Quantitative Physiological Assessment of Stress Via Altered Immune Functioning Following Interaction With Differing Automotive Interface Technologies

Abstract

Technology can enhance or diminish a user's psycho-physiological stress level; the ability to quantify these responses can help evaluate and refine design. The capability of drivers to accomplish basic tasks utilizing differing sensory modalities while maintaining lane discipline within a computer-simulated environment was assessed. Fifteen healthy subjects provided capillary blood samples before and after using three human–machine interface designs—touch-screen, voice control, and multimodal. Using a chemiluminescent technique termed Leukocyte Coping Capacity, the ability of leukocytes to produce reactive oxygen species in vitro was assessed. Significant poststressor changes in leukocyte activity of varying magnitude were observed following the use of all interfaces; with the multimodal interface provoking the most pronounced response and voice control the least. Although still requiring further research, the results support the proposition for using immune responsiveness as a means for quantifying psychological stress during assessment of ergonomic design and psycho-physiological and social interaction.

Acknowledgments

This research was sponsored by Jaguar Cars Limited, Engineering Centre, Whitley, Coventry, United Kingdom. This work formed part of a PhD program of research. The PhD studentship was sponsored by financial assistance, the supply of test vehicles, and other specialist equipment including driving simulation technology by Jaguar and Land Rover Research and Development, Jaguar Cars Limited. The sole request of the sponsor was for the research team to design a simulator-based study incorporating production test vehicles for the purpose of testing and investigating the ability of the Leukocyte Coping Capacity protocol and other physiological parameters to act as a means for objectively quantifying changes in stress level following interaction with human–machine interfaces of differing ergonomic design. At no point did the sponsor provide any preconceptions as to the expected outcome of the study. We are grateful to Dr. Paul Johnson for statistical advice and the volunteers who gave freely of their time and good will to participate in the study.