Wow - this one carries a ton of implication with it if you think about what the data infers.

Anyone else get the feeling we'll see this story a week or so from now in The NY Post with the sensational title "Scientists Develop Gay Test"?

Did they test it with other images, specifically non-erotica images of humans? Perhaps it's not erotica that's so stimulating, but the fact that there's something there at all, but hidden.

This doesn't account for the homosexual/heterosexual differences, but perhaps they would be more likely to notice the gender of their attraction regardless of the level of "erotica" posed.