Miyako Shirakawa was a 19-year-old college student when she was raped by an older man. She said that when the attack started, her mind went blank and she froze up.

"When I became aware, he was on top of me," said Shirakawa, 54, now a psychiatrist who treats sexual abuse victims.

That type of response "is a common, instinctive reaction — it's a form of psychological self-protection," said Shirakawa, who became pregnant because of the rape, which she didn't report to police, and had an abortion.