Jared M. Bartels

Stability of the WISC-IV in a Sample of Elementary and Middle School Children

This study investigated test-retest stability of the Wechsler Intelligence Scale for Children, Fourth Edition, in 43 elementary/middle school students tested on two occasions approximately 11 months apart. Subtest stability coefficients ranged from .26 (Picture Concepts) to .84 (Vocabulary [VC]). Composite stabilities ranged from .54 (Processing Speed Index) to .88 (Full Scale Intelligence Quotient [FSIQ]). On 11 subtests and three indexes, the standardization sample stability coefficients were significantly larger than those of the present sample, with only the VC subtest and FSIQ having high levels of test-retest stability. Mean practice effects were not significant, but range of gain or loss for some individuals was large. On the FSIQ, 42% changed >±5 points on retest. The FSIQ is less stable than one might infer from the large stability coefficient and small mean practice effect.

Internal Consistency Reliability of the Wisc–IV among Primary School Students

Internal consistency reliabilities of the WISC–IV subtest and index scores were estimated for a sample of 76 primary school students from a small Midwestern community. Means for age and Full Scale IQ were 8.2 yr. (SD = 2.3) and 110.5 (SD = 11.7), respectively. Internal consistency reliabilities were compared with those for the WISC–IV standardization sample of 200. The range of reliabilities for the subtests was from .76 for Picture Concepts to .94 for Arithmetic and from .92 for Perceptual Reasoning Index to .96 for Verbal Comprehension Index and Full Scale IQ. The Full Scale IQ internal consistency reliability is comparable to that of the standardization sample. However, in all but one instance the reliabilities were greater than those of the normative sample.

WAIS-III VIQ-PIQ and VCI-POI discrepancies in lateralized cerebral damage.

We evaluated Verbal IQ (VIQ)–Performance IQ (PIQ) and Verbal Comprehension Index (VCI)–Perceptual Organization Index (POI) discrepancies among 16 patients with right-sided and 20 with left-sided cerebral lesions. Means for age and education among left hemisphere-damaged patients were 46.25 years (SD = 17.42) and 12.17 years (SD = 2.87). Means and standard deviations for age and education were 47.86 years (SD = 16.83) and 12.27 years (SD = 2.46) for those with right-sided damage. Left hemisphere lesions produced nonsignificant VIQ < PIQ and VCI < POI means, whereas right hemisphere damage resulted in significant VIQ > PIQ and VCI > POI mean discrepancies. Additional analyses indicated that neither discrepancy score was effective in identifying lateralized brain damage.

Perceptions of psychology as a science among university students: the influence of psychology courses and major of study.

The goal was to examine the relationship between the number of psychology courses students have taken and their perceptions of psychology as a science. Additionally, differences in perceptions of psychology among psychology, education, and natural science majors were examined. Results indicated that students who had taken four or more psychology courses had more favorable perceptions of psychology as a science compared to those who had taken no courses or one course and those who had taken two to three courses. No significant differences in overall perceptions of psychology emerged among students in the three majors.

Predicting Neuropsychological Test Performance on the Basis of Temporal Orientation

ABSTRACT Temporal orientation is often disrupted in the context of psychiatric or neurological disease; tests assessing this function are included in most mental status examinations. The present study examined the relationship between scores on the Temporal Orientation Scale (TOS) and performance on a battery of tests that assess memory, language, and cognitive functioning in a sample of patients with Alzheimers disease (N = 55). Pearson-product moment correlations showed that, in all but two instances, the TOS was significantly correlated with each neuropsychological measure, p values ≤ .05. Also, severely disoriented (i.e., TOS score ≤ −8) patients were consistently ‘impaired’ on memory tests but not on tests of language and general cognitive functioning.

Estimating WISC-IV Indexes : Proration versus linear Scaling

This investigation compared proration and linear scaling for estimating Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) verbal comprehension (VCI) and perceptual reasoning (PRI) composites from all relevant two subtest combinations. Using 57 primary school students and 41 clinical referrals, actual VCI and PRI scores were highly correlated with estimated index scores based on proration and linear scaling (all rs> or =.90). In the school sample, significant mean score differences between the actual and estimated composites were found in two comparisons; however, differences between mean scores were less than three points. No significant differences emerged in the clinical sample. Results indicate that any of the two subtest combinations produced reasonably accurate estimates of actual indexes. There was no advantage of one computational method over the other.

WAIS-III FSIQ and GAI in Ability-Memory Discrepancy Analysis

The present investigation compares WAIS-III FSIQ-WMS-III with GAI-WMS-III discrepancies in 135 male inpatients with suspected memory impairment. Full Scale IQ and GAI scores were highly correlated, r = .96, with mean values of 92.10 and 93.59, respectively. Additional analyses with the ability composites compared to each WMS-III index (IMI, GMI, and DMI), the GAI consistently produced larger difference scores than did the FSIQ; however, effect sizes were relatively small (ES = .12). Lastly, case-by-case analyses demonstrated concordance rates of 86% for the FSIQ-IMI and GAI-IMI comparisons, 85% for the FSIQ-GMI and GAI-GMI, and 82% for the FSIQ-DMI and GAI-DMI.

Associations between Climate and IQ in the United States of America

Relations between average temperature of each of the 48 contiguous states and estimates of state IQ were inspected. Additional state variables were controlled in the correlational analyses, namely gross state product, percent Hispanic, Black, and Asian in the state population, and the pupil-to-teacher ratio for each state. A significant correlation between average temperature and state IQ was found (r = -.70, p<.001). Possible explanations are discussed.

Base Rates of “10 to 11” Clocks in Alzheimer's and Parkinson's Disease

We extended the work of Rouleau et al. (I. Rouleau, D. P. Salmon, N. Butters, C. Kennedy, & K. McGuire, Quantitative and qualitative analyses of clock drawings in Alzheimers and Huntingtons disease. Brain and Cognition, 18, 1992, 70–87) and Ryan et al. (J. J. Ryan, S. J. Lopez, & S. W. Sumerall, Base rate of “10 to 11” clocks among patients referred for neuropsychological evaluation. Perceptual and Motor Skills, 81, 1995, 1138) by providing base rates for “10 to 11” clocks in samples of healthy elderly (n = 168), Alzheimers disease (AD; n = 81), and Parkinsons disease (PD; n = 105). Groups were comparable in age and education. Stimulus bound clocks occurred in 3.0% of controls, 30.9% of AD, 5.7% of PD, and 10.2% of the combined sample. The 10.2% base rate is consistent with Ryan et al. for a mixed sample and Rouleau et al. for healthy elderly and patients with AD or Huntingtons disease.

Comparability of the GMI and DMI for the WMS-III.

This study compared the new Delayed Memory (DMI) with the General Memory (GMI) index of the WMS-III using 134 inpatients with substance abuse disorders. The WMS-III Immediate Memory Index (IMI) and the GMI are not parallel because the latter includes Auditory Recognition Delayed. A solution to this dilemma is the DMI, in that it directly parallels the original IMI. The GMI and DMI scores were highly correlated, r = .98, and mean values differed by<1 point (90.77 and 90.66, respectively). Difference score comparisons (i.e., IMI-GMI with IMI-DMI and FSIQ-GMI with FSIQ-DMI) yielded similar results (ts<1). Case-by-case analyses demonstrated concordance rates of 99% for the IMI-GMI and IMI-DMI comparisons and 94% for the FSIQ-GMI and FSIQ-DMI contrasts.