Thesis (Ph. D.)--University of California, San Diego, 2003. / Vita. Includes bibliographical references (leaves 102-109).

Bilingual speakers have shown better performance than their monolingual peers on tasks that examine a range of cognitive abilities (e.g. attention, phonological awareness); however, other studies report no group differences. Two reasons may explain the inconsistencies across studies: 1) many studies did not examine and control, when needed, group differences in cognitive abilities that could influence performance on the ability in question; 2) variability in the language proficiency and linguistic similarity between first (L1) and second (L2) language. The current project examined language-related cognitive abilities (i.e. phonological awareness) and general cognitive abilities (i.e. attention and inhibition) in two studies of 8-10 year-old children in Hong Kong. Study 1 investigated whether these abilities, as well as reading, were affected by bilingualism and L1-L2 linguistic distance. There were three groups: English monolingual, Cantonese- English bilingual, and European language-English bilingual. All children had similar educational backgrounds, as they attended English speaking International schools. Particular effort was made to control for group differences in cognitive abilities that could act as confounding variables, which included: intelligence, English proficiency, working memory, and short-term memory. There were no group differences on the tasks of attention and inhibition. However, there were for phonological awareness and reading. L1-L2 linguistic distance provided an advantage over the monolinguals on phonological awareness as only the European bilinguals group performed better than the monolinguals. Whereas, bilingual children of linguistically distant L1- L2 (Cantonese-English) demonstrated difficulty with phonological awareness and reading tasks using nonwords but not real words compared with the other groups. The results suggest that children who speak two linguistically distant languages may have difficulty transferring L2 skills from familiar words to novel words, which is a skill needed in literacy development. Study 2 explored the influence of L2 proficiency on the two sets of abilities. The data from the English monolingual and Cantonese bilingual group in Study 1 was analyzed with data from a new group of children, those who spoke Cantonese (L1) and were learning English as a L2 (ESL). Once again, particular effort was made to statistically control for cognitive abilities that could act as confounding factors. The results of the general cognitive abilities show no group differences. The results of the phonological awareness task show that the ESL group performed worse than the English monolingual and Cantonese bilingual group. This was explained by their low L2 proficiency, as well as difference in the instructional method of English reading. The results of this project advance our understanding of bilingualism. Bilingual advantages are not observed in all children learning a L2 but are influenced by factors embedded in bilingualism (i.e. L2 proficiency, L1-L2 linguistic distance). This highlights that the effects of bilingualism need to be qualified. Additionally, bilingualism does not produce wide-spread advantages; rather, the influence of speaking two languages can affect one cognitive domain, such as language-related abilities, but not the general cognitive abilities within the same groups of children. The results are discussed in relation to the larger body of work and direction of future work is suggested. / published_or_final_version / Speech and Hearing Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / Education / Master / Master of Education

published_or_final_version / Education / Master / Master of Education

This thesis replicates and explores some of the recent findings by Robert Siegler regarding the development ofaddition skills in grade one children. Siegler states that children employ a number ofdifferent strategies to solve single digit addition problems, these strategies coexist and compete, and cognitive variability is an essential aspect of cognitive development. He also advocates the use ofthe microgenetic approach in order to explore cognitive development. Many of Siegler' s observations were replicated while the microgenetic approach produced valuable information. Consideration of Siegler's work resulted in two research questions being formulated, both concerning the actual selection of strategies. First, a prediction analysis was employed to test the hypothesis that children attempt to match the most appropriate strategy to the problem presented according to a principle ofleast effort (defined as the attempt to maximise benefit and minimise cost). The predictions were stipulated prior to the analysis and were based on the arithmetic development literature. It was predicted that children would tend to retrieve the answers to small problems and tie-problems or calculate the answer by counting on from the larger addend by the amount indicated by the small addend (which involves reversing the order of the addends when the first addend is the smaller of the two). The strategy selections (n=229) made by a sample of 12 grade one learners on 21 single digit addition problems were categorised and compared to the predictions. The prediction analysis reduced the expected error by 63%, supporting the least effort model of strategy choice. The result is statistically significant (2=10.231, p / Thesis (M.A.)-University of Natal, Pietermaritzburg, 2000.

This dissertation explores the nature and ontogeny of infants' ability to match phonetic information in comparison to non-speech information in the face and voice. Previous research shows that infants' ability to match phonetic information in face and voice is robust at 4.5 months of age (e.g., Kuhl & Meltzoff, 1982; 1984; 1988; Patterson & Werker, 1999). These findings support claims that young infants can perceive structural correspondences between audio and visual aspects of phonetic input and that speech is represented amodally. It remains unclear, however, specifically what factors allow speech to be perceived amodally and whether the intermodal perception of other aspects of face and voice is like that of speech. Gender is another biologically significant cue that is available in both the face and voice. In this dissertation, nine experiments examine infants' ability to match phonetic and gender information with dynamic faces and voices. Infants were seated in front of two side-by-side video monitors which displayed filmed images of a female or male face, each articulating a vowel sound ( / a / or / i / ) in synchrony. The sound was played through a central speaker and corresponded with one of the displays but was synchronous with both. In Experiment 1,4.5-month-old infants did not look preferentially at the face that matched the gender of the heard voice when presented with the same stimuli that produced a robust phonetic matching effect. In Experiments 2 through 4, vowel and gender information were placed in conflict to determine the relative contribution of each in infants' ability to match bimodal information in the face and voice. The age at which infants do match gender information with my stimuli was determined in Experiments 5 and 6. In order to explore whether matching phonetic information in face and voice is based on featural or configural information, two experiments examined infants' ability to match phonetic information using inverted faces (Experiment 7) and upright faces with inverted mouths (Experiment 8). Finally, Experiment 9 extended the phonetic matching effect to 2-month-old infants. The experiments in this dissertation provide evidence that, at 4.5 months of age, infants are more likely to attend to phonetic information in the face and voice than to gender information. Phonetic information may have a special salience and/or unity that is not apparent in similar but non-phonetic events. The findings are discussed in relation to key theories of perceptual development.

