No Effect of Verbal Labels for the Shapes on Type II Categorization Tasks

Category learning is thought to be mediated—in at least some category structures—by hypothesis-testing processes. Verbal labels for the stimuli and stimulus individuation have been shown to facilitate the formation, testing, and application of rules of category membership (Fotiadis & Protopapas, 2014). We sought to replicate the phenomenon of facilitation due to verbal names for the stimuli by training participants for two consecutive days to either learn new names for abstract shapes, or learn shape-ideogram pairings; a third group was unexposed to the shapes. After training, participants were given a Type II categorization task—thought to be mediated by verbal processes of rule discovery—utilizing the trained shapes. We hypothesized that verbal labels for the shapes and shape individuation would provide facilitative effects in learning to categorize. Results revealed no effect of training on categorization performance. This study suggests that caution should be taken when generalizing findings across perceptual modalities or different experimental paradigms.