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This thesis studies the acquisition of spatial knowledge, through the use of virtual reality, and the role that audio can have in this type of learning. Two versions of a simulator were developed, one with the presence of audio and the other one without. 26 participants, divided into two groups (one group per version), were tested the simulator. The goal is to understand if the version with audio would lead to greater learning than the other. The results show that there was no difference between the groups and that they have learned in the same way. Both groups have subjects who suffered nausea or dizziness, with a greater presence in the group with the audio. Future work could consider trying to reduce the problem of these symptoms to have a clearer analysis.

The following dissertation describes a personal course of research into audio morphing technology, with a primary focus on how such research might impact the composition of contemporary, research-based art music. These two primary concerns have been augmented through considerations of both: the broader literature of musical morphology, and selected analyses from the history of western art music that employ an idiosyncratic interpretation of audio morphing principles. I have attempted throughout to tightly focus these discussions through the lens of my own compositional activity, embodied by the accompanying dissertation composition for ten musicians/sound technicians (for chelsea smith) and its chapter-length analysis. Therefore, following a terminological distinction between appearances and usages of the terms morphing and morphology in the existing literature (Chapter 1), the above materials will be organized in order of their importance to my compositional activity. As such, the analysis of my dissertation composition (Chapter 2) will be presented first. This will be followed by a summary of my technical research (Chapter 3), and three highly personalized interpretations of how morphing principles might be said to apply to works from the past repertoire of the western tradition (Chapters 4-6). The morphing principles alluded to above include: the primacy of pure sound, the decomposition of complex sonic phenomena into simpler elements, the importance of continuous transformation, and the connection of disparate sonic entities through continua of new material. Such principles will not only inform my analyses of past music, but will also be revealed as central to my compositional perspective in for chelsea smith. / Graduate / 0413 / emaildfm@gmail.com

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With the wide-spread adoption of hypermedia systems and the World Wide Web (WWW) in particular, these systems have evolved from simple systems with only textual content to those that incorporate a large content base, which consists of a wide variety of document types. Also, with the increase in the number of users, there has grown a need for these systems to be accessible to a wider range of users. Consequently, the growth of the systems along with the number and variety of users require new presentation and navigation mechanisms for a wider audience. One of the new presentation methods is the audio-only presentation of hypertext content and this research proposes a novel solution to this problem for complex and dynamic systems. The hypothesis is that the proposed Audio Browser is an efficient tool for presenting hypertext in audio format, which will prove to be useful for several applications including browsers for visually-impaired and remote users. The Audio Browser provides audio-only browsing of contents in a Petri-based hypertext system called Context-Aware Trellis (caT). It uses a combination of synthesized speech and pre-recorded speech to allow its user to listen to contents of documents, follow links, and get information about the navigation process. It also has mechanisms for navigating within documents in order to allow users to view contents more quickly.

Crickets provide a useful model system to study how animals analyze sound frequency. While much is known about how sound frequency is represented by central neurons and in behavior, little is yet known about auditory receptor neurons. I investigated physiological and anatomical properties of auditory receptor fibers (ARFs) and functional organization of their axon terminals, using single-unit recording and staining techniques. Behavioral experiments suggest that crickets are sensitive to two broad frequency ranges, centered at 4--5 kHz for acoustic communication and at 25--50 kHz for predator detection. However, cricket ARFs fall into three distinct populations, based on characteristic frequency (CF; low frequency, ∼3--5.5 kHz; mid frequency, 9--12 kHz; ultrasound, ≥18 kHz). One striking characteristic of single ARFs is the occurrence of multiple sensitivity peaks at different frequencies, which implies that the wide audible range of crickets is mediated by these multiple sensitivity peaks, even though CFs of ARFs are clustered at the three small ranges. To understand how populations of ARFs code sound intensity, level-response functions are examined. Physiological parameters derived from level-response functions are diverse, and are systematically related to threshold within each population. Low-frequency ARFs comprise two distinct anatomical types, based on the distributions of axon terminals, which also differ physiologically. Thus, based on CF and anatomy, cricket ARFs can be classified into four distinct populations. To understand how information flows from peripheral to central neurons, the positions of varicosities, i.e. output sites, of ARF axon terminals are mapped on a two-dimensional coordinate system. In crickets, the ARF axon terminals are functionally organized with respect to frequency and intensity. Anatomical organization with respect to threshold is related to physiological organization, which may reduce non-linear effects in postsynaptic

Social (public speaking) anxiety disorder is the most prevalent of all anxiety disorders, and it often impairs social and occupational functioning. Intervention studies indicate that cognitive-behavioral therapy (CBT) is an efficacious treatment for social anxiety. However, access to therapists skilled in CBT for social anxiety is often difficult. In order to respond to the problem of access, the use of videoconferencing for mental health care has developed. No published study has investigated the efficacy of CBT for social anxiety when provided via videoconferencing. The purpose of this study, therefore, was to determine the efficacy of CBT for social anxiety when provided via videoconferencing. A single-case replication design was employed that included a baseline period of 3 weeks, followed by 12 weeks of . treatment, 1-week post-intervention period, and 3-month follow-up. Five participants completed treatment. It was hypothesized that participants would reduce their social anxiety symptoms (i.e., decrease anxiety during speech task, increase duration of speech task, and decrease public speaking anxiety) assessed on standardized measures of social anxiety. Exploratory analyses of changes in self-monitored social anxiety, negative cognitions (public self-consciousness, fear of negative evaluation, internal attributions), working alliance, client satisfaction with treatment, and client comfort with videoconferencing were also performed. Analyses included visual and statistical significance, as well as clinical significance (i.e., endstate functioning, social phobia diagnostic status). The results indicated that two of three hypotheses were supported (i.e., anxiety during speech task reduced and duration of speech task increased over time). At 3-month follow-up, treatment gains were maintained or improved further; 3 participants no longer met the DSM-IV-TR criteria for social anxiety disorder, and 4 participants met criteria for moderate or high level of endstate functioning (i.e., clinical significance). Exploratory analyses revealed that self-monitored social anxiety decreased for 3 of 5 participants, and that a decrease in negative cognitions was associated with a decrease in social anxiety. Working alliance ratings remained high throughout treatment. Satisfaction with videoconferencing decreased over treatment for the participant who did not improve. Generally, comfort with videoconferencing increased over time. The results offer preliminary support for further research about the efficacy of the intervention.

Investigating the Neural Correlates of Crossmodal Facilitation as a Result of Attentional Cueing: An Event-Related fMRI Study. Degree of Masters of Science, 2008 Zainab Fatima Institute of Medical Science, University of Toronto ABSTRACT Attentional cueing modulated neural processes differently depending on input modality. I used event-related fMRI to investigate how auditory and visual cues affected reaction times to auditory and visual targets. Behavioural results showed that responses were faster when: cues appeared first compared to targets and cues were auditory versus visual. The first result was supported by an increase in BOLD percent signal change in sensory cortices upon cue but not target presentation. Task-related activation patterns showed that the auditory cue activated auditory and visual cortices while the visual cue activated the visual cortices and the fronto-polar cortex. Next, I computed brain-behaviour correlations for both cue types which revealed that the auditory cue recruited medial visual areas and a fronto-parietal attentional network to mediate behaviour while the visual cue engaged a posterior network composed of lateral visual areas and subcortical structures. The results suggest that crossmodal facilitation occurs via independent neural pathways depending on cue modality.