Pavlovian incentive learning and responding

Instrumental learning is formally defined as the learning of a stimulus-response contingency. As a result of this learning, the organism emits responses contingent upon the stimulus. 

In the habit modality, response is mainly controlled by stimuli that precede rather than follow it (outcomes) (Dickinson, 1994). As a result of this, devaluation of response outcome fails to impair habit responding. Habit responding takes place as a result of exhaustive training on high ratio schedules or under variable interval schedules where reinforcement is loosely related to response (Dickinson, 1994). 

Dickinson and associates (Dickinson and Balleine, 1994, 1995) refer to learning of the current value of the outcome as instrumental incentive learning and to the value of the outcome as incentive value. 

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