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published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

The topic of this work is motor imagery. Through 7 different studies, the process and proprieties of motor imagery and its impact on motor learning were assessed. It was found that this cognitive activity is closely linked to the motor system. This characteristic underlies the positive effects of motor imagery on motor learning. This can have many practical applications in the domain of sport and motor rehabilitation.

Call number: LD2668 .T4 1986 W32 / Master of Science / Physical Education, Dance, and Leisure Studies

Over the past several decades, cognitive and behavioral scientists have been researching the most effective practices for training muscles to produce specific movements consistently and accurately. That research has led to relatively wide acceptance of several best practices for the training of motor skills. One such practice is the reduction in the frequency with which augmented (external) feedback is provided by the instructor/trainer during skill-acquisition. This theory of low-frequency feedback has been examined by research in a wide variety of fields ranging from exercise and sport to voice therapy and rehabilitation. Prior to the study reported here, however, this theory had not been applied the acquisition of vocal skills associated with classical singing techniques. The current research consisted of an alternating treatment single-subject study, which was conducted on a college campus over the course of a 15-week semester. 8 college voice students (3 male and 5 female) ranging in age from 18 to 25 participated in voice lessons provided by the researcher and aimed at improving the overall quality of the voices of the participants. Over the course of the15 weeks, the instructor alternated between providing a high-frequency feedback (HFF) instruction condition and a low-frequency feedback (LFF) instruction condition. At the beginning of each session, a vocal sample was recorded to test the retention of the skills trained in the previous lesson. Those recordings were evaluated by a panel of five college voice instructors who provided a numerical score (out of a possible 100 pts.) for each sample on the basis of tone quality, breath management, and intonation. The results of this study indicated that three of the eight subjects retained more vocal skill ability during the HFF phases of the study, while the remaining five subjects retained less vocal skill ability during the HFF phases of the study. It was also seen that the three subjects who responded favorably to the HFF instruction condition were also those whose scores were higher throughout the duration of the study. These findings would appear to indicate that an HFF instruction condition may be more beneficial to more experienced or more skilled singers, while an LFF instruction condition may be more beneficial to more novice singers. In the final chapter of this report, several modifications to this study are suggested along with suggestions for future research regarding the application of other principles from motor-learning theory to the acquisition of new vocal skills.

The ability of spatial transfer to occur in movement sequences is reflected upon in theoretical perspectives, but limited research has been done to verify to what extent spatial characteristics of a sequential learning task occur. Three experiments were designed to determine participants’ ability to transfer a learned movement sequence to new spatial locations. A 16-element dynamic arm movement sequence was used in all experiments. The task required participants to move a horizontal lever to sequentially projected targets. Experiment 1 included 2 groups. One group practiced a pattern in which targets were located at 20, 40, 60, and 80° from the start position. The other group practiced a pattern with targets at 20, 26.67, 60, and 80°. The results indicated that participants could effectively transfer to new target configurations regardless of whether they required proportional or non-proportional spatial changes to the movement pattern. Experiment 2 assessed the effects of extended practice on proportional and non-proportional spatial transfer. The data indicated that while participants can effectively transfer to both proportional and non-proportional spatial transfer conditions after one day of practice, they are only effective at transferring to proportional transfer conditions after 4 days of practice. The results are discussed in terms of the mechanism by which response sequences become increasingly specific over extended practice in an attempt to optimize movement production. Just as response sequences became more fluent and thus more specific with extended practice in Experiment 2, Experiment 3 tested whether this stage of specificity may occur sooner in an easier task than in a more difficult task. The 2 groups in Experiment 3 included a less difficult sequential pattern practiced over either 1 or 4 days. The results support the existence of practice improvement limitations based upon simplicity versus complexity of the task.

This dissertation is comprised of three studies investigating the hypothesis that people who stutter (PWS) differ from people who do not stutter (PNS) in their motor skill learning abilities. The first study in this dissertation examined the ability to learn a novel sequential speech task following a 24-h retention period. Despite slower sequence durations compared to the PNS, PWS showed the ability to retain what they had learned for all measured variables on day one and following a 24-h consolidation period. The second study in this dissertation examined the ability to learn a sequential finger tapping task by observing the ability to produce the sequence under both tests of retention and interference. For tests of retention, PWS showed the ability to retain improvements in performance for all measured variables, albeit at slower