Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2008. / Title from first page of PDF file (viewed July 10, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 332-356).

Thesis (M.Communication Pathology) -- University pf Pretoria, 2000. / Summary in English and Afrikaans.

Thesis--M. Soc. Sc., University of Hong Kong. / Typewritten.

published_or_final_version / Sports Science / Master / Master of Science in Sports Science

Speech, writing, and tool-use are all prime examples of everyday learned motor skills that together with dance, music, and sports performance represent the full glory of human cultural expression afforded by dexterous digits, limbs, and bodies. Learning to subconsciously move parts of our body is an underappreciated function of the brain. This dissertation aims to illuminate this process through a series of studies using the zebra finch as a model system. It addresses two major questions. First, what level of modularity is involved in motor learning? Specifically, can we decompose complex learned skills, such as the zebra finch song, into their distinct components such as spectral and temporal aspects? And if so, how independent are these various aspects of motor skill learning and execution from one another? Second, to what degree are the basal ganglia, essential and phylogenetically conserved parts of the motor system, involved in different aspects of motor skill learning? In Chapter 1 of this dissertation, I describe the complex learned vocalization of the zebra finch as a model for understanding these questions, highlighting the use of a rapid and well-controlled learning paradigm termed conditional auditory feedback (CAF). In Chapter 2, using CAF, focal lesions and recordings, I test the role of a songbird basal ganglia pathway in distinct aspects of motor learning. I find that the basal ganglia pathway is necessary for learning spectral but not temporal aspects of the song whereas a pre-motor cortical area encodes changes in the temporal but not spectral structure, suggesting a modularity in birdsong motor learning. In Chapter 3, I infer the mechanisms underlying the basal ganglia-independent temporal learning. Further CAF experiments demonstrate that the nervous system is capable of flexibly modifying temporal structure in one part of the song without affecting the timing in the rest of the song, uncovering yet another level of modularity in encoding song structure. Chapters 2 and 3 provide evidence for the modularity in learning the mean spectral and temporal structure. However, motor performance is also characterized by its trial-to-trial variability around the mean. In Chapter 4, I describe CAF experiments to interrogate the neural basis underlying changes in variability around a mean. I show that spectral variability can be modulated in a very specific manner and independently in different parts of the song. I show that this temporally-specific modulation of variability is mediated by the basal ganglia. Overall, the dissertation suggests that complex motor skills emerge from basic functional modules that independently learn, modulate, and control distinct aspects of learned motor output.

In adult rats, following unilateral stroke-like injury to the motor cortex, there is significant loss of function in the forelimb contralateral to the ischemic damage. In the remaining motor cortex, changes in neuronal activation patterns and connectivity are induced following motor learning and rehabilitation in the brains of adult animals. Rehabilitative training promotes functional recovery of the impaired forelimb following motor cortical strokes; however, its benefits are most efficacious when coupled with other rehabilitative treatments. Multiple lines of evidence suggest that focal cortical electrical stimulation (CS) enhances the effectiveness of rehabilitative training (RT) and promotes changes in neural activation and plasticity in the peri-lesion motor cortex. Specific examples of plastic events include increases in dendritic and synaptic density in the peri-lesion cortex following CS/RT compared to rehabilitative training alone. The objective of these studies was to investigate which conditions, such as timing and method of delivery of CS, when coupled with RT, are most efficacious in promoting neuronal plasticity and functional recovery of the impaired forelimb following ischemic cortical injury in adult animals. The central hypothesis of these dissertation studies is that, following unilateral stroke-like injury, CS improves the functional recovery of the impaired forelimb and promotes neural plasticity in remaining motor cortex when combined with RT. This hypothesis was tested in a series of experiments manipulating post-ischemic behavioral experience with the impaired forelimb. Adult rats were proficient in a motor skill (Single Pellet Retrieval Task) and received ischemic motor cortex lesion that caused impairments in the forelimb. Rats received daily rehabilitative training on a tray reaching task with or without concurrent cortical stimulation. Epidural cortical stimulation, when paired with rehabilitative training, resulted in enhanced reaching performance compared to RT alone when initiated 14 days after lesion. These results were found to be maintained well after the treatment period ended. Rats tested 9-10 months post-rehabilitative training on the single pellet retrieval task continued to have greater reaching performance compared to RT alone. However, delayed onset of rehabilitative training (3 months post-infarct) indicated that CS does not further improve forelimb function compared to RT along. It was further established that CS delivered over the intact skull (transcranial stimulation) of the lesioned motor cortex was not a beneficial adjunct to rehabilitative training. Together these dissertation studies provide insight into the effectiveness and limitations of CS on behavioral recovery. The findings in these studies are likely to be important for understanding how post-stroke behavioral interventions and adjunct therapies could be used to optimize brain reorganization and functional outcome. / text

published_or_final_version / Psychology / Master / Master of Social Sciences

No description available.

No description available.

The purpose of this study was to explore the relationship between divergent thinking and Schmidt's schema theory of motor learning in a population of first year University physical education students. / Problem solving teaching methodology was used as the intervention program in this study and the main sources of data were the Torrance Tests of Creative Thinking and tests of Schmidt's schema theory designed by the researcher. Descriptive data were used to explain the intervention program. / A mixed model analysis of variance was used to compare the pre-test and post-test performance on Torrance Tests of Creative Thinking (TTCT), and the Pearson product-moment correlation technique was used to compare the results of the TTCT post-test and the Schmidt test. / Results showed minimal differences attributable to the intervention and no relationships between the two tests. Analysis of the descriptive data suggests several limitations to the intervention program and some suggestions for further research are offered.