Children's interaction with peers supports cognitive development in numerous ways. The claim investigated in the present study is that these benefits include support at a metacognitive level that children provide one another, specifically in the form of meta-level speech aimed at regulating the other's behavior. This proposition originates in Vygotsky's views of a bi-directional zone of proximal development between peers with resulting transfer from inter-mental to intra-mental planes. Sixty-four 7th graders participated in the study. Students who shared a position on a social issue engaged in electronic dialogs with a succession of pairs who held an opposing position. In one condition (Stay), students worked with the identical same-side partner over six twice-weekly dialog sessions. In the other condition (Switch), students worked with a new same-side partner at each session. Students experienced both conditions, half of them first the Stay condition and then, discussing a new topic, the Switch condition. Condition order was reversed for the other half of participants. Students engaged in more frequent meta-talk in the Stay than the Switch condition; Stay conversations contained more frequent regulatory utterances than Switch conversations and a greater proportion of planning statements. Electronic dialogs produced in the Stay condition contained a higher proportion of meta-talk than those produced in the Switch condition; however, differences favoring the Stay condition in direct counterargument use were found at only one of two data collection points. On the whole, differences suggest that collaborators scaffolded one another’s meta-level development through regulatory conversation that evolved over time as collaborators developed their relationships, and that, for Stay pairs, this evolving shared regulatory talk extended to the electronic discourse. There was no consistent evidence, however, that this success extended to argument strategies on the discourse task.

Introduction: Excessive consumption of high fat, high sugar foods may precipitate cognitive decline. This effect may be more pronounced during cognitive development. The present single-blind randomized controlled trial (RCT) was conducted to examine the effect of a moderate fat, low added sugar (MF/LS) dietary intervention on cognitive function in 8-11 yr old preadolescents with a pre-established high fat, high sugar (HF/HS) dietary pattern. Participants included 17 non-obese (BMI Percentile: 25.4 - 91.3) low to middle income preadolescents randomized to 2 weeks of their usual HF/HS diet (control) or a MF/LS intervention diet. Method: The MF/LS intervention diet was restricted to 25% of calories/day from total fat and <10% of calories from added sugar while the HF/HS control diet was maintained at > 40% of calories/day from total fat and >15.9% of calories from added sugar. All food served was measured to the tenth of a gram. Any uneaten portion of food was weighed to obtain accurate measures of actual intake. NDSR dietary analysis software was used to assess macronutrient, micronutrient and added sugar intakes. Participants were weighed weekly to ensure they remained in energy balance throughout the duration of the study. Pre-post cognitive assessment served as the primary outcome measure. A battery of age appropriate tests from the Penn Computerized Neurocognitive Battery (CNB) as well as the widely used and a previously validated Trail Making task were selected to assess executive function, speed of processing, working memory, attention and spatial ability. Results: Both ANCOVA and a repeated measures approach were used to evaluate the mean difference of post-intervention scores between conditions, controlling for pre-intervention scores and other covariates including age, gender, sleep and mood. For each statistical approach, 10 tests were run, encompassing each of the cognitive assessments given and, for some, their delayed counterpart. Based on the ANCOVA analysis, participants randomized to the MF/LS intervention had a faster median response time (RT) for correct responses on 2 of the 10 tests analyzed, including the initial facial recognition task and its delayed counterpart. Compared to controls, the intervention group displayed 1) a faster total correct RT while controlling for gender (p = 0.02), 2) a faster true negative RT when controlling for gender and age (p = 0.012), and 3) a faster delayed task median total correct RT when controlling for gender and age (p = 0.005). No significant differences between groups were detected for the other assessments. Based on a repeated measures approach, none of the 10 tests analyzed reached statistical significance. Multiple regression analyses revealed a dose response effect on face recognition RT based on % intake of daily calories from total sugar, added sugar, total fat and saturated fat such that a 10% increase in % calories from total sugar, added sugar and saturated fat decreased processing speed for total correct responses on the initial facial recognition task by 0.58 seconds whereas a 10% increase in % total fat decreased processing speed on the same task by 0.44 seconds. The multivariate regression analyses controlled for gender and pretest scores. Conclusions: A 2-week MF/LS dietary intervention may improve delayed face recognition in low to middle income preadolescents with a pre-established HF/HS dietary pattern. Although the intervention appeared to demonstrate a positive effect on 2 measures of cognitive function (initial and delayed facial recognition), after Bonferroni correction, these results only remained significant for the delayed task median total correct RT when controlling for gender and age (p = 0.005). Thus, study results must be interpreted with caution as they may simply be an artifact of chance finding in the ANCOVA statistical analysis. Further investigation of benefits proffered by decreasing % total sugar, % added sugar, % total fat and % saturated fat intake to preadolescent cognition is warranted. Future work should focus on replicating the present study in a larger sample, using hippocampal-dependent specific tasks.

