Abstract
•Cognitively normal individuals aged 72 - 73 recruited from a UK-based National Birth Cohort with (n = 33) and without carotid atherosclerosis (n = 33) underwent a Stroop color word task with concurrent assessment of functional near infrared spectroscopy (fNIRS) and hemodynamics.•Carotid atherosclerosis was associated with a decrease in the extent of brain activation as measured by fNIRS in response to the Stroop test.•The differences were observed despite no differences in time required to complete the task or number of errors made, or changes in mean arterial pressure or heart rate.•The results suggest that carotid atherosclerosis is associated with alterations in functional brain activation patterns without impaired Stroop task performance.
There is an increasing body of evidence suggesting that vascular disease could contribute to cognitive decline and overt dementia. Of particular interest is atherosclerosis, as it is not only associated with dementia, but could be a potential mechanism through which cardiovascular disease directly impacts brain health. In this work, we evaluated the differences in functional near infrared spectroscopy (fNIRS)-based measures of brain activation, task performance, and the change in central hemodynamics (mean arterial pressure (MAP) and heart rate (HR)) during a Stroop color-word task in individuals with atherosclerosis, defined as bilateral carotid plaques (n = 33) and healthy age-matched controls (n = 33). In the healthy control group, the left prefrontal cortex (LPFC) was the only region showing evidence of activation when comparing the incongruous with the nominal Stroop test. A smaller extent of brain activation was observed in the Plaque group compared with the healthy controls (1) globally, as measured by oxygenated hemoglobin (p = 0.036) and (2) in the LPFC (p = 0.02) and left sensorimotor cortices (LMC)(p = 0.008) as measured by deoxygenated hemoglobin. There were no significant differences in HR, MAP, or task performance (both in terms of the time required to complete the task and number of errors made) between Plaque and control groups. These results suggest that carotid atherosclerosis is associated with altered functional brain activation patterns despite no evidence of impaired performance of the Stroop task or central hemodynamic changes.