inform educational issues in a society in which many learners are faced with the task of acquiring a second language past the earliest stages of childhood and at risk for academic failure unless they acquire the second language rapidly. The inhibitory processes that are the target of the planned investigation hold implications for better understanding the ability of bilinguals to maintain the two languages under conditions that may support the use of only one language. The research will also contribute to the training of an increasingly diverse group of language scientists by including undergraduate research students who are themselves bilingual.