The problem of this study was to describe and analyze the computer programming abilities and thought processes of five-year-old children using a conventional microcomputer and the Apple LOGO language. This dissertation reports on the behavior of five kindergarten children and the counts they made as they learned to program in LOGO on an Apple XI Plus microcomputer. The five participants were randomly selected from a group of ten five-year-olds who passed a screening test of numeral and capital letter recognition. The sample included three girls and two boys, all of whom were white. The students met individually with the researcher and the computer for about twenty minutes every day during a ten-week period.

The following thesis examines factors that affect children’s imitation, and presents evidence that imitation is a composite ability which involves multiple mechanisms developing throughout childhood. In Chapter 1 previous findings are reviewed to highlight the mechanisms underlying the ability to reproduce other people’s actions. The evidence suggests that imitation, whilst based on basic action control mechanisms in infancy, is also affected by higher-order cognitive processes in later childhood. Previous literature is still unclear on how the influence of such processes changes at different ages. Chapter 2 used a successive-models task with children aged 2 to 12 years to reveal how children’s imitation changes with age. Results showed that whilst children under the age of 5 years did not imitate deviant models as much as the first model, children above the age of 6 years begin to copy multiple models faithfully, particularly after the age of 10 years. Chapter 3 investigated the role of multiple factors that may have made children under the age of 5 years imitate deviant models less than the original model. In particular, it was found that model evaluations, object associations, and motor inhibitory skills all affect children’s imitation of multiple models. These findings support the interpretation that imitation requires different abilities depending on the type of action that is being imitated. Chapter 4 shows that children’s imitation also depends on the type of goal that they associate with the action. By pre-school age children will imitate actions faithfully if they believe that the goal of the action was the movement itself. The results of the thesis support the idea that imitation, while involving general processes of action control, is also affected in a top-down manner by higher-order cognitive abilities after infancy.

M.Ed. (Educational Psychology) / Diversity is an important component of the South African society. Traditional standardised methods of assessment have been discouraged or abandoned. as they have been found to be discriminatory. Arguing for a systematic assessment process, Siegel (1999:307) states that the standardised methods are the best way to achieve understanding as to the reasons for the breakdown in Iearning and ensure effective intervention. The objective of this study was therefore to establish whether the Cognitive Assessment System (CAS), a cognitive assessment tool, correlates and is a predictor of achievement in the South African context. In order to examine the validity of this claim. I selected 32 black, Grade 6 learners, from a school In 8 Northern Johannesburg suburb, to determine whether the scores obtained on the CAS, correlate and predict achievement in the areas of reading and scholastic work. The quantitative research Involved identifying correlations between three data areas, the CAS. Woodcock Diagnostic Reading Battery (WDRB). and the scholastic marks obtained from school subjects for December 2000 and June 2001. As a result of this research and data analysis. high correlations were obtained between the three data areas. In addition the achieved scores of the WDRB were found to correlate with predicted scores taken from the learner's CAS Full Scale score. It was therefore concluded, that the Full Scale score of the CAS is predictive of achievement as measured by the six sub-tests taken from the WDRB. The findings of this study thus indicate that the CAS cognitive assessment tool could. within certain limitations, be used in the South African context to improve diagnostic interpretations and subsequent interventions. The challenge remains for additional research to be undertaken to explore the diagnostic value of the CAS in the wider community.

