Survivors of pediatric brain tumor (BT) experience impaired executive function (EF) and adaptive behavior (i.e. the ability to complete daily living tasks independently). The literature hypothesizes that executive dysfunction contributes to suboptimal adaptive behavior outcomes in BT survivors; however, the aspects of EF that drive this relationship remain unexplored. Task-switching is an EF component that involves switching between concurrently presented tasks. This skill is critical for many day-to-day activities and may therefore contribute to observed adaptive functioning difficulties. This study investigates relationships between performance on two task-switching measures and adaptive behavior outcomes in BT survivors compared to healthy controls.

86 survivors of pediatric BT (Mage(SD)= 23.42(4.24), 44 females) and 86 age- and sex-matched controls (Mage(SD) = 23.09(4.40), 44 females) from the Atlanta area completed the Delis-Kaplan Executive Function System Trail Making Test (TMT) and Verbal Fluency Test (VFT). Respectively, the Letter-Number Sequencing (LNS) and Category Switching (CS) conditions were isolated as measures of task-switching. Baseline conditions, representing the foundational skills needed to perform these timed task-switching measures rapidly (TMT: Letter Sequencing, Number Sequencing; VFT: Category Fluency), were included as covariates in all regressions. Informants familiar with the participants’ daily living were interviewed with the Scales of Independent Behavior-Revised (SIB-R) to measure adaptive behavior in four domains (Motor Skills, Social Communication, Personal Living, Community Living). Linear regressions and t-tests confirmed group differences on task-switching performance and on adaptive functioning outcomes, respectively. Then, linear regressions investigated relationships between performance on each task-switching measure (LNS, CS) and SIB-R scores for survivors. A group by task-switching interaction was added to directly explore group differences in these relationships. α=.0125 was used due to Bonferroni correction for the four SIB-R comparisons within each task-switching measure.

BT survivors were more impaired than controls on LNS, CS, and SIB-R scores (p<.05, except Personal Living p=.058). For TMT, decreased performance on LNS predicted lower SIB-R scores in Social Communication (p=.001, r2semipartial=.14), Personal Living (p=.002, r2semipartial=.13), and Community Living (p=.003, r2semipartial =.11), but not Motor Skills (p=.184) in BT survivors. Strength of significant relationships was greater for survivors than controls (all p<.002). For VFT, decreased performance on CS predicted lower SIB-R scores in Personal Living (p=.036, r2semipartial =.06) and Community Living (p=.04, r2semipartial =.05), but not in Motor Skills (p=.716) or Social Communication (p=.14) in BT survivors. Positive relationships between CS and SIB-R scores for all 4 domains were greater in survivors than controls (p<.0125).

These findings reveal a robust, positive relationship between task-switching performance and independent, daily behaviors that is specific to BT survivors. The relationship between LNS and Motor Skills may have been weakened by covariates involving baseline motor abilities; however, CS results suggest that task-switching is important for motor skills in survivors relative to controls. Community living skills were impaired in survivors and consistently related to task-switching performance. This work may inform interventions to target task-switching abilities and consequently, promote everyday living skills. Interventions aimed at vulnerabilities in adaptive behavior may help increase independence and quality-of-life as survivors transition to adulthood.