Research of motion sickness for EVs in city scenario with functional near-infrared spectroscopic imaging

With the widespread adoption of electrified vehicles (EVs), particularly in the realm of intelligent cockpits and autonomous driving, motion sickness among occupants has emerged as a significant concern. While numerous studies have been conducted in controlled laboratory settings, focusing primarily on specific driving scenarios like constant acceleration, velocity, or maneuvering frequency, the real-world implications remain elusive. In this paper, we introduce a novel and intuitive approach that harnesses functional near-infrared spectroscopy imaging to delve into the nuances of motion sickness. Specifically, we investigate the alterations in oxyhemoglobin concentration within the prefrontal cortex, a key indicator of motion sickness, during urban driving cycles. Thirty-six healthy subjects participated in our study, serving as rear-seat passengers under typical urban driving conditions. Throughout the experiment, we continuously monitored their brain activity using functional near-infrared spectroscopic imaging, enabling us to capture subtle changes in oxyhemoglobin concentrations within the prefrontal cortex. Subjective motion sickness scores were captured using the 11-point MIsery SCale (MISC) every 2 min throughout the driving process. The experimental results revealed that the dorsolateral and ventral lateral prefrontal lobes exhibited the greatest sensitivity to the adverse effects of motion sickness. Notably, alterations in O₂Hb concentrations within these brain regions strongly correlated with the severity of motion sickness symptoms reported by the participants. These revelations offer profound insights into the neural underpinnings of motion sickness among electric vehicle occupants and could pave the way for the development of more targeted countermeasures to alleviate this condition. As the severity of motion sickness increases, the cerebral blood oxygen concentration in the prefrontal region decreases significantly. Consequently, both blood flow and information processing capacity in this region are notably diminished. Our findings suggest that this physiological indicator may serve as a reliable reflection of the motion sickness symptoms reported by the subjects.