Feeling Tired? Scientists Use Brain Scans to Measure Fatigue

Yawning in the middle of the day is completely normal for people with hectic schedules. How do you know whether it’s a sign to grab a cup of coffee or a red flag of an underlying condition? Why do people with depression, multiple sclerosis, and other neurological conditions often feel exhausted throughout the day? Researchers believe they finally have the tools to answer these…