Will working memory training generalize to improve off-task behavior in children with Attention-Deficit/Hyperactivity Disorder?

Publication: Neurotherapeutics

Institution: University of California, Davis

Investigator(s): Chloe T. Green, Debra L. Long, David Green, Ana-Maria Iosif, J. Faye Dixon, Meghan R. Miller, Catherine Fassbender, Julie B. Schweitzer

Program: Cogmed RM

Background & Aim: The DSM-IV-TR defines Attention Deficit Hyperactivity Disorder (ADHD) as severe and persistent problems of inattention, impulsivity, and hyperactivity across settings. ADHD is diagnosed in 3-7% of the population, making it the most common neuropsychiatric disorder affecting children. Impaired working memory (WM) is a central deficit in ADHD. WM is the system responsible for maintaining information in memory, manipulating it, and using it to guide behavior. WM is a key factor influencing a child’s ability to learn and there is a direct relationship between poor performance on WM tasks and poor school performance. In light of findings that Cogmed improves WM in children with ADHD, researchers at the University of California were interested to learn whether Cogmed improves behavior associated with classroom learning, such as remaining on-task and inhibiting off-task behavior. Thus, the aim of this study was to assess the impact of Cogmed on behavior via the Restricted Academic Setting Task (RAST), a simulated classroom setting task and observational system that is a strong indicator of children’s behavioral response to pharmacological treatment for ADHD.

Population & Sample Size: N = 26 children with ADHD, ages 7 – 14 years
• n = 12 children in adaptive Cogmed training group
• n = 14 children in non-adaptive Cogmed training group

Design: Randomized, placebo controlled, double-blinded, test-retest
T1 = baseline, T2 = post-test

I. Children in adaptive training group improved significantly over children in non-adaptive training group on:

1) Non-trained tasks of WM (Digit Span and Letter-Number Sequencing; WISC)

2) Frequency and type of off-task behavior (looking away from task and playing with an object unrelated to task; RAST)

II. No significant differences between the groups on fidgets, vocalizes, and out-of-seat measures (RAST)

III. No significant improvements on parent ratings of behavior (Conners’ Parent Rating Scale-Revised; CPRS-R)

Summary and Implications: This randomized, placebo controlled, double-blinded study of 26 children with ADHD was the first known research to demonstrate the impact of WM training on an ecologically valid measure of observable ADHD-associated behaviors. Children who trained with the standard Cogmed program (adaptive WM training) improved significantly over children in the placebo group (non-adaptive WM training) on non-trained, widely used, standardized measures of WM (Digit Span and Letter-Number Sequencing; WISC) and on measures of the Restricted Academic Setting Task (RAST) that related to attention.

The RAST, a simulated classroom setting task and observational system, was used to assess aspects of off-task behavior during the completion of an academic assignment. In this study, the RAST was administered to participants pre- and post-Cogmed. To start, a child was asked to sit at a table and play independently with a toy or game. After 5 minutes, the researcher entered the room and moved the toy or game to the side and instructed the child to complete a series of worksheets (academic task) for 15 minutes. Before the researcher left the room, the child was also instructed not to leave his/her seat or to touch any of the toys or games in the room. An observer then recorded the child’s behavior through a one-way mirror and every 30 seconds tallied any of the following behaviors: off- task (looking away from the paper), out-of-seat (leaves chair), fidgets (repetitive purposeless motions), vocalizes, and play with object (touches an object in the room unrelated to the task). Importantly, two coders were utilized to ensure reliability of scoring and both coders were blind to group membership of the participants.

Results from the RAST revealed that children in the Cogmed (adaptive training) group had a sharp reduction in off-task (looking away from the paper) behavior compared to non-adaptive participants. The researchers suggested that this measure might have been the most related to attention and has implications for children with ADHD who struggle with inattentive symptoms. Children in adaptive training also showed reduced play with object (touches an object in the room unrelated to the task) on the RAST which may also relate to reduced inattention. WM training thus resulted in far transfer to observable behaviors in ADHD children. There were however no significant differences between the groups on fidgets, vocalizes and out-of-seat behaviors.

Contrary to previous Cogmed studies of children with ADHD that found significantly improved parent ratings of behavior (Klingberg et al., 2005; Beck et al., 2010), researchers in this study found no significant difference between parent ratings of behavior (CPRS-R) for adaptive and non-adaptive training participants. The researchers suggested that the differences in the sample population of the current study may be an explanation for why change was not detected on parent rating scales. For example, the children in the adaptive training group in Klingberg et al. (2005) were not medicated, whereas the majority of adaptive training participants in this study were taking stimulant medications. It is thus possible that children in this study had less room to show improvement on rating scales versus children in the Klingberg et al. study.

This randomized, placebo-controlled, double-blinded study of WM training in ADHD children is the first known research to demonstrate improved performance on a laboratory measure of ADHD-associated behaviors. Improvement in WM, a function that plays a central role in academic achievement, was detected using the widely accepted WISC Working Memory Index. Further, far transfer to decreased off-task behavior was observed in the adaptive WM training group using an ecologically valid task (RAST). These findings present compelling evidence that WM training has the potential to improve on-task behavior in academic settings – a notable area of deficit in ADHD youths.