Human newborns' response to decreased sound pressure level (SPL) was investigated with a localized headturning habituation procedure. Following criterion orientation (three headturns toward the sound out of four consecutive trials) and habituation (three consecutive trials with no headturns or headturns away from the sound), study 1 and 2 assessed newborn female infants' (M age = 41 hrs.) responses to lower-volume sounds immediately following habituation and following a 55-sec delay, respectively. Generalization of habituation to decreased volume following delay with recovery immediately following habituation was observed. Immediate recovery to decreased SPL contradicts a selective receptor adaptation view because a lower-intensity stimulus does not engage a separate set of receptor cells. It is proposed that generalization of habituation following delay involves recognition of the sound as familiar despite variations in volume.

The study reported in this thesis was aimed at investigating taste preferences and caloric compensation in one to two year old children with non-organic failure to thrive (FTT) as compared to normally developing children of the same age. The sample studied included 28 cases with non-organic FTT, and 28 controls with normal growth. The study comprised two experiments. The first tested the child's relative preference for sucrose sweetened solutions versus water. The test session included six 60 second presentations of tastant at three levels of concentration n i.e. water, 0.2 Mol sucrose solution, and 0.4 Mol sucrose solution, with at least 30 second intervals between presentations. The second experiment measured caloric compensation, by testing the child's intake from a standard meal on two occasions, after a pre-load of no-calorie or high-calorie drink. In addition meal time behavioural observations were made, and information about the child’s feeding history was obtained from parent reports. All children regardless of whether they were failing to thrive or not preferred 0.2 Mol sucrose solution to 0.4 Mol sucrose and to water. The energy intake of children with FTT was lower than that of controls, and meal-time behaviours showed some differences between groups in both the child and parent behaviours. Unlike the controls the FTT children showed no caloric compensation, but showed a trend towards the opposite of compensation. Analysis of growth data showed that FTT in the sample studied was present from birth.

Recognizing and learning one’s native language requires knowledge of the phonetic and rhythmical characteristics of the language. Few studies address the rich source of language information available in a speaker’s face. Solely visual speech permits language discrimination in adults (Soto-Faraco et al., 2007). This thesis tested infants and adults on their ability to use only information available in a speaker’s face to discriminate rhythmically dissimilar languages. Monolingual English infants discriminated French and English using only visual speech at 4 and 6 months old, but failed this task at 8 months old. To test the role of language experience, bilingual (English/French) 6 and 8-month-old infants were tested and successfully discriminated the languages. An optimal period for sensitivity to visual language information necessary for discriminating languages may exist in early life. To confirm an optimal period, adults who had acquired English as a second language were tested. If English was learned before age 6 years, adults discriminated English and French, but if English was learned after age 6, adults performed at chance. Experience with visual speech information in early childhood influences adult performance. To better understand the developmental trajectory of visual language discrimination, visual correlates of phonetic segments and rhythmical information were examined. When clips were manipulated to remove rhythmical information, infants used segmental visual phonetic cues to discriminate languages at 4, but not 8 months old. This suggests that a decline in non-native visual phonetic discrimination (similar to the decline seen for non-native auditory phonetic information; Werker & Tees, 1984), may be impairing language discrimination at 8 months. Infants as young as newborn use rhythmical auditory information to discriminate languages presented forward, but not backward (Mehler et al., 1988). This thesis showed that both 4 and 8-month-old infants could discriminate French from English when shown reversed language clips. Unlike auditory speech, reversed visual speech must conserve cues that permit language discrimination. Infants’ abilities to distinguish languages using visual speech parallel auditory speech findings, but also diverge to highlight unique characteristics of visual speech. Together, these studies further enrich our understanding of how infants come to recognize and learn their native language(s).

Thesis (MAResearch)--University of South Australia, 2002.

