Thesis (M.A.)--York University, 2004. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 40-49). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ99368

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 40-46).

Thesis (Ph. D.)--Georgia State University, 2006. / Title from title screen. Mary Beth Walker, committee chair; Laura O. Taylor, M. Melinda Pitts, Sally Wallace, committee members. Electronic text (89 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed May 21, 2007. Includes bibliographical references (p. 84-88).

published_or_final_version / Nursing Studies / Master / Master of Nursing

published_or_final_version / Nursing Studies / Master / Master of Nursing

published_or_final_version / Nursing Studies / Master / Master of Nursing

No description available.

The violation of expectation (VOE) paradigm and related habituation methods are the primary tools used to study higher-level cognition in preverbal infants. A common assumption of the paradigm is that longer looking to impossible events than possible events is indicative of infants' surprise at witnessing the impossible. Experiments can thus be designed to reveal infants' prior expectations for the behaviour of objects in the environment and so forth. This thesis explored the nature of infants' expectations in VOE-type events, and introduces pupil dilation as a novel dependent measure in tests of infant cognition. Chapter 1 reviews the history of, and rationale for, the use of habituation testing in infants, and presents the case for pupil dilation's potential as a viable and useful measure for tests in infancy. Chapters 2, 3 and 4 present four experiments in which infants are habituated to either possible or impossible events, before being tested on all event types, in order to explore the role of online learning in the formation of infants' expectations in VOE tasks. Both looking times and pupil dilation data were used as dependent measures in each of these tasks. In Chapter 5 Baillargeon's (1987; Baillargeon, Spelke, & Wasserman, 1985) influential 'drawbridge' experiments and the many subsequent replications of them are reviewed before a further replication is introduced in which the novel contribution of pupil dilation data is assessed. The discussion focuses on the findings of the empirical work of this thesis, and concludes that it is crucial to incorporate efforts to refute hypotheses into the designs of tests for infant cognition, and also that pupil data is a valuable complementary measure to, and potentially even superior than, looking times.

In the first six months of life, infants systematically explore the laryngeal parameters of phonation and pitch. In existing research, laryngeal vocalizations, defined as "vegetative" or "reflexive", are characterized by the presence of "strained" and "rough" phonation with "high degrees of vocal tension" and dynamic pitch variations. Previous studies have focused exclusively on the development of linguistic precursors, including only "speech-like" sounds with "normal" or modal phonation. These studies have excluded laryngeal vocalizations (i.e. grunts, squeals and growls) from their experimental analyses and therefore have not provided an accurate description of early phonetic development. This thesis attempts to fill the gap in the phonetic and articulatory description of the infant vocal capacity by investigating the exploration and development of the laryngeal mechanisms involved in the production of laryngeal phonation and laryngeal pitch. In order to account for the productive capability of infants, it is necessary to consider the vital role of the primary articulator in the adult and infant larynx, the aryepiglottic laryngeal sphincter. The mechanism of the laryngeal sphincter is actively engaged in early infancy to protect the tracheal airway from inundation. In this study, two quantitative analyses of one English-speaking infant's vocalizations in the first six months of life were conducted. In analysis one, auditorily based analysis of 824 vocalizations was performed using the phonetic taxonomy of laryngeal modalities developed by Esling and colleagues (Esling, Benner & Bettany, 2004a; Esling, 2002). The incidence of five phonatory settings (i.e. harsh voice, creaky voice, whisper, modal voice and falsetto) and three pitch levels (low, mid and high) was reported. In analysis two, the laryngeal parameters involved in "range exploration", defined in this study as the instance of within-vocalization phonatory altemations, were quantified by means of acoustic analysis. 120 randomly selected vocalizations (20 from each of the six months) were used in this analysis component. The durations of the vocalizations and of individual phonatory settings within each vocalization were calculated using spectrographic analysis and compared statistically. The present study was able to accurately identify the phonetic range and productive repertoire of infant vocalizations produced in the first six months of life. Four main findings were reported in this study: (1) the default setting in early infancy is laryngeally constricted and low-pitched, (2) the infant's phonetic repertoire of phonation and pitch expands at four months (3) the incidence of within-vocalization phonatory altemations increases at four months and, (4) the productive integration of phonation and pitch is acquired by the sixth month of life.

M.Tech.