Multidimensional assessment of cognitive function in community-dwelling older adults: fNIRS dual-task assessment and...

Motor-cognitive dual-task performance is closely related to age-related changes in cognitive and motor function. Community-based approaches combining cognitive screening with neurophysiological and nutritional assessment may help characterize cognitive health in older adults. This study explored the feasibility of combining prefrontal oxygenated hemoglobin (Oxy-Hb) responses measured using functional near-infrared spectroscopy (fNIRS) during a seated motor-cognitive dual-task paradigm with cognitive screening and nutritional evaluation among older adults attending community salons.

A total of 127 community-dwelling older adults attending local salons were included. Cognitive function was assessed using the Montreal Cognitive Assessment-Japanese version (MoCA-J) and the Mini-Mental State Examination. Nutritional intake and body composition were evaluated using a food frequency questionnaire and bioelectrical impedance analysis. Prefrontal Oxy-Hb responses were recorded using an 8-channel fNIRS system during a seated motor-cognitive dual-task condition. Exploratory hierarchical multiple regression analyses examined associations between MoCA-J scores and Oxy-Hb responses. Age and sex were entered as covariates, and all eight fNIRS channels were entered simultaneously using the forced-entry method. Multiple comparisons across fNIRS channel predictors were addressed using Benjamini-Hochberg false discovery rate correction.

Approximately 60.3% of participants scored below the MoCA-J cutoff, suggesting possible cognitive decline based on screening. For the MoCA-J total score, the overall regression model was significant, and adding the eight fNIRS channels significantly improved model fit beyond age and sex. After false discovery rate correction, Ch6 was positively associated and Ch8 was negatively associated with MoCA-J total score. In exploratory subdomain analyses, Ch8 remained significantly associated with naming and attention scores. Nutritional and body composition analyses suggested a marginal negative association between fat intake and MoCA-J scores, whereas protein mass was positively associated with MoCA-J scores.

fNIRS-derived prefrontal Oxy-Hb responses during a seated motor-cognitive dual-task paradigm, together with nutritional and body composition indicators, may provide complementary information for characterizing cognitive health in community-dwelling older adults. Although exploratory and requiring longitudinal validation, this multidimensional assessment approach may contribute to practical community-based strategies for dementia prevention and healthy aging.