| The purpose of this thesis was to investigate working memory in a sample of long-term survivors of ALL. Three studies were completed. The mean age of participants was 14 years. In Study One, measures of IQ and Verbal and Visual Memory were administered to 16 long-term survivors of ALL and two control groups: 11 siblings of the ALL survivors, and 16 long-term survivors of Wilms' tumor. Although mean IQ scores were within one standard deviation of the normative mean, long-term survivors of ALL performed below control groups on Full Scale IQ, Verbal IQ, and Performance IQ. Long-term survivors of ALL scored below the survivors of Wilms' tumor on the General Memory Index. Siblings did not differ from either treatment group on any memory measure. There were no significant group differences on tests of immediate and delayed verbal and visual memory or delayed recognition.;Study Three specifically examined working memory. The three groups were administered the Petrides Self-Ordered Pointing Test, an experimental task shown to reflect functioning in the mid-dorsolateral prefrontal cortex, which has been consistently linked to the maintenance/monitoring phase of working memory in humans. No significant group differences were found on this test once age was covaried. ALL survivors were significantly lower on the Finger Windows subtest and the Working Memory Indices of the CMS/WMS-III and Behavior Rating Inventory of Executive Function questionnaire. These results do not implicate self-ordered pointing and the corresponding brain regions measured by this test as being impacted by treatment in this population. However, subtle implications remain that suggest working memory is indeed affected in this population. Further research involving Baddeley's central executive component of working memory is suggested.;Study Two investigated the prevalence of leukoencephalopathy in 15 of the 16 survivors of ALL using MRI and CT scans. The structural integrity of their brains were rated on a scale from 0 (no abnormality) to 4 (severe leukoencephalopathy). Forty percent of the group had a score greater than 0 on MRI, and 33% had a score greater than 0 on CT. There was no association between MRI/CT scores and measures of IQ and memory. |
