Date of Award


Document Type

Open Access Dissertation




College of Arts and Sciences

First Advisor

Jeffrey Schatz


Objective: Children with sickle cell disease (SCD) and cancer are at risk for working memory impairment due to the disease and treatment. However, inconsistency in adherence to cognitive training programs conducted with this population suggests that adaptations are necessary in order to improve the effectiveness of this intervention. In addition, it is unclear whether gains in working memory translate to improvement in classroom functioning.

Methods: Children engaged in cognitive training exclusively over the summer in order to improve adherence to Cogmed Working Memory Training. A total of 17 children ages 7- 17 with a diagnosis of SCD (n = 14) and cancer (n = 3) were enrolled in the study. Of the 17 children, 5 children completed the program (at least 80% of sessions), 5 children completed between 8 and 15 sessions, and 7 children did not complete any sessions. I conducted further analyses to measure changes in working memory performance from time 1 to time 2 on the WISC-V as well as generalizability to a measure of functional attention performance. I also collected parent feasibility ratings

Results: Parents generally endorsed that training during the summer was convenient (77.8%) and would recommend Cogmed to others. However, adherence rates did not exceed 80% as hypothesized. Follow-up analyses indicated a non-significant improvement in group means on the WISC-V Working Memory Composite Score or individual working memory subtests for all groups. However, changes in group means showed a large effect size for completers, t(4) = -1.66, p = .17, d = .87 and a medium effect for partial completers, t(4) = -.62, p = .57, d = .37. Conversely, group means for the Working Memory Composite showed only a small effect for non-completers, t(3) = - .34, p = .76, d = .10. Similar effect sizes were found for the Digit Span and Letter- Number Sequencing subtests but not the Picture Span subtest. The hypothesis that gains in working memory would generalize to measures of functional attention and working memory was not supported.

Conclusions: Overall, this study demonstrates that training over the summer does not significantly increase adherence to the program but may serve as a feasible option for many families with a child with a chronic illness. Although the sample size was too small to detect a statistically significant increase in working memory, effect sizes were of medium size in partial completers and large in completers, suggesting comparable effects as studies with larger samples that have demonstrated efficacy. Differences in baseline attention skills for completers versus non-completers suggest that the TEA-Ch, a measure of functional attention, may be an important tool for selecting children most likely to complete the full program. Further research with larger samples sizes is needed in order to confirm study results and test alternative methods for improving adherence in this population.


© 2018, Kelsey Smith