Reading disability, as the most commonly diagnosed learning disability, continues to pose a tenacious problem to teachers, practitioners and researchers. In an effort to understand the causes of reading disability, voluminous research has been undertaken over the past decades to pinpoint its causes or developmental stumbling blocks. One approach, the Planning, Attention, Simultaneous, and Successive processing (PASS) model, combines neuropsychological theory with elements from cognitive psychology. Based on this model, the Cognitive Assessment System (CAS), as well as methods of intervention for reading disability were developed. Although many studies have been conducted that investigated reading disability in terms of PASS cognitive processes, the final version of the CAS and its predictive utility with respect to reading disability has not been explored to date. The present study aimed to investigate the utility of the CAS, administered at the beginning of grade 1, to predict reading proficiency at the end of grade 1. The sample was comprised of 119 “average” (i.e., belonging to the general population) grade 1 students from schools of the Calgary Board of Education (CBE). The Basic Battery of the CAS was administered to the children in the sample at the beginning of grade 1, as well as four reading subtests of the Woodcock-Johnson Tests of Achievement – Third Edition (WJ-III ACH) at the end of grade 1. The WJ-III ACH yielded a cluster score for basic reading and one for reading comprehension. Correlational and regression analyses were used to address the first aim of this study, namely to explore the relationship between students’ scores on the CAS and their later reading proficiency. To this end, the children’s CAS Full Scale scores and WJ-III ACH cluster scores were subjected to a hierarchical regression analysis, whereby age, gender, and - xviii - SES were kept constant by entering them first in the equation. Next, the relationship between students’ PASS scale scores and the CAS subtest scores respectively and scores on the WJ-III ACH Basic Reading and Reading Comprehension Cluster scores was explored by means of stepwise regression analysis. To improve on the generalizability of results, the regression analyses were conducted on a randomly drawn analysis sample consisting of 80% of the sample, and cross-validated on the remaining 20% of the sample. The second aim of the present study was to ascertain whether clusters could be identified on the basis of CAS performance as well as levels of reading proficiency. To this end, the children’s CAS FS scores, PASS scale scores, and CAS subtest scores were subjected to cluster analyses. The investigation of aim 1 yielded some encouraging results, in that it was found that, together with the covariates: • The CAS FS emerged as a moderately strong predictor of both basic reading and reading comprehension; • Successive processing, in particular the Word Series subtest, significantly predicted basic reading skills; • Successive and simultaneous processing, particularly the Nonverbal Matrices and Sentence Repetition subtests, were significant predictors of reading comprehension; The second aim, which explored the relationship between patterns of CAS cognitive processes and their relationship with reading proficiency, yielded: • Two clusters with distinctly different PASS scale scores and with significant differences between their levels of reading proficiency. Higher PASS scales scores, particularly on the Attention and Planning scales, were associated with higher reading proficiency scores. • Four clusters with distinctly different CAS subtest scores that were also associated with distinctly different levels of reading performance. Good - xix - reading proficiency was associated with good CAS performance, whereas weaker reading proficiency was linked to weaker CAS performance. Biographical variables, such as age and SES were found to be related to performance on the CAS and reading proficiency, while gender did not emerge as an important predictor variable. The present study demonstrated the usefulness of the CAS, particularly its Successive and Simultaneous scales, as potential early predictor of reading disability. An exploration of the relationship between patterns of CAS cognitive processes and later reading proficiency also yielded encouraging and interesting results.

This dissertation explores the nature and ontogeny of infants' ability to match phonetic information in comparison to non-speech information in the face and voice. Previous research shows that infants' ability to match phonetic information in face and voice is robust at 4.5 months of age (e.g., Kuhl & Meltzoff, 1982; 1984; 1988; Patterson & Werker, 1999). These findings support claims that young infants can perceive structural correspondences between audio and visual aspects of phonetic input and that speech is represented amodally. It remains unclear, however, specifically what factors allow speech to be perceived amodally and whether the intermodal perception of other aspects of face and voice is like that of speech. Gender is another biologically significant cue that is available in both the face and voice. In this dissertation, nine experiments examine infants' ability to match phonetic and gender information with dynamic faces and voices. Infants were seated in front of two side-by-side video monitors which displayed filmed images of a female or male face, each articulating a vowel sound ( / a / or / i / ) in synchrony. The sound was played through a central speaker and corresponded with one of the displays but was synchronous with both. In Experiment 1,4.5-month-old infants did not look preferentially at the face that matched the gender of the heard voice when presented with the same stimuli that produced a robust phonetic matching effect. In Experiments 2 through 4, vowel and gender information were placed in conflict to determine the relative contribution of each in infants' ability to match bimodal information in the face and voice. The age at which infants do match gender information with my stimuli was determined in Experiments 5 and 6. In order to explore whether matching phonetic information in face and voice is based on featural or configural information, two experiments examined infants' ability to match phonetic information using inverted faces (Experiment 7) and upright faces with inverted mouths (Experiment 8). Finally, Experiment 9 extended the phonetic matching effect to 2-month-old infants. The experiments in this dissertation provide evidence that, at 4.5 months of age, infants are more likely to attend to phonetic information in the face and voice than to gender information. Phonetic information may have a special salience and/or unity that is not apparent in similar but non-phonetic events. The findings are discussed in relation to key theories of perceptual development. / Arts, Faculty of / Psychology, Department of / Graduate

