MOSCOW — Evgenia Medvedeva has bugs in her head. At least that’s how the world’s top women’s figure skater calls the little demons and doubts that she needs for success.

Just 17 years of age and already a two-time world champion, the Russian prodigy cruised to victory in the season’s opening Grand Prix event Saturday, keeping her on course as favorite for the Olympic gold medal in February.

Despite her dominance, Medvedeva said she’s on an emotional tightrope every time she skates, and that’s how she likes it.

A devotee of old-fashioned self-motivation — she’s never worked with a sports psychologist — Medvedeva likes to skate with a few doubts and hang-ups, known colloquially in Russian as “bugs in your head.”

“You need these bugs because they make you disciplined,” she said Sunday. Without them, Medvedeva said she’d relax too much and make mistakes, but “too many of these bugs can cause you horrible problems too, when they start eating at you from inside.”

Medvedeva has kept her balance with consummate skill so far. She’s undefeated in almost two years.

Medvedeva is reluctant to discuss the Olympics, where she seems almost certain to be Russia’s top medal contender. Reigning champion Adelina Sotnikova isn’t skating this season citing injury, while Sochi’s breakout star Yulia Lipnitskaya has retired following battles with anorexia.

Asked about her No. 1 status on the Russian team, Medvedeva said simply: “For me, the main thing is not to think about it at all, just go out and do what I love to do.”

Off the ice, she’s an often light-hearted figure who jokes with teammates, practices intensely and enjoys South Korean pop music.

On it, she’s fiercely competitive and drawn to programs marked by passionate emotion — often with a dark side.

In her free program this season, Medvedeva takes on the role of Anna Karenina, the doomed heroine of the 19th-century Russian novel of the same name. The Karenina of the novel is a married woman and a mother, not to mention a literary icon, but Medvedeva says her youth is no barrier to taking on the role.

“If you go back to the time of Anna Karenina, when the novel was written, then if a girl’s already 25 or 26 and she’s unmarried, she’s considered a spinster,” Medvedeva said. “So I don’t think I’m not old enough, because I’m almost 18, and I can skate that character from within as she should be skated.”

Dramatic performances let you “skate your emotions to the fullest,” Medvedeva said Sunday. “I mean suffering, compassion, contemplation.”