Executive efficacy on Stroop type interference tasks. A validation study of a numerical and manual version (CANUM)

Abstract This paper presents CANUM, a new numerical and manual version of the Stroop interference task. The stimulus used replaces the classical color-word conflict with a quantity-number conflict, considering the interference that is also generated between the symbolic value of the number and the amount of times it is repeated. CANUM also replaces the vocal answer with a simple right-left keyboard response. The aim was twofold: firstly, to ensure a general measure of attentional control capacity not linked to the verbal factor; and secondly, to widen the population to whom the test might be applied, avoiding the restrictions on reading ability inherent to the classical Stroop task. The results obtained in a sample of school children reveal a level of high reliability in terms of internal consistency, as well as a significant predictive validity in relation to two criterial measures: general intelligence and working memory capacity. This supports its usefulness as an instrument for the assessment of executive function and controlled attention applicable across a wide age range, both for research purposes as well as for clinical and educational goals.