Thesis (MHlthSc(OccTh))--University of South Australia, 1999

Infants born extremely prematurely (ie. &lt29 weeks gestation) or with extremely low birth weight (ie. &lt1000 grams) are at high-risk of major and minor motor sequelae that persist into the school years. Most of the research on the outcome of these high-risk infants has concentrated on the prevalence of major disability. The majority of high-risk children at school age have normal intelligence and no sensorineural disability. Despite this, these ???apparently normal??? high-risk children have a higher incidence of minor morbidities. Motor coordination problems are frequently reported, yet further investigation into the emergence of minor motor dysfunction, or its impact on academic achievement and everyday activities is seldom explored. The aim of this thesis was to provide a comprehensive investigation into motor dysfunction, which is commonly found in ???apparently normal??? high-risk children. This was addressed in a series of five studies that intended to provide insight into the emergence, prevalence, nature, and prediction of motor dysfunction in otherwise ???normal??? high-risk children. Study 1 examined the development of gross and fine motor skills from infancy to school age using a longitudinal cohort study design. ???Apparently normal??? high-risk children (n=58) were assessed with the Peabody Developmental Motor Scales at 18 months corrected age, 3 and 5 years. A significant proportion continued to have fine motor deficits to school age (64%), reflecting a persistent problem with fine motor skills throughout this period. The proportion of infants with gross motor deficits significantly increased from 18 months to 5 years (81.1%), particularly for the ???micropreemies???. Whilst there was no gender difference found, the development of gross and fine motor skills appeared to be influenced differently by the home environment. Study 2 examined the impact of motor dysfunction on performance at school age. The prevalence of Developmental Coordination Disorder (DCD) in ???apparently normal??? high-risk children was determined using a controlled cohort study design. In addition, the nature of DCD in this population was explored by testing sensorimotor abilities that possibly underlie the motor dysfunction. Fifty (50) high-risk children with IQ&lt85 and no identified sensorineural disability were assessed at 8 years of age along with a matched control from their respective class at school. The Movement Assessment Battery for Children and a battery of sensorimotor tests were administered. Results indicated a significantly higher prevalence of DCD (42%) in the high-risk group in comparison to the control group (8%). In relation to sensorimotor abilities that may influence motor performance, the high-risk group scored significantly lower on most of tests, however it was neurological ???soft signs???, postural praxis, and sequencing praxis that contributed to DCD in the high-risk group. Study 3 was designed to investigate the impact of motor dysfunction on a motor-based task performed within the school setting. Specifically, this study described handwriting skills in ???apparently normal??? high-risk children, determined the prevalence of handwriting dysfunction, and investigated sensorimotor abilities that may be associated with problematic handwriting. The high-risk cohort and matched controls described in study 2 were also administered a number of handwriting tests. High-risk children were found to have poorer handwriting legibility and speed in comparison to their classmates. The prevalence of handwriting dysfunction in the high-risk group was 46%, significantly higher than controls (18%). Hand preference, pencil grasp used, and pain whilst writing were comparable to the control group. The contribution of underlying sensorimotor abilities to handwriting dysfunction in the high-risk population however was not evident. By using the same subjects in studies 2 and 3, the co-morbidity of handwriting dysfunction with DCD could be determined. Of those high-risk children identified with DCD, 43% had co-morbid handwriting dysfunction. Study 4 explored the relationship between perinatal and environmental variables to Developmental Coordination Disorder and handwriting dysfunction in high-risk children. Perinatal and environmental variables of the 50 ???apparently normal??? high-risk children that participated in the previous study were analysed. Results indicated prolonged rupture of membranes (PROM) and retinopathy of prematurity (ROP) were significantly and independently associated with DCD, perhaps reflecting the impact of the antenatal infection process and visual development related to ROP on motor outcome in high-risk children. Perinatal variables were not associated with handwriting dysfunction, but high-risk males were more likely to have handwriting dysfunction. Maternal education and paternal occupation were associated with aspects of handwriting. Whilst handwriting is a motor-based activity, it appears to be influenced by environmental variables, similar to other academic areas for the high-risk population. Study 5 sought to determine whether a motor assessment at an earlier age could predict DCD in the ???apparently normal??? high-risk population at school age. Motor assessment at 12 months, 3 and 5 years for the high-risk subjects who participated in study 2 were analysed using Receiver Operator Curves (ROC curves). The 3 year assessment with the Peabody Developmental Motor Scales was the best predictor of DCD at 8 years, with the Griffiths Locomotor Scale at 3 years yielding a similar result. Findings suggest that high-risk children who scored below the specified cut-off points on 3 year motor assessments and who had a history of PROM or ROP were at greater risk of having motor-based problems that had the potential to interfere with functioning at school.

Thesis (Ph. D.)--University of California, San Diego, 2008. / Title from first page of PDF file (viewed February 14, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Thesis (M.S.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references (leaves 38-41)

Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 2002? / Includes list of publications arising from the thesis. Bibliography: leaves 327-341.

Thesis (Ph.D.)--University of Western Australia, 2003.