Formal learning contexts often present information to learners in an inert and highly abstract form, making it unlikely that learners would ever use this information in their every-day lives. Learners do, however, show a greater propensity for retaining information that is seen as having relevance in their lives. Constructivism is an educational paradigm that has gained popularity amongst educationists. The core tenet of this paradigm is that learners learn through interaction with their environment and that all knowledge construction is based on previous life experience. Information that is presented to learners in a contextualised form not only has a better chance of being retained in long-term memory, but also has a greater likelihood of being applied in relevant life situations. This publication deals with the research, design and delivery of important information concerning diseases that have a major impact in Southern Africa. Firstly, learners at the University of Natal, Durban were polled for their existing knowledge concerning four widespread diseases, namely HIV/AIDS, tuberculosis, malaria and cancer. Aspects of these diseases where learners demonstrated a low level of awareness were defined as the primary learning objectives for an educational 3D- immersive microworld. Areas of knowledge concerning the transmission, symptomatic expression, biology and prevention of these diseases were generally not well represented in the learner sample. Hence, information regarding these aspects is presented to learners in a contextualised form within the microworld. Motivation for learners to play in this microworld is provided by a storyline that was researched and written for the portal. In addition, the model used in the storyline design was evaluated for its effectiveness as a tool to be used in the planning of future educational games. A model, the Puzzle Process model, was proposed to inform the design of puzzle interfaces for these types of interactive learning environments, and puzzle interfaces were designed for the virtual environment according to the model guidelines. The learning environment was tested as part of the formative evaluation with a small sample of learners. The testing process made use of both quantitative and qualitative methodologies to evaluate the effectiveness of the learning environment as a possible learning tool. Comparison of pre- and post-gameplay questionnaires showed that learners gained a more indepth and richer understanding of the topics being dealt with in the portal. In particular, the puzzle objects situated in the environment stimulated learners to negotiate meanings for the puzzle interfaces and, in the process, encouraged learners to discuss the topic being dealt with. Results from this study also show that the longer learners discussed and negotiated a certain knowledge domain, the greater their increase in richness of information was for that knowledge domain after gameplay. These results highlight the importance of social dialogue in the knowledge construction process and suggest that environments like these have great potential based on their ability to encourage learners to talk to one another and their facilitators while negotiating mutually acceptable knowledge. The original Puzzle Process model, as well as the Game Achievement model and the Game Object model were modified to account for the need for social dialogue and content. These more comprehensive models are instrumental for use in future virtual world environment design. / Thesis (Ph.D.)-University of KwaZulu- Natal, Durban, 2004.

This research project attempted to test assumptions about the development of private speech' and its relationship to attentional modes of engagement, and task performance. Results showed an ontogenetic trend from audible, externalised types of private speech to less audible, more internalised forms, consistent with Vygotsky's assumption that private speech undergoes a curvilinear course of development. Use of on-task private speech was accompanied by greater task attentional focus in the form of motor and looking behaviourial modes of engagement and a reduction in non-attention behaviour and successful performance in problem-solving. "The relation of word to thought, and the creation of new concepts is a complex, delicate and enigmatic process unfolding in our soul." (Tolstoy, 1903, 143, in Vygotsky, 1986) / Thesis (M.A.) - University of Natal, Durban, 2000

Two sets of connectionist simulations of children's acquisition of distance (d), time (t), and velocity (v) concepts using a generative algorithm, cascade-correlation (Fahlman & Lebiere, 1990), are reported. Pure condition simulations represent a situation in which memory demands across the concepts are equal. The limited memory condition explores the effects of differing memory demands. / It was found that the rules that correlated most highly with network responses during training were consistent with the developmental course of children's concepts (Wilkening, 1981; 1982). Networks integrated the defining dimensions of the concepts first by identity rules (e.g., v = d), then additive rules (e.g., v = d-t), and finally multiplicative rules (e.g., v = d $ div$ t). / The results are discussed in terms of similarity to children's development, the effects of memory demands, the contribution of connectionism to cognitive development, and directions for future research. It is argued that cascade-correlation provides an explicit mechanism of developmental change--weight adjustment and hidden unit recruitment.

The Kaufman Assessment Battery for Children is a relatively new instrument designed to measure the cognitive abilities of children ages 2 1/2 to 12 1/2. The battery was predominantly based upon Luria's theory of cognitive processing which proposes a simultaneous and sequential dichotomy for the analysis of information. Exploratory and confirmatory factor analyses have generally supported this theory. However, across different age groups and with special populations, analyses have been inconsistent.Few alternative structures for the battery have been tested, especially with special populations.The purpose of the present study was to assess the viability of a two factor structure based upon the modality of input for a group of students referred for learning difficulties. One hundred and twelve students, ages 7 to 12 1/2, who had been referred by teachers because of learning difficulties were used in the study. The thirteen subtests of the K-ABC were specified as being associated with a visual input factor, an auditory input factor, or both. Confirmatory factor analysis, as performed by the LISREL VI computer program, was then used to test this hypothesis. Unreasonable parameter estimates led to the rejection of the model for this sample. This lack of confirmation is discussed in terms of high correlations among estimates, misspecification of the model, sample homogeneity, and lack of independence among the subtests in terms of input modality. It was concluded that input modality was not a major factor in performance on the battery for this particular sample.