Project Summary: Elderly individuals suffering from age-related cognitive or physical decline are prone to depression, sleep disturbances, and chronic stress, which can decrease their quality of life. This project will examine whether continuous measurements of physiological correlates of daily living can help elders and their caregivers to better identify and understand recurrent patterns that contribute to such negative outcomes. Measurements will be collected using a first-of-its-kind sensor (the E4) that non-invasively collects multiple physiological measures (heart rate, electrodermal activity, temperature, and three-dimensional movements), 24 hours a day, inside or outside, rain or shine, without requiring any maintenance or attention by the user. E4 recordings make it possible to track a person’s movements, sleep patterns, activity levels, and emotional arousal throughout the week. Enabling caregivers and care recipients to objectively assess when and how problems arise during daily living can empower them to make adjustments that may decrease the frequency of such episodes.