Molnar, M. 1 , Polka, L. 2 , Baum, S. 2 & Steinhauer, K. 2
1 Basque Center on Cognition, Brain and Language (BCBL). Donostia. Spain.
2 McGill University, Montreal, CANADA
It is well established that monolingual speakers’ speech perception abilities are highly tuned to the sounds of their native language, and that this language specificity affects how they distinguish the sounds of a second language. However, it is not well understood how the speech perception skills of simultaneous bilinguals, who are native speakers of two languages, are shaped. In order to investigate speech processing in this population, we set up two studies investigating the vowel perception of monolingual and simultaneous bilingual users of English and French.
First, using a behavioral vowel categorization paradigm, we assessed how the control of active language mode or language context (English, French, or bilingual) affects the perception of acoustically similar cross-language vowel categories. As expected, monolingual speakers demonstrated a language-specific perceptual pattern for the vowels, however the bilingual participants displayed different patterns in each active language mode and were able to accommodate acoustically similar vowel categories relevant in the target language. These findings indicate that simultaneous bilinguals rely on a finely detailed perceptual space and are flexible as they adapt their perception to different language environments.
Second, using event-related brain potentials, we measured pre-attentive processing involved in vowel perception as reflected by the mismatch negativity (MMN). The simultaneous bilingual listeners exhibited a MMN pattern that is distinct from both monolingual listener groups even during the earliest levels of speech processing, as the simultaneous bilingual pre-attentive system is tuned to access sub-phonemic detail with respect to both of their input languages, including detail that is not readily accessed by either of their monolingual peers. This automatic access to fine phonetic detail may be essential in supporting the bilinguals’ ability to make rapid, effortless shifts in perception across different communication contexts (French, English, bilingual).