Cognitive Ability Scores Research Articles

Genetic structure of spatial and verbal working memory.

Working memory (WM) encompasses both short-term memory (storage) and executive functions that play an essential role in all forms of cognition. In this study, the genetic structure of storage and executive functions engaged in both a spatial and verbal WM span task is investigated using a twin sample. The sample consists of 143 monozygotic (MZ) and 93 dizygotic (DZ) Japanese twin pairs, ages 16 to 29 years. In 155 (87 MZ, 62 DZ) of these pairs, cognitive ability scores from the Kyodai Japanese IQ test are also obtained. The phenotypic relationship between WM and cognitive ability is confirmed (r = 0.26-0.44). Individual differences in WM storage and executive functions are found to be significantly influenced by genes, with heritability estimates all moderately high (43%-49%), and estimates for cognitive ability comparable to previous studies (65%). A large part of the genetic variance in storage and executive functions in both spatial and verbal modalities is due to a common genetic factor that accounts for 11% to 43% of the variance. In the reduced sample, this common genetic factor accounts for 64% and 26% of the variance in spatial and verbal cognitive ability, respectively. Additional genetic variance in WM (7%-30%) is due to modality specific factors (spatial and verbal) and a storage specific factor that may be particularly important for the verbal modality. None of the variance in cognitive ability is accounted for by the modality and storage genetic factors, suggesting these may be specific to WM.

Developmental instability and schizotypy

Introduction. It has been suggested that evidence of developmental disturbance of cognition and lateralisation in schizophrenia can be best understood from the perspective of developmental stability (DS), an indicator of the extent to which an individual develops according to a specified ontogenic programme in the presence of environmental noise. Higher levels of fluctuating asymmetry (FA; the difference between right and left side of a quantitative morphological trait such as dermatoglyphics) are thought to reflect less DS. We examined this issue for dimensions of schizotypy. Methods. Associations between FA, measures of laterality and cognitive function on the one hand, and negative and positive dimensions of schizotypy on the other, were examined in a sample of 260 healthy adolescents aged 11.9–15.6 years. FA was measured as a–b ridge count right–left differences. Neuropsychological measures yielded a general cognitive ability score and a frontal function score. Laterality was assessed with the Annett scale. Results. Measures of psychosis proneness were normally distributed. Negative schizotypy was associated with more FA and lower general cognitive ability in a dose–response fashion. The association with FA was more apparent in boys. No associations existed with laterality or frontal function. Conclusion. The negative dimension of schizotypy may be associated with early developmental instability, resembling the pattern seen in the negative symptom dimension of schizophrenia. Measures of fluctuating asymmetry may be more sensitive with regard to the schizotypy phenotype than measures of laterality.

An Epidemiological-Cohort Study of DAS Processing Speed Factor: How Well Does it Identify Concurrent Achievement and Behavior Problems?

This study evaluated the criterion-related validity for the Speed of Processing (SP) factor of the Differential Ability Scales (DAS; Elliott, 1990). The SP factor is comprised of one subtest score (Speed of Information Processing) based on results from factor analyses. Participants were an epidemiological sample (N= 1,400) stratified, within age levels, in proportion to census data on demography (e.g., race, gender, parents' educational levels). From this cohort, groups with unusual SP strengths and SP weaknesses were identified using General Cognitive Ability (GCA) scores from the DAS as contrasts (i.e., SP>GCA and GCA>SP differences at a population prevalence < 5%). The SP>GCA group (n= 60) and the GCASP group (n = 60) were matched to respective controls (where each control n = 60) on the demographic variables listed above and GCAs. Each group and its control were compared across three norm-referenced measures of achievement and six teacher-rated indices of behavioral adjustment. Comparisons failed to show significant differences on any criterion variable. Results are discussed in the context of how well epidemiological samples evaluate the validity of ability profiles and the need for future research to use more representative measures of processing speed (i.e., those with two or more subtests contributing to the factor).

Physical Activity and Measures of Cognitive Function in Healthy Older Adults: The MacArthur Study of Successful Aging

To investigate the association between physical activity and cognitive ability, cross-sectional data from a representative cohort of 1,189 adults (70–79 years old) participating in the MacArthur Study of Successful Aging were examined. The frequency of current house/yardwork and recreational activities was assessed using five categories of responses. A total physical activity score was derived, and cognitive ability was assessed. The total physical activity score showed a modest yet significant bivariate correlation with the total cognitive ability score. In the multivariate analysis, physical activity showed a significant association with the total cognitive ability score, independent of gender, self-rated health, average peak expiratory flow rate, body mass index, number of current social relationships, and visual contacts in the past month. When education was added to the model, however, the effect of physical activity was substantially diminished. Higher levels of physical activity appear to be associated with some cognitive benefits among a population of healthy older adults, although this association is influenced strongly by their joint association with education.

