Feasibility/Acceptability of Attentional-Control Training in Survivors

Inclusion Criteria: * Aged 8-16 years at time of screening. * History of diagnosis of acute lymphoblastic leukemia (ALL) or brain tumor (BT). * At least 1 year from completion of planned therapy and stable from a disease standpoint. * Participating child and caregiver are fluent in spoken English. * Availability of a caregiver who is willing and capable of providing support and supervision during cognitive training. * Participating child is either not taking any prescribed stimulant medication for attention difficulties or has been prescribed a stable dose of stimulant medication for attention difficulties for at least 30 days prior to enrollment. * Only patients with a T-score ≥ 75th percentile on the CPT-3 Omission Errors scale or on the BRIEF-2 Cognitive Regulation Index will be randomized. Exclusion Criteria: * A history of photosensitive seizures. * A motor, visual, or auditory handicap that prevents computer use. * A mental health condition that precludes, or takes treatment precedence over, participation in the cognitive training. * Participants identified during the baseline assessment as having a full-scale IQ \< 80, as estimated by WASI-II (Vocabulary and Matrix Reasoning), will not be randomized.