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Description
The development of self-regulation is believed to play a crucial role in predicting later psychopathology and is believed to begin in early childhood. The early postpartum period is particularly important in laying the groundwork for later self-regulation as infants' dispositional traits interact with caregivers' co-regulatory behaviors to produce the earliest

The development of self-regulation is believed to play a crucial role in predicting later psychopathology and is believed to begin in early childhood. The early postpartum period is particularly important in laying the groundwork for later self-regulation as infants' dispositional traits interact with caregivers' co-regulatory behaviors to produce the earliest forms of self-regulation. Moreover, although emerging literature suggests that infants' exposure to maternal stress even before birth may be integral in determining children's self-regulatory capacities, the complex pathways that characterize these developmental processes remain unclear. The current study considers the complex, transactional processes in a high-risk, Mexican American sample. Data were collected from 305 Mexican American infants and their mothers during prenatal, 6- and 12-week home interviews. Mother self-reports of stress were obtained prenatally between 34-37 weeks gestation. Mother reports of infant temperamental negativity and surgency were obtained at 6-weeks as were observed global ratings of maternal sensitivity during a structured peek-a-boo task. Microcoded ratings of infants' engagement orienting and self-comforting behaviors were obtained during the 12-week peek-a-boo task. Study findings suggest that self-comforting and orienting behaviors help to modulate infants' experiences of distress, and also that prenatal stress influences infants' engagement in each of those regulatory behaviors, both directly by influence tendencies to engage in orienting behaviors and indirectly by programming higher levels of infant negativity and surgency, both of which may confer risk for later regulatory disadvantage. Advancing our understandings about the nature of these developmental pathways could have significant implications for targets of early intervention in this high-risk population.
ContributorsLin, Betty (Author) / Crnic, Keith A (Thesis advisor) / Lemery-Chalfant, Kathryn S (Committee member) / Mackinnon, David P (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The

Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The results suggested that, depending on the nature of data, optimal specification of (1) decision rules to select the covariate and its split value in a Classification Tree, (2) the number of covariates randomly sampled for selection, and (3) methods of estimating Random Forests propensity scores could potentially produce an unbiased average treatment effect estimate after propensity scores weighting by the odds adjustment. Compared to the logistic regression estimation model using the true propensity score model, Random Forests had an additional advantage in producing unbiased estimated standard error and correct statistical inference of the average treatment effect. The relationship between the balance on the covariates' means and the bias of average treatment effect estimate was examined both within and between conditions of the simulation. Within conditions, across repeated samples there was no noticeable correlation between the covariates' mean differences and the magnitude of bias of average treatment effect estimate for the covariates that were imbalanced before adjustment. Between conditions, small mean differences of covariates after propensity score adjustment were not sensitive enough to identify the optimal Random Forests model specification for propensity score analysis.
ContributorsCham, Hei Ning (Author) / Tein, Jenn-Yun (Thesis advisor) / Enders, Stephen G (Thesis advisor) / Enders, Craig K. (Committee member) / Mackinnon, David P (Committee member) / Arizona State University (Publisher)
Created2013
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Description
The parent-child relationship is one of the earliest and most formative experiences for social and emotional development. Synchrony, defined as the rhythmic patterning and quality of mutual affect, engagement, and physiological attunement, has been identified as a critical quality of a healthy mother-infant relationship. Although the salience of the quality

The parent-child relationship is one of the earliest and most formative experiences for social and emotional development. Synchrony, defined as the rhythmic patterning and quality of mutual affect, engagement, and physiological attunement, has been identified as a critical quality of a healthy mother-infant relationship. Although the salience of the quality of family interaction has been well-established, clinical and developmental research has varied widely in methods for observing and identifying influential aspects of synchrony. In addition, modern dynamic perspectives presume multiple factors converge in a complex system influenced by both nature and nurture, in which individual traits, behavior, and environment are inextricably intertwined within the system of dyadic relational units.

The present study aimed to directly examine and compare synchrony from three distinct approaches: observed microanalytic behavioral sequences, observed global dyadic qualities, and physiological attunement between mothers and infants. The sample consisted of 323 Mexican American mothers and their infants followed from the third trimester of pregnancy through the first year of life. Mothers were interviewed prenatally, observed at a home visit at 12 weeks postpartum, and were finally interviewed for child social-emotional problems at child age 12 months. Specific aspects of synchrony (microanalytical, global, and physiological) were examined separately as well as together to identify comparable and divergent qualities within the construct.

Findings indicated that multiple perspectives on synchrony are best examined together, but as independent qualities to account for varying characteristics captured by divergent systems. Dyadic relationships characterized by higher reciprocity, more time and flexibility in mutual non-negative engagement, and less tendency to enter negative or unengaged states were associated with fewer child social-emotional problems at child age 12 months. Lower infant cortisol was associated with higher levels of externalizing problems, and smaller differences between mother and child cortisol were associated with higher levels of child dysregulation. Results underscore the complex but important nature of synchrony as a salient mechanism underlying the social-emotional growth of children. A mutually engaged, non-negative, and reciprocal environment lays the foundation for the successful social and self-regulatory competence of infants in the first year of life.
ContributorsCoburn, Shayna Skelley (Author) / Crnic, Keith A (Thesis advisor) / Dishion, Thomas J (Committee member) / Mackinnon, David P (Committee member) / Luecken, Linda J. (Committee member) / Arizona State University (Publisher)
Created2015
Description
Infants partake in a developmental process between birth and 18 months which takes them from small movement while lying on their anterior side, through to walking, running, and jumping. In order to properly progress through this process, infants must learn to crawl before they learn to walk; though this

Infants partake in a developmental process between birth and 18 months which takes them from small movement while lying on their anterior side, through to walking, running, and jumping. In order to properly progress through this process, infants must learn to crawl before they learn to walk; though this process can be altered by the influence of infant locomotor devices.

The use of infant locomotor devices such as walkers, jumpers, and exersaucers are widely controversial amongst parents and pediatricians. Parents often cite benefits to the child with device exposure, whereas pediatricians often warn against the use of them. The concern of the pediatricians lay within the risk that comes along with increased mobility, as well as the upright position the device puts the child in. The child is often unable to place themselves in this position outside of the device due to not being ready in their developmental pathway. The device places the child upright with their legs hanging below with their feet not flat on the ground supporting weight. This position can place strain on the infants’ hips, lower back, and trunk.

Research shows that infants with prolonged device exposure tend to reach their locomotor milestones later than infants with average to ideal exposure. Infants with prolonged device exposure have also been found to score lower on developmental assessments. To reduce the risk of injury and developmental delay, the American Academy of Pediatrics ban the production and sale of infant walkers, and advised parents allow their children to play in more natural positions, rather than the position the locomotor devices place the child in.
In order to bridge the gap of education provided to parents and caregivers, and the knowledge of the pediatricians, further research should be done to collect up to date data of the impact of these devices and the long-term impact of these devices past the age of three. Working to expand the educational outreach to parents, particularly in the medical setting, would also be beneficial in working to reduce the exposure infants have to these devices and in turn, the number of injuries and developmental delays associated with use.
ContributorsMcHale, Annika (Author) / Nolan, Nicole Blaize (Thesis director) / Cataldo, Donna (Committee member) / Educational Leadership & Innovation, Division (Contributor) / School of Social and Behavioral Sciences (Contributor) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12