How bilinguals perceive speech depends on which language they think they're hearing

Phonetic discrimination, phonological awareness, and pre-literacy skills in Spanish-English dual language preschoolers

The current study explores variation in phonemic representation among Spanish-English dual language learners (DLLs, n = 60) who were dominant in English or in Spanish. Children were given a phonetic discrimination task with speech sounds that: 1) occur in English and Spanish, 2) are exclusive to English, and 3) are exclusive to Russian, during Fall (age m = 57 months) and Spring (age m = 62 months, n = 42). In Fall, English-dominant DLLs discriminated more accurately than Spanish-dominant DLLs between English-Spanish phones and English-exclusive phones. Both groups discriminated Russian phones at or close to chance. In Spring, however, groups no longer differed in discriminating English-exclusive phones and both groups discriminated Russian phones above chance. Additionally, joint English-Spanish and English-exclusive phonetic discrimination predicted children's phonological awareness in both groups. Results demonstrate plasticity in early childhood through diverse language exposure and suggest that phonemic representation begins to emerge driven by lexical restructuring.

An analysis of the perception of stop consonants in bilinguals and monolinguals in different phonetic contexts: A range-based language cueing approach

Bilinguals' observed perceptual shift across language contexts for shared acoustic properties between their languages supports the idea that bilinguals, but not monolinguals, develop two phonemic representations for the same acoustic property. This phenomenon is known as the double phonemic boundary. This investigation replicated previous findings of bilinguals' double phonemic boundary across a series of go/no-go tasks while controlling for known confounding effects in speech perception (i.e., contrast effects) and differences in resource allocation between bilinguals and monolinguals (i.e., left-hand or right-hand response). Using a range-base language cueing approach, we designed 2 experiments. The first experiment tested whether a voice onset time (VOT) range representative of either Spanish or English phonetic categories can cue bilinguals, but not monolinguals, to use language-specific perceptual routines. The second experiment tested a VOT range with a mixture of Spanish and English phonetic categories to determine whether directing attention to a specific phonetic category can disambiguate the competition of the nonattended category. The results for Experiment 1 showed that bilinguals can rely on the distributional patterns of their native phonetic categories to activate specific language modes. Experiment 2 showed that attention can change the weight given to a native phonetic distinction. However, this process is restricted by the internal phonetic composition of the native language(s).

Consequences of multilingualism for neural architecture

Language has the power to shape cognition, behavior, and even the form and function of the brain. Technological and scientific developments have recently yielded an increasingly diverse set of tools with which to study the way language changes neural structures and processes. Here, we review research investigating the consequences of multilingualism as revealed by brain imaging. A key feature of multilingual cognition is that two or more languages can become activated at the same time, requiring mechanisms to control interference. Consequently, extensive experience managing multiple languages can influence cognitive processes as well as their neural correlates. We begin with a brief discussion of how bilinguals activate language, and of the brain regions implicated in resolving language conflict. We then review evidence for the pervasive impact of bilingual experience on the function and structure of neural networks that support linguistic and non-linguistic cognitive control, speech processing and production, and language learning. We conclude that even seemingly distinct effects of language on cognitive operations likely arise from interdependent functions, and that future work directly exploring the interactions between multiple levels of processing could offer a more comprehensive view of how language molds the mind.