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<p> Emotion perception in speech has been shown to facilitate greater understanding and learning in adults as well as children. There is an atypical RH specialization for speech perception that exists in individuals with Down Syndrome (DS). Individuals with DS have a typical left hemisphere specialization for motor control and speech production, similar to those individuals from the general population which may cause a functional dissociation between speech perception and motor control for these individuals (Heath et al., 2000). What remains unknown is how this atypical lateralization may influence speech perception when emotional intonation is included with verbal stimuli. Using a free recall dichotic listening paradigm, it was found that individuals with DS process verbal stimuli similarly to mental-age matched peers (individuals with a developmental delay, and individuals for the general population.) To investigate this further, a directed attention paradigm was employed. Participants listened to a particular ear for either a particular word or emotion. It was found that individuals from the general population were more accurate than individuals from either of the other two groups for perception of the word. Also, an effect for Ear was found with the right ear being significantly more accurately perceived than the left for all three groups. When emotion was attended to specifically, the left ear was more accurately perceived than the right. These results are somewhat consistent with previous findings (e.g., Bulman-Fleming & Bryden, 1994) for participants from the general population however the expected lateralization in DS group was not evident. This lack of atypical RHA in individuals with DS may be related to the task itself.</p> / Thesis / Master of Science (MSc)

<p> Two experiments are reported that examine motor overflow in Down syndrome and nonretarded persons. The two main purposes of the experiments were to determine the utility of motor overflow as a diagnostic tool and the relationship between motor overflow and transfer of training. In Experiment 1, nonretarded children and adults performed a unimanual finger-sequencing task. It was found that motor overflow follows a developmental course. As well, a positive relationship was found between motor overflow and intermanual transfer of training, and children were able to reduce their ipsilateral motor overflow with training. These results indicate that caution should be taken in diagnosing central nervous system dysfunction of a structural nature using motor overflow. In Experiment 2, similar procedures were used to examine younger children and Down syndrome adults. It was found that with conscious effort, even the children could reduce their motor overflow. A positive relationship between transfer of training and motor overflow was also evidenced in Down syndrome subjects. As well, there was greater transfer of training from the left hand to the right hand than the reverse, in both Down syndrome adults and young, nonretarded children. These findings are discussed in reference to factors affecting the appearance of motor overflow and what can be learned about cerebral specialization in nonretarded and special populations.</p> / Thesis / Master of Science (MSc)

Twelve children without intellectual disability and 12 children and adolescents with Down syndrome were administered a short form of Roy and Black's (1998) Apraxia Battery. Participants with Down syndrome also completed a free-recall dichotic listening test. While the mean laterality indices for the group with Down syndrome was negative, indicative of a left ear-right hemisphere specialization for speech perception, they were not significantly different from zero. There was a wide range of individual variability in laterality, and individuals with a left ear advantage for speech perception performed more poorly on the portions of the apraxia battery that involved verbal instruction. The possibility that individuals with Down syndrome who have apraxia may constitute an important subset of individuals with Down syndrome was considered. The results are discussed within the framework of Elliott, Weeks, and Elliott's (1987) biological dissociation model. / Thesis / Master of Science (MS)

This study attempts to resolve to what extent individuals with Down syndrome benefit from advance information provided visually, versus the same information provided verbally when performing a manual aiming task. Adults with Down syndrome and undifferentiated developmental handicaps, as well as control subjects without a developmental handicap, performed manual aiming movements to targets 10.5 cm. away. On a particular trial, subjects were cued about the specific movement either visually or verbally. The cue provided either 50% or 80% certainty. Nonhandicapped control subjects initiated and completed their manual aiming movements more quickly than subjects with mental handicaps. As well, individuals with Down syndrome were found to be slower and more variable in reaction time than individuals in the other mentally handicapped group when valid information was provided verbally but not when the cue was provide visually. These results provide support for the Elliott and Weeks (1990) model of biological dissociation. Specifically, the atypical hemispheric lateralization for speech perception exhibited by individuals with Down syndrome results in a disruption in communication between functional systems responsible for the processing of verbal langauge, and the organization of complex movement. / Thesis / Master of Science (MS)

The neurobehavioural organization of speech perception and production in persons with Down Syndrome (DS) is still not clearly understood. The current study investigated the cerebral specialization for speech production using a mouth asymmetry paradigm. In right handed, non-handicapped subjects the mouth asymmetry methodology has shown a facilitation on the right side of the mouth during expressive speech. The right mouth asymmetry is believed to reflect the dominance of the left hemisphere for speech production (Graves, Goodglass & Landis, 1982). In the present study the lateralization for the production of speech was investigated in 10 right handed participants with Down syndrome and 10 non-handicapped subjects. The results indicated that a tendency for a right mouth advantage (RMA) at the initiation and end of speech production occurred in both subject groups. Surprisingly, the degree of asymmetry did not differ, suggesting that the focal representation of speech production is lateralized similarly in both subject groups. Additionally, a high proportion of verbal errors were made by individuals with DS. These results are consistent with the model of biological dissociation (Elliott & Weeks, 1993), which asserts that individuals with DS are impaired on verbal-motor tasks due to the functional separation between speech perception centers in the right cerebral hemisphere, and speech production centers in the left cerebral hemisphere. / Thesis / Master of Science (MS)

