WPPSI Research Articles

Intellectual Development of Children Born of Mothers who Fasted in Ramadan during Pregnancy

The long-term effects of Ramadan fasting during pregnancy on the brain development of the fetus are still not clear. The aim of this study was to evaluate the effects of maternal fasting during Ramadan on the intelligence quotient of their progeny. A historical cohort study was conducted on 191 children aged between 4 to 13 years, 98 whose mothers fasted throughout Ramadan when they were pregnant with their children (case group) and 93 children whose mothers did not fast (control group). The children were selected from 15 schools via a questionnaire filled out by their mothers. Detailed demographic, medical history, and socioeconomic status data were collected by interviewing the mothers. All children aged between 6 to 13 were administered the Wechsler Intelligence Scale for Children-Revised (WISC-R), and those aged between 4 to 6 were administered Wechsler Preschool and Primary Scales of Intelligence (WPPSI), and intelligence quotient was estimated. Cases included 47 boys and 51 girls aged 8.5+/-2.5 years and controls included 44 boys and 49 girls aged 8.7+/-2.5 years. There were no significant differences in sex and age between two groups. Among background and confounder variables, the percentage of Caesarean section and the duration of breast-feeding were significantly different between case and control groups; 29% Caesarean section in cases vs. 45% in controls (p < 0.05) and 17.2+/-9 months breast-feeding for cases vs. 14.5+/-9 months for controls (p < 0.05). There were no significant differences in socioeconomic status of families between the groups whereas socioeconomic status accounted for approximately 17% of the variances in the average of full-scale intelligence quotient scores. Adjusted mean and standard deviation of full-scale intelligence quotient scores, performance and verbal, were 111+/-10, 109+/-11 and 110+/-11 for the case group and 112+/-10, 110+/-11 and 110+/-11 for the control group respectively. No significant differences were observed between the IQ scores of the two groups. Fasting during gestation did not adversely affect IQ of children whose mothers had fasted during Ramadan while being pregnant.

Cocaine, anemia, and neurodevelopmental outcomes in children: a longitudinal study.

This longitudinal study investigated the rates of iron-deficiency (ID) and iron-deficiency anemia (IDA) among prenatally cocaine-exposed and nonexposed two- and four-year-old children and assessed their relationships to neurodevelopmental outcomes. The sample consisted of 143 two-year-old (70 exposed and 73 nonexposed) and 274 four-year-old (139 exposed and 135 nonexposed) low socioeconomic status children recruited from an ongoing longitudinal study. Hematological assessments included hemoglobin, serum ferritin, mean corpuscular volume, transferrin saturation, and blood lead levels. The neurodevelopmental outcomes consisted of the Bayley Mental (MDI) and Motor (PDI) Development indices at two years, and the Wechsler Preschool and Primary Scales of Intelligence (WPPSI) and the Peabody Developmental Motor Scales (PDMS) at four years. The rate of IDA in four-year-old children was significantly greater among the cocaine-exposed compared to the nonexposed group (p =.026), while the rates at two years were not significant. Exposure to IDA at two years was associated with a significant decrease in concurrent motor scores (p =.011) after adjustment for relevant covariates. Peak exposure to IDA, defined as being anemic at 2 and/or 4 years of age, was associated with a significant (p <.05) decrease in Full Scale IQ after adjustment. Cocaine exposure was not a significant predictor of Full Scale IQ with the inclusion of peak IDA and lead in the model. These findings indicate the need for greater pediatric surveillance of IDA and lead in cocaine-exposed infants, in order to reduce long-term neuropsychological deficits.

Cognitive and emotional outcome after pediatric liver transplantation.

The aim of the study was to evaluate the cognitive and emotional development after pediatric liver transplantation. A total of 21 patients, aged 4-16.9 yr (median 9.6 yr) were tested 1-9 yr (median 4.2 yr) after the transplantation. The pretransplant diagnoses included biliary atresia (eight patients), various metabolic diseases (n = 6), acute liver failure (n = 3), and miscellaneous (n = 4). The cognitive functions were tested with Wechsler preschool and primary scale of intelligence (WPPSI)-R or Wechsler intelligence scale for children (WISC)-III according to age. The Piers-Harris self-concept scale and the evaluation of human figure drawings according to Koppitz were used to detect emotional problems. All tests in all patients were performed by the same psychologist. A significantly lower result on cognitive tests was seen when compared with the expected normal values (p < 0.01). The number of patients with results within or under the lower normal range was higher than expected. Although the mean value of the Piers-Harris self-concept scale was normal, there was a large spread within the group. Indicators of emotional problems were found in the human figure drawings of 50% of the patients. To some extent, low cognitive scores coincided with low scores on self-concept scale and indicators of emotional difficulties. We conclude that the high degree of cognitive and emotional problems after liver transplantation is an important argument for routine psychologic follow-up and support in these patients.

