No abstract

The aim of this study was to examine executive function (EF) skills in girls with fragile X or Turner syndrome, using the Contingency Naming Test (CNT). The CNT is a Stroop-like task involving a 1- or 2-attribute contingency rule. We predicted that girls with fragile X would make errors reflecting poor cognitive flexibility and working memory limitations. We predicted that girls with Turner syndrome would have sufficient cognitive flexibility to perform the CNT accurately, but would have difficulty with verbal inhibition and would thus make more self-corrections than girls in a comparison group. The hypotheses were partially supported: relative to their Full Scale IQ-matched comparison group, girls with fragile X or Turner syndrome were slower on the warm-up naming task; girls with fragile X made more errors on the 1-attribute task, and girls with Turner syndrome were less efficient on both the 1- and 2-attribute tasks, without making more self-corrections. These results support previous findings of executive dysfunction associated with fragile X or Turner syndrome. The results suggest that both low IQ and fragile X status contribute to working memory limitations in girls with fragile X and that EF inefficiency in girls with Turner syndrome is due to both working memory limitations and slower response times.

Performance on the Medical Symptom Validity Test (MSVT) was examined in 193 consecutively referred patients aged 8 through 17 years who had sustained a mild traumatic brain injury. A total of 33 participants failed to meet actuarial criteria for valid effort on the MSVT. After accounting for possible false positives and false negatives, the base rate of suboptimal effort in this clinical sample was 17%. Only one MSVT failure was thought to be influenced by litigation. The present results suggest that a sizable minority of children is capable of putting forth suboptimal effort during neuropsychological exam, even when external incentives are not readily apparent. The MSVT appears to have good potential value as an objective measure for detecting symptom invalidity in school-age youth.

Children with velocardiofacial syndrome (VCFS; N=14) and a comparison group of siblings (N=8) underwent comprehensive neuropsychological assessment to examine the relationship between cognitive functioning and psychopathology. Significant group differences were obtained on tests of full scale and verbal intellectual functioning and perceptual-motor skills. With the exception of performance on tests of attention and executive functioning, children with VCFS displayed a profile consistent with nonverbal learning disability (NLD). However, within group comparisons revealed significantly poorer visuospatial intellectual and nonverbal memory functioning in sibling controls as well. No significant group differences were obtained on tests of motor speed, academic, language, attention, memory, or executive functioning, with significant variability in children with VCFS frequently accounting for the lack of robust differences. Parent-report measures revealed profiles consistent with ADHD. No clinically significant symptoms of psychosis, depression or anxiety were noted on either self- or parent-report measures. Wisconsin Card Sorting Test performance was found to be highly and negatively correlated with the Thought Problems subscale of the Child Behavior Checklist (CBCL) for VCFS children only, suggesting a possible at-risk indicator for later onset psychopathology.