The mechanism by which knowledge enters into memory has been a source of debate for some time. Theorists have proposed several models that aim at explaining the sequence of events from the perception of a stimulus, to its entrance into long-term storage. Much of this work was prompted by early research into the nuances of classical conditioning where it was first firmly established that organisms are capable of detecting covariations of stimuli within their environment. Subsequent work in the field has shown that these covariations form the basis for the mental representation of our surroundings, as well as the basis of learning. Work within the field of classical conditioning, along with the advance of computer technology and neuroscience has made these architectural models even more complex. Furthermore, experiments designed to support some of these proposed models have revealed that there are several conditions that can either aid or inhibit the transition of information into permanent storage. In this review we explore a number of these models, along with some classic critiques that have been levied against them. We also provide some history into the form of knowledge, termed 'implicit knowledge', as well as some of the proposed mechanisms of implicit knowledge acquisition. We conclude by exploring the newly proposed theoretical framework within which implicit learning theory operates.

Keywords: learning mechanisms, implicit learning, knowledge acquisition, network models