Imagine lying down in an MRI machine with images flashing above you. The pictures are too fast for you to actually see them consciously, but your brain, quick as it is, does see them. On a screen a few feet away, colors appear and spread through an image of your brain, identifying where blood flows and what parts are more active at every moment.

The scientist at the computer ticks some boxes every couple of seconds, making notes and pointing to areas of your brain that are lighting up.

Once the experiment is over, you sit on a chair as the scientist reports their findings: "You are attracted to both women and men and enjoy spankings and light bondage. Oh, and you really have a thing for redheads."

As ludicrous as this scenario sounds, we're getting rather close to being able to identify sexual preferences via brain scans. A recent study by European scientists provided a proof of concept of this technique. In short, the study showed that heterosexual men's brains reacted with signs of sexual arousal when shown subliminal images of naked women and women masturbating. The participants themselves didn't remember what they saw.

The researchers argue that this technique is a fraud-proof way of showing that someone is a pedophile, for example. If the brain lights up when seeing subliminal images of children, then you have somehow "proved" that a person has deviant sexual interests.

Ethics and Politics

Does the fact that it works make this technique ethical? Right now, in our generally sexually permissive culture, we may not see much of a problem with it. After all, if it's just to identify pedophiles, that's a good thing, right?

Yet, consider that sexual mores and norms change across time. What if one day we believe, again, that homosexuality is deviant? Or that masochists are harming themselves and are mentally ill? What if we, again, legislate against sexual acts that right now are considered acceptable? And what about countries that currently have anti-LGBTQ laws?

The problem with this research is one that applies to lots of science and technology breakthroughs.

Just Because We Can, Doesn't Mean We Should

In a world where anti-LGBTQ, anti-sexual freedom politics is taking over country after country, such a technique could be used to identify so-called "deviants." Authoritarian regimes might use this research and scan people to eliminate "undesirables" not only for their actions, but now for thoughts and reactions that are out of their conscious control.

Even when it comes to identifying pedophiles, this research brings up a "Minority Report" dilemma. If you have the capacity to stop people before they even think of committing a crime, should you do it? If a pedophile who has lived their lives lawfully and never acted on their desires is identified, should they be arrested on the spot? Which civil liberties will be in danger because it is now possible to police our unconscious reactions to subliminal images?

Although the research is interesting in theoretical terms, the ethical and political implications could get in the way of the last 50 years of progress towards sexual freedom. For now, though, this is only a proof of concept. They have yet to test it on women, non-heterosexual people, and other sexual minorities. Are we in danger, right now? Probably not. But can this research be used to fuel a thought police right out of 1984? Absolutely.