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B F Pennington

Publications and source records attributed to B F Pennington.

72 records · Page 4Linked to original sources
PubMed1987

Unexpected reading precocity in a normal preschooler: implications for hyperlexia.

This is a case study of a left-handed, preschool boy of superior intelligence who read very early and at a level well beyond what his IQ would predict. He is developmentally normal with no signs of autism or related disorders. His reading age was 9.3 at age 2-11 and 11.2 at 4-2; these levels are considerably beyond what would be predicted by his IQ or language age. He was able to read nonwords and both regular and irregular words equally well, indicating his mechanisms of lexical access in reading are similar to those of normal readers. Unlike classical hyperlexics, his reading comprehension for both single words and sentences was well above age level. When his precocious reading first appeared, he was also advanced in reading-related linguistic skills, such as phoneme awareness, auditory verbal short-term memory, and word retrieval, but not in visuospatial skills. These results imply that neither pathological language and/or social development, nor pathological variation in the normal mechanisms of lexical access in reading are necessary causes for reading precocity in early childhood. A model for integrating subtypes of precocious readers with subtypes of normal and dyslexic readers is proposed.

Child, Gifted↗
PubMed1987

Word recognition and comprehension skills in hyperlexic children.

Five hyperlexic boys (4-5 to 10-1 years), who had been diagnosed with infantile autism or pervasive developmental delay in early childhood, were evaluated. Measures of intelligence, single-word recognition and comprehension, and picture naming were administered to determine the precocity or deficiency of reading recognition and comprehension, the underlying mechanisms of oral reading, and possible parallels with the acquired dyslexia subtypes. The results indicated that hyperlexia may be operationalized as unexpected reading precocity as compared to IQ; however, reading comprehension was not unexpectedly deficient. The phonological route to reading appeared to be preferred to the lexical route, and the overall pattern of performance most closely paralleled that of the surface dyslexic subtype.

Autistic Disorder↗
PubMed1986

Spelling errors in adults with a form of familial dyslexia.

We compared the spelling errors on the WRAT II made by adults (N = 24) with an apparent autosomal dominant form of dyslexia to those made by their normal adult relatives (N = 17) and by spelling-age matched normal controls (N = 17) using a computerized error evaluation program (SEEP). The normal adult relatives were significantly better than the dyslexics in both reading and spelling, but did not differ in age, education, or IQ. SEEP evaluated each error independently for both phonological and orthographic accuracy at 2 levels of complexity. Each level of complexity was analyzed separately using a 3 X 2 (group X dimension) analysis of variance. The main finding of interest was a significant group X dimension interaction effect at the complex level, which indicated that the dyslexics had a qualitatively different profile across the 2 dimensions than either normal group who had parallel profiles. The dyslexics performed like the younger normal group on the complex phonological dimension but like the adult normal group on the complex orthographic dimension. These results indicate a dissociation in this form of familial dyslexia between these 2 dimensions of spelling development, and suggest that these dyslexics may fit the subtype of dysphonetic or phonological dyslexia. The implications of these results for the underlying cognitive deficit in this form of dyslexia are discussed.

Adult↗
PubMed1985

The neuropsychological phenotype in Turner syndrome.

Numerous studies have demonstrated a significant depression in performance IQ (PIQ) in Turner Syndrome (TS) females, but the neuropsychological interpretation of this finding remains unclear. The present study addressed the following questions regarding the neuropsychological phenotype in TS: Are TS women neuropsychologically impaired? Is the impairment lateralized and How consistent is the neuropsychological phenotype across TS individuals? Unlike previous studies, the present study utilized both normal and brain damaged female controls. All subjects were given an extended Halstead-Reitan neuropsychological battery. The TS females were significantly worse than normals but not significantly different from brain damaged females in their overall level of neuropsychological functioning. However, their impairment was not lateralized. Their pattern of lateralizing findings was similar to that found in the Diffuse and Normal groups, but significantly different from either the right or left unilateral lesion groups. Fairly consistent deficits were found on tests of visuospatial skills and long term memory, but there was considerable variability in all the other test findings among TS individuals. The results are discussed in relation to the recent findings (Inglis and Lawson, 1981) that verbal-performance IQ discrepancies may be unreliable indicators of lateralized cerebral dysfunction in females. Hence the depressed PIQ in TS appears not to indicate predominantly right hemisphere dysfunction and may not even indicate a consistent underlying neuropsychological phenotype.

