ABSTRACT
The physiological psychologist might need to know when the learning occurred to a few milliseconds if the learning is to be related to specific brain events. Learning can be simply divided into associative and non-associative forms. Non-associative learning is the simplest learning that an organism can engage in. It includes habituation and sensitization. Associative learning is where learning takes place as a result of a new association between two or more events. Instrumental conditioning is learning by consequence. As well as being able to distinguish different types of learning, it is useful to distinguish between the different types of memory that can be investigated. The 'search for the engram' has been hotly debated, with some critics suggesting that memories are coded via patterns of activity in groups of neurons rather than by a specific change in one neuron. Hence the engram is represented by a change in a neuron's output characteristics as a result of having learned something.
