A wealth of empirical evidence has now accumulated concerning animals' categorizing photographs of real-world objects. Although these complex stimuli have the advantage of fostering rapid category learning, they are difficult to manipulate experimentally and to represent in formal models of behavior. We present a solution to the representation…

We comment on Goldstein, Davidoff, and Roberson's replication and extension ("Journal of Experimental Child Psychology, 102", 219-238 [2009]) of our study of the effect of toddlers' color term knowledge on their categorical perception (CP) of color ("Journal of Experimental Child Psychology, 90", 114-141 [2005]). First, we discuss how best to…

Children often perseverate, repeating prior behaviors when inappropriate. This work tested the roles of verbal labels and stimulus novelty in such perseveration. Three-year-old children sorted cards by one rule and were then instructed to switch to a second rule. In a basic condition, cards had familiar shapes and colors and both rules were stated…