Cognitive differences between healthy monolingual and bilingual anglophones on the English version of the Dépistage Cognitif de Québec: A new screening tool for atypical dementia: Developing topics. (7th December 2020) - Lévesque, Marianne
Abstract: Background: Cognitive abilities between monolingual and bilingual individuals may differ, making it important to validate new cognitive screening tools using psychometric testing. Otherwise assessments could be subject to misinterpretation, leading to inaccurate diagnoses. The current project aimed to compare healthy older monolingual and bilingual anglophones on the English version of a new cognitive screening test designed for better recognition of atypical dementia; the Dépistage Cognitif de Québec (DCQ, www.dcqtest.org ). The DCQ was developed at la Clinique Interdisciplinaire de mémoire de Québec, and its psychometric properties have been well studied, including its sensitivity and specificity to detect atypical dementia compared to current standardized cognitive screening tests (Laforce et al., 2018; Sellami et al., 2018). Methods: The DCQ was administered by qualified psychometricians to 85 healthy native English‐speaking participants aged 50 years and over, in various sites across North America. The Montreal Cognitive Assessment (MoCA) was used to determine participants' eligibility. Language proficiency was established using the Language Experience and Proficiency Questionnaire (LEAP‐Q). Results: Amidst the anglophone participants recruited, 30 monolingual anglophones and 29 bilingual anglophones met the inclusion criteria. The two groups had similar age, education and MoCA scores. Monolinguals and bilinguals were compared on their total DCQ scores as well as on each of the 5 indexes of the DCQ: Memory, Visuospatial, Executive, Language and Behavioural. Statistical analysis showed a significant advantage for the bilingual participants on the total DCQ scores and on the Language index, which was later washed out following a Bonferroni correction. No significant differences were found between groups on any of the other indexes. Conclusion: This study is the first to explore psychometric properties of the DCQ in older monolingual and bilingual participants tested in their native language. The results highlight the importance of identifying and characterizing linguistic diversity before using new screening tools in clinical settings. The potential cognitive advantages of bilingualism, even in healthy older adults, should be considered when interpreting test data and explicitly discussed in neuropsychological reports. Similar studies should be conducted for all future cognitive screening measures, especially to further examine the differences between groups on language‐related tasks.