Abstract not available

This thesis describes three boys diagnosed with dyspraxia and their whanau (families and extended families) as they enter and become part of a community gymnastics group in a city in New Zealand. The study builds on literature that has defined dyspraxia in terms of dysfunction, but generally failed to resolve the disorder. Through the social perspective of health and well-being, participation of children and adults with disabilities has been explored in terms of the person and the environments in which they participate; however, the influence activity itself has on participation has not been thoroughly described. There has been a growing interest in the participation of children with disabilities in recreation and leisure activities and this study provides an in depth cultural perspective of such participation in New Zealand context. This study aims to answer the question "What do children with dyspraxia and their whanau do in a gymnastics group, and what does it mean to them to participate?". The overarching question is "What is the culture of a community gymnastics group in which children with dyspraxia participate?". Ethnographic methodology is employed to ensure that the participants' perspectives, including the beliefs, values and meaning that their participation holds is portrayed, while the associated activities and behaviours are also captured. As the boys with dyspraxia and their whanau entered the gym, they built on their previous experiences to make sense of what they needed to do and what meaning the environment held. I had not planned on the boys being integrated with an established group, but on the first night they spontaneously joined in with a noncompetitive, mixed age, boys group. The parents perceived the Club as professional, while the boys were initially intimidated. Fortunately, the equipment, which made the gym look like a playground, enticed the boys to participate. To shift the boys from their initial perception of the gym being a playground, the coaches used two styles of An Ethnography of Children with Dyspraxia Participating in Gymnastics coaching to support and encourage their participation, while suppressing behaviour that did not fit with the norms of the Club. The boys needed to develop gymnastics skills and fit into the group to become gymnasts. The boys succeeded in fitting into the group by both developing skills and adapting their behaviour, while the type of boys without dyspraxia, the style of coaching afforded, the range of equipment and the activity of gymnastics itself meant that some of their initial difficulties were accommodated and they were seen as group members. The participants developed values and beliefs about what the boys participation in the group meant. Having fun and developing confidence and fitness were highlighted, while the social aspects (making friends and the whanau experiences) were also seen as important. The parents and coaches felt that the boys' experiences in gymnastics had an impact on them that would transfer to the world beyond the gym. This study contributes a qualitative perspective on the participation of children with disabilities in a sports occupation, with a focus on the cultural context of their participation.

In a honey bee colony, the queen uses queen mandibular pheromone (QMP) to induce young worker bees to feed and groom her. Among its many behavioural and physiological effects, QMP reduces dopamine levels in the brains of young worker bees. Dopamine is a biogenic monoamine involved in numerous functions including motor control and aversive learning. This study investigates the effects of QMP on motor activities and aversive learning behaviour and the potential link between QMP and dopamine levels in the brain of young bees. In young bees under the age of 15-days, QMP dramatically reduced locomotor activity and inhibited aversive learning behaviour. Interestingly in older bees these behaviours were not affected by pheromone. Treating young bees with the dopamine precursor, L-dopa (3.25 [mu]g/mI), partially rescued the levels of locomotor activity in QMP-treated bees, and reduced QMP�s effects on aversive learning. This suggests that blocking effects of QMP on both locomotor activity and aversive learning result at least in part from QMP-induced changes in brain dopamine levels. Two components of the QMP blend, 4-hydroxy-3-methoxyphenylethanol (HVA) and methyl p-hydroxybenzoate (HOB) were examined more closely. Both HVA and HOB are structurally similar to dopamine. HVA was found to mimic the effects of the full QMP blend on aversive learning. Treating bees with HVA reduced aversive learning in young bees. In contrast, treatment with HOB did not affect learning ability. This strongly suggests that HVA is one of the key components that mediates the actions of QMP on aversive learning. The final section of this thesis investigates why it might be advantageous to honey bee queens to block aversive learning and reduce locomotor activity in young worker bees. The study reveals age-related differences in behaviours that individual worker bees display towards QMP. Young bees reared with QMP or collected from a queenright hive showed attraction to QMP. Conversely, older bees displayed avoidance behaviour towards QMP. By blocking the establishment of aversive memories, young bees may be prevented from forming an association between QMP and any unpleasant side effects induced by this pheromone. This may confer significant benefit to the queen by increasing the likelihood of young workers remaining in her attendance.

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Nancy Getchell, Dept. of Health, Nutrition, and Exercise Sciences. Includes bibliographical references.

