Relation of addiction genes to hypothalamic gene changes subserving genesis and gratification of a classic instinct, sodium appetite.
This study was a true eye opener for me. The idea of "free will" and "choice" is thrown into complete disarray here.
Basically, what this study shows is that the unconcious part of your brain will use dopamine signalling and other feel good reward chemistry in your brain in an attempt to control your behaviour in such a way so that you do what *it* thinks is ultimately best for your survival or prosperity.
Notice however, that whether or not the action your unconciousness is encouraging you to do REALLY IS in your best benefits is a different matter. That is to say, your unconciousness is not always RIGHT.
Free will and choice can only exsist in a situation where the outcomes of any of your actions are negligible to your survival and/or prosperity.