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.