Book Review: Essentials of WISC-III and WPPSI-R Assessment

Book Review: Essentials of WISC-III and WPPSI-R Assessment

Cytomegalovirus infection in pregnancy

Objectives: To investigate the effects of intrauterine human cytomegalovirus (HCMV) infection on pregnancy outcomes and infant development. Methods: The study group consisted of the HCMV-IgM-positive offspring of 75 pregnant women, and a control group of the non-infected offspring of 73 pregnant women. Chorionic villi, amnionic fluid, and umbilical blood were obtained to detect HCMV–late mRNA with a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The pregnancy outcomes were followed up. For all offspring, neurological development was evaluated with neurosonography, audiologic development with the brainstem auditory evoked potential (BAEP), and psychomotor development with the Beyley Scale of Infant Development (BSID). Results: In the study group the positive rate of late mRNA was 50% in the chorionic villi and 67.65% in the amnionic fluid and the umbilical blood; the incidence of abnormal pregnancy outcomes (abortion, preterm delivery, stillbirth, etc.) was much higher than in the control group (40% vs. 6.57%; χ 2=24.06; P=0.001); the abnormal rate of neurosonography results at birth and 3 months after birth was higher in the study group than in the control group ( P<0.05), as were BAEP values 4 months after birth (χ 2=8.960; P=0.003). Scores for the Infant Mental Development Index (MDI) were apparently lower than in the control group. When congenitally infected children were tested at the age of 5.5–6.5 years with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI), their rate of mental retardation was still found to be approximately 20%. Conclusions: Intrauterine HCMV infection is closely related to abnormal pregnancy outcomes, infant neurological damage, mental retardation, and hearing loss.

Interpreting the WPPSI subtests scores of language impaired children--a structural approach.

The problem of characterising more specifically the cognitive requirements involved in subtests from standardised measures of intelligence represents a main problem in the research on exceptional populations. Seventy-five specifically language impaired (SLI) preschool children and 49 normally developing children were administered the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). The scaled scores on the WPPSI were categorised according to Bannatyne's suggested regrouping to determine whether the pattern Spatial > Conceptual > Sequential could be observed in the data. The predicted pattern was only partially confirmed for language impaired children. The scaled scores on the WPPSI were then recategorized according to their structural complexity. Since structurally complex tasks contain more categories than the structurally simpler tasks, the pattern structurally Simple > Moderate > Complex was predicted and confirmed for language impaired children. Furthermore, it was hypothesized that the structurally Complex categories would discriminate better between language-impaired children and normally developing children than any other recoded categories. This hypothesis was confirmed. The low scores obtained by language impaired children on structurally Complex categories were interpreted as the result of capacity limitations in information processing rather than a deficit of any particular mental ability.

Efecto de las galletas fortificadas con hierro heme sobre el estado intelectual en preescolares

In undeveloped countries such as Peru there is a high prevalence of ferropenic anemia. In addition, iron deficiency produces cognitive alterations that could be corrected by iron treatment. To evaluate the effect of administration of heme iron-fortified cookies on the intellectual status of preschool children. Using the Goodenough-Harris Test (GHT) and Wechsler Preschool and Primary Scale of Intelligence (WPPSI) we studied the intellectual status of 53 children who received heme iron-fortified cookies for 6-8 weeks and 55 controls without fortification, in 2 occasions (before and after intervention). We observed a significantly higher improvement in children who received iron respect to controls for GHT score (p < 0.001), WPPSI score (p < 0.05), WPPSI attention-concentration subscale (p < 0.01) and WPPSI pure attention subscale (p < 0.05). Administration of heme iron-fortified cookies may improve the intellectual performance of low-income preschool children.

