"The relative strength of response to the form, color, and number dimensions of the Wisconsin Card Sorting Test cards was compared in two tasks: a problem-solving type task using probabilistic reinforcement of these cues, and a perceptual abstraction task involving speed of sorting on the three stimulus dimensions." The contrasting results from these two tasks "suggest the need for differentiating between a perceptually determined process of abstraction and a supra-perceptual process of conceptualization." (PsycINFO Database Record (c) 2006 APA, all rights reserved)