Check out this article from the Guardian, which reports that "Researchers used brain scans to show that when straight men looked at pictures of women in bikinis, areas of the brain that normally light up in anticipation of using tools, like spanners and screwdrivers, were activated," while "Scans of some of the men found that a part of the brain associated with empathy for other people's emotions and wishes shut down after looking at the pictures."
Just to make it clear: the photos in question weren't merely photographs of beautiful women, or even scantily clad beautiful women; they were pictures of scantily clad women with no heads. The lack of anything that would indicate real female personhood is the most significant feature of this image, for instance, not the fact that it was painted by a "master" and is owned by the Louvre.
Also, the study points out that not all of the men "had very little activity in the prefrontal cortex and other brain regions that are involved with understanding another person's feelings and intentions" after seeing the images. The article doesn't elaborate as to why this was, but I'm guessing that explicit education on the fact that women are actually people, can achieve a lot in helping men to retain their empathy when it comes to women.