Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Victoria-Maria MacDonald, Florida State University, College of Education, Dept. of Educational Leadership and Policy Studies. Title and description from dissertation home page (viewed Sept. 23, 2004). Includes bibliographical references.

Thesis (Ph.D.)--Florida State University, 2004. / Typescript. Includes bibliographical references (leaves 165-176).

Thesis (M.S.)-- Springfield College, 2006. / Bibliography: leaves 186-195.

Thesis (M.S.)--Springfield College, 2006. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

An examination of the composing processes of blind writers was conducted to determine the strategies used by these composers. Two individuals blind from birth and two persons blinded later in life participated in the study. Using participant observation and stimulated recall, the researcher examined the composing processes of these subjects. Each individual participated in four writing sessions and used the compose-aloud technique where by the composer repeats orally any thoughts that occur during writing. In addition, an interview was conducted with each participant which provided a writing history, attitude toward writing, and composing strategies. Results of the research indicated that blind writers use the same basic processes of writing as reported for sighted writers. Blind writers in this study did not make written plans prior to writing and spent between one and four minutes in prewriting. Planning was an ongoing feature of the composing process. The writers in this study demonstrated the recursive feature of composing. Rescanning was a continual part of their composing sessions . Three of the subjects reported using rescanning for planning and editing. One individual reported using rescanning for editing only. Some differences were found in the blind writers as compared to the research on sighted composers. First, blind writers averaged 39 rescansions per essay, while research on the sighted reported approximately six rescansions in each session. The difference in the number of rescansions between these two groups may be a result of the blind writer's need to locate position on the page or from a difference in short-term memory in the sighted and non-sighted. Writers blind from birth demonstrated a difference in the ability to organize an essay in the extensive mode. These composers made no global plans. Rather they allowed the writings to unfold as they wrote. This research would indicate that sight may have a role in composing.

It has been hypothesized that a disproportionate percentage of the blind population are learning disabled. In the past, norms and technology were not available to assess in a cost effective manner the blind client's neuropsychological functioning. Norms for the Wide Range Achievement Test - Revised (WRAT-R2) are now available for a blind population without any neuropsychological dysfunctioning. This study utilized the adapted WRAT-R2 and the Comprehensive Vocational Evaluation System (CVES), a neuropsychological test battery adapted for the blind, to investigate the possibility that learning disabilities are present in the adult blind population. Suspected learning disabled, blind subjects were compared with normal blind subjects. There were significant neuropsychological differences between the two groups.

Present trends in communication links between devices have opted for wireless instead of wired solutions. As a consequence, unlicensed bands have seen a rise in the interference level as more and more devices are introduced into the market place that take advantage of these free bands for their communication needs. Under these conditions, the receiver's ability to recognize and identify the presence of interference becomes increasingly important. In order for the receiver to make an optimal decision on the signal-of-interest, it has to be aware of the type (modulation) of interference as well as how the received signals are affected (channel) by these impediments in order to appropriately mitigate them. This dissertation addresses the blind (unaided) identification of the signal modulations and the channel in a Multiple Input Multiple Output (MIMO) system. The method presented herein takes advantage of the modulation induced periodicities of the signals in the system and uses higher-order cyclostationary statistics to extract the signal and channel unknowns. This method can be used to identify more signals in the system than antenna elements at the receiver (overloaded case). This dissertation presents a system theoretic analysis of the problem as well as describes the development of an algorithm that can be used in the identification of the channel and the modulation of the signals in the system. Linear and non-linear receivers are examined at the beginning of the manuscript in order to review the a priori information that is needed for each receiver configuration to function properly. / Ph. D.

While haptics, tactile displays, and other topics relating to non-visual user interfaces have been the subject of a variety of research initiatives, little has been done specifically related to those for blind driving. Many automation technologies have been developed for the purpose of assisting and improving the safety of sighted drivers, but to enable a true driving experience without any sense of sight has been an essentially overlooked area of study. Since 2005, the Robotics & Mechanisms Laboratory at Virginia Tech has assumed the task of developing non-visual interfaces for driving through the Blind Driver Challenge®, a project funded by the National Federation of the Blind. The objective here is not to develop a vehicle that will autonomously mobilize blind people, but to develop a vehicle that a blind person can actively and independently operate based on information communicated by non-visual interfaces. This thesis proposes some generalized considerations for the development of non-visual interfaces for driving, using the instructional interfaces developed for the Blind Driver Challenge® as a case study. A model is suggested for the function of blind driving as an open-loop control system, wherein the human is an input/output device. Further, a discussion is presented on the relationship between the bandwidth of information communicated to the driver, the amount of human decision-making involved in blind driving, and the cultivation of driver independence. The considerations proposed here are intended to apply generally to the process of non-visual interface development for driving, enabling efficient concept generation and evaluation. / Master of Science

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Early visual processing is subject to binocular interactions because cells in striate cortex show binocular responses and ocular dominance (Hubel & Weisel, 1968). The work presented in this thesis suggests that these physiological interactions can be revealed in psychophysical experiments using normal human observers. In the region corresponding to the blind spot, where binocular interactions differ from areas of the visual field which are represented by two eyes, monocular contrast sensitivity is increased. This finding can be partially explained by an absence of normal binocular interactions in this location (Chapter 2). A hemianopic patient was studied in an attempt to discover whether the effect in normal observers was mediated by either a mechanism in striate cortex or via a subcortical pathway. However, the results were unable to distinguish between these two explanations (Chapter 3).In a visual search task, no difference in reaction time was observed for targets presented to the region corresponding to the blind spot compared with targets presented to adjacent binocularly represented areas of the visual field. Since performance was unaffected by the monocularity of the region corresponding to the blind, pop-out for orientation may be mediated beyond striate cortex where cells are binocularly balanced (Chapter 5). Further support for this contention was provided by studies of orientation pop-out in central vision which found that dichoptic presentation of stimuli did not affect the degree of pop-out obtained and that in general, visual search for a target based solely on eye of origin is impossible (Chapter 6). However, a task that measured orientation difference sensitivity more directly than the search experiments, found that thresholds were higher for dichoptically presented stimuli. This suggests the involvement of neurons that receive a weighted input from each eye. A model of orientation difference coding can account for the results by assuming that the range of inhibition across which orientation differences are coded is narrower for dichoptic stimuli leading to a greater resolvable orientation difference (Chapter 7).