Assessing aging-related changes of the brain-heart interconnection using functional near-infrared spectroscopy

OBJECTIVE: The brain and the heart are linked through brain-heart interactions (BHIs) controlled by the autonomic nervous system and are susceptible to deficits caused by aging and cognitive disorders. Here, we studied changes in the wavelet magnitude and phase coherences (wavelet phase coherence, WPC) of functional near-infrared spectroscopy (fNIRS) and heart rate (HR) signals to investigate age-related alterations to the BHI, while performing a dual-task (DT) function. METHODS: Twenty-two healthy young (HY) controls, 15 cognitively normal (CN) older adults, and 7 older adults with mild cognitive impairment (MCI) were recruited. fNIRS channels covered areas in the frontal and parietal lobes. Participants performed an upper extremity function (UEF) DT involving simultaneous elbow flexion-extension and backward counting. RESULTS: Wavelet coherence was significantly larger in older adults compared to young adults (p < 0.032) and was significantly smaller in MCI participants compared to CN older adults (p < 0.022). WPC was significantly lower in older adults with MCI than CN older adults (p < 0.019) in most brain regions. CONCLUSIONS: Results suggest that the BHI may alter through aging and cognitive impairment, as quantified through coherence measures comparing fNIRS and HR signals. SIGNIFICANCE: Current findings could be implemented as a screening methodology for alterations in autonomic function due to aging and cognitive impairment.