What Does Large-scale Electrodermal Sensing Reveal?

Electrodermal activity (EDA) is a physiological measure that is used to index sympathetic arousal in response to stressors and other perturbations. However, EDA is underutilized in real-world, population-level research and clinical practice because of a paucity of remote measurement capabilities on commodity devices. The current study examined the capabilities of continuous remote measurement of EDA at scale to quantify physiological changes in the context of diurnal and circadian rhythms, demographic differences, high arousal contexts such as public holidays and high arousal moments (e.g., the Super Bowl). We first demonstrated the accuracy of a novel EDA sensor developed for the Fitbit Sense 2 wearable device within a controlled, arousal-inducing experiment. We then retrospectively analyzed 10 million hours of continuous EDA data collected from over 16,000 people. We show that continuously sampled in-situ EDA from Sense 2 has similar population-level diurnal patterns as those established from more tightly controlled in-lab experiments. Following this, variation of SCL across day of the week and season are presented. Finally, EDA dynamics occurring in response to commonly held stressful or exciting events such as Thanksgiving and the Super Bowl are described which we interpret as a natural experiment eliciting autonomic arousal. ### Competing Interest Statement The authors were all employed by Google and received company stock as part of their normal compensation.