Psycholinguistic, cognitive, and neural implications of bimodal bilingualism

Abstract

Bimodal bilinguals, fluent in a signed and a spoken language, exhibit a unique form of bilingualism because their two languages access distinct sensory-motor systems for comprehension and production. Differences between unimodal and bimodal bilinguals have implications for how the brain is organized to control, process, and represent two languages. Evidence from code-blending (simultaneous production of a word and a sign) indicates that the production system can access two lexical representations without cost, and the comprehension system must be able to simultaneously integrate lexical information from two languages. Further, evidence of cross-language activation in bimodal bilinguals indicates the necessity of links between languages at the lexical or semantic level. Finally, the bimodal bilingual brain differs from the unimodal bilingual brain with respect to the degree and extent of neural overlap for the two languages, with less overlap for bimodal bilinguals.

Implicit co-activation of American Sign Language in deaf readers: An ERP study

“…A number of production studies have shown that hearing bimodal bilinguals are less likely to strongly inhibit a non-target language, as compared to unimodal bilinguals, most likely because the two languages differ in articulators (see, e.g., Emmorey, Giezen, et al, 2016, for a review). If activation of ASL is less strongly suppressed for a similar reason during comprehension, the residual activation could give rise to the behavioral phonological interference effect observed here.…”

“…Several recent studies using behavioral methods have extended the unimodal literature to provide preliminary evidence of cross-modal language co-activation in both hearing and deaf bimodal bilinguals (see Emmorey, Giezen, & Gollan, 2016; Ormel & Giezen, 2014, for reviews), and many of these studies employed the implicit phonological priming paradigm (e.g., Kubus et al, 2015; Morford et al, 2014; Morford et al, 2011; Villameriel et al, 2016). For example, Morford and colleagues (2011) compared processing of English word pairs with ASL translations that shared two out of three phonological parameters (handshape, location, movement) to word pairs with ASL translations that did not overlap phonologically.…”

The development of bimodal bilingualism

“…There has been a good deal of recent research on the psycholinguistic and neurolinguistic aspects of bimodal bilingualism (for reviews see, Emmorey et al, 2015; Ormel & Giezen, 2014). This research has shown, among other findings, continued evidence for activation of both languages even in single-language contexts (both Deaf and hearing bilinguals); as well as decreased processing cost for activating sign with speech (hearing bimodal bilinguals) compared to the cost of inhibiting one spoken language (hearing unimodal bilinguals).…”

“…There are many bilingual effects concerning interactions between spoken and sign languages that appear in the signing (Kuntze, 2000; Lucas & Valli, 1989) or writing (Lillo-Martin, 1998; Menéndez, 2010) of Deaf signers. It remains to be seen to what extent these effects are equivalent to the bilingual effects observed in those who access a sign language visually and a spoken language through the oral/aural modality, but there are clear psycholinguistic similarities (Emmorey Giezen & Gollan 2015). …”

Code-blending with depicting signs

“…In this squib, we analyze production data from hearing bimodal bilinguals -adults whose native languages include a sign language and a spoken language. Bimodal bilinguals engage in a bilingual phenomenon akin to code-switching, but unique to the bimodal situation: code-blending (Emmorey, Giezen, & Gollan, 2016). In code-blending, aspects of a spoken and signed utterance are produced simultaneously; this is possible since the articulators of speech and sign are largely separate.…”