Impaired cerebrovascular function contributes to the genesis of age-related cognitive
decline. In this study, the hypothesis is tested that impairments in neurovascular
coupling (NVC) responses and brain network function predict cognitive dysfunction
in older adults. Cerebromicrovascular and working memory function of healthy young
(n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed.
To determine NVC responses and functional connectivity (FC) during a working memory
(n-back) paradigm, oxy- and deoxyhemoglobin concentration changes from the frontal
cortex using functional near-infrared spectroscopy are recorded. NVC responses are
significantly impaired during the 2-back task in aged participants, while the frontal
networks are characterized by higher local and global connection strength, and dynamic
FC (p < 0.05). Both impaired NVC and increased FC correlate with age-related decline
in accuracy during the 2-back task. These findings suggest that task-related brain
states in older adults require stronger functional connections to compensate for the
attenuated NVC responses associated with working memory load.