In spite of the long-standing tradition of including measures of visual-motor integration in psychological evaluations, visual-motor abilities have not been included in the Cattell-Horn-Carroll (CHC) theory of cognitive abilities or its complementary cross-battery approach to assessment. The purpose of this research was to identify the shared constructs of a popular test of visual-motor integration and a test of intellectual functioning, and to investigate how a test of visual-motor integration would be classified within the CHC model. A large normative sample of 3,015 participants that ranged in age from 5 to 97 years completed the Bender Visual-Motor Gestalt Test, Second Edition (Bender-Gestalt II; Brannigan & Decker, 2003) and the Stanford-Binet Intelligence Scale, Fifth Edition (SB5; Roid, 2003). Correlational analyses indicated positive moderate correlations across all age ranges between the Bender-Gestalt II Copy measure and the SB5 Nonverbal Visual-Spatial Processing subscale and between the Bender-Gestalt II Recall measure and the SB5 Nonverbal Visual-Spatial Processing and Nonverbal Working Memory subscales. Exploratory factor analyses revealed a three-factor model for four age groupings and four-factor model for one age grouping, suggesting factors which represent crystallized ability, fluid reasoning, and visual-motor ability. The results of this study suggest that the Bender-Gestalt II measures abilities that are not included in the SB5. Therefore, the Bender-Gestalt II would complement an intelligence test such as the SB5 in order to form a CHC Visual Processing (Gv) broad ability factor. These findings also address the need for further research to validate the constructs measured by newer versions of widely-used tests of cognitive ability.

Have you ever attempted to rub your abdomen with one hand while tapping your head with the other? Separately these movements are easy to perform but doing them together (bilateral task) requires motor adaptation. Motor adaptation is the process through which the Central Nervous System improves upon performance. Transfer of learning is the process through which learning a motor task in one condition improves performance in another condition. The purpose of this study was to determine whether transfer of learning occurs during bilateral goal-directed reaching tasks. It was hypothesized that transfer of learning would occur from the non-dominant to the dominant arm during bilateral tasks and that position and load feedback from the arms would affect the rate of adaptation and transfer of learning. During the experiments, subjects reached with one or both their index finger(s) to eight targets while a velocity dependent force perturbation (force environment) was applied to the arm(s). Three groups of bilateral tasks were examined: (1) unilateral reaching, where one arm learned to reach in a force environment, while the other arm remained stationary and therefore did not provide movement related position or load feedback; (2) bilateral reaching single load, where both arms performed reaching movements but only one arm learned a force environment and therefore the other arm provided movement related position feedback but not load feedback; (3) bilateral reaching two loads, where both arms performed reaching movements and both learned a force environment, while providing movement related position and load feedback. The rate of adaptation of the force environment was quantified as the speed at which the perturbed index finger trajectory became straight over the course of repeated task performance. The rate of adaptation was significantly slower for the dominant arm during the unilateral reaching tasks than during the bilateral reaching single load tasks (p<0.05). This indicates that the movement related position feedback from the non-dominant arm improved significantly the motor adaptation of the dominant arm; therefore transfer of learning occurred from the non-dominant to the dominant arm. The rate of adaptation for the non-dominant arm did not differ significantly (p>0.05) between the unilateral reaching and bilateral reaching single load tasks. Results also indicated that the rate of adaptation was significantly (p<0.05) faster for both the non-dominant and the dominant arms during the bilateral reaching two loads tasks than during the bilateral reaching single load tasks. The latter results indicate that transfer of learning occurred in both directions - from the dominant to the non-dominant arm and from the non-dominant to the dominant arm - when position and load feedback was available from both arms, but only when the force environment acted in the same joint direction. This study demonstrated that transfer of learning does occur during bilateral reaching tasks and that the direction and degree of transfer of learning may be modulated by the position and load feedback that is available to the central nervous system. This information may be used by physical therapists in order to improve rehabilitation strategies for the upper extremity.

