Normative neuropsychological test performance: effects of age, education, gender and ethnicity

Normative data on neuropsychological test performance for a sample of 131 adults (ages 18-49) is presented. All subjects were native speakers of English screened for past or present medical, neurological and psychiatric disorders, including substance abuse. A broad-based battery including measures of intellectual skills, memory and learning, receptive and expressive language, auditory and visual information processing and attention, sensory processing, motor skills, and self-reported anxiety and depression was administered. Means, standard deviations and percentile rankings for all tests are reported. Regression analyses were computed to consider the concurrent influence of sociodemographic factors on all tests. Significant effects of age (M=27.1 yrs), education (M=14.6 yrs), gender (58% male), and ethnicity (62% white) were observed for relatively few test scores. Younger age at testing was associated with better continuous performance test scores. Higher education levels were associated with higher vocabulary and reading scores. Males had higher WAIS-R Information scores and faster Finger Tapping scores compared to females Ethnicity was associated with Full-scale IQ, and additional tests with a verbal component, e.g., Boston Naming Tests, and non-verbal component, e.g., Drawing Tests. We conclude that sociodemographic factors infrequently account for more than 10% of the variance for many neuropsychological test scores.

Male prevalence for reading disability is found in a large sample of black and white children free from ascertainment bias

Male vulnerability to neurodevelopmental disorders remains controversial. For one disorder, reading disability, this sex bias has been interpreted as an artifact of referral bias. We investigated sex differences for the incidence of reading disability within a large prospective sample of White (N = 16,910) and Black (N = 15,313) children derived from the National Collaborative Perinatal Project (NCPP). Children were classified as having either moderate or severe reading disability when they had reading scores lower than 1.5 or 2.0 standard errors of prediction, respectively, given their age and intelligence. Reading disability was about twice as common in boys than girls (p < .001), irrespective of race, severity of disability, or exclusion of children with attentional disturbances or high activity levels. We conclude that there is a clear sex bias toward males for the incidence of reading disabilities.

A re-examination of the sex ratios of families with a neurodevelopmentally disordered child

It has been claimed that mothers with certain hormonal imbalances and/or immunological disorders are more likely to give birth to male than female children and that they are more likely to give birth to a neurodevelopmentally disordered (ND) child. Liederman and Flannery (1995) reported that the sex ratio of families with an index ND child did not significantly differ from the sex ratio of families without an index ND child. The data were derived from the National Collaborative Perinatal Project (NCPP). James (in the current issue) challenged us to reconsider the standard against which we judged the sex ratio of siblings of ND children, since the 1.10 sex ratio that we obtained for the siblings of non-ND children is much higher than the sex ratio of children born during that period according to the U.S. Census Bureau. In the current paper, the NCPP data were reexamined and it was demonstrated that the high sex ratio of siblings in our non-ND sample was not due to various retention or recruitment biases. Thus, we suggest that use of the sex ratio of siblings of non-ND children was the proper standard against which to judge the sex ratio of ND families, and that our data provide no evidence to support the notion that these families are male biased.

Language before and after temporal lobectomy: specificity of acute changes and relation to early risk factors

We evaluated language functions in 154 patients with left hemisphere speech dominance undergoing anterior temporal lobectomy (ATL). Measures of phonemic and semantic fluency, confrontation naming, repetition, comprehension, and reading were administered before and 3 weeks postoperatively. Patients were grouped by focus (left, LT; right, RT) and presence of early risk factors for development of seizures (ER, early risk, < or = 5 years; NER, no early risk): (LT-ER, n = 45; RT-ER, n = 49; LT-NER, n = 27; RT-NER, n = 33). Preoperatively, the LT group showed a selective naming deficit as compared with the RT group. Postoperatively only the LT-NER group showed significant overall decline in language. For this group, the change was attributable to a selective decline in naming as compared with other functions. These data indicate that there is a specific risk to naming after dominant ATL for adult temporal lobe epilepsy (TLE) patients with a left hemisphere focus and the absence of an early risk factor for the development of seizures.

Is there really a syndrome involving the co-occurrence of neurodevelopmental disorder talent, non-right handedness and immune disorder among children?

This paper is the first large-scale attempt to test Geschwind and Galaburda's (1985a, 1985b, 1985c) hypothesis that there should be a four-way association among neurodevelopmental disorders (NDs), special talents, non-right handedness, and immune disorders. In a sample of 11,578 children, several two-way associations were found, but not those most strongly predicted by the theory. For example, non-right handedness was not associated with NDs considered to be secondary to left hemisphere dysfunction (e.g., articulation disorder, reading disability, verbal aptitude deficits). Instead, non-right handedness was associated with NDs that involve generalized brain damage (e.g. cerebral palsy, mental retardation, and seizures). One immune disorder (asthma) was associated with one ND (attention deficit disorder); immune disorder was not associated with non-right handedness. Less than 1% of this sample manifested the co-occurrence of any three or four of these markers. In sum, there was little evidence in support of the syndrome suggested by Geschwind and Galaburda (1985a, 1985b, 1985c).

