Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 149-160). Available also in a digital version from Dissertation Abstracts.

It is argued in Chapters 1 to 4 that in cognitive psychology in general, and in the disciplines of language acquisition and cognitive development in particular, there is substantial benefit to be derived from distinguishing between two representational systems, one system being deployed in long-established or highly-practiced functions, and the second deployed in novel tasks, or where difficulties interrupt the first system. It is also argued that the proper subject of cognitive development is the second of these systems. Chapters 5 and 6 are concerned in different ways with the origins of language in the individual, in particular with the question of what innate knowledge of language might be justified. It is concluded that many questions regarding innate knowledge remain open, and that a source in human evolution for knowledge of language is no more likely than sources in individual or social development. In Chapter 7 it is argued that representational drawing emerges late in the 4th year of life, and some new techniques are described for studying early representational drawing. Following these treatments of external systems of representation, Chapter 8 offers a general developmental theory of forms of representation, extending Piaget's insight that mental representation is co-extensive with thought, and that the main axis of cognitive development is the content of thought and representation. Chapters 9 to 12 apply this theory to the representation of belief and desire, and of extrinsic and intrinsic qualities of objects, by 11/2 to 4 year-old children. Chapter 13 introduces a new method for analyzing the free classification task, a task sometimes used to assess children's ability to think about intrinsic qualities, and applies this method to various data sets. Chapter 14 applies these insights and results to the problem of characterizing concepts and concept development and favourably discusses the idea that more precise knowledge of this aspect of development may help to explain certain features of early language acquisition.

Thesis (Ph. D.)--Open University. BLDSC no. DX187535.

This dissertation discusses the convergence of aided augmentative and alternative communication (AAC) systems, the language acquisition and development of young children who are minimally verbal or nonverbal who acquire their native language while simultaneously learning to use an aided AAC system, and explicit and implicit elements that influence language outcomes. Factors investigated include those related to language acquisition universals, the AAC system, the young aided AAC user, and practices, philosophies, and beliefs of speech-language pathologists (SLPs). Further examined were: (a) language acquisition parallels in atypical populations who do not possess the full range of senses who have been shown to develop language, and (b) analogies between the linguistic structures of pidgins, interlanguages, and the syntax of young aided AAC users. This dissertation employed a survey methodology to capture the practices and beliefs of SLPs as a means of identifying potential contributing factors to the reduced linguistic outcomes of these children. Quantitative findings revealed statistically significant differences in SLPs’ perceptions of confidence and qualification with the two populations of children with language impairments who use an oral modality and young aided AAC users. Descriptive trends across all constructs measured suggested differences in SLPs’ practices, belifes, and perspectives in their work with these two populations. The analysis of the syntactic structures of the language of young aided AAC users revealed definitive parallels with the construct of interlanguages.