published_or_final_version / abstract / toc / Orthopaedics and Traumatology / Master / Master of Philosophy

published_or_final_version / Physiology / Master / Master of Philosophy

No description available.

When a formant transition (isolated transition) and the remainder (base) of a synthesized syllable are presented to opposite ears most subjects perceive two simultaneous sounds, a syllable and a nonspeech chirp. The isolated transition determines the identity of the syllable at one ear and, at the same time, is perceived as a chirp at the opposite ear. This phenomenon, called duplex perception, has been interpreted as the result of the independent operation of two perceptual modes, the phonetic and the auditory mode. In order to test this hypothesis, the isolated transition was preceded and followed by a series of identical transitions sent to the same ear. This streaming procedure weakened the contribution of the transition to the perceived phonetic identity of the syllable. This weakening effect could have been explained in terms of the habituation of an hypothetical phonetic feature detector sensitive to the repetition of identical transitions. For this reason, the same effect was replicated by capturing the isolated transition with others which were aligned on the same frequency-by-time trajectory as the isolated one. These findings are consistent with the idea that the integration of the transition with the base was affected by the operation of general-purpose auditory processes. This contrasts with the hypothesis that the phonetic mode integrated the dichotic stimuli independently of the auditory mode.

The objectives of the investigation were to establish diagnostic reference data; and to examine and report on the effects of sex difference and contralateral masking on the normal BAER. BAERs were elicited from the target (R) ear using clicks presented at 70dBnHL both in the absence and presence of three (50, 6O and 70dBHL) levels of contralateral broadband masking noise. Relevant latency and amplitude data were obtained from 60 selected normal hearing Indian undergraduate female (N=30; X age = 20.33 years) and male (N=30; X age = 21.33 years) students aged between 18 and 25 years (X age = 20.73 years). Diagnostic reference data were established for the absolute latencies of peaks I to VI; relative latencies of peaks I-III; III-V and I-V; absolute amplitudes of peaks I and V and the relative amplitude ratio of peaks V:I. The application of the MANOVA revealed an overall significant (p < 0,05) sex difference effect while no significant differences were observed between the masked and non-masked normal BAER. Furthermore, there were no significant overall interactional effects of sex difference and masking on the BAER. These results are discussed in terms of the literature and implications for clinical application and further research. / Thesis (M.Sc.)-University of Durban-Westville, 1989.

Copies of author's previously published articles inserted. / Bibliography: leaves I-LXIV. / xxxviii, 239 [77], Lxiv leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Assesses the diagnostic and prognostic value of early electroencephalography (EEG) and somatosensory evoked potential studies in cortical and non-cortical ischaemic stroke. Both conventional and topographic/quantitative studies were performed. A parallel study was carried out on healthy volunteers to provide an effective control. Equipment and quantitative EEG (qEEG) variability was also assessed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1998?

Thesis (Ph. D.)--University of Adelaide, Dept. of Medicine, 1998? / Copies of author's previously published articles inserted. Includes bibliographical references (leaves I-LXIV).

Thesis (Ph. D.)--University of Sydney, 2001. / Includes published articles. Title from title screen (viewed Apr. 24, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Physics, Faculty of Science. Includes bibliography. Also available in print form.

Thesis (M.S. in neuroscience)--Washington State University, August 2008. / Includes bibliographical references (p. 22-29).

Thesis (Ph. D.)--UCLA, 2009. / Vita. Description based on print version record. Includes bibliographical references (leaves 69-79).