Orientador: Gimol Benzaquen Perosa / Coorientador: Flávia Helena Pereira Padovani / Banca: Lígia Maria Suppo de Souza Rugolo / Banca: Maria Beatriz Martins Linhares / Resumo: Como conseqüência dos avanços recentes na área de Obstetrícia e Perinatologia, houve uma redução significativa nos índices nacionais de mortalidade infantil e altas taxas de sobrevida de crianças nascidas prematuras. No entanto, não se verificou o mesmo impacto na redução das sequelas durante o desenvolvimento e na qualidade de vida da criança, tanto na infância, como na adolescência e idade adulta. Há relatos na literatura que associam prematuridade com sequelas físicas e psicossociais, aumentando-se a chance de problemas comportamentais e cognitivos, especialmente na idade escolar. Entretanto, os resultados não são conclusivos e poucos estudos associam esses déficits com qualidade de vida, geralmente avaliada segundo percepção dos pais. O presente estudo teve por objetivo avaliar a qualidade de vida de crianças nascidas prematuras, em idade pré-escolar e escolar, sua associação com condições de nascimento, variáveis socioeconômicas, desempenho cognitivo e comportamental; e levantar possíveis preditores de risco e proteção. Para tanto, foram utilizados os seguintes instrumentos: AUQEI (Autoquestionnaire Qualité de Vie Enfant Imagé), HUI 3 (Health Utility Index 3), CBCL (Child Behavior Checklist), WISC e WPPSI (Wechsler Intelligence Scale). Dos 57 participantes com idade variando de 5 a 8 anos, 33,3% eram extremo baixo peso e 75,4% prematuras extremas. Na avaliação cognitiva, 56,1% das crianças tiveram desempenho cognitivo de regular a superior, 22,8% foram consideradas limítrofes e 8,8% intelectualmente deficientes. Com relação ao comportamento, 36,8% apresentavam problemas em nível clínico, especialmente hiperatividade e déficit de atenção (21,1%) e ansiedade (19,5%). Houve relação significativa entre escolaridade materna, reinternação no primeiro ano de vida e problemas comportamentais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: As an outcome of the recent advancement in the fields of Obstetrics and Perinatology, a significant reduction in the national rates of child mortality and high survival rates of children born preterm have been observed. However, there has not been a similar impact on reducing sequelae during children's development or on the quality of life of children in both childhood and adolescence or in adulthood. There are reports in the literature that associate prematurity with physical and psychosocial sequelae that increase the chances for behavioral and cognitive problems, particularly at school age. However, results are not conclusive, and few studies associate such deficit with quality of life, generally evaluated according to parents' perception. This study aimed at evaluating the quality of life of children born preterm that are now at preand school age, its association with birth conditions, socioeconomic variables, cognitive and behavioral performance as well as at assessing possible risk and protection predictors. To that end, the following instruments were used: AUQEI (Autoquestionnaire Qualité de Vie Enfant Imagé), HUI 3 (Health Utility Index 3), CBCL (Child Behavior Checklist), WISC and WPPSI (Wechsler Intelligence Scale). Of the 57 participants at ages ranging from 5 to 8 years, 33.3% were extremely low weight, and 75.4% were extremely preterm. In the cognitive assessment, 56.1% of the children showed cognitive performance from fair to superior, 22.8% were considered to be borderline, and 8.8 were intellectually impaired. As regards behavior, 36.8% showed problems at the clinical level, especially hyperactivity and attention deficit (21.1%) and anxiety (19.5%). There was a significant relation between maternal education, re-hospitalization in the first year of life and behavioral problems with cognitive performance. Concerning quality... (Complete abstract click electronic access below) / Mestre

