An indepth exploration of how a goal-directed behaviour (or habit) is different from a Stimulus-Response, and how each of them are formed in our brains, and then acted upon.
"Normal eating is goal-directed behavior; compulsive overeating is not.
Compulsive overeating is a complex stimulus-response behavior. The
stimulus varies (boredom, anger, happiness, sexual frustration, anxiety,
and emotional triggers, etc.). The strength of the response may also
differ. It could range from eating until your stomach feels slightly
uncomfortable to eating until you vomit. Regardless, at the end of the
day, compulsive overeating is just a goal-directed habit that has become
a stimulus-response habit running amuck. [1] How does this neuro-drama unfold in the brain?"
http://www.huffingtonpost.com/billi-gordon-phd/how-a-habit-becomes-a-cab_b_5367784.html