Most cognate research suggests facilitation effects in picture naming, but how these effects manifest in bilinguals after brain damage remains unclear. Additionally, whether this effect is captured in clinical measures is largely unknown. Using data from the Boston Naming Test, we examined the naming of cognates and noncognates, the extent of cognate facilitation produced, and the individual differences in bilingual language experience associated with naming outcomes in forty Spanish–English bilingual persons with aphasia (BPWA) relative to thirty-one Spanish–English healthy bilinguals (HB). Results suggest that naming performance in L1 and L2 in both groups is modulated by lexical frequency, bilingual language experience, and by language impairment in BPWA. Although the two groups showed similarities, they deviated in benefit drawn from the extent of phoneme/grapheme overlap in cognate items. HB showed an association between cognate facilitation and bilingual language experience, while cognate facilitation in BPWA was only associated with L2 language impairment.

Cognates – words that share form and meaning between languages – are processed faster than control words. However, is this facilitation effect merely lexical in nature or does it cascade to phonological/orthographic (i.e., sub-lexical) processes? This study compared cognate effects in spoken and typewritten production, which share lexical, but not sub-lexical processes. Dutch–English bilinguals produced English names for pictures representing Dutch–English cognates and control words in either the spoken or typewritten modality. Onset latencies were shorter and accuracy was higher for cognates vs. control words and this effect was similar in both modalities. Compared to controls, total latencies in the written modality were similar for cognates with much cross-linguistic overlap, but longer for ones with less overlap. Additionally, error analysis showed that cognates were more affected by L1 interference than controls. These results suggest two different cognate effects: one at the lexical and one at the sub-lexical level.

Most research showing that cognates are named faster than non-cognates has focused on isolated word production which might not realistically reflect cognitive demands in sentence production. Here, we explored whether cognates elicit interference by examining error rates during sentence production, and how this interference is resolved by language control mechanisms. Twenty highly proficient Spanish–English bilinguals described visual scenes with sentence structures ‘NP1-verb-NP2’ (NP = noun-phrase). Half the nouns and half the verbs were cognates and two manipulations created high control demands. Both situations that demanded higher inhibitory control pushed the cognate effect from facilitation towards interference. These findings suggest that cognates, similar to phonologically similar words within a language, can induce not only facilitation but robust interference.

Many language pairs chosen in language switching studies differ randomly on multiple linguistic levels, thus obscuring the nature of switching costs. Contact-induced languages, i.e., creoles (e.g., Spanish-based Palenquero) and mixed languages (e.g., Media Lengua), having arisen in intense language contact scenarios, relate systematically to their source languages by displaying high proportions of cognates or shared grammar. This configuration can speak to the relative contribution of lexicon and grammar to switching costs. Results from a production and comprehension task show that switching costs are systematically tied to a language pair's grammatical distance. This suggests that switching costs may result from the re-generation of the morphosyntactic frame on switch trials. Emphasizing the value of testing psycholinguistic theories outside of the usual Western populations, the current study provides insight into the degree of shared mental representations between contact-induced languages and their source languages.

Determining bilingual status has been complicated by varying interpretations of what it means to be bilingual and how to quantify bilingual experience. We examined multiple indices of language dominance (self-reported proficiency, self-reported exposure, expressive language knowledge, receptive language knowledge, and a hybrid), and whether these profiles related to performance on linguistic and cognitive tasks. Participants were administered receptive and expressive vocabulary tasks in English and Spanish, and a nonlinguistic spatial Stroop task. Analyses revealed a relation between dominance profiles and cognate and nonlinguistic Stroop effects, with somewhat different patterns emerging across measures of language dominance and variable type (continuous, categorical). Only a hybrid definition of language dominance accounted for cognate effects in the dominant language, as well as nonlinguistic spatial Stroop effects. Findings suggest that nuanced effects, such as cross-linguistic cognate effects in a dominant language and cognitive control abilities, may be particularly sensitive to operational definitions of language status.

Bilinguals dynamically activate lexical items in one or both languages depending on a number of factors. We explored the interaction effects of semantic constraints, language context, and L2-proficiency on cross-language interaction and switch costs in bilinguals who habitually codeswitch between Algerian Arabic (AA) and French. We recorded response times to French cognates and non-cognates embedded in auditory AA or French sentences. High proficiency bilinguals could restrict selection to the target language regardless of the language context. In lower proficiency bilinguals, however, selection was specific to the target language in non-switching contexts but was nonspecific in switching contexts where cross-language interaction yielded inhibitory and facilitatory cognate effects. Results of this study therefore suggest that lexical selection in codeswitching bilinguals is dynamic and is dependent on proficiency, semantic constraints and language context. This within-subject study using auditory stimuli contributes towards a more ecological methodology in investigating sentence processing in codeswitching bilinguals.