You know what happens to women when they watch Katherine Heigl movies or episodes of "The Bachelor"? 

Well, it happens to men also - when they think there might be beer nearby.

Really, it is almost Pavlovian, except the saliva is mental too. A PET scan study found that even when no alcohol was involved, the flavor of beer caused striatal dopamine release in men.(1) 

The striatum in men (and women - and all primates - but this particular study is about men, so, let's stay on message) consists of the caudate nucleus and the putamen and it gets input from the cerebral cortex and structures like the amygdala and hippocampus.

How does that relate to beer? And why no women in the study?

The second question can be answered quickly. The study was supposed to be open to both genders but heavy-drinking females who preferred beer and didn't also use drugs or tobacco were too rare, so they stuck to men. You know how it is sometimes true that what you don't learn in a science study has value? That is the care here too. They have triangulated on some ideal characteristics for the woman you might be seeking this weekend (SCIENCE!). Add in a few piercings and there is probably no place she won't let you put it, guys. 

After screening out anyone with illicit drugs in their system or cigarette use (or who expressed a dislike for Gatorade, since that was part of the trial also), they ended up with 49 males. They were all classified on a scale from social to heavy drinking. 4 qualified as alcoholics using DSM-IV criteria. 

What did an MRI and two PET scans show? Beer flavor increased desire to drink beer, even absent alcohol. 

The location of increased dopamine response - instead of blaming your parents for your binge drinking, you can now blame the right ventral striatum. Credit and link: doi:10.1038/npp.2013.91

Obviously some of that could be conditioned cues, that is why I mentioned Pavlov's dog. 

Or perhaps what happens is that a presynaptic mechanism bypasses dopamine neurons and triggers dopamine release directly (Sarah Threlfell et al, Neuron DOI: 10.1016/j.neuron.2012.04.038) - if it can happen with light from microelectrodes, then a light bulb in your brain that goes off at 5 PM on a Friday might cause it as well.

Obviously the dopamine is not the problem - it is implicated in illicit drug use, sure, but it also has numerous positive effects, like if you are a drug user and get happy when you read an article saying drug use is good for you, or if you are motivated to seek rewards and positive behavior. The distance between desire and dread is really only about 5 millimeters.

Striatal dopamine is a factor in both normal and pathological behavior, sometimes it can just be a matter of degree.(2) The more you knock down barriers to normal dopamine response, the easier it is for things to get weird, like you thinking everyone likes the way you dance in a restaurant.

Let's be honest, there had to be alcohol already at work for editors at Boing Boing and Scientific American to sign off on the virtually unlimited liability of "Drunk Science" - after they sobered up they wisely pulled the plug on the whole idea.

Citation: Brandon G Oberlin, Mario Dzemidzic, Stella M Tran, Christina M Soeurt, Daniel S Albrecht, Karmen K Yoder and David A Kareken, 'Beer Flavor Provokes Striatal Dopamine Release in Male Drinkers: Mediation by Family History of Alcoholism', Neuropsychopharmacology (2013) 38, 1617–1624; doi:10.1038/npp.2013.91


(1) Somewhere, non-alcoholic beers are crafting a way to put this in a marketing campaign. 

(2) Like with most anything. You know that they say; a feather is sexy, but a whole chicken is kinky.