Friday, October 23, 2009

Research Bytes 10-23-08: RIAS/WAIS-III,Gv,imagery,neuropsychology,test norms

Articles that caught my eye during my weekly search of a wide range of professional literature.

Smith, B. L., McChristian, C. L., Smith, T. D., & Meaux, J. (2009). The relationshipo of the Reynolds Intellectual Assessment Scales and the Wechsler Adult Intelligence Scale-Third Edition. Perceptual and Motor Skills, 109(1), 30-40.

The purpose of this study was to compare scores on the Reynolds Intellectual Assessment Scales (RIAS) with scores on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) in a group of college students diagnosed with a Learning Disability, Attention-Deficit Hyperactivity Disorder (ADHD), or a combination of the two. The RIAS Composite Index score was significantly higher than the WAIS-III Full Scale IQ, although scores on both tests were in the average range. Correlations between the two tests were significant on all measures. Male students were significantly higher than female students on both the RIAS Composite Index and on the WAIS-III Full Scale IQ. Although the ADHD group was higher on IQ than the Learning Disabled and combined disorder groups on all IQ measures, no significant differences were found.

Heilbronner, R. L., Sweet, J. J., Morgan, J. E., Larrabee, G. J., & Millis, S. R. (2009). American Academy of Clinical Neuropsychology Consensus Conference Statement on the Neuropsychological Assessment of Effort, Response Bias, and Malingering. Clinical Neuropsychologist, 23(7), 1093-1129.
During the past two decades clinical and research efforts have led to increasingly sophisticated and effective methods and instruments designed to detect exaggeration or fabrication of neuropsychological dysfunction, as well as somatic and psychological symptom complaints. A vast literature based on relevant research has emerged and substantial portions of professional meetings attended by clinical neuropsychologists have addressed topics related to malingering (Sweet, King, Malina, Bergman, & Simmons, 2002). Yet, despite these extensive activities, understanding the need for methods of detecting problematic effort and response bias and addressing the presence or absence of malingering has proven challenging for practitioners. A consensus conference, comprised of national and international experts in clinical neuropsychology, was held at the 2008 Annual Meeting of the American Academy of Clinical Neuropsychology (AACN) for the purposes of refinement of critical issues in this area. This consensus statement documents the current state of knowledge and recommendations of expert clinical neuropsychologists and is intended to assist clinicians and researchers with regard to the neuropsychological assessment of effort, response bias, and malingering.

Thompson, W. L., Slotnick, S. D., Burrage, M. S., & Kosslyn, S. M. (2009). Two Forms of Spatial Imagery: Neuroimaging Evidence. Psychological Science, 20(10), 1245-1253
Spatial imagery may be useful in such tasks as interpreting graphs and solving geometry problems, and even in performing surgery. This study provides evidence that spatial imagery is not a single faculty; rather, visualizing spatial location and mentally transforming location rely on distinct neural networks. Using 3-T functional magnetic resonance imaging, we tested 16 participants (8 male, 8 female) in each of two spatial imagery tasks—one that required visualizing location and one that required mentally rotating stimuli. The same stimuli were used in the two tasks. The location-based task engendered more activation near the occipito-parietal sulcus, medial posterior cingulate, and precuneus, whereas the transformation task engendered more activation in superior portions of the parietal lobe and in the postcentral gyrus. These differences in activation provide evidence that there are at least two different types of spatial imagery.

Dellatolas, G., Watier, L., LeNormand, M. T., Lubart, T., & ChevrieMuller, C. (2009). Rhythm Reproduction in Kindergarten, Reading Performance at Second Grade, and Developmental Dyslexia Theories. Archives of Clinical Neuropsychology, 24(6), 555-563.
Temporal processing deficit could be associated with a specific difficulty in learning to read. In 1951, Stambak provided preliminary evidence that children with dyslexia performed less well than good readers in reproduction of 21 rhythmic patterns. Stambak's task was administered to 1,028 French children aged 5–6 years. The score distribution (from 0 to 21) was quasi-normal, with some children failing completely and other performing perfectly. In second grade, reading was assessed in 695 of these children. Kindergarten variables explained 26% of the variance of the reading score at second grade. The Stambak score was strongly and linearly related to reading performance in second grade, after partialling out performance on other tasks (oral repetition, attention, and visuo-spatial tasks) and socio-cultural level. Findings are discussed in relation to perceptual, cerebellar, intermodal, and attention-related theories of developmental dyslexia. It is concluded that simple rhythm reproduction tasks in kindergarten are predictive of later reading performance.

Crawford, J. R., Garthwaite, P. H., & Slick, D. J. (2009). On percentile norms in neuropsychology: Proposed reporting standards and methods for quantifying the uncertainty over the percentile ranks of test scores. Clinical Neuropsychologist, 23(7), 1173-1195.
Normative data for neuropsychological tests are often presented in the form of percentiles. One problem when using percentile norms stems from uncertainty over the definitional formula for a percentile. (There are three co-existing definitions and these can produce substantially different results.) A second uncertainty stems from the use of a normative sample to estimate the standing of a raw score in the normative population. This uncertainty is unavoidable but its extent can be captured using methods developed in the present paper. A set of reporting standards for the presentation of percentile norms in neuropsychology is proposed. An accompanying computer program (available to download) implements these standards and generates tables of point and interval estimates of percentile ranks for new or existing normative data.

McGee, C. L., Delis, D. C., & Holdnack, J. A. (2009). Cognitive Discrepancies in Children at the Ends of the Bell Curve: A Note of Caution for Clinical Interpretation. Clinical Neuropsychologist, 23(7), 1160-1172.
Discrepancies between IQ scores on the Wechsler Abbreviated Scale of Intelligence (WASI) and scores from the Delis-Kaplan Executive Function System (D-KEFS) were examined at different levels of intellectual functioning in 470 normal-functioning youths (aged 8-19) from the co-standardization sample of the WASI and D-KEFS. Results demonstrated that children with lower IQ scores often had significantly higher D-KEFS scores, whereas children with higher IQ scores often had significantly lower D-KEFS scores. Similar patterns were identified for discrepancies between Verbal and Performance IQ indices. These findings are similar to those found in the adult literature. Clinicians are advised to be cautious when weighing the clinical significance of cognitive discrepancies at the ends of the bell-curve and should avoid interpreting discrepancies in isolation.

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