[Truncated abstract] Some children with Specific Language Impairment (SLI) show poor performance on behavioural tasks designed to measure rapid auditory processing, such as the Repetition Test developed by Tallal and colleagues. Stemming from concerns about whether this task reflects higher-order, cognitive variables, this thesis sought to determine whether the performance deficits SLI children show were evident at the neurophysiological level, with minimal cognitive influences, such as attention, using paradigms designed to elicit the mismatch negativity (MMN) and late discriminative negativity (LDN). In the first two studies, a MMN paradigm, equivalent to the Repetition Test, was trialled with a group of 8 adults. In this paired paradigm, the second tone of a pair of pure tones ascending in frequency ('low'-'high') was occasionally replaced with a 'low' tone. The aim was to determine a 'long' and 'short' intra-pair interval (IPI) with which MMN was generated utilizing this paradigm and that were congruent with the Repetition Test findings (i.e., a long IPI at which SLI were able to perform the task, and a short IPI at which SLI children's performance was selectively impaired). In Study One, MMN to a within-pair frequency change was generated with the 30 ms IPI, but not the 700 ms IPI. The grouping parameters of the temporal window of integration (TWI) and temporal distinctiveness were considered less than optimal for the grouping of the pairs presented at 700 ms IPI for the pre-attentive system to register the within-pair frequency change. ... The frequency difference limens (DLs) of the SLI group were significantly higher than a group of 18 normally developing age- and intelligence-matched peers, but there was no significant difference between the groups in their performance on a control intensity discrimination task. The iii SLI group also showed poorer reading skills, yet frequency discrimination was related to oral language ability only. In the final study, MMN was measured to examine the pre-attentive neurophysiological basis of the SLI group's frequency discrimination deficit. Two frequency deviants that were just above each group's 75% DL on the frequency discrimination task were employed in a simple frequency change paradigm: 40 Hz difference for the control group, and 80 Hz difference for the SLI group. MMN and LDN were elicited in the group of 15 normally developing children to their 40 Hz suprathreshold frequency difference and to the 80 Hz difference. A significant MMN was not observed in the group of 13 SLI children to the 40 Hz difference, which was below their threshold level. However, despite discrimination at the behavioural level, MMN did not reach significance in the SLI group to their 80 Hz suprathreshold frequency difference, yet LDN was observed. MMN was larger in both groups for the 80 Hz difference. Furthermore, MMN and LDN amplitude to the suprathreshold deviants were predictive of both frequency and intensity DLs. These results suggested that SLI children have a pre-attentive neurophysiologically mediated insensitivity to small frequency differences, and that MMN (and LDN) to suprathreshold frequency deviants is a sensitive indicator of group discrimination differences and brain-behaviour relationships in children with and without SLI.

The purpose of this study was to investigate the relationship of family size, birth order, socioeconomic status, and parent-child relationships to young children's intellectual development. Seventy-four children, 39 boys and 35 girls, with a mean age of 4 years-8 months, and their parents (mothers and fathers), selected from 9 preschool programs and daycare centers in Corvallis, Oregon, acted as subjects for this study. Ninety-five percent of the families came from upper or upper-middle socioeconomic classes. All the families were intact, consisting of children and their biological parents, representing one-, two, and three-child families. The children in this study were either first-, second- or third-born children. Family socioeconomic status was determined via Hollingshead's Four Factor Index of Social Status. Information on family size and birth order was obtained through a Demographic Questionnaire. Parent-child relationship was assessed via the Parent Attitude Research Instrument-Short Form. Children's intellectual level was measured with the Peabody Picture Vocabulary Test-Revised. Zajonc and Markus' Confluence Theory, Page and Grandon's Admixture Theory, and Falbo and Polies Parent-Child Relationships Theory were utilized as the basis for investigating the relative contributions of family size, birth order, socioeconomic status, mother-child relationship, and father-child relationship to children's intellectual development. The regression procedure was used in data analyses. The .05 probability level was used as the criterion for statistical significance. Findings revealed that the variables of socioeconomic status and quality of father-child relationships contributed significantly to children's intellectual development. The higher the socioeconomic status of the family, and the more supportive the father-child relationships, the higher the children's intellectual development scores. Birth order and family size made no contributions to children's intellectual development. These findings, therefore, provided support for Page and Grandon's Admixture Theory and Falbo and Polies Parent-Child Relationships Theory, but not for Zajonc and Markus' Confluence Theory. / Graduation date: 1995

Thesis (Ph. D.)--University of Notre Dame, 2007. / Thesis directed by John G. Borkowski for the Department of Psychology. "April 2007." Includes bibliographical references (leaves 68-75).

Thesis (PhD) - Faculty of Design, Swinburne University of Technology, 2008. / Submitted in partial fulfillment of the requirements of the degree of Doctor of Philosophy, [Faculty of Design], Swinburne University of Technology - 2008. Typescript. Bibliography: p. 348-357.

Thesis (Ph. D.)--Open University. BLDSC no. DX187535.

Thesis (M.A.)--The University of North Carolina at Greensboro, 2008. / Directed by Stuart Marcovitch; submitted to the Dept. of Psychology. Title from PDF t.p. (viewed Jan. 28, 2010). Includes bibliographical references (p. 38-43).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 191-201). Available also in a digital version from Dissertation Abstracts.