Gestures serve many functions, including aiding language access and message construction, particularly in spatial tasks. Some researchers have argued that gesture frequency is linked to proficiency in bilinguals, although results have been inconsistent. We tested Nicoladis’ (2007) proposal that bilinguals’ proficiency interacts with task: namely, more spatial tasks elicit greater proficiency effects. French–English bilinguals completed a cartoon-retell task (high spatial) and an interview task (low spatial) in both languages. We measured bilingual proficiency categorically by first language (L1) and continuously by assessing receptive vocabulary, oral fluency, and word types. Participants gestured more in the cartoon-retell task, but there were minimal proficiency effects and no interactions between proficiency and task. Interestingly, only participants with English as their L1 gestured more in their second language (L2), potentially due to ‘rustiness’, or lexical access difficulties in French from low usage in the majority English community.

Mandarin speakers often use gestures to represent time laterally, vertically, and sagittally. Chinese Sign Language (CSL) users also exploit signs for that purpose, and can differ from the gestures of Mandarin speakers in their choices of axes and direction of sagittal movements. The effects of sign language on co-speech gestures about time were investigated by comparing spontaneous temporal gestures of late bimodal bilinguals (Mandarin learners of CSL) and non-signing Mandarin speakers. Spontaneous gestures were elicited via a wordlist definition task. In addition to effects of temporal words on temporal gestures, results showed significant effects of sign. Compared with non-signers, late bimodal bilinguals (1) produced more sagittal but fewer lateral temporal gestures; and (2) exhibited a different temporal orientation of sagittal gestures, as they were more likely to gesture past events to their back. In conclusion, bodily experience of sign language can not only impact the nature of co-speech gestures, but also spatio-motoric thinking and abstract space-time mappings.

Cognate facilitation and cognate interference in word production have been elicited separately, in different paradigms. In our experiment, we created conditions for facilitation and interference to occur sequentially, and identified the levels at which the two processes manifested. Bilinguals translated cognates and noncognates from L2 to L1 and typed the translations. Response-onset latencies were shorter for cognates (cognate-facilitation) but execution latencies were longer, and cross-language orthographic errors were more frequent for cognates than for noncognates (cognate-interference). Facilitation at onset followed by interference during word execution suggests that the language-selection mechanism operated efficiently at the lexical level but inefficiently at the sublexical level. It also suggests that language selection is not an event with irreversible outcome, but selection at one level may not guarantee language-selectivity at subsequent levels. We propose that a model of bilingual language production that specifies multiple language-selection processes at multiple loci of selection can accommodate this phenomenon.

The current study investigates how second-language (L2) proficiency contributes to cognitive control differences among three groups of unbalanced Chinese–English bilinguals matched for socioeconomic status (SES), intelligence (IQ), education, age, culture, and L1 background. A Flanker task and the Wisconsin Card Sorting Test (WCST) were administered to measure conflict monitoring, inhibition, and mental set shifting. ANOVA analyses revealed faster performance for the High-L2 Group compared to the Low-L2 Group in the congruent, neutral, and incongruent conditions of the Flanker task. However, there were no group differences on the WCST. Multiple step-wise regression analyses showed that L2 proficiency was a predictor for the Flanker task performance in all three conditions, SES in the neutral and the incongruent condition, and IQ in the congruent condition. These results suggest that L2 proficiency, along with SES and IQ, contribute significantly to cognitive control differences in conflict monitoring among young-adult bilinguals.

In the present study, we examined the effect of speaker certainty on word-learning performance in English-speaking monolingual (MAge = 6.40) and Spanish–English bilingual (MAge = 6.58) children. No group differences were observed when children learned novel words from a certain speaker. However, bilingual children were more willing to learn novel words from an uncertain speaker than their monolingual peers. These findings indicate that language experience influences how children weigh cues to speaker credibility during learning and suggest that children with more diverse linguistic backgrounds (i.e., bilinguals) are less prone to prioritizing information based on speaker certainty.