Converging evidence for domain-general developmental trends of mental attentional capacity: Validity and reliability of full and abbreviated measures.

Our ability to understand the world around us hinges on our cognition. Theoretically, children's abilities improve with age; however, a lively discussion exists on how factors such as task domain, task interference, and task difficulty, as indexed mainly by relevant cues, affect cognitive performance. Practically, cognitive measures take a substantial amount of time to administer, which poses limitations for researchers in the field of psychology. The current study addressed theoretical and practical questions regarding the nature of child cognition using full and abbreviated versions of classic, recent, and new tasks of mental attentional capacity. We employed a cross-sectional design testing 483 participants in six groups (7-30 years of age) on the new Number Matching Task (NMT), the established Color Matching Task (CMT), and the classic Figural Intersection Task (FIT). Results confirm theoretical predictions of the developmental increase in mental attentional capacity and the adjunct hypothesis that tasks with high interference are better to assess the developmental trajectory of mental attentional capacity quantitatively. NMT scores are significantly equivalent to CMT scores and the theoretically predicted mental attentional capacity, and the abbreviated CMT and NMT produce comparable scores to those of the full tests. We determined that the NMT can be administered developmentally and is appropriate for use in assessing mental attentional capacity in studies with both children and adults.