Dominance, Cerebral↗
PubMed1985

Neuropsychological deficits in early treated phenylketonuric children.

In this preliminary study, six early treated children with phenylketonuria (PKU) were compared on the Halstead Neuropsychological Battery for Older Children with three groups of children with documented neurological disorders involving predominantly the left, the right, or bilateral dysfunction. The children with PKU had an overall level of neuropsychological impairment similar to that of the brain-damaged groups. The PKU group did not show a consistent pattern of lateralization, but there was some specificity to their deficits. The analyses showed that they were most similar to the right-hemisphere group. The children with PKU tended to show deficits consistently in two neuropsychological domains, conceptual and visuospatial skills, which would help explain their reported difficulty with mathematics. Further work is needed to test these results in a larger sample and to examine possible relationships with dietary compliance.

Achievement↗
PubMed1983

Genetic influences on learning disabilities and speech and language disorders.

This paper is a comprehensive review of known examples of genetically influenced learning disabilities (LDs) and speech and language disorders (SLDs). The review is divided between 2 broad classes of studies: (a) those which begin with an LD or SLD phenotype that appears to be familial and attempt to learn more about the specifics of genetic transmission, if any; and (b) those which begin with a group of individuals, all of whom share a given documented genetic risk factor, to see if it leads to a specific LD or SLD. Included in the first category are familial dyslexia, stuttering, and other speech and language disorders. In the second category are included sex chromosome anomalies, treated PKU, and minor autosomal anomalies. Issues of definition, variability, and developmental changes in the cognitive phenotype are discussed throughout. The implications of this work for our understanding of cognitive development and its bases in brain development and genetics are also discussed.

Adolescent↗
PubMed1982

Learning disabilities in children with sex chromosome anomalies.

Studies of clinical populations have suggested that genetic factors may be involved in the etiology of learning disabilities. The present study included 44 children (ages 7-16) with sex chromosome anomalies (SCA) who were identified in a 10-year sex chromosome screening of all newborns in 2 large hospitals and thus represents an unbiased sample of children with a genetic etiology. 17 chromosomally normal siblings are included as controls. All subjects were given IQ and achievement tests, and extensive, repeated school histories were taken from parents and school personnel. Results demonstrate that SCA children are at an increased risk for encountering learning problems and receiving special education intervention in school. Furthermore, the nature of the learning disabilities may be karyotype specific, although the results are not invariant within karytypes. 45,X children demonstrate a visuo-spatial deficit as evidenced by lower-performance IQ scores and an increased incidence of handwriting problems, while 47,XXY children experience a verbal language deficit seen in lower verbal IQs and a tendency toward more reading delays. 47,XXX children demonstrate a more global delay crossing most cognitive skill areas, although retardation is rare. Mosaic children are relatively unaffected by their karyotypic variations and hence serve as a second control group which guards against the effects of a negative self-fulfilling prophecy. It is concluded from this evidence that learning disabilities can have a genetic basis, although the specific biological mechanism that affects cognitive development in this population remains elusive.

Child↗
PubMed1976

Children's perceptions of deviance and disorder.

First-, fourth-, seventh-, and eleventh-grade boys and girls were interviewed on the topic of deviant behavior among their peers. They were also asked to make deviance judgments on 2 story characters whose behaviors exemplified qualities that typically evoke an attribution of psychological disorder on the part of adult judges. 1 story described loss of control and aggression, the other a distorted and paranoid perception of social reality. The pattern of reaction to the stories was consistent with age-related shifts in the basic for deviant status. First graders largely failed to think in terms of group norms. The transition from the middle grades to adolescence was marked by greater emphasis on social consensus--both in psychological perspective and group behavior.

