Cognitive interference can occur while processing multiple attributes of stimuli.
With this method, interference occurs when the semantic attribute of a stimulus is incongruent with its physical attribute. Use of digit-Stroop tasks should indicate whether similar brain networks become activated during semantic and physical interference when humans attend to the opposite attribute, thereby providing evidence of a generalized network for cognitive interference. The digits in a pair, drawn between 2 and 9, could differ in physical size or in numerical value. For congruent digit pairs, the number with the larger value also had the larger size, therefore having congruence in two cognitive dimensions. For incongruent digit pairs, the number with the larger value had a smaller size, therefore differing in two cognitive dimensions.