There is a different, tighter relationship between associative learning and associative structures concerning how to modulate an association. Associative theorists, especially from Pavlov onward, have been clear on the functional characteristics necessary to modulate an already created association. There have been two generally agreed upon routes: extinction and counterconditioning. Suppose that, through associative learning, you have learned to associate a CS with a US. How do we break that association? Associationists have posited that one breaks an associative structure via two different types of associative learning (/unlearning). Extinction is the name for one such process. During extinction one decouples the external presentation of the CS and the US by presenting the CS without the US (and sometimes the US without the CS). Over time, the organism will learn to disconnect the CS and US.