Stability of Cognitive Measures in Children of Average Ability

Fifty-nine normal Dutch children in the age range of 4.4–12.3 years performed a wide battery of tests three times, each with a test-retest interval of 6 months. Stability coefficients and mean change in score of the Verbal (VIQ), Performance (PIQ), and Full Scale Intelligence Quotient (FSIQ) of the Wechsler Intelligence Scale for Children-Revised (WISC-R) were 0.78, 0.68, and 0.78, respectively. Up to 58% of the subjects showed a significant change in WISC-R IQ scores. VIQ, PIQ, and FSIQ stability coefficients of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) were 0.69, 0.79, and 0.84, respectively. The Stroop cards showed excellent reliability; the Dutch version of the Rey Auditory Verbal Learning Test, Rey Complex Figure Task, Beery Developmental Test of Visual-Motor Integration, and Trail Making Test Part B showed fairly good reliability; and the Trail Making Test Part A and relative score of the memory tests yielded poor reliability.

Cerebral Magnetic Resonance Imaging and Mental and Motor Function of Very Low Birth Weight Children at Six Years of Age

In this follow-up study, 20 of a geographically based year cohort of 31 surviving non-disabled VLBW (birthweight < 1500 g) children were examined at six years of age. The aim of the study was to relate cerebral MRI findings to neuro-development in these non-disabled children at six years of age. All MRI scans were evaluated for myelination pattern, periventricular gliosis, ventricular dilation and cortical atrophy. The Peabody motor test and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) were used in the evaluation of motor, mental and perceptual function. A diagnosis of attention deficit disorder with hyperactivity was made based on the examiner's impression of the child during the examination and based on the parent's history. We found that ten (50%) of the children had periventricular gliosis, mainly in centrum semiovale (CS) (nine children) and in central occipital white matter (COW) (six children). Gliosis in CS was related to lower scores on the Peabody gross motor test for locomotion, indicating involvement of corticospinal tracts. Additional gliosis in COW was related to both fine motor and gross motor impairments. We speculate that this indicates damage to both motor and visual pathways, affecting eye-hand coordination and balance function. No relationship between MRI deviations at six years and mental function based on performance, verbal and total IQ scores was found. However, there was a significant relationship between periventricular gliosis in COW and C5 and low scores on the WPPSI performance subtests: Picture completion test and Block design test. This may indicate visual and spatial perception problems, caused by damage to posterior visual pathways and occipito-thalamic tracts dealing with visuo-motor integration.

The relation between the Leiter IQ and the WPPSI Performance IQ in assessment of language impaired children

Normal nonverbal IQ is a criterion that is part of virtually every definition of specific language impairment (SLI). The present paper examines difference between two measures of nonverbal IQ in a group of language impaired children (n = 25). The two measures were the Leiter International Performance Scale (5) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) (10). Large difference in mean IQs were found between the two scales. The biter overestimated nonverbal IQ at low levels, and underestimated IQ at higher levels relatively to the WPPSI. Implications for assessment of language impaired children are discussed.

Toxocara canis infection in preschool age children: risk factors and the cognitive development of preschool children.

Risk factors for Toxocara canis (T. canis) infection were evaluated in a prospective study of disadvantaged preschool children. In addition, the hypothesis that T. canis exposure is associated with lower intelligence was tested. Seropositivity was tested at 2 years, 3 years, and at 4 years 10 months (4-10). Intelligence was measured at age 4-10 by the Full Scale IQ of the Wechsler Preschool and Primary Scales of Intelligence (WPPSI). Pica and ownership of a dog were unrelated to seropositivity. Seropositive children had lower scores on the Mental Development Index (MDI) of the Bayley Scales of Infant Development at age 1 year (prior to likely exposure). They also had less favorable scores on a measure of the quality of childrearing. These findings suggest that, for disadvantaged children, lower initial intelligence and less advantageous child rearing are risk factors for T. canis exposure. Seropositive children also had higher blood lead levels, probably as a result of the common pathway of hand to mouth transmittal. Seropositivity at 3 years, at age 4-10, or, cumulatively, at any of the age 2, 3, or 4-10 assessments was associated with the WPPSI IQ after adjustment for sociodemographic factors. Exposure at age 4-10-years was significantly associated with reduced IQ scores (p = 0.030). However, when the age 1 year MDI score was controlled, the estimate became nonsignificant. We, thus, can neither confirm nor deny a relationship of T. canis and intelligence, but the importance of considering prior developmental status is emphasized.

