Newborns were once viewed as having the ability to distinguish between all possible speech contrasts present in the world’s languages. However, recent work suggests that this view is an oversimplification of young infants’ perceptual abilities. This study used the Stimulus Alternation Preference Procedure (SAPP) to examine 6- and 10- month-old infants’ ability to discriminate between voiced and voiceless stops (lexically contrastive in English) as well as voiced and pre-voiced stops (not lexically contrastive in English). Six-month-olds distinguished between voiced and voiceless stops, but not between voiced and pre-voiced stops. Ten-month-olds failed to discriminate either contrast. We tentatively conclude that 1) pre-voicing may be a subtle contrast requiring experience to perceive, and 2) the SAPP might not be an ideal method to examine discrimination abilities in 10-month-olds.

Newborns were once viewed as having the ability to distinguish between all possible speech contrasts present in the world’s languages. However, recent work suggests that this view is an oversimplification of young infants’ perceptual abilities. This study used the Stimulus Alternation Preference Procedure (SAPP) to examine 6- and 10- month-old infants’ ability to discriminate between voiced and voiceless stops (lexically contrastive in English) as well as voiced and pre-voiced stops (not lexically contrastive in English). Six-month-olds distinguished between voiced and voiceless stops, but not between voiced and pre-voiced stops. Ten-month-olds failed to discriminate either contrast. We tentatively conclude that 1) pre-voicing may be a subtle contrast requiring experience to perceive, and 2) the SAPP might not be an ideal method to examine discrimination abilities in 10-month-olds.

Infant word recognition is sometimes hindered by variability in the speech input. Previous research has shown that, at 9 months, monolinguals do not generalize wordforms across native- and accented-speakers (Schmale & Seidl, 2009). In the current study however, it was predicted that bilingual infants would be advantaged in accommodating for accented speech due to experience with phonetic variability across their two phonological systems. It was also predicted that this hypothesized ability would be restricted to accommodating for an accent derived from a familiar language (e.g., French-English bilinguals would accommodate for French-accented English but not Mandarin-accented English), since this type of variability would be consistent with the language sounds to which infants were regularly exposed. Study 1 set the experimental stage by identifying native and non-native speakers with similar voices, as perceived by a group of adults. This was done in order to restrict variability across speakers to differences in accent, rather than biological differences in voice (e.g., a higher or lower pitched voice). Following speaker selection, acoustic measurements of vowels and word stress placement were taken to compare native and non-native speakers and confirmed several expected deviations between native and accented speech. Study 2 tested the hypothesis that bilingual infants would be advantaged in accommodating for these deviations when the accent is derived from a familiar phonology. Using a headturn preference procedure (HPP), 9- and 13-month-old English-learning monolinguals and French-English learning bilingual infants were tested on their ability to recognize familiarized English wordforms across a native- and French-accented speaker. Bilinguals in both age groups succeeded in generalizing wordforms across speakers, however monolingual infants failed regardless of age. Study 3 tested whether bilinguals’ success would persist when the accented speaker’s first language was unfamiliar. Infants in this study failed as a group to generalize across native- and Mandarin-accented productions of English wordforms. However, bilinguals who received balanced exposure to their two languages performed better in accommodating for Mandarin accented speech than unbalanced bilinguals. This hints at a general ability to ignore irrelevant phonetic information, perhaps due to an advantage in cognitive control.

