02/13/2013 11:01 am ET Updated Apr 15, 2013

Revelry, Revulsion and Residential Treatment: Your Brain's Fine Line Between Love and Hate

Though I love a frosty glass of ale now and then, I'll never forget how much I hated my first beer. The scene was pretty typical: I was a teenager at a party, someone handed me a bottle of cheap brew, and I cracked it open and took a sip -- more out of curiosity than anything. The taste, I remember, was so bitter that I barely choked it down. Many grimacing gulps later, I wandered into a bedroom and collapsed for a nap.

Even as my tolerance -- and my palate -- have matured over the years, I've always found it curious that we humans are so dedicated to developing a (literal) taste for the beautiful in the midst of the revolting. A few drinks tend to summon happy feelings; no question -- but that doesn't entirely account for the Scotch aficionado's rapture when tasting rare barrels -- or for a cigar buff's love of a smooth Cuban smoke. Connoisseurs are known to cross oceans and dodge laws to taste their favorite products -- which would be silly if all they were after was a pleasant buzz.

That's not to say, of course, that cultivated taste can't lead to addiction -- which is why some folks with a lot of time and money on their hands have a tendency to spend some time in rehab clinics, and why we have so many organizations devoted to helping people find residential treatment centers. Though chemicals can offer us all sorts of pleasures, a chemical addiction can turn just about any hobby into a compulsion -- whether that hobby is drinking, gambling or (by some accounts) even romance.

And that's the strange thing about addiction: Though external chemicals like alcohol can play a part, it's our own brain chemistry that lies at the root of every compulsion. In that sense, all addictions are chemical ones.

In fact, a new study has uncovered a way in which your brain's emotional chemistry can turn even repulsive tastes into addictive pleasures. The key, it seems, is salience: How much a certain sensation stands out in relation to other experiences. The more salient an experience is, the greater its potential to repulse and to attract us.

As the journal Current Biology reports, a team led by the University of Michigan's Mike Robinson offered a group of mice the choice between two tastes: sugary sweetness or "disgustingly intense" saltiness. As you might expect, the rats were revolted by the saltiness, but spent all day licking happily at the sugary taste. That night, while the mice slept, the scientists sneakily injected them with a chemical cocktail that made them crave sodium -- and when the mice awoke the next morning, they sprinted straight for the salt.

What's interesting about this finding isn't that the rats craved the salty taste, but that it stuck out so strongly in their memories even after they'd avoided it all day. "The cue becomes avidly 'wanted,'" Robinson says, "despite [the mice's] knowledge the salt always tasted disgusting." And that, he suspects, is because disgust and desire are more closely entangled than we might think.

Recent research has found that both emotions involve most of the same brain circuitry. Hate tends to invoke more goal-oriented, rational processing, while love carries a smattering of positive emotion -- but the neural correlates of both are strikingly similar. As the old saying goes, there really is a thin line between love and hate. This also makes sense from a philosophical standpoint: Love and hate are both forms of obsession.

This could offer some clues about why we're driven to keep trying liquor even if we hate its taste. The more its pleasure eludes us -- even as we watch others enjoying it -- the more driven we are to experience that pleasure for ourselves. Or maybe, like those mice, we just can't help thinking of the things that disgust us the most.