The counting Stroop: a cognitive interference task

The counting Stroop is a validated Stroop task variant. Initially designed as a functional magnetic resonance imaging ( fMRI) task for identifying brain regions subserving cognition and attention ( dorsal anterior midcingulate cortex ( daMCC) and dorsolateral prefrontal cortex ( DLPFC)), it has been used to study cognition in healthy volunteers and to identify functional brain abnormalities in neuropsychiatric disorders, such as attention deficit hyperactivity disorder ( ADHD). During the counting Stroop, subjects report by button- press the number of words ( one to four) appearing on the screen, regardless of word meaning. Neutral- word control trials contain single semantic category common animals ( e. g., 'dog' written three times), while interference trials contain number words that are incongruent with the correct response ( e. g., 'two' written four times). The counting Stroop can be completed in approximately 20 min per subject and can be used offline ( behavioral performance) or with fMRI, positron emission tomography, event- related potentials, magnetoencephalography or intracranial recordings.