Cognates are studied in many psychological studies of bilingual language processing. Despite their frequent use, there is no clear operationalized definition of what constitutes a cognate. We conducted a literature search in three major journals to better understand how cognate status is typically defined and operationalized. In these journals, we analyzed similarity of cognate and non-cognate stimuli. We found that approximately 60% of the reviewed studies operationalized cognate status empirically. Stimulus analyses revealed a similarity continuum between cognates and non-cognates without a consistent cut-off. Based on these results, we make recommendations for future research.

We examined brain and cognitive reserve related to bilingualism in older adults with, or at-risk for, Alzheimer's disease (AD) from the Canadian Consortium on Neurodegeneration in Aging and the Quebec Consortium for the Early Identification of Alzheimer's Disease. We used surface-based morphometry methods to measure cortical thickness and volume of language-related and AD-related brain regions. We did not observe evidence of brain reserve in language-related regions. However, reduced hippocampal volume was observed for monolingual, but not bilingual, older adults with AD. Thus, bilingualism is hypothesized to contribute to reserve in the form of brain maintenance in the context of AD.

Foreign language can either enhance decision-making by triggering more deliberation or worsen it due to cognitive overload. We tested these two hypotheses in one response bias: acquiescence. In three experiments, 413 participants made dichotomous decisions about whether 100 personality traits described them or not. Participants showed more acquiescence in a foreign language (vs. native), giving more certifying responses when deciding on known traits. Reaction time results suggest that a foreign language particularly impacts rejection more than certification of their comprehension. These findings support the cognitive overload hypothesis and provide valuable insights for the influence of language on response bias.

Network science was used to create and examine semantic networks of cue and response words from a word association task in learners of Kaqchikel (an endangered language indigenous to Guatemala) and monolingual English speakers. English speakers provided a wide range of responses indicative of creative language use, whereas the Kaqchikel learners provided straightforward and utilitarian responses. The observed differences in network structure in the English/Kaqchikel learners resembled the structural differences previously observed in more/less creative individuals, suggesting an alternative account of the “foreign language effect” based on the size and structure of the semantic network in the native/foreign language.