Timeline: 15 years BACKGROUND: In the past 30 years, hundreds of scientists have investigated the ain-the-zonea feeling that athletes say gives them the sense that they can accomplish anything. When Boston Celtic Larry Bird talked about the game seeming to actually slow down during crunch time, helping him to read defenses more clearly and feel more fleet-footed, he was probably experiencing a natural dopamine high. Dopamine increases muscle-reaction speed and alters the perception of time. But these flow states, as they're known among psychologists, are probably triggered by a surge of several mindscrambling, euphoria-inducing, reflex-quickening neurochemicals, such as norepinephrine and serotonin. Although studies have yet to quantify how much flow states actually raise an athlete's performance, anecdotal evidence has convinced Michael Sachs, a sport psychologist at Temple University. aAthletic abilities are so elevated by the experience,a he says, athat just about any championship-level, gold-medal peak performance has a flow state at its core.a Elite athletes would do anything for a pill or injection that stimulates this feeling. WHERE IT'S AT: In 2004, neuroscientist Arne Dietrich, then at the Georgia Institute of Technology, identified anandaminea€"the body's version of THC, the psychoactive chemical in marijuanaa€"as the chemical most likely responsible for flow states. This theory received a boost this spring, when scientists at the University of Bonn in Germany found elevated levels of endorphins in the brains of test subjects. These molecules are too big to penetrate the blood-brain barrier on their own, so the current thinking is that anandamine ferries them in and that it's the endorphins that provide the actual high. Still, most scientists think there are other neurochemicals in play, and figuring out the exact combination may take years. With so much pharmacological interest in neuro-enhancement, though, scientists in the field say it's only a matter of time. DETECTION: To spot cheaters, Sachs says, you'll need to differentiate between the neurochemicals responsible for a natural flow state and one that's triggered artificially. aBut these chemicals may be perfectly identical to the natural stuff,a he says. aI just don't think detection may ever be possible.a Left: When a goalie is ain the zone,a fast-flying pucks are easier to catch.

Steve Cross