Cognitive functioning, neurologic status and brain imaging in classical galactosemia.

A historical group of 45 children (4-18 years) and adults (18-39 years) with classical galactosemia had deficits of cognitive function that were variable and not related to the age at diagnosis or to severity of illness at presentation. There was a trend for patients to score highest on visual processing tasks. The standardized tests of speech and memory skills fell within the same range as the Broad Cognitive Ability score, indicating that the speech and language deficits may be part of a more global set of cognitive impairments. Scores on the Beery Visual Motor Integration and Block Design Tests fell in approximately the same range as other cognitive abilities. In addition, there was a high incidence of abnormality detected on MRI and 12 patients had neurologic symptoms that included ataxia, tremor and dysmetria. These abnormalities did not correlate with the age at diagnosis, severity of illness at presentation or scores on cognitive testing. The pathophysiology of neurologic and neuropsychologic impairments remains unknown. Since these appear to be unrelated to the duration of galactose exposure, other factors impacting on outcome need to be understood so that strategies can be developed to improve what appears to be a global impairment of cognitive function.

Alzheimer's Residents' Cognitive and Functional Measures

The aim of this field experiment was to compare the effects of a special care unit (SCU) on residents with Alzheimer's disease (AD) who lived on the SCU and on traditional (integrated) nursing home units. Twenty-two subjects, 13 on the SCU and 9 on traditional integrated units were compared. Repeated measures ANOVA was used to assess differences between the two groups and within the groups over two bimonthly pretests and two bimonthly posttests. No significant differences on cognitive or functional abilities scores were evident for the groups and no significant differences were found over time. However, consistent with the prediction of the Progressively Lower Stress Threshold Model, the SCU subjects' function was better than subjects on traditional units when measured by socially accessible behaviors.

Relationship between Scores on Developing Cognitive Abilities Test and Scores on Medical College Admissions Test for Nontraditional Premedical Students

The relationship of students' performance on the Developing Cognitive Abilities Test (DCAT), a test of scholastic aptitude, and their subsequent performance on the Medical College Admission Test (MCAT) were examined for 122 nontraditional premedical students who participated in a medical educational preparatory program. A stepwise multiple regression analysis produced moderate, though significant multiple correlations among subscores on the two tests. While there were a few exceptions, for the most part all of the subscores on the Developing Cognitive Abilities Test made a significant contribution to the regression equation in the prediction of scores on MCAT subtests. Implications for the value of the Developing Cognitive Abilities Test as an admissions tool as well as providing direction for possible intervention are discussed.

The effects of chronological age, gender, and delay of entry on academic achievement and retention: Implications for academic redshirting

School records for 313 students were reviewed to determine the effects of age of entry and gender on later academic achievement and grade retention. Twelve of these students were of legal age for school entry but were redshirted. Our findings indicated statistically significant but relatively small achievement differences between oldest and youngest children when cognitive ability scores were controlled. Redshirts, however, did not appear to gain any advantage in achievement as a result of delaying school entry.

Predictors of Sat Mathematics Scores of Gifted Male and Gifted Female Adolescents

A regression analysis was conducted to determine the relative importance of a series of variables in the prediction of SAT-Mathematics (SAT-M) scores of gifted males and females. Among the variables considered were visual-spatial ability, cognitive reasoning ability, learning style, and SAT-Verbal (SAT-V) scores. Scores on the visual-spatial task were analyzed for speed of response as well as ability. For both sexes, reasoning skills were the predominant factor in the prediction formulas. Differences in the two formulas seemed to reflect males' greater facility with process skills necessary for the SAT-M. Implications are discussed regarding how to interpret the differential performance of gifted males and females on the SAT-M.

Neonatal sex-steroid hormones and cognitive abilities at six years.

Five sex-steroid hormones (testosterone, androstenedione, estradiol, estrone, and progesterone) were assayed in umbilical cord blood. Cognitive abilities were assessed as a part of a 6-year follow-up laboratory visit. Four subtests were given: reading, numbers, listening, and spatial ability. There were no significant differences between boys and girls in cognitive ability scores. Higher levels of perinatal androgens (testosterone and androstenedione) were significantly associated with low age-6 spatial ability in girls. Multiple regression analyses revealed a significant proportion of the variance in cognitive abilities in girls could be accounted for by testosterone and androstenedione. No significant predictions were found for boys. The finding of a stable inverse association between sex and effect of hormones on abilities is discussed.

A Public School Validation Study of the Achievement Sections of the Woodcock-Johnson Psycho-Educational Battery with Learning Disabled Students

This study investigated selected aspects of the concurrent validity of the achievement sections of the Woodcock-Johnson Psycho-Educational Battery. A random sample of 30 elementary students referred for possible learning disabilities was selected and each student was evaluated by two different staffing committees, one having achievement information from traditionally used school district tests of Key Math, Brigance Inventory of Basic Skills, PIAT, and WRAT while the second evaluation committee had Woodcock-Johnson achievement information in place of the traditionally used tests. Identical LD placement decisions were reached on 23 out of 30 students evaluated (p < .05). In addition, it was found that Woodcock-Johnson cognitive ability scores correlated +.63 with WISC-R scores and were about 12 IQ points lower on the average.

