John Ratey is a renowned psychologist and author, born on April 7, 1948. His research focuses on human behavior and mental health, particularly on Attention-Deficit/Hyperactivity Disorder (ADHD) and the impact of exercise on the brain. Dr. Ratey's work has had a significant influence in both academic and public circles, with his book 'Spark: The Revolutionary New Science of Exercise and the Brain' gaining widespread popularity.