Galvanic Skin Response as a Measure of Soldier Stress

Abstract : In the ever-increasing realm of "high-tech" Soldier systems, one factor remains fairly constant: the human factor. The use of multiple high-tech and increasingly complex systems is intended to add capabilities to Soldiers and to reduce stress and workload. However, these systems may add increased levels of stress and workload onto Soldiers who are already at heightened levels of each because of the environments in which the systems are employed. To gauge what levels of stress and workload are being impinged upon these Soldiers, researchers have used a small number of tools at their disposal. The two primary tools used are self-report surveys and salivary amylase. Surveys are quick and cheap but subjective, while salivary amylase tests are objective but time-consuming, intrusive, and expensive. As requirements increase to incorporate larger numbers of high-tech and more complex systems with Soldier-in-the-loop (SIL) systems, researchers will need a method to gather stress data in an accurate, timely, and less intrusive manner. This report discusses the use of a third method to measure Soldier stress: galvanic skin response (GSR). The first step of this process compared the survey method with the GSR method to determine if GSR data are similar to survey stress data in terms of statistics and trends. The ultimate goal of the research (this phase and ensuing research) is to determine if the GSR method is a suitable "middle ground" between the survey method and the salivary amylase method. GSR has the potential to provide researchers with a tool for objectively measuring Soldier stress that is quick, effective, and unobtrusive during research, training, and operational conditions. Stress levels were tested with soldiers using a head-tracked sensor suite (HTSS), aided target recognition technology, and a crew-aiding behavior interface. Results of the survey-GSR comparison and recommendations for ensuing research are presented.