Language impaired children: A note on the relation between Språklig Test 1 (Bo Ege) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI)

In a group of 35 language impaired preschool children, we found a relatively high correlation (r =. 69) between the tri-level conceptual hierarchy represented in the Ege test (Spraklig tests 1) and verbal IQ as measured by the WPPSI (the Wechsler Preschool and Primary Scale of Intelligence, Wechsler, 1967). It is argued that acquisition of conceptual hierarchies as assessed by the Ege test, is based on an underlying ability that might be referred to as verbal declarative ability. This kind of ability is to be contrasted with verbal procedural ability; i.e., the ability to carry out verbal procedures. In the work with language impaired children both types of abilities ought to be assessed.

Language impaired children: Differences between verbal and nonverbal abilities

Specific language impairment has been defined by excluding other types of difficulties like peripheral hearing loss, mental retardation, emotional disturbances, etc. It has also been advocated that discrepancy criteria could be used, for example the discrepancy between language measures and nonverbal IQ. Language measures and measures of nonverbal IQ represent very global measures of cognitive functioning. The present paper relates to the problem of definition and assessment of specific language impairment by suggesting that a distinction ought to be made between two aspects of verbal and nonverbal cognitive functioning. The subtests on WPPSI (the Wechsler Preschool and Primary Scale of Intelligence, Wechsler, 1967) were sorted into groups representing declarative and procedural knowledge. Declarative knowledge corresponds to “knowing that”/“seeing that” and procedural knowledge corresponds to “knowing how”/“seeing how”. In a group of 90 language impaired children, mean age 5.9 years, we found marked disc...

Rising IQ scores in British children: recent evidence.

Between 1987 and 1990 IQ scores for 333 5-year-old white school children were obtained using the Wechsler Pre-School and Primary Scale of Intelligence (WPPSI) and the results were compared with 112 children assessed in 1967. The mean full scale IQ score of 113.3 was 8 points higher than the mean of 105.1 in the 1967 study. These findings indicate that the rate of increase of IQ scores was comparable and probably higher than that reported in the U.S.A. for the period 1932-78. It is important that this large increase is taken into account for correct interpretation of IQ test results.

Impaired motor function (clumsiness) in 5 year old children: correlation with neonatal ultrasound scans.

All 155 surviving children from a cohort of 200 very low birthweight infants originally studied in 1984-5 were traced. These infants had careful sequential ultrasound examinations in the neonatal period. The children were examined again at entry into school at 5 years of age. The test of motor impairment (TOMI) and the vocabulary subscale of the Wechsler preschool and primary scale of intelligence (WPPSI) were administered to 152 of the index cohort and 144 control children of the same age in the same class at school. Twelve of the cohort had cerebral palsy, but eight of these were in mainstream schools. The index group scored significantly higher on both the TOMI and the WPPSI subscale compared with the controls. The index cases were subdivided on the basis of their neonatal ultrasound scans into four groups: group 1, consistently normal; group 2, 'prolonged flare'; group 3, germinal matrix haemorrhage-intraventricular haemorrhage (GMH-IVH), without parenchymal haemorrhage, but no evidence of prolonged flare; and group 4, both GMH-IVH and prolonged flare. The group of index children with consistently normal ultrasound scans had a higher TOMI and lower WPPSI compared with their controls. There was a statistically significant increase in the TOMI subscore 1 (manual dexterity) in group 4 infants compared with group 1, but not differences between the other groups. Regression analysis suggests that neither prolonged flare nor GMH-IVH has an important individual contribution to the variation, but the low birth weight does have a significant relationship with motor impairment. It appears that relatively minor ultrasound appearances such as prolonged flare and GMH-IVH are associated with motor impairment (clumsiness) at 5 years, but this has a small effect compared with low birth weight.

CORRELATIONS FOR WECHSLER INTELLIGENCE SCALE FOR CHILDREN-REVISED AND THE WECHSLER PRESCHOOL AND PRIMARY SCALE OF INTELLIGENCE FOR IRANIAN CHILDREN

This study focused on the relationship between the Wechsler Intelligence Scale for Children—Revised (WISC—R) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) given to 40 6-yr.-old Iranian children. Pearson correlations between the WISC—R and the WPPSI IQs and between scaled scores on the corresponding subtests were significant. The comparison of mean IQs and scaled scores indicates that the WISC—R yielded a significantly higher Verbal IQ and higher scores on Information, Vocabulary, Comprehension, and Picture Completion than the WPPSI. The mean difference between corresponding Verbal and Full Scale IQs was not significant. These results suggest that scores on the two instruments correlated well for these 6-yr.-old Iranian children and the content on which IQs for the recently restandardized WISC—R and WPPSI are based are related.

