Quantitative models of Pavlovian conditioning.

Over the last few years, research on learning and memory has become increasingly interdisciplinary. In the past, theories of learning, as a prerogative of psychologists, were generally formulated in purely verbal terms and evaluated exclusively at the behavioral level. At present, scientists are trying to build theories with a quantitative and biological flavor, seeking to embrace more complex behavioral phenomena. Pavlovian conditioning, one of the simplest and ubiquitous forms of learning, is especially suited for this multiple level analysis (i.e., quantitative, neurobiological, and behavioral), in part because of recent discoveries showing a correspondence between behavioral phenomena and associative properties at the cellular and systems levels, and in part because of its well established quantitative theoretical tradition. The present review, examines the mayor quantitative theories of Pavlovian conditioning and the phenomena to which they have been designed to account. In order to provide researchers from different disciplines with a simple guideline about the rationale of the different theoretical choices, all the models are described through a single formalism based on the neural network connectionist perspective.