Prior Verbal Description of Novel Stimuli Improves the Learning of Information Integration Categories but not Rule-Described Categories

A prominent theory of category learning assumes that people rely on two parallel and competing systems that make use of either the abstraction of verbal rules (explicit system) or the gradual association of the category exemplars with the appropriate response (implicit system). Because the explicit system relies on verbal processing, we hypothesized that priming the verbal system by asking participants to provide a verbal description of some of the stimuli prior to classification would enhance the learning of rule-described categories but would have no effect on the learning of information integration categories. Our results failed to confirm the hypothesis, and we observed the opposite pattern: prior verbal description enhanced learning of the information integration categories but not the rule-described categories. Our data and subsequent modelling suggest that participants in both categories tended to rely on a rule-based strategy, but participants were quicker to abandon that strategy when they had prior exposure to the stimuli.