The child's understanding of open systems, as exemplified by an ecosystem and a socio-economic system, was assessed in a Piagetian type interview with 8 males and 8 females in each of grades 3, 5, 7, 9, 11 and first year post-secondary (n=96). Since Piagetian theory has been based on tasks using mainly inanimate, physical content, the generalizability of Piagetian stages and sequences to the two open systems content domains was tested. Tasks assessing the four concrete operations examined were repeated in each of the physical, the bio-ecological and the societal domains. Typical stage and sequence patterns were observed in all three domains. Post-concrete operations were represented by three formal operations in the physical domain and four systemic operations in each of the open systems domains. Logical and philosophical arguments for the qualitative difference between formal and systemic logic were presented. Three blind judges reached spontaneous agreement on 84.6% of the scores assigned for the systemic task protocols. A scalogram analysis and comparisons of the differences between pass/fail proportions indicated that the systemic operations of systems synthesis and transitive recycling were more difficult than the formal operational tasks by a Guttman step of the same size as that between the formal and concrete stages. A cluster analysis showed those most difficult systemic tasks to be grouped as if they were a part of a separate structure d'ensemble. Further analyses indicated that the greater difficulty of these two systemic operations could not be attributed to the greater un-familiarity of the task contents. Systemic task success rates were zero for respondents below grade 9 (14 years) and consistently fell far below formal task success rates for same aged peers'. The most difficult systemic operations satisfied the criteria for membership in a fifth stage as well as any other Piagetian operations do for their imputed stage membership. Nevertheless, an alternative interpretation construing systemic operations as post-concrete developments parallel and complementary to formal operations could not be ruled out. The implications of the findings for the areas of cognitive development, social development and social psychology were discussed. / Arts, Faculty of / Psychology, Department of / Graduate

No description available.

