Come Memorial Day weekend, you can usually find Frank Farley, PhD, and a band of about a half-dozen devoted fellow psychologists in the stands at the Indianapolis 500 waiting for the green flag to signal the race's start.

"When those incredibly powerful engines start up, the roar is deafening, and the whole racetrack shakes and reverberates," says Farley, a Temple University professor.

Yet Farley sees something deeper at work than just spectacle at the Indy 500-namely, the human desire to pursue thrills for their own sake.

"It's kind of a focused example of thrill-seeking, of the vicarious enjoyment of thrills," he says.

He started coming to the race in part because of his friendship with Richard Hurlbut, PhD, a former president of the Wisconsin Psychological Association and clinical psychologist in Stevens Point, Wis. Hurlbut arranges the tickets and hotel rooms for psychologists making the annual pilgrimage.

Hurlbut's father owned an auto parts store and got free tickets to the race when he was a boy. Hurlbut stopped going for a while during his college years and first career as a high school English teacher, but started attending again with his psychologist colleagues in the early 1980s.

Together, they observe the full range of human behavior-"from the most classy things to the most debasing things," Hurlbut says-at what's been described as the largest regularly scheduled gathering of humanity in North America. It's all there, from drivers performing at their mental and physical peak, roaring more than 220 miles per hour six inches from the lip of a concrete wall, to the beer-belly bacchanalia among the tens of thousands of fans packed in the infield. There's slightly less inebriation than in years past, though, when at least one old, beat-up car would be doused with gasoline and ceremonially torched once the race started, he says.

Besides watching their fellow fans, the psychologists follow the careers of the drivers such as Rick Mears, a four-time Indy winner who has gone on to become a successful coach. Despite suffering a crushing foot injury during his driving career, Mears worked his way back into racing and recovered his ability to maintain a constant speed, completing lap after lap on the 2.5 mile track with times varying by as little as two-hundredths of a second.

"The people that get to that level are remarkably good, and remarkably devoted to what they're doing, and they risk their lives," Hurlbut says.

Back home at his practice, Hurlbut sometimes draws on Indy 500 lore to help treat people with chronic pain. His favorite is the tale of a 1920s race winner whose leg welded to the manifold after some protective metal ripped loose. It wasn't until after the driver completed the 200-lap, 500-mile race that he noticed that the heat had severely burned his leg.

Just like the driver, people can sometimes overcome their pain if they're intensely focused on something else, Hurlbut says.

--C. Munsey