Adolescent↗
PubMedDate not supplied

Problem solving limitations among cytogenetically expressing fragile X women.

Neurocognitive deficits among fragile X individuals have been reported for both high and low functioning individuals. Recent findings from our research suggest a specific neurocognitive phenotype among fragile X women that is characterized by deficits on tests of frontal lobe functioning. In this paper, we examine in more detail the performance of 10 cytogenetically expressing women and 10 control women on 2 problem solving measures considered sensitive to frontal lobe functions: the Contingency Naming Test and the Tower of Hanoi. The results pertaining to each test suggest that fragile X women, relative to control women, are less able to solve a problem when the difficulty of the problem is increased by requiring simultaneous consideration of additional information. These findings have important implications for remediation strategies designed for affected fragile X individuals.

Adolescent↗
PubMedDate not supplied

Fragile X syndrome in a normal IQ male with learning and emotional problems.

The present case study features an adult male who was diagnosed with fragile X syndrome after the identification of this syndrome in his more affected brother. The patient presented with a Full Scale IQ within the broad range of normal and has been diagnosed with a schizotypal personality disorder. He shows significant deficits in the social and emotional aspects of daily life, but has striking cognitive strengths relating to reading and vocabulary as compared to most males affected with fragile X syndrome. DNA testing of blood leukocytes revealed that he has a fully expanded FMR1 CGG repeat mutation associated with almost complete lack of methylation. Protein studies demonstrate a limited production of FMRP, the protein produced by the FMR1 gene. It is believed that the near absence of methylation of the fully expanded mutation and the resultant expression of the FMR1 protein is responsible for the strong cognitive abilities of this fragile X patient.

Adult↗
PubMedDate not supplied

Executive functions in young children with autism.

The executive dysfunction hypothesis of autism has received support from most studies of older people with autism; however, studies of young children have produced mixed results. Two studies are presented that compare the performance of preschoolers with autism (mean = 51 months/4.3 years of age) to a control group matched on age, and verbal and nonverbal ability. The first study (n = 18 autism and 17 control) found no group differences in performance on 8 executive function tasks (A not B, Object Retrieval, A not B with Invisible Displacement, 3-Boxes Stationary and Scrambled, 6-Boxes Stationary and Scrambled, and Spatial Reversal), but did find that children with autism initiated fewer joint attention and social interaction behaviors. The second (longitudinal) study of a subset of the children (n = 13 autism and 11 control) from the first study found that neither groups' performance on Spatial Reversal changed significantly over the course of a year. The results of these studies pose a serious challenge to the executive dysfunction hypothesis of autism.

Attention↗
PubMedDate not supplied

Early reading development in children at family risk for dyslexia.

In a 3-year longitudinal study, middle- to upper-middle-class preschool children at high family risk (HR group, N = 67) and low family risk (LR group, N = 57) for dyslexia (or reading disability, RD), were evaluated yearly from before kindergarten to the end of second grade. Both phonological processing and literacy skills were tested at each of four time points. Consistent with the well-known familiarity of RD, 34% of the HR group compared with 6% of the LR group became RD. Participants who became RD showed deficits in both implicit and explicit phonological processing skills at all four time points, clearly indicating a broader phonological deficit than is often found at older ages. The predictors of literacy skill did not vary by risk group. Both risk groups underwent a similar developmental shift from letter-name knowledge to phoneme awareness as the main predictor of later literacy skill. This shift, however, occurred 2 years later in the HR group. Familial risk was continuous rather than discrete because HR children who did not become RD performed worse than LR non-RD children on some phonological and literacy measures. Finally, later RD could be predicted with moderate accuracy at age 5 years, with the strongest predictor being letter-name knowledge.

Achievement↗
PubMedDate not supplied

Comorbidity of reading disability and attention-deficit/hyperactivity disorder: differences by gender and subtype.

