Abstract This investigation involved measures of the reaction times of normally developing children who were asked to name a series of centrally presented picture stimuli of varying vocabulary age and dimension. Results of the ANOVA on reaction times indicated a significant main effect of vocabulary level and an interaction of Dimension×Vocabulary level for the normally developing children. Post-hoc tests showed significant differences between two- and three-dimensional pictures for higher-level vocabulary items, but not for lower-level vocabulary items. This finding indicates that central operations involved in picture naming are influenced differentially by the physical characteristics of the stimulus items. The finding that two-dimensional higher-level vocabulary items were associated with significantly longer reaction times than the three-dimensional higher-level vocabulary suggests that dimensionality may be a critical feature for rapid lexical access for higher-level picture vocabulary. Clinically, the employment of three-dimensional forms may facilitate access to stored visual object memory for advanced levels of picture vocabulary. Learning outcomes: As a result of this activity, participants will be able to (1) identify the various visual and verbal processes involved in the naming of pictures; and (2) understand the influence of physical characteristics of pictures on reaction time in rapid naming tasks.