Cerebrovascular and cardiorespiratory responses in young, mid-aged, and older adults during simulated driving
University of New Brunswick
Very little is known about the cerebrovascular and cardiorespiratory adjustments drivers make during typical driving task on highways and in urban areas. Near infrared spectroscopy (NIRS) can measure changes in oxygenated (HbO2) and deoxygenated (HHb) haemoglobin concentration in the prefrontal cortex (PFC) during physical activities including driving. Heart rate responses can be measured through an electrocardiogram (ECG). This study recruited 29 participants to fulfill three age categories: young adults (18-25), mid-aged adults (26-64), and older adults (65+). Participants completed a Useful Field Of View (UFOV) test and four driving sessions using a driving simulator. Neuroimaging studies have suggested that the PFC plays a role in executive function while psychocognitive driving models have suggested that planning, judgement, and decision making are necessary cognitive skills for safe driving. This study investigated the cognitive and physiological stresses and demands of navigating urban areas and highways on a driving simulator and compared age groups. There were no statistically significant differences between age groups in UFOV scores of divided and selective attention or for heart rate variability (HRV) variables. Heart Rate (HR) increased by ~3 beats per minute (BPM) during city driving and HbO2 increased slightly during driving tasks. Throughout most of the study, tissue oxygenation index (TOI) remained near resting baseline values. The general trend was slightly increased hemodynamic responses during driving with periods of decreased PFC activity.