A test of the integrity of the components of Baddeley's model of working memory in attention-deficit/hyperactivity disorder (ADHD)

Background: The integrity of working memory in attention-deficit/hyperactivity disorder (ADHD) was tested within the framework of Baddeley's model. Methods-1: Buffers and rehearsal mechanisms were assessed by presenting children with or without ADHD (ages 8 to 15) with 1-7 target letters and a probe after 2-10 s. They decided if the probe was the same (verbal task) or in the same location (spatial task) as any of the targets. Results-1: There was no interaction between group and delay or memory load in either task. Methods-2: The central executive was assessed on a dual task. Results-2: Although children with ADHD did not differ from controls in simple response time (RT) or in digits recalled, they showed greater decrements in RT when performing the 2 tasks concurrently. Conclusions: Findings suggest that children with ADHD (1) do not have generalized impairments in working memory, (2) rehearse verbal and spatial information in the same manner as healthy children, (3) may have an impairment in the central executive component of working memory, which controls ability to divide attention between two tasks.