The current study aimed to evaluate the psychometric properties and diagnostic accuracy of the 32-item version of the Multilingual Naming Test (MINT) in a sample of English and Spanish monolinguals and bilingual older adults from two ethnic groups (EA; European Americans and HA; Hispanic American) with typical and atypical aging. An IRT model was used to identify 24 MINT Items assessed across ethnicity and language testing groups (Spanish and English). We analyzed the discriminant and predictive validity of the 32-item and 24-item scales across diagnostic groups (cognitively normal [CN], mild cognitive impairment [MCI], and dementia [AD]). Diagnostic accuracy was then assessed with both versions applying ROC (Receiver Operating Characteristics) curve reporting using AUC (Area Under the Curve). We expected the MINT to distinguish between the CN and AD groups but not between CN and MCI and the MCI and AD. We conducted IRT analyses to evaluate the cross-language validity of the items from the 32-item MINT in English and Spanish through Rasch Analysis across our two ethnic groups. Finally, we tested the association between MINT scores and MRI volumetric measures of language-related areas in both cerebral hemispheres’ temporal and frontal lobes.

The sample comprised 281 participants (178 females) enrolled in the 1Florida Alzheimer’s Disease Research Center (ADRC), with 175 participants self-identified as HA (51 tested in English and 124 in Spanish) and 106 EA, all of them monolingual English speakers. The participants were classified into three diagnostic groups: 1. CN (n = 94); 2. MCI (n = 148); and 3. AD (n = 39). Participants are evaluated yearly through a comprehensive neuropsychological battery, including the MINT is a standard CN task that requires patients to retrieve words upon presentation of a line drawing.

We obtained a ceiling effect in four items (Butterfly, Glove, Watch, and Candle). Four items were easier in English (Blind, Gauge, Porthole, and Pestle) and four in Spanish (Dustpan, Funnel, Anvil, and Mortar). In the 32-item version of the MINT, EA scored significantly higher than HA, but when removing those eight items, the ethnic difference was attenuated and no longer statistically significant (controlling for education). The ROC curves showed that both versions of the MINT had poor accuracy when identifying CN participants and were acceptable in identifying dementia participants but unacceptable for classifying MCI participants. The 32-item MINT in English and Spanish and the 24-item MINT in Spanish were significantly correlated with the bilateral MTG. However, the 24-item MINT in English was only correlated with this area’s volume in the right hemisphere. The left FG correlated with MINT scores regardless of language and MINT version. We also found some differential correlations depending on the language of administration. The bilateral hippocampi, STG, MTG and FG, and right ITG were significantly correlated only with MINT Spanish scores, while the left ITG was significant only when either version of the MINT was administered in English.

Our results highlight the importance of analyzing cross-cultural samples when implementing neuropsychological tests.