Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Mother-child and father-child "serve and return" interactions at 9 months: Associations with children's language skills at 18, 24, and 30 months(2023) Chen, Yu; Cabrera, Natasha J; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Infants learn language through the back-and-forth interactions with their parents where they “serve” by vocalizing, gesturing, or looking and parents “return” in a temporally and semantically contingent way. My dissertation focuses on these “serve and return” (SR) interactions between 9-month-old infants and their mothers and fathers (n = 296 parents and 148 infants) from ethnically and socioeconomically diverse backgrounds by examining the variability in SR interactions explained by maternal and paternal psychological distress, the association between SR interactions and children’s language skills at 18, 24, and 30 months, and the moderation effect of maternal and paternal SR interactions on language outcomes. Psychological distress was indicated by parent-reported depressive symptoms, parenting stress, and role overload, and SR interactions were transcribed and coded from video-taped parent-child toy play activities during home visits. I report three major findings. First, neither maternal nor paternal psychological distress was significantly associated with and SR interactions at 9 months, controlling for demographic factors. Second, fathers who responded to their child’s serves more promptly and mothers who provided more semantically relevant responses had children with higher receptive and expressive language skills, respectively, at 18 and 30 months. Third, fathers’ semantically relevant responses were negatively associated with children’s receptive language skills at 24 months; however, this main effect was moderated by mothers’ semantically relevant responses. Understanding how mothers and fathers engage in temporally and semantically contingent social interactions with their children during the first year, especially among families from diverse backgrounds, would enable programs and policies to more effectively promote early language development and reduce gaps in school readiness.Item Action and perception: Neural indices of learning in infants(2016) Yoo Chon, Kathryn Hye Jin; Fox, Nathan A; Neuroscience and Cognitive Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Early human development offers a unique perspective in investigating the potential cognitive and social implications of action and perception. Specifically, during infancy, action production and action perception undergo foundational developments. One essential component to examine developments in action processing is the analysis of others’ actions as meaningful and goal-directed. Little research, however, has examined the underlying neural systems that may be associated with emerging action and perception abilities, and infants’ learning of goal-directed actions. The current study examines the mu rhythm—a brain oscillation found in the electroencephalogram (EEG)—that has been associated with action and perception. Specifically, the present work investigates whether the mu signal is related to 9-month-olds’ learning of a novel goal-directed means-end task. The findings of this study demonstrate a relation between variations in mu rhythm activity and infants’ ability to learn a novel goal-directed means-end action task (compared to a visual pattern learning task used as a comparison task). Additionally, we examined the relations between standardized assessments of early motor competence, infants’ ability to learn a novel goal-directed task, and mu rhythm activity. We found that: 1a) mu rhythm activity during observation of a grasp uniquely predicted infants’ learning on the cane training task, 1b) mu rhythm activity during observation and execution of a grasp did not uniquely predict infants’ learning on the visual pattern learning task (comparison learning task), 2) infants’ motor competence did not predict infants’ learning on the cane training task, 3) mu rhythm activity during observation and execution was not related to infants’ measure of motor competence, and 4) mu rhythm activity did not predict infants’ learning on the cane task above and beyond infants’ motor competence. The results from this study demonstrate that mu rhythm activity is a sensitive measure to detect individual differences in infants’ action and perception abilities, specifically their learning of a novel goal-directed action.Item BEYOND STATISTICAL LEARNING IN THE ACQUISITION OF PHRASE STRUCTURE(2009) Takahashi, Eri; Lidz, Jeffrey; Linguistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The notion that children use statistical distributions present in the input to acquire various aspects of linguistic knowledge has received considerable recent attention. But the roles of learner's initial state have been largely ignored in those studies. What remains unclear is the nature of learner's contribution. At least two possibilities exist. One is that all that learners do is to collect and compile accurately predictive statistics from the data, and they do not have antecedently specified set of possible structures (Elman, et al. 1996; Tomasello 2000). On this view, outcome of the learning is solely based on the observed input distributions. A second possibility is that learners use statistics to identify particular abstract syntactic representations (Miller & Chomsky 1963; Pinker 1984; Yang 2006). On this view, children have predetermined linguistic knowledge on possible structures and the acquired representations have deductive consequences beyond what can be derived from the observed statistical distributions alone. This dissertation examines how the environment interacts with the structure of the learner, and proposes a linking between distributional approach and nativist approach to language acquisition. To investigate this more general question, we focus on how infants, adults and neural networks acquire the phrase structure of their target language. This dissertation presents seven experiments, which show that adults and infants can project their generalizations to novel structures, while the Simple Recurrent Network fails. Moreover, it will be shown that learners' generalizations go beyond the stimuli, but those generalizations are constrained in the same ways that natural languages are constrained. This is compatible with the view that statistical learning interacts with inherent representational system, but incompatible with the view that statistical learning is the sole mechanism by which the existence of phrase structure is discovered. This provides novel evidence that statistical learning interacts with innate constraints on possible representations, and that learners have a deductive power that goes beyond the input data. This suggests that statistical learning is used merely as a method for mapping the surface string to abstract representation, while innate knowledge specifies range of possible grammars and structures.Item Paths to compliance: Differing influences of maternal behavior in temperamentally fearful and exuberant infants(2007-04-15) Ghera, Melissa Marie; Fox, Nathan A; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The goal of this study was to describe the expression of compliance in temperamentally positive and negatively reactive children and the factors that contribute to individual differences in expression of compliance within and between these groups. As part of a larger project examining temperament over time, 244 infants and their mothers were evaluated at 9- and 36-months of age. At 9 months of age, maternal responsiveness and sensitivity (see Kochanska, 1998) were evaluated and infants underwent the Laboratory Temperament Assessment Battery (Lab-TAB; Goldsmith and Rothbart, 1999), while mothers and infants were jointly evaluated for expression of mutually positive affect (Kochanska, 1998). At 36 months, maternal discipline and child compliance were observed in the home (see Kochanska & Aksan, 1995). Regardless of temperament, children displayed more situational compliance during a forbidden toy paradigm as compared to a clean-up context. During forbidden toy, temperamentally positive children displayed more situational compliance than their negative counterparts, while no such differences were found during clean-up. Structural equation modeling techniques revealed differential contributors to the display of compliance based on child temperament and context of interaction. During clean-up, no direct contributors to the display of compliance were found for temperamentally positive children; however avoidant behavior on the part of the child led to suboptimal maternal behavior. For temperamentally negative children, approach behaviors were associated with more optimal maternal behavior. Maternal responsiveness led to increased situational compliance for these children. In the forbidden toy context, the path from avoidance to affect was significant and negative for both temperamentally reactive groups. For temperamentally negative children, increased avoidant behavior was associated with decreased gentle discipline, while approach behaviors were associated with increased gentle discipline. Additionally, any type of discipline, gentle or punitive, was significantly, negatively predictive of committed compliance. For temperamentally positive children, displays of avoidance decreased displays of mutually positive affect. Also, use of gentle discipline was significantly, inversely related to child displays of committed compliance, as well as significantly, positively related to their displays of situational compliance. Discipline also mediated the relation between affect and compliance, as well as responsiveness and compliance, for the temperamentally positive group.