The Influence of "Hot" Executive Function on the Verbal Working Memory of Attention Deficit Hyperactivity Disorder (ADHD) and Reading Disability (RD) Children

Abstract

The deficit of "cool" executive function (EF) associated with dorsolateral prefrontal cortex (DLPFC) in attention deficit hyperactivity disorder (ADHD) has been substantially confirmed. But whether ADHD children show the deficit of "hot" EF associated with orbital and medial prefrontal cortex (OMPFC) remains unknown, and till now no research made an explicit exploration for interaction models between the two EFs. Commonly different from some studies related to the children’s gambling task, in which the "hot" EF impeded "cool" EF, this study aims to explore the facilitation of the "hot" EF to "cold" EF in the entertaining verbal N-back task. Pure cognitive processions were involved in boring N-back task while both "hot" EF and "cold" EF were involved in the entertaining N-back task. Participants were 77 children age between seven and twelve, of whom 60 were classified as having ADHD and /or reading disability (RD). All the disorder participants were recruited at a clinic and normal children were recruited from a elementary school. A four-group mixed design consisting of reading disabilities only (RD, n=15), reading disabilities and ADHD (RD+ADHD, n=24), ADHD only (ADHD, n=21) and a comparison group (n=17) was utilized. In the experiment, two adapted N-back working memory paradigms were used to explore verbal working memory ability, one was a traditional N-back task, another was entertaining N-back task. There are the same difficulty and materials between the two tasks. The results indicate that ADHD and RD groups behaved worse than comparison group and no significant differences had been detected between ADHD and RD groups in the boring task. A significant increase in ADHD had been found when comparing entertaining task with boring task. No significant differences had been detected between ADHD and comparison groups. Also, no significant changes related to the task types had been found in RD children. All these findings suggest that ADHD and RD children both show verbal working memory problems, however they have different mechanisms. The "hot" EF facilitates the performance of ADHD in verbal working memory task while not to RD. These results support the Haber model indirectly. According to this model, "hot" EF modulates "cool" EF by a special pathway.