Stroop Interference in a Match-to-Sample Task: Implications for Semantic and Response Competition Accounts

The Stroop effect has long been studied when investigating attentional processes; however, debate remains concerning the source of the effects during a matching Stroop task. Semantic competition describes competing semantic processes associated with the word and color dimensions of the stimulus prior to response selection. Response competition describes competing response codes activated by articulating the word versus the color dimension at the time of response selection. We presented the Stroop sample and response options consecutively without retention interval (Experiment 1), and we presented sample and response options simultaneously (Experiment 2). Collectively, results indicated RT interference on incongruent trials, both when the foil response option was related to the irrelevant dimension and when the foil response option was unrelated to the irrelevant dimension. Stroop asymmetry was only observed when sample and response options were presented simultaneously. The matching task may serve as an ideal method to dissociate semantic from response competition.