IntroductionEndocrine disrupting chemicals (EDCs) are agents, found either singly or used in mixtures, that disrupt the endocrine system or its production of hormones and may cause adverse effects in the exposed individuals or populations and, in the case of pregnant women, their offspring. It is presumed that maternal thyroid hormones contribute to fetal brain development. The EDCs that could impair maternal thyroid hormone function might result in subtle deficits in neurodevelopmental outcomes in children. Polychlorinated biphenyls (PCBs) are a class of EDCs produced in the past century and are still found in the environment. This dissertation aims to explore, elaborate, and embellish the associations between prenatal exposure to PCBs, the metabolites associated with PCBs, and child cognitive and motor development. The next aim of this dissertation is to explore the associations between prenatal exposure to PCBs, the metabolites associated with PCBs, and maternal thyroid hormones. Five chapters are included in this dissertation: First, an introduction to PCBs and specific aims; second, a systematic review of the literature, including the studies where prenatal exposure to PCBs or the hydroxylated PCB metabolites (OH-PCBs) and their relationship with various domains of children's neurodevelopment were investigated; third, an empirical study of exploring the associations between prenatal exposure to a mixture of PCB, OH-PCBs and children cognitive and motor skills measured in different ages; fourth, an empirical study of investigating the associations between prenatal exposure to a mixture of PCB, OH-PCBs and maternal thyroid hormones with potential for investigating the mediation of possible associations observed in the third chapter by maternal thyroid hormone concentrations; fifth, a discussion of the findings, implications for public health research, and practice and conclusions. Materials and Methods The systematic review included peer-reviewed studies indexed in several repositories (N=71 studies) from the inception of the repositories. This systematic review of the studies measured the PCBs directly in prenatal or immediately after delivery in maternal serum, cord blood, placenta, or breast milk. The empirical studies used the data available on mothers and children from "Child Health and Development Studies." Eleven PCB congeners and five OH-PCB metabolites were measured in the maternal serum post-partum among a random subset of the participants. I used a mixture analysis, Bayesian Kernel Machine Regression (BKMR), and generalized linear models (GLM) to assess the association between concentrations of PCB congeners and OH-PCB metabolites measured three days post-partum and children's cognitive and motor skills scores at age five, and cognitive skills measured at a follow-up at ages 9-11. BKMR and GLM were also used to explore the associations between PCB congeners and OH-PCB metabolites and maternal free thyroxine (FT4) and thyroid-stimulating hormone (TSH). Results The systematic review found that prenatal exposure to PCBs was possibly associated with poor cognitive development and poor attention in early and middle childhood. The evidence regarding motor development, behavior, and other neurodevelopmental outcomes were not conclusive at any stage in childhood. There was an indication for sex-specific associations with worse cognition and attention scores among boys. There was also evidence in individual studies regarding the possible association between prenatal exposure to OH-PCBs and neurodevelopmental outcomes. There were significant differences between the studies in markers of exposure, exposure assessment timing, outcome assessment, and the methodological approaches to assess the association. In the second empirical study, I found that in the crude and adjusted BKMR models among the OH-PCB metabolites, cognitive skills test scores at age five increased with each decile increase in the mixture of OH-PCB metabolites compared to when all of the metabolites were fixed at their 50th percentile among all the children and the boys and girls. These associations were largely driven by OH-PCB153 and OH-PCB146, metabolites associated with the congener PCB153. In the third empirical study, among OH-PCB metabolites attributed to PCB congeners, I observed suggestive evidence for a positive association with maternal FT4, particularly in the highest percentile of exposure to overall OH-PCB metabolites. I did not observe an association between exposure to the mixture of PCB congeners and Maternal FT4 or TSH. Nonetheless, the overall patterns suggested a positive association between exposure to PCB congeners and maternal FT4.No associations of the overall mixture of PCBs and OH-PCB metabolites were observed with maternal TSH concentrations in the BKMR models. Nonetheless, in single metabolite risk estimates, I found that 3’-OH-PCB138 was positively associated with maternal TSH values when the 3’-OH-PCB138 was fixed at its 90th percentile compared to when it was in its 10th percentile, fixing all the other congeners in their 10th, 50th, and 90th percentiles. Finally, there was an indication of a possible antagonistic interaction between 4-OH-PCB107 and 3’-OH-PCB-138 in the association of OH-PCBs with maternal FT4 such that 3’-OH-PCB138 tended to have a positive association with maternal FT4 when 4-OH-PCB107 was fixed in the 90th percentile and tended to have a negative association with maternal FT4 when 4-OH-PCB107 was fixed in their 10th percentile when all the other metabolites were fixed in their median value. Conclusions There were patterns of positive associations of OH-PCB metabolites with the children’s cognitive outcomes and maternal FT4 and maternal TSH. Nonetheless, the observed associations were weak in magnitude, often including the null value. The BKMR allowed me to explore and investigate the interactions between different components of the mixture and the overall mixture effect on the outcomes. My dissertation indicated the necessity of a holistic approach to address the impact of exposure to environmental toxins, specifically due to the detected findings regarding interactions between OH-PCB metabolites.

This study examined the use of cognitive skills by 5-year-old Alaskan Native children on a standardized testing instrument. The Wechsler Preschool and Primary Scales of Intelligence (WPPSI) were administered to 23 boys and 17 girls of predominantly Tlingit, Tsimshean, and Haida ancestry. A standardized parent interview was used to collect bio-demographic data. Mean scores for the sample displayed significant differences between the Performance and Verbal scales, with the strongest performance in the Spatial subtests, and lowest in the Sequential subtests. Scores were significantly associated with variables representing culture-specific self identity and behavior, but were most strongly associated with family size. Factor Analysis suggested a distinct three factor structure consisting of (1) a Performance-Spatial, (2) a Verbal-Semantic, and (3) a Sequential factor. Variability in the use of cognitive skills, non-verbal behavior, and selective attention are viewed as unique cultural adaptations which can impede interethnic communication, creating negative outcomes in the education of American Indian and Alaskan Native children.

No description available.