There are two types of classical conditioning— Classical Reward Conditioning and Classical Aversive Conditioning . In classical reward conditioning, a reinforcer rewards the overt behaviour whereas in c lassical aversive conditioning, an aversive stimulus is paired with a conditioned stimulus (CS). This is how a neutral stimulus gets associated with a meaningful stimulus, thus deriving the capacity to elicit a similar response.

Instrumental conditioning, on the other hand, is a form of learning wherein the consequences of behaviour produce changes in the response, thus determining the probability of occurrence of the behaviour. Unlike classical conditioning, it is a voluntary process of formation and strengthening of S-R association. It is readily seen in human learning.The distinctiveness of instrumental conditioning is that the association between response and reinforcing stimulus depends on the consequences of the responses. Besides these two major types, we have also talked about cognitive learning. It centers on the cognitive maps we construct out of our experiences and how these maps guide our behaviour. Alongside we also discussed social learning which included notion of local enhancement, social facilitation, observational learning and imitation.

Psychobiology of Learning

Laboratory studies of S-R learning have been mostly conducted on rats, with few researchers opting for cats, dogs and even human babies. As you must be aware, there is a difference in the viewpoints of theorists proposing learning by conditioning and cognitive theorists. The former emphasize on stimulus-response (S-R) association whereas the later lay emphasis on consequence based expectations. According to Tolman (1932, 1948) animal learn from “what leads-to-what” and accordingly expect consequences of their behaviour. Findings of studies on rats suggest that hippocampus and caudate nucleus are the brain structures responsible for these two forms of learning. Hippocampus selectively mediates cognitive memory whereas caudate nucleus mediates S-R habit formation. Hippocampus is supposed to facilitate rapid subjective learning from own experiences whereas cortex facilitates integration of multiple experiences so as to generalize certain things. This is a slow process. Different stimuli are organized into an associative group by chunking. This forms the basis of conditioning. It has been proposed that hippocampus is instrumental in cortical chunking. The table given below summarizes the brain areas involved in Pavlovian conditioning.