Clearly, hardcore roller coaster enthusiasts are not your average theme park visitors. Many travel extensively, trying to ride as many different coasters as they can, while others find a favorite that fits the bill for habitual thrills. For Frank Farley, a psychologist at Temple, the typical coaster yogi is a classic "Big T" personality, i.e., someone who craves novelty, intensity and excitement. (The "T" is for thrill, with "little t" types preferring routine and risk-averse activities.) "Roller coasters provide a whole smorgasbord of stimulation," Farley said. "Rapid breathing, elevated heart rate — there’s a Niagara of changes going on in the brain."