Methods: The investigators will recruit 45 children being treated with MTX or GCs at Dana Children's Hospital. To determine acute impact on memory, a battery of memory tests will be administered before and after a cycle of MTX and before and after a cycle of GCs. In addition, traumatic symptoms will be assessed at each post-chemotherapy evaluation point Expected results: The investigators expect poorer memory performance after MTX and after GCs and that these performance declines will correlate with lower rates of traumatic symptoms.