title: Utility of the N-back task in survivors of childhood acute lymphoblastic leukemia.
abstract: The N-back task is often used in functional brain imaging studies to activate working memory networks; however, limited information is available on its association to clinical outcomes in children or cancer survivors. A total of 137 survivors of acute lymphoblastic leukemia (ALL; mean current age = 14.3 years, SD = 4.8; time since diagnosis = 7.6 years, SD = 1.6) completed the N-back task and comprehensive neurocognitive testing, including standardized measures of attention, processing speed, and working memory. Results indicated that females demonstrated significantly slower reaction times (0-back p = .02; 1-back p = .03) than males. Survivors <15 years old at the time of testing demonstrated a significant decrease in accuracy as working memory load increased compared to survivors ≥15 years old (p < .001). Performance on the N-back task was associated with nonverbal working memory (rs = .56, p < .001) in survivors ≥15 years of age. For younger survivors, N-back performance was more strongly associated with attention skills. Results suggest the N-back assesses different cognitive constructs at younger compared to older childhood ages. These age differences should be considered in interpreting functional brain imaging results.
authors.affiliation: a Department of Epidemiology and Cancer Control , St. Jude Children's Research Hospital , TN , USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Luxton
authors.forename: Tara M
authors.initials: TM
authors.lastname: Brinkman
authors.forename: Cara
authors.initials: C
authors.lastname: Kimberg
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Robison
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Hudson
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Krull
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002658:Developmental Disabilities / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology*; D009483:Neuropsychological Tests; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications* / Q000401:mortality*; D012372:ROC Curve; D011930:Reaction Time / Q000502:physiology; D012691:Serial Learning; D017741:Survivors / Q000523:psychology*; D055815:Young Adult
keywords: Childhood acute lymphoblastic leukemia; N-back; Working memory