Effects of Language and Acculturation on Neurocognitive Performance of Japanese Americans

Objective: Despite significant work in African and Hispanic American populations, little information is available regarding performance of Japanese Americans on neuropsychological tests. The aim of this study was to examine the effects of dominant language and acculturation levels on the performance of Japanese Americans on selected neurocognitive tests. Method: Based on their self-identified dominant language, 48 English-dominant speaking (ES) Japanese Americans (M-age = 64.48, SD = 10.52) and 52 Japanese-dominant speaking (JS) Japanese Americans (M-age = 60.17, SD = 11.15) were assessed on a neurocognitive battery. Results: Significant differences in test performance were observed between the groups, with the JS group performing poorer on the measures of naming ability, verbal and olfactory learning/memory, and language, compared to the ES group. Levels of acculturation explained that group difference. The Brief Visuospatial Memory Test-Revised (BVMT-R) showed no group differences, suggesting lack of language proficiency and acculturation biases in this ethnic sample. Within the JS group, self-reported English proficiency and years of education obtained in Japan explained variance in addition to age, education, and gender, in performance on the Boston Naming Test and the Letter Fluency Test, respectively. Conclusions: The present study highlights the need for culturally sensitive evaluation in the neuropsychological assessment of this population. The variability in backgrounds contributed to the variability in performance between and within groups. Factors in addition to age and education, including the effects of primary language and acculturation, warrant consideration when evaluating the neuropsychological performance of Japanese Americans in research and clinical settings.