The effects of dual verbal and visual tasks on featural vs. relational category learning

Many studies have examined the distinction between featureand relation-based categories (Gentner, 2005; Genter & Kurtz, 2005; Jung & Hummel, 2009; Tomlinson & Love, 2011). Those findings suggest that featural and relationl categories have fundamentally different learning algorithms, where relational categories rely on explicit representations and thus require working memory and attention, as opposed to featural categories which may be learned more implicitly. In this study, we investigated further the distinction between feature-and relation-based category learning using a dual task methodology. Our results revealed an interaction: featural category learning was more impaired by a visuospatial dual task than by a verbal dual task, whereas relational category learning was more impaired by the verbal dual task. Our results suggest that in contrast to featural category learning, which may involve mainly non-verbal mechanisms, relational category learning appears to place greater demands on more explicit and attention-demanding verbal or verbally-related learning mechanisms.