According to behaviourism in psychology, conditioning is the way in which new connections between stimulus and response are learned, and therefore forms the basic pattern of learning. It comes in two forms. In classical or Pavlovian conditioning (known as type S) an animal such as a dog comes to associate a neutral signal with one which already produces a result, with the consequence that the hitherto neutral stimulus itself produces the result. In the famous case, after becoming associated with food in the mouth (the unconditioned stimulus), the bell (the conditioned stimulus) stimulates the dog to salivate (the conditioned response). In instrumental or operant conditioning (type R) the animal learns to do something to produce the result. The essential behaviourist claim is that this kind of association has its own laws, and can be studied without postulating that the animal has come to know something or expect anything. The claim is that the relationship between stimulus and response is essentially simple and passive, depending only on the temporal contiguity between the stimulus and the reward. Nor is there any need to postulate cognition in the animal. This claim is not, however, borne out in experience: for example, whether an animal performs some learned action on a stimulus can vary with the varying degree to which it now wants the likely result of that action.