Master of Science / School of Family Studies and Human Services / Bronwyn S. Fees / Jennifer R. Francois / The mother-infant relationship affects the child’s exploratory and separation behavior, how the child perceives strangers, and significantly impacts the conceptual framework of typical social relationships in the infant’s brain. The purpose of this study was to examine infants’ regulatory strategies, specifically, the relationship between the mother-infant dyad, and the infant’s response to a stressful situation. Eight, 5-month-old infants and their mothers participated in the Face-to-Face Still-Face experiment and a play session to assess maternal sensitivity. Data from the mother-infant dyads were collected during each phase of the Face-to-Face Still-Face paradigm (i.e., play, still-face, and reunion). Maternal sensitivity was assessed using an adapted version of Ainsworth’s four scales of maternal sensitivity. The infant’s strategies for re-engagement with the mother were assessed using eye-tracking methodology to identify specific eye gaze behaviors used during each phase of the still-face experiment. The infants who had more sensitive mothers showed an increase in fixation duration during the reunion phase of the procedure, which could be indicative of a trusting relationship in which the child knows the mother is there to help them regain control of their emotions. Implications of these findings are discussed for the use of eye-tracking methodology as a more flexible and potentially more accurate measure of studying infants’ patterns of ocular focus.

Infant word recognition is sometimes hindered by variability in the speech input. Previous research has shown that, at 9 months, monolinguals do not generalize wordforms across native- and accented-speakers (Schmale & Seidl, 2009). In the current study however, it was predicted that bilingual infants would be advantaged in accommodating for accented speech due to experience with phonetic variability across their two phonological systems. It was also predicted that this hypothesized ability would be restricted to accommodating for an accent derived from a familiar language (e.g., French-English bilinguals would accommodate for French-accented English but not Mandarin-accented English), since this type of variability would be consistent with the language sounds to which infants were regularly exposed. Study 1 set the experimental stage by identifying native and non-native speakers with similar voices, as perceived by a group of adults. This was done in order to restrict variability across speakers to differences in accent, rather than biological differences in voice (e.g., a higher or lower pitched voice). Following speaker selection, acoustic measurements of vowels and word stress placement were taken to compare native and non-native speakers and confirmed several expected deviations between native and accented speech. Study 2 tested the hypothesis that bilingual infants would be advantaged in accommodating for these deviations when the accent is derived from a familiar phonology. Using a headturn preference procedure (HPP), 9- and 13-month-old English-learning monolinguals and French-English learning bilingual infants were tested on their ability to recognize familiarized English wordforms across a native- and French-accented speaker. Bilinguals in both age groups succeeded in generalizing wordforms across speakers, however monolingual infants failed regardless of age. Study 3 tested whether bilinguals’ success would persist when the accented speaker’s first language was unfamiliar. Infants in this study failed as a group to generalize across native- and Mandarin-accented productions of English wordforms. However, bilinguals who received balanced exposure to their two languages performed better in accommodating for Mandarin accented speech than unbalanced bilinguals. This hints at a general ability to ignore irrelevant phonetic information, perhaps due to an advantage in cognitive control.

Through observation of young children much has been learned regarding elementary word acquisition and ordering, sentence formulation, and expansion of verbal experience; but little research regarding what precedes "the word" has been done. The present study was concerned with that period in infancy prior to communicative speech production. The purpose of the present study was to answer the question: Can one selectively reinforce a particular babble?

Potassium i.s one of the major constituents of the human body but its role in metabolism is not clearly defined. One reason for this is the predominant intracellular distribution of the ion and the attendant difficulties in the detection of deficiency states. Serum potassium levels are of little value as over 95% of the potassium in the body is intracellular. Balance studies and the analysis of biopsy material have been used. However, they are so time consuming that they are only of use in establishing the diagnosis retrospectively and give very little indication of the severity of the deficit. Exchangeable potassium measurements do give an indication of the severity of the deficit. However, they involve the administration of an isotope which is not always available because of its short half-life. The development of the whole body counter has overcome most of these problems.