Thesis (D. Phil.(Biokinetics, Sport and Leisure Sciences))--University of Pretoria, 2002. / Summary in English and Afrikaans. Includes bibliographical references.

published_or_final_version / Physiology / Master / Master of Medical Sciences

Accurate perception and control of self-motion is vital for human survival. Most animals rely on vision for navigating through complex environments. In this thesis, I investigated how vision influence perception and guide self-motion from two aspects: (1) what visual information humans pick up from the environment to form their perception and guide their self-motion; (2) how the degeneration of the basal ganglia and cerebellum, the two largest subcortical nuclei connecting the visual and motor areas of the brain, affect the controller’s performance. Study 1 examined the condition under which optic-flow information beyond velocity field helps heading perception. I systematically varied the amount of information in velocity field through manipulations of field of view (FOV). The amount of optic-flow information beyond velocity field was manipulated by two types of displays. I found heading bias increased with the reduction of FOV only when optic-flow information beyond velocity field was not available. Study 2 investigated whether the information investigated in Study 1 is sufficient and necessary for active control of heading. I used the similar display simulations as study 1 with the exception that the vehicle orientation was perturbed pseudo-randomly. Participants used a joystick, under both velocity and acceleration control dynamics, to continuously rotate the vehicle orientation back to its heading direction. The results showed that participants’ accurate performance under condition that only provided velocity field information was further improved when optic-flow information beyond velocity field was available. Study 3 examined the relative contributions of three visual cues (i.e., heading from optic flow, bearing, and splay angle) for lane-keeping control. Observers controlled the car’s lateral movement to stay in the center of the lane while facing two random perturbations affecting the use of bearing or splay angle information. I found that performance improved with enriched flow information. In the presence of splay angles, participants ignored bearing angle information. Study 4 investigated the roles of the basal ganglia and cerebellum in motor control task using brain-damaged patients. Participant’s task was to use the joystick to keep a blob in the center of the display while the horizontal position of the blob was perturbed pseudo-randomly. This task is not a self-motion task but mimics real-world lane-keeping control. Both the Parkinson’s disease patients and cerebellar patients showed impaired motor control performance in comparison with the healthy controls. In conclusion, the visual information used for motor control in general depends on the task. For traveling along a curved path, the velocity field contains sufficient information for heading perception and heading control. Optic-flow information beyond velocity field improves heading perception when the velocity field does not contain sufficient information. It also helps heading control when available. For lane-keeping control, adding optic flow information improves participants’ performance. Splay angle information plays a more important role than does bearing angle information. The visual information used for motor control changes when certain brain areas are damaged. Parkinson’s disease patients and cerebellar patients show the inability to process visual input effectively for online motor control. / published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Previous research has shown that fundamental movement skills (FMS) proficiency influences physical activity (PA) in children, such that those who are more proficient tend to be more active. Sufficient PA engagement in childhood has been associated with positive health outcomes, but little is known about PA levels in children with disabilities. Children with cerebral palsy (CP) represent the largest diagnostic group in pediatric rehabilitation. In one systematic review and six studies, FMS proficiency and PA levels among children with CP were measured, analyzed, and compared with typically developing children. The lack of a valid objective PA measurement method for children with CP was determined in the systematic review, and the first study (Chapter 2) validated the Actigraph accelerometer as a valid objective PA measurement instrument in this population group. FMS measurement in children with CP was addressed in the second study (Chapter 3), which showed that process-and product-oriented measurement are both important in characterizing FMS proficiency in a holistic manner. With the said measurement techniques validated, the third study (Chapter 4) utilized a cross- sectional study design to examine FMS proficiency and PA in children with and without CP. It was found that children were less active and more sedentary during weekends than weekdays. FMS proficiency was negatively associated with sedentary time and positively associated with time spent in moderate to vigorous PA in both groups of children. Process-oriented FMS measures were found to have a stronger influence on PA in children with CP than in typically developing children. With the intention to examine these relationships in a cause-effect study design, a theoretical model for FMS training programs was tested in children with and without disabilities in the fourth and fifth studies (Chapter 5). A movement training approach that minimized the amount of practice errors was found to facilitate improvements in FMS proficiency. This approach was then utilized in the sixth study (Chapter 6), wherein the relationship of FMS proficiency and PA were examined in a quasi-experimental design. It was found that by training FMS, weekend PA was heightened and weekend sedentary time was decreased among children with CP. In comparison, typically developing children manifested decreased weekend sedentary time after FMS training. The findings from these studies contribute to understanding the measurement of FMS and PA in children with CP, the implementation of FMS training in children in general, and the relationship between FMS and PA in children with and without disabilities. / published_or_final_version / Human Performance / Doctoral / Doctor of Philosophy