Performance of Hispanics and Non-Hispanic Whites on the NIH Toolbox Cognition Battery: the roles of ethnicity and language backgrounds

Objective: This study examined the influence of Hispanic ethnicity and language/cultural background on performance on the NIH Toolbox Cognition Battery (NIHTB-CB). Method: Participants included healthy, primarily English-speaking Hispanic (n = 93; Hispanic-English), primarily Spanish-speaking Hispanic (n = 93; Hispanic-Spanish), and English speaking Non-Hispanic white (n = 93; NH white) adults matched on age, sex, and education levels. All participants were in the NIH Toolbox national norming project and completed the Fluid and Crystallized components of the NIHTB-CB. T-scores (demographically-unadjusted) were developed based on the current sample and were used in analyses. Results: Spanish-speaking Hispanics performed worse than English-speaking Hispanics and NH whites on demographically unadjusted NIHTB-CB Fluid Composite scores (ps <.01). Results on individual measures comprising the Fluid Composite showed significant group differences on tests of executive inhibitory control (p =.001), processing speed (p =.003), and working memory (p <.001), but not on tests of cognitive flexibility or episodic memory. Test performances were associated with language/cultural backgrounds in the Hispanic-Spanish group: better vocabularies and reading were predicted by being born outside the U.S., having Spanish as a first language, attending school outside the U.S., and speaking more Spanish at home. However, many of these same background factors were associated with worse Fluid Composites within the Hispanic-Spanish group. Conclusions: On tests of Fluid cognition, the Hispanic-Spanish group performed the poorest of all groups. Socio-demographic and linguistic factors were associated with those differences. These findings highlight the importance of considering language/cultural backgrounds when interpreting neuropsychological test performances. Importantly, after applying previously published NIHTB-CB norms with demographic corrections, these language/ethnic group differences are eliminated.