The author participated in an international survey organised by the British Medical Research Council (MRC) epidemiological unit in Cardiff, Wales which set out to compare the prevalence of asthma in several countries. The motivation for participating in this study was that very little previous prevalence data for asthma is available for coloured or white children in South Africa. A protocol designed by the British MRC Epidaemiology Unit was followed. One thousand one hundred and seventy four white children aged 12 years attending a random selection of primary schools in the Southern Suburbs of Cape Town were studied. A standard MRC questionnaire on asthma was completed by parents. The subjects then underwent an exercise challenge test (ECT) which involved running on the level for six minutes. During the ECT, we measured the forced expiratory volume in 1 second (FEVl) before and after the exercise. A fall in post exercise FEVl of 15% or greater was regarded as evidence of bronchoconstriction and considered diagnostic of asthma. This method is thought to identify 70-90% of asthmatics (Anderson 1985, Lee et al 1989, Pierson 1988). Using this criterion, 52 (4.4%) of the children had asthma. The prevalence of 4.4% in this study is higher than 3.1% reported in a previous study of black children in Guguletu (Van Niekerk et al, Clinical Allergy 1979). However, the age spectrum of children was different in that study. Terblanche et al (1990) report the prevalence of exercise induced bronchoconstriction (EIB) in white and coloured children to be 5.87% and 4.05% respectively. The level of FEVl reduction for a diagnosis of EIB approved for this study was lower than usually accepted. Using conventional criteria for a diagnosis of EIB, Burr et al (1989) reported a prevalence of 7.7% in Cardiff, Wales. This study confirms that exercise induced asthma is a common problem in 12-year old white children in Cape Town.

Indiana University-Purdue University Indianapolis (IUPUI) / A survey of 441 children between the ages of 6 and 36 months, born and reared with a fluoridated water supply, revealed dental caries in 2.5 percent of those 6 to 17 months of age, 9.1 percent of those 18 to 23 months of age, and in 38.7 percent of the children 24 to 26 months of age. No significant differences were found in defs and deft relative to sex, race, or socioeconomic status. Caries prevalence is affected by method of feeding; children who had prolonged bottle-feeding (more than 15 months) had significantly increased caries. In 299 Caucasian children, gingivitis was present in 13.2 percent of those 6 to 17 months of age, 33.9 percent of those 18 to 23 months of age, and in 38.5 percent 24 to 36 months of age. There was little difference in the severity of the gingivitis, although significant difference in the frequency of gingivitis was demonstrated. The prevalence of gingivitis increased with age. Young children with dental caries also showed an increased prevalence of gingivitis. The presence of gingivitis, the presence of dental caries, and the absence of professional dental care in these young children all illustrate the necessity for prevention and treatment of oral disease in children under 36 months of age.

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine Johannesburg, August 2013 / Asthma control is a central focus of the updated version of the GINA Guidelines, in which clinicians are encouraged to concentrate on assessment of control, defined by symptoms, lung function and the presence or history of exacerbations. Control is of critical importance in asthma and is now more important than the actual level of severity. Measures of asthma control do not necessarily perform well and all of them need to be looked at as a whole as studies have shown. Many factors have been found to be associated with poor asthma control ranging from concomitant rhinitis and co morbidities to poor compliance with medications or inappropriate inhaler technique in addition to home or environmental factors. Several factors around the home of asthmatic patients contribute to poor asthma control which includes parental smoking or smoking by other relatives within the home, biomass fuel exposure, exposure to aeroallergens and animal danders which all leads to failure in achieving control despite adequate drug therapy. This cross sectional study was conducted in 115 asthmatics children with the aim of determining the level of asthma control and home circumstances that contributes to poor asthma control. Most patients were males and blacks with 55.65% of patients having controlled asthma. Use of biomass fuel was uncommon in this study and none of the home circumstances was found to be associated with poor asthma control in this study. Day time and nocturnal asthma symptoms were significantly associated with poor asthma control. Good adherence to medications was found to be associated with asthma control similar association was not seen with good inhaler technique. The higher the FEV1 percent predicted the better the asthma control. Day time and nocturnal asthma symptoms were associated with FEV1. Results from this study need confirmation in a representative population study. Further longitudinal study is required to see if home circumstances may affect asthma control in patients that had controlled asthma.