Modeling the Stroop phenomenon: processes, processing flow, and development

A model of the Stroop phenomenon is proposed which postulates that the classic effect is an additive function of three parameters, that is, dimension selection (decision making about which dimension to respond to), dimension identification (encoding and identification of the relevant dimension), and interference control (filtering out of interference from non-relevant dimensions). The study used stimuli addressed to three symbol systems (verbal, numerical, and figural), two types of stimulus composition (compatible vs. incompatible), and two types of dimension selection (decision needed about the to-be-identified dimension vs. no decision needed). Participants were 9, 11, 13, and 15 years old and they were tested twice. The model was found to hold under all stimulus and presentation conditions. Moreover, it was found that the three parameters are differentially related to age. The implications of the model for general theories of cognition and cognitive development are discussed.