This project considers how disability studies and rhetorical studies—specifically the area of medical rhetoric—might usefully inform one another. In particular, this project examines prenatal testing for Down syndrome as a rhetorical situation that initiates and circulates many different discourses about Down syndrome. Chapter One begins by examining a frequently cited statistic in critiques of prenatal testing—the estimated pregnancy termination rate after a prenatal diagnosis of Down syndrome. It explores the validity of this statistic and uses this discussion to suggest that the effects of prenatal testing on social understandings of Down syndrome are complex and largely unknown. Chapter Two argues that intellectual disabilities, like Down syndrome, are underrepresented in disability studies literature and that their absence can be partially attributed to models of disability used in the field. Chapter Three argues that rhetorical analysis provides a means of examining how Down syndrome is discursively constructed. Chapter Four describes the events of prenatal testing for Down syndrome and analyzes the events as a rhetorical situation. In addition, it reviews feminist, disability, and cultural critiques of prenatal testing demonstrating the strengths of each strand of scholarship and suggesting where rhetorical analysis might provide new information. Chapters Five and Six provide analysis of two commentaries on the rhetorical situation of prenatal testing—genetic counseling discourse and parent discourse. These chapters find that ideal genetic counseling discourse offers pregnant women some opportunities to resist medicalization but also exhibits tension between what counselors say they do and what their rhetorical practice affords, especially regarding disability. In addition, analysis shows that users of prenatal testing are concerned with several factors of decision-making that are either not emphasized or ignored entirely in genetic counseling discourse. This project concludes that although different discourses about Down syndrome are available, elements of the prenatal testing situation make it easier for participants to draw on some discourses rather than others. Furthermore, it appears that certain events in the prenatal testing situation—such as the offer of amniocentesis—operate rhetorically in tacit ways, obscuring the relationship between the choice to undergo genetic screening and perceived meanings of Down syndrome. / Ph. D.

Down syndrome (DS) is the most common genetic condition caused by an extra copy of chromosome 21. Adults with DS have cardiovascular and metabolic alteration, which may lead to an increased number of cardiovascular disease risk factors in this population. Such impairments may affect their ability to exercise and perform moderate-to-vigorous physical activity (MVPA). Moreover, MVPA may affect arterial health differently in adults with DS due to endothelial dysfunction and sympathetic impairment. The purpose of this dissertation was to investigate differences in cardiovascular health and physical activity (PA) profiles between adults with and without DS. Specific aims of this dissertation were to determine whether traditional cardiovascular disease risk factors predict arterial stiffness in adults with and without DS, investigate differences in PA and sedentary behavior (SB) levels and patterns using population-specific activity intensity cut-points in adults with and without DS, and to investigate whether DS moderates the relationship between SB and MVPA levels and arterial stiffness. Results from stepwise linear regression indicated that age, DS, and waist circumference significantly predicted arterial stiffness for the entire sample, and that many of the risk factors that predict arterial stiffness in adults without DS – body composition, blood pressure, and MVPA – do not predict arterial stiffness in adults with DS. Results from mixed-model ANOVA indicated that adults with DS had less sedentary time but greater MVPA than adults without DS and that adults with DS performed greater number of sedentary and MVPA bouts than adults without DS; however, these bouts were of shorter duration. Lastly, results from moderation analysis indicated that DS moderated the relationship between MVPA and arterial stiffness; however, the effect of age was greater than MVPA or DS on arterial stiffness. Adults with DS have greater number of cardiovascular disease risk factors than adults without DS; however, this does not appear to increase arterial stiffness. Furthermore, adults with DS may have better PA and SB profiles than adults without DS; however, MVPA levels do not affect arterial stiffness in this population. Therefore, differences in cardiovascular health and PA profiles may identify disparities in health between adults with and without DS.

Autonomous physical activity (PA) is challenging for adults with Down syndrome (DS) therefore PA programs tailored around facilitators of PA in individuals with Down syndrome (DS) that also align with Self-determination theory (SDT) components could be a feasible and effective way of increasing PA. The purpose was to assess the feasibility and effectiveness of a physical activity program based on self-determination theory in adults with Down syndrome. A dance program was conducted twice a week for 8 weeks. Each session was 60 minutes long. Adults with DS (n = 8) were tested before and after intervention for basic psychological needs satisfaction and physical performance. There were significant changes in some physical and psychological measures. The study demonstrated that a low-resource dance program based on SDT can be a feasible and effective way to engage adults with DS in physical activity