Similarity- versus rule-based generalization in rats

Humans and non-human animals are capable of learning complex discriminations that seemingly reflect general rules. However, this does not necessitate that they actually understand the underlying rules; their behavior may be mediated by simple associations. One way to investigate the underlying cognitive mechanisms is to investigate behavior of human and non-human animals in similar yet novel situations. Abstraction of a rule and subsequent application of that rule to a novel set of cues seems to be beyond the scope of association formation models. In 1998, Shanks and Darby provided evidence for rule-based generalization of negative and positive patterning in humans. To investigate the contributions of similarity- versus rule-based processes to generalization in rats, we trained 24 animals on a negative and a positive pattern simultaneously. Despite the fact that the rats were capable of learning the patterning problems, generalization was based on similarities rather than rules. We will discuss the implications of our findings for the processes that underlie patterning performance in rats.status: publishe