Specificity of preventative pediatric intervention effects in early infancy

The efficacy of two contrasting short term preventative interventions administered to a heterogeneous sample of new mothers during the perinatal period was evaluated. The first was infant-centered and used the Brazelton Neonatal Behavioral Assessment Scale (NBAS) as a method of highlighting newborn behavior to new mothers. The second was mother-centered and consisted of an in-depth interview focused on the mothers' concerns about parenting. Mothers were randomized into groups and were administered intervention by experienced clinicians at 3 days in the hospital and again at 14 and 30 days at home. Effects of intervention on maternal reports of parenting stress, mother-infant interactive behavior, and infant developmental quotient were evaluated at 4 months infant age. It was hypothesized that participation in the infant-centered intervention would be related to more positive maternal and infant outcomes at 4 months. It was also expected that the impact of each intervention would be moderated by differences in maternal and infant risk and parity. Hierarchical multiple regressions controlling for risk and parity yielded no significant main effects of intervention at 4 months. However, significant interactions of intervention with parity and risk were observed, indicating that intervention was beneficial for specific groups of mothers. These data suggest that early intervention should be tailored to the needs of individual groups of mothers.

The sex ratios of families with a neurodevelopmentally disordered child

It has been conjectured that mothers who give birth to neurodevelopmentally disordered (ND) children may have hormonal or immunological characteristics that bias them toward giving birth to male children. We examined this hypothesis in an epidemiological sample of 2,080 ND children drawn for the National Collaborative Perinatal Project (NCPP) who had one of nine kinds of NDs. No assumptions were made regarding the sex ratio of non-ND children since this could be computed from NCPP data for 11,213 families. The sex ratio of families with ND children was not significantly biased toward boys as compared to the sex ratio of families with non-ND children, provided that the index ND child was excluded from the analysis.

A test of the immunoreactive theory for the origin of neurodevelopmental disorders in the offspring of women with immune disorder

Gualtieri and Hicks (1985) proposed that male vulnerability for neurodevelopmental disorders (NDs) was partially due to intrauterine immune attack of the fetus. One group of mothers with heightened immunoreactivity might be women with immune disorder. This was tested within an epidemiological sample of 17,283 mother/child pairs. Maternal immune disorders considered were ulcerative colitis or asthma. NDs in the child included: cerebral palsy, mental retardation, seizures, articulation disorder, reading, or arithmetic disability, verbal or performance aptitude deficits, and attention deficit disorder. Unlike prior studies, we controlled for demographic perinatal variables that might confound interpretation of the data. Results indicated that immune dysfunction in the mother, be it autoimmune (ulcerative colitis) or defensive (asthma) was not associated with an increased incidence of any NDs in the offspring, but mothers with ulcerative colitis did have a disproportionate number of offspring who were non-right handed. Few variables discriminated between the children of ulcerative colitis mothers who became right handed when compared to those who did not. We suggest that a) only certain maternal autoimmune disorders such as systemic lupus erythematosus (but not ulcerative colitis or asthma) elevate the risk of intrauterine immune attack and b) the elevated rate of non-right handed offspring among ulcerative colitis mothers was not an instance of immune attack but instead represents some kind of genetic association.

Special talents in Geschwind's and Galaburda's theory of cerebral lateralization: an examination in a female population

Geschwind and Galaburda (1985) proposed that delayed growth of posterior left hemisphere sites in male dyslexics are associated with markers of anomalous dominance (AD) and special cognitive talents. We found that talent in a female population was related to the strength of nonright-handedness, and was elevated in right-handed individuals with histories of familial left-handedness. Subjects reporting a history of dyslexia tended to be musically talented. While immune disorders were not related to talent for the whole population, they did co-occur with talents in a group of 10 individuals reporting 7 or more AD markers.

Fall conception increases the risk of neurodevelopmental disorder in offspring

Hormonal imbalances in utero may render males more vulnerable to neurodevelopmental disorder (ND) than females. Since hormonal activity can be influenced by photoperiod, the relationship between season of conception and incidence of ND in offspring was examined within 11,578 mother/child pairs. Fall conception significantly elevated the odds for mental retardation, reading, arithmetic disability, or performance aptitude deficits (but not seizures, articulation disorder, cerebral palsy, or verbal aptitude deficits), and decreased the odds for reading talent (even when socioeconomic class, prenatal visits, infections, fever, vomiting, edema, anemia, and weight loss were covaried). Since the seasonality effect was not stronger in males, and was not specific to those NDs caused by left hemisphere dysfunction, the predictions of Geschwind and Galaburda (1985a, 1985b, 1985c) were not confirmed.

Are individual differences in fantasy play related to peer acceptance levels?

Individual differences in fantasy play, as they relate to cognitive competence and peer acceptance, were examined in a sample of 66 children between the ages of 4 and 8 years. Each child's free-play behaviors were videotaped and then coded for frequency of fantasy play and nonfantasy play, as well as for the unreality level and unfamiliarity level of the fantasy play. Solitary play was rarely observed; therefore all play measures that were coded were social (i.e., play involving at least one partner). Cognitive competence measures included self-ratings and teacher ratings of academic skills. Peer acceptance measures included self-ratings and teacher ratings of friendships and social activities. Results showed that high-fantasy players had higher self-ratings of peer acceptance than did average-fantasy players. High-fantasy players, however, had lower teacher ratings of peer acceptance than did average-fantasy players. These differential relations could be related to an inability on the part of high-fantasy players to distinguish imagined popularity from actual peer acceptance levels. Future research is recommended to provide more detailed characterizations of individual differences in fantasy play and how they relate to outcomes in the social, cognitive, and affective domains.