Selective improvement in cognitive test scores of extremely low birthweight infants aged between 2 and 5 years.

The cognitive development at 2 and 5 years of a cohort of extremely low birthweight (ELBW) children (birthweight 500-999 g) was compared with that of cohorts of larger very low birthweight (VLBW) children (birthweight 1000-1500 g) and normal birthweight (NBW) children (birthweight greater than 2500 g) to determine whether the improvements in cognitive function of ELBW infants between 2 and 5 years are apparent or real. At 2 years of age, ELBW children had a mean Mental Developmental Index (MDI) on the Bayley Scales of 90.4, significantly lower than the means of 100.3 for the larger VLBW children (P = 0.006), and 107.8 for the NBW children (P = 0.0002). However by 5 years the mean scores on the Wechsler Preschool and Primary Scales of Intelligence (WPPSI) full-scale for the ELBW and larger VLBW children were virtually identical (105.9 and 106.0 respectively)--but still lower than the mean WPPSI full-scale of 114.6 for the NBW children. After standardizing the MDI and WPPSI scores relative to the NBW children, the ELBW children improved between 2 and 5 years (paired t-test, t = 3.2, P = 0.004) whereas the larger VLBW infants did not. We postulate that ELBW children require more time than larger VLBW children after birth to compensate for perinatal and other stresses, and that developmental delay at 2 years may not always persist to 5 years.

Validity of Preschoolers' Self-Drawings as an Index of Human Figure Drawing Performance

Fifteen preschoolers were administered the Goodenough-Harris Draw-a-Person Test (DAPT) (Harris, 1963), Ayres and Reid's (1966) assessment of self-drawings, and the General Information subtest, which is a verbal measure of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) (Wechsler, 1967). High correlations were obtained between the man, woman, and man/woman converted scores of the DAPT and the self-drawings that were scored with Ayres and Reid's procedure. These data indicate that Ayres and Reid's self-drawing scoring system may be a useful replacement for the longer DAPT when clinicians want a quick and easy method of assessing a child's figure drawing abilities. Low correlations between all of the figure drawing and WPPSI scores are consistent with other data that indicate that figure drawing ability is more highly correlated with the performance than with the verbal components of IQ tests.

Comparison of an Intelligence Test and a Screening Battery as Predictors of Reading Ability in Low Income, Mexican American Children

Reading performance of low income, Mexican American children was predicted from scores on the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and the Florida Kindergarten Screening Battery (FKSB). The WPPSI and the FKSB were administered when the subjects were five years of age. School reading grades and reading scores from the Iowa Test of Basic Skills (lTBS) comprised reading performance measures. Results indicate that the WPPSI and the FKSB were highly similar in their ability to predict later reading performance levels. Both measures were able to account for a significant amount of variation in reading grades and ITBS reading scores. Verbal subtests in both measures were more poorly correlated with reading performance than were perceptual-performance subtests.

Correction of developmental and intelligence test scores for premature birth

When using tests of infant development and intelligence in children born prematurely, the subject's age is commonly corrected for the degree of prematurity. However, there is disagreement: first, on whether this correction should ever be applied, and second, at what age to discontinue the adjustment. In a theoretical model, the difference between corrected and uncorrected scores in early infancy was massive and the difference remained clinically important until the age of 8.5 years in children who were born extremely prematurely. The clinical implications of using corrected or uncorrected scores were then evaluated in 174 very low birthweight children without severe sensorineural disabilities and with paired Bayley Mental Development Index (MDI) and Wechsler Preschool and Primary Scales of Intelligence (WPPSI) full scale scores. Failure to correct for prematurity reduced the mean MDI by 12.1 points but reduced the mean WPPSI by only 4.1 points. The disparity between individual MDI and WPPSI scores increased significantly with decreasing gestational age if uncorrected scores were used (P = 0.015) but not if scores were corrected. Using corrected scores, the MDI correctly predicted the WPPSI category in 86.1% of children (P less than 0.001) but in only 54.6% using uncorrected scores (the difference was not significant). It is suggested that a practical solution to the dilemma is to correct test scores for prematurity in the age range 2-8.5 years recognizing that only in extremely immature infants will uncorrected scores be substantially lower than corrected ones at a later age.