The emergence of language is a phenomenon that lies at the core of higher human cognition and which continues to be the source of controversy and debate. In a series of three studies, the present thesis examined issues pertaining to language acquisition, (i) providing insight into the origins of language by addressing the question of whether the basis of babbling is fundamentally motoric or linguistic, (ii) positing new properties of babbling in order to discriminate between the linguistic and non-linguistic behaviors produced by babies, and (iii) describing the processes underlying babies' transition from babbles to first words. In Manuscript 1, using Optotrak, the manual activity of six hearing babies was examined (at ages 6, 10 and 12 months; 3 babies were exposed to a signed language and 3 to a spoken language). Analyses revealed that only the sign-exposed babies produced linguistic activity (manual babbling) at a frequency of approximately 1 Hz and subsequent videotape analyses revealed that babbling was produced in the linguistic signing space. Non-linguistic activity was produced by both groups of babies at approximately 2.5 Hz and fell outside the signing space. In Manuscript 2, the oral activity of ten hearing babies acquiring a spoken language was examined for evidence of mouth asymmetry (between ages 5 and 12 months). Right mouth opening was observed only while the babies were babbling (reflecting left hemisphere language specialization), as contrasted with equal or left mouth opening for non-linguistic oral activity. In Manuscript 3, a combination of sources (videotapes, parental reports, interviews, and experimenter notes) was used to examine how six hearing bilingual babies acquired the meanings of words/signs across their two languages (from ages 7 to 26 months; 3 babies were exposed to a signed and a spoken language and 3 to two spoken languages). The babies constrained, organized, and used their first words/signs in simila

Thesis (M.A.)--University of Adelaide, Dept. of Psychology, 1983. / Includes bibliographical references (leaves 361-376).

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 676-721). Also available by subscription via World Wide Web.

Thesis (M.A.)--Youngstown State University, 1997. / Includes bibliographical references (leaves 53-56).

Thesis (M.A.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 58-62)

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [154]-163).

Thesis (B.Sc)--University of Hong Kong, 2005. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2005." Also available in print.

Thesis (Ed. D.)--Teachers College, Columbia University. / Typescript; issued also on microfilm. Sponsor: Dwayne E. Huebner. Dissertation Committee: Patrick C. Lee. Bibliography: leaves 120-133.

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (p. 222-230). Also available in print.