Interdimensional interference in the Stroop effect: uncovering the cognitive and neural anatomy of attention

In the classic Stroop effect, naming the color of an incompatible color wor d (e.g. the word RED printed in green ink; say 'green') is much slower and more error- prone than is naming the color of a control item (e.g. XXX or C AT printed in green; say 'green'). This seemingly simple interference pheno menon has long provided a fertile testing ground for theories of the cognit ive and neural components of selective attention. We present a sketch of th e behavioral phenomenon, focusing on the idea that the relative automaticit y of the two dimensions determines the direction and the degree of interdim ensional interference between them. We then present an outline of current p arallel processing explanations that instantiate this automaticity account, and we show how existing interference data are captured by such models. We also consider how Stroop facilitation (faster response of 'red' to RED pri nted in red) can be understood. Along the way, we describe research on two tasks that have emerged from the basic Stroop phenomenon - negative negativ e priming and the emotional Stroop task. Finally, we provide a survey of br ain Imaging research, highlighting the possible roles of the anterior cingu late in maintaining attentional set and in processing conflict or competiti on situations.