a cognitive technique for assessing selective attention, inhibition control, and the ability to resist distracting stimuli. The subject is asked to focus on the central target stimulus (usually an arrow or a letter) and ignore lateral “flank” stimuli, which may be congruent (coincident in direction or meaning) or incongruent (opposite). An increase in reaction time and the number of errors in incongruent tests indicates difficulties in inhibition and attention control. The test is widely used in cognitive psychology, neuroscience, and clinical practice to assess executive functions.