Validity assessment of the Woodcock-Johnson Broad Cognitive Ability and Scholastic Aptitude cluster scores for behavior-disordered adolescents

Validity assessment of the Woodcock-Johnson Broad Cognitive Ability and Scholastic Aptitude cluster scores for behavior-disordered adolescents

Parent-infant resemblance for general and specific cognitive abilities in the Colorado adoption project

Previous publications emanating from the Colorado Adoption Project have reported significant relationships between parental general cognitive ability ( g) and infant Bayley MDI scores. The present study compared infant Bayley factor scores representing separable dimensions of infant cognition with parental general and specific cognitive abilities for 182 adoptive families and 164 nonadoptive families. Parent/offspring correlations between 12-month Bayley factors and parental cognitive abilities suggest only minimal relationships for both parental g and specific abilities. At 24 months, more parent/offspring resemblance was present; moreover, Bayley factors that were related to parental cognition tended to be related to parental g, not to specific abilities. The finding of significant parent/offspring relationships at 24 months between biological parents and their adopted-away infants, as well as between nonadoptive parents and their infants, suggests some genetic continuity from infancy to adulthood.

Multiple regression data using the WISC-R and the Woodcock-Johnson tests of cognitive ability

Using a sample of 100 behavior disordered male adolescents, correlations between the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Woodcock-Johnson Tests of Cognitive Abilities (WJTCA) were computed. All WISC-R subtests correlated with the W-J Broad Cognitive Ability score at the .0001 level. Analysis of the forward selection multiple regression procedure resulted in the inclusion of only WISC-R Verbal subtests for the first six steps. Implications of such results were discussed and a predictive equation reported.

An Investigation of the Reported Discrepancy between the Woodcock-Johnson Tests of Cognitive Ability and the Wechsler Intelligence Scale for Children-Revised

Concern generated by results of previously published research led to this replication and comparison study. The purpose was to investigate the validity of the Woodcock-Johnson Tests of Cognitive Abilities (WJTCA) by analyzing the reported discrepancies between the WJTCA and Wechsler Intelligence Test for Children-Revised (WISC-R). Means and correlations from the performance of normal, learning disabled, and emotionally disturbed children (n=60= on both tests were analyzed. Results attest to the validity of the WJTCA general cognitive ability score and indicate subscale differences between the tests that should be considered interpreting test results.

Linearity of offspring-parent regression for general cognitive ability.

Composite general cognitive ability scores were computed for members of 843 families from the Americans of European Ancestry sample in the Hawaii Family Study of Cognition (HFSC) and were analyzed for linearity of offspring-parent resemblance. Regressions of midoffspring on midparent values using various subgroupings of the data set, as well as a test for the significance of the quadratic regression obtained from an analysis of the entire sample, provided little or no evidence for nonlinear offspring-parent resemblance. These results differ from those recently reported by Reed and Rich [(1982), Behav. Genet.12:535–542], possibly because all family members tested in the HFSC are within the normal range of mental ability, whereas the Reed and Rich sample consists of families having a history of mental retardation.

Medical Student Performance

Studies of the evaluation of medical students' clinical performance frequently do not differentiate between ratings by house officer and attending staff evaluators. This practice is not appropriate, since research investigations have shown that house officers rate medical students' clinical performance higher and have higher interrater agreement than do attending staff This investigation studies one aspect of the validity of medical students' clinical performance ratings and demonstrates that there are higher correlations between house officer ratings of student knowledge and student cognitive ability scores than there are between attending staff evaluations and student ability scores.

The Relationship of Cognitive Abilities Scores with Social Studies Achievement

For a sample of 219 elementary school pupils in the fifth grade, intercorrelations were investigated among four subtest measures: (a) Metropolitan Achievement Test (MAT)—Social Studies, (b) Cognitive Abilities Test (CAT)—Verbal, (c) CAT—Quantitative, and (d) CAT—Non—Verbal. The CAT Verbal score yielded the highest correlation of .73 with the MAT measure.

Reliability of Group-Test Scores for Cognitive Controls and Intellectual Abilities over a One-Year Period

Test-retest rs over a period of 1 yr. are presented for scores from group tests of cognitive controls and intellectual abilities for which validity and split-half or short-form reliability estimates were reported earlier by Gardner and Lohrenz (1969). In spite of limitations on the possible reliabilities of certain scores, the reliability estimates obtained for these time-saving group procedures suggest that they can be used effectively for most purposes.