On the application of short-term heart rate variability indices to track changes in cognitive arousal

Abstract

Studies have demonstrated that Heart Rate Variability (HRV) can be utilized as an effective tool for monitoring the level of arousal. The autonomic nervous system (ANS) is frequently measured by heart rate and principally controlled by the coordinated parasympathetic and sympathetic systems, which also regulate fluctuations in arousal. In HRV studies short-term analysis is more affordable and easier to measure rather than long-term analysis. Here, to track arousal changes, 31 participants (18 male and 13 female) with a mean age of 32 years were examined in both relaxed and aroused stages. Relax and arousal states are measured in two stages, each lasting five minutes. Relaxed status was carried out with closed eyes and listening to nature sounds. The arousal status was performed by playing a Stroop test while listening to traffic noise or death metal music. After data acquisition, 28 HRV features are calculated for each five-minute epoch. The observations have demonstrated that novel indices such as FnQ and ACI produced better results in arousal detection by using short-term (5 min) HRV analysis among all of the obtained indices. Moreover, the performance of ACI was significantly superior to the rest since it is a robust and easy-to-compute index. Consequently, ACI can be used as a powerful tool for monitoring cognitive arousal.

Postprint (published version)