On the automaticity of relational stimulus processing: The (extrinsic) relational Simon task.

We introduce the (extrinsic) relational Simon task as a tool for capturing automatic relational stimulus processing. In three experiments, participants responded to a perceptual relation between two stimuli. Results showed that participants were faster and more accurate to respond when the (task-irrelevant) conceptual relation between these stimuli was compatible (rather than incompatible) with the (extrinsic) relational meaning of the required responses. This effect was replicated irrespective of the type of stimulus materials used, irrespective of the similarity between the relational information that was task-relevant and the relational information that was task-irrelevant, and irrespective of the complexity of the task-irrelevant relational information. Our findings add to a growing body of evidence showing that relational stimulus processing can occur under conditions of automaticity.