Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

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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Now showing 1 - 3 of 3
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    Infants' representations and memories of their social-emotional interactions
    (2013) Sherman, Laura Jernigan; Cassidy, Jude; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    According to several theorists, infants form mental representations and memories of their social-emotional interactions (e.g., Bowlby, 1969/1982), but very few studies have investigated these claims. Across two studies, I hypothesized that 10-month-old infants would form representations and memories of their social-emotional interactions. In Study 1, infants (N = 24) were familiarized to a positive and negative puppet and their representations and memories were assessed with visual-paired comparison (VPC) and forced-choice tests. Ten minutes after their interactions, but not immediately after, significantly more infants chose the positive puppet (17/24, p = .030). To better understand these results, I conducted another study in which infants (N = 32) were randomly assigned to be familiarized to either a positive and neutral puppet or a negative and neutral puppet. In the positive condition infants were more likely to choose the positive puppet immediately after (12/16, p =.038), but not 10 minutes after the interactions, whereas in the negative condition infants' choices were at chance - but older infants were more likely choose the neutral puppet (Mdiff = 11.50 days, p = .022). In both studies, no effects emerged with infants' preferential looking. Overall, the results indicated that infants' representations and memories of their brief social-emotional interactions were stronger for positive than negative interactions. Results are discussed with regard to existing theory and research and the negativity bias hypothesis.
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    Comparing Me to You: Comparison Between Novel and Familiar Goal-Directed Actions Facilitates Goal Extraction and Imitation
    (2011) Gerson, Sarah A.; Woodward, Amanda L; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Recognizing the goals of others' actions is critical for much of human development and social life. Origins of this knowledge exist in the first year and are a function of both acting as an intentional agent and observing movement cues in actions. In this dissertation, I explore a new mechanism I believe plays an important role in infants' understanding of novel actions---comparison. In four studies, I examine how the opportunity to compare a familiar action with a novel, tool use action (through physical alignment of the two actions) helps 7- and 10-month-old infants extract and imitate the goal of a tool use action. In Studies 1 and 2, 7-month-old infants given the chance to compare their own reach for a toy with an experimenter's reach using a claw later imitated the goals of an experimenter's tool use actions. In contrast, infants who engaged with the claw, were familiarized with the claw's causal properties, learned the associations between claw and toys, or interacted in a socially contingent manner with the experimenter using the claw did not later imitate the experimenter's goals. Study 3 replicated the finding that engagement in physical alignment facilitated goal extraction and imitation and indicated that this was true for older infants (10-month-olds). It also demonstrated that observation of the same physical alignment did not lead to goal imitation at this age. Finally, Study 4 revealed that 10-month-old infants could learn about the goals of novel actions through the observation of physical alignment when a cue to focus on the goal of the two actions was presented during the alignment process (i.e., a verbal label), indicating that infants gained a conceptual representation of the goal and used structure mapping to extract the common goal between actions. Infants who heard a non-label vocalization during the observation of physical alignment did not later imitate the experimenter's goals. The nature, breadth, and implications of these findings are discussed. Together, these findings indicate that infants can extract the goal-relation of a novel action through comparison processes; comparison could thus have a broad impact on the development of action knowledge.
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    The emotional modulation of the startle reflex in 9-month-old infants
    (2004-04-30) Marshall, Dalit Himmelfarb; Fox, Nathan A; Human Development
    The purpose of this research project was to investigate whether the startle reflex of 9-month-old infants can be modulated by emotional stimuli, as well as to examine the specific characteristics of infants' startle reactions in an emotion-modulated paradigm. Two studies were conducted to address these questions. In Study 1, 32 9-month-old infants viewed photographs of happy, neutral, and angry facial expressions. Infants' startle responses to acoustic probes during the presentation of the facial stimuli were recorded and compared across the three affective conditions. Autonomic and looking time data were also gathered in order to evaluate the contribution of other factors, such as attention, to the modulation of the startle reflex. The results of this study indicated a pattern of startle modulation opposite to that documented in adults. Infants demonstrated a potentiated startle reflex during the viewing of happy faces and an inhibited response during the viewing of angry faces. Differences in heart period and looking time between the affective conditions suggested that these findings were driven, at least in part, by greater allocation of attentional resources to angry expressions. To further examine the role of emotion in infants' startle modulation, an independent group of 25 9-month-old infants was tested in a second, modified emotion-modulated startle paradigm that involved the presentation of acoustic startle probes while infants were engaged in a pleasant game of peek-a-boo, an affectively neutral presentation of a spinning bingo wheel, and a mildly frustrating arm restraint episode. Autonomic and behavioral data were also gathered. As expected, the results revealed startle potentiation during the unpleasant condition and startle inhibition during the pleasant condition, indicating the existence of the emotion-modulated startle reflex in 9-month-old infants. Results of both studies are discussed in terms of the role of emotion and attention in startle modulation, the maturation of the appetitive and defensive brain systems in infants, and the importance of establishing a rigorous and age-appropriate startle paradigm to foster the study of infants' emotionality. Suggestions for further studies utilizing such a paradigm to investigate different aspects of emotional reactivity in infancy are also proposed.