Can your smartwatch detect neurological disease?

A few years ago, most people bought a smartwatch mainly to count steps, track exercise, or check messages. Today, the same small device can continuously monitor movement, physical activity, heart rate, and sleep. This has led neuroscientists to ask whether information collected from the wrist might also tell us something useful about neurological health.

A smartwatch cannot see the brain. It cannot perform an MRI, measure dopamine, or examine neurons. What it can do is repeatedly measure functions that the nervous system controls, including how we move, walk, sleep, and respond to our surroundings. Neurological diseases can gradually alter these functions, sometimes before the changes become obvious in everyday life. Researchers are therefore studying wearable devices as sources of digital biomarkers, objective measurements collected through digital technologies that may provide information about health and disease .