Sexy women in bikinis really do inspire some men to see them as objects, according to a new study of male behavior.

Brain scans revealed that when men are shown pictures of scantily clad women, the region of the brain associated with tool use lights up.

Men were also more likely to associate images of sexualized women with first-person action verbs such as "I push, I grasp, I handle," said lead researcher Susan Fiske, a psychologist at Princeton University.

And in a "shocking" finding, Fiske noted, some of the men studied showed no activity in the part of the brain that usually responds when a person ponders another's intentions.

This means that these men see women "as sexually inviting, but they are not thinking about their minds," Fiske said. "The lack of activation in this social cognition area is really odd, because it hardly ever happens."

Dehumanizing

Fiske and colleagues asked 21 heterosexual male volunteers to first take a test that scores people based on different types of sexist attitudes. The subjects were then shown pictures of both skimpily dressed and fully clothed men and women.

Most of the men best remembered headless photographs of women in bikinis, even if they'd only seen the image for two-tenths of a second, Fiske reported this weekend in Chicago during the annual meeting of the American Association for the Advancement of Science.

And the men who scored higher as "hostile sexists"—those who view women as controlling and invaders of male space—didn't show brain activity that indicates they saw the women in bikinis as humans with thoughts and intentions.

Scientists have seen this absence of activation only once before, in a study where people were shown off-putting photographs of homeless people and drug addicts.

If a similar study were done with women, Fiske told National Geographic News, it would be hard to predict whether a woman shown a scantily clad male body would dehumanize him in the same way.

Evolutionary psychologists have proposed that women tend to look for mates who have wealth and power, so some of Fiske's colleagues have suggested running a similar test where women are shown pictures of men next to expensive cars or other affluent symbols.