This study used a community sample of 494 twins with a reading disability (223 girls, 271 boys) and 373 twins without a reading disability (189 girls, 184 boys) to assess the relation between reading disability (RD) and attention-deficit/hyperactivity disorder (ADHD). Symptoms of DSM-III and DSM-IV ADHD were classified into symptoms of inattention and symptoms of hyperactivity-impulsivity (H/I). Results indicated that individuals with RD were more likely than individuals without RD to meet criteria for ADHD and that the association between RD and ADHD was stronger for symptoms of inattention than for symptoms of H/I. Parents and teachers reported similar rates of ADHD, suggesting that ADHD symptoms were pervasive across settings and were not solely attributable to academic frustration. Analyses of possible gender differences revealed that RD was significantly associated with inattention in both girls and boys but associated with H/I only in boys. This difference may provide a partial explanation for the discrepancy between the gender ratio obtained in referred (approximately 4 boys to 1 girl) and nonreferred (1.2 to 1.5 boys to 1 girl) samples of individuals with RD. Specifically, the hyperactive and impulsive behaviors exhibited by boys with RD may be more disruptive than the inattentive behaviors exhibited by girls and may therefore precipitate more frequent referrals for clinical attention.

Adolescent↗
PubMedDate not supplied

Differential genetic etiology of reading disability as a function of IQ.

To test the hypothesis that the genetic etiology of reading disability differs as a function of IQ, composite reading performance data from 223 pairs of identical twins and 169 pairs of same-gender fraternal twins in which at least one member of each pair was classified with reading disability were subjected to multiple regression analysis (DeFries & Fulker, 1985, 1988). In the total sample, heritability of the group deficit in reading performance (h(g)2) was .58 (+/- .08). However, when the basic regression model was fitted separately to data from twin pairs with average Wechsler (1974, 1981) full scale IQ scores below 100 or 100 and above, resulting estimates of h(g)2 were .43 and .72, respectively, a significant difference (p < or = .03, one-tailed). The results of fitting extended regression models to reading performance and continuous IQ data provide evidence that the genetic etiology of reading disability differs as a linear function of IQ (p < or = .007, one-tailed). These results suggest that IQ is relevant for the diagnosis of reading disability and that environmental influences may be more salient as a cause of reading difficulties in children with lower IQ scores.

Adolescent↗
PubMedDate not supplied

Reliability and validity of the adult reading history questionnaire.

The reliability and validity of a revised version of Finucci's (1982) Reading History Questionnaire was examined in two adult samples. One sample included 84 adults from an ongoing study of familial dyslexia, and a second sample was composed of parents of 107 children from a longitudinal study of reading development. Internal consistency was demonstrated by Cronbach's alphas of .94 and .92 in the two samples. Test-retest reliability was demonstrated by significant correlations (.87 and .84 in the two samples) over several years between an earlier and revised form of the questionnaire. Validity was demonstrated via (a) correlations between the questionnaire score and reading measures (rs = .57-.70), (b) the results of a discriminant function analysis that used questionnaire scores to predict reading disability diagnosis, and (c) the finding that the questionnaire had substantial incremental validity in predicting reading skill in a hierarchical regression analysis that first entered IQ and SES. These results indicated that the questionnaire is both reliable and valid.

Adult↗
PubMedDate not supplied

A twin study of mathematics disability.

Although results obtained from recent twin and adoption studies suggest that individual differences in mathematics performance are due in part to heritable influences, no genetic analysis of mathematics disability (MD) has been previously reported. In this article we present data from the first twin sample ascertained for mathematics deficits (40 identical and 23 same-sex fraternal twin pairs in which at least one member had MD). When mathematics performance data from these twin pairs were subjected to a multiple regression analysis, evidence for a significant genetic etiology was obtained. However, tests for the differential etiology of MD as a function of reading performance level were nonsignificant. Results of this first twin study of MD indicate that the condition is significantly heritable, but data from additional twin pairs will be required to test hypotheses of differential etiology more rigorously.

Achievement↗