General Research Fund Award (GRF), 2025-26
Principal investigator: Mohammad Momenian

Abstract

Background: It is unclear whether healthy aging results in less efficient semantic prediction in real-time language comprehension. Given substantial variability in the reported degree of decline in cognitive functions during healthy aging, one explanation for the mixed findings could be that an individual differences approach is not adopted in most studies.

Purpose: The proposed study will examine whether language deterioration is a consequence of healthy aging or a downstream consequence of decline in other cognitive functions which are influenced by healthy aging. This is an important question given that Hong Kong’s aging population is increasing and that language is the basis of social participation.

Methods: Healthy young (25-40 years old) and older (over 65) participants will be recruited from Hong Kong. Cantonese spoken sentences that vary in semantic predictability will be designed. Simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) recordings will be conducted while participants listen to these sentences. The simultaneous EEG-fMRI has rarely been done in previous research. It allows a set of real-time models describing where and when semantic prediction occurs in the healthy brain across the lifespan. For analysis of neural data, a novel multivariate approach called EEG-fMRI fusion will be used. This analysis combines the data from both modalities into a single space. To account for individual differences, metrics such as working memory, verbal fluency, processing speed, inhibitory control, non-verbal intelligence, and participants’ language experiences are included in the analyses. These variables are known to predict cognitive decline in aging. The inclusion of individual differences enables us to draw conclusions on how much of the differences reported between younger and older people can actually be attributed to aging itself. The use of two acquisition modalities simultaneously and inclusion of a variety of individual differences are novelties of this study which could help advance the field of healthy aging.

Implications: Findings help healthcare professionals gain a deeper knowledge of how much language comprehension changes with aging and to what extent individual differences could mediate the effects of aging on language comprehension. Findings could be used in programs that aim to improve quality of life and cognitive functions in older adults. The fact that this study will be conducted in Hong Kong will create a more realistic and contextualized picture of healthy aging in Hong Kong. This evidence-based, contextualized approach could inform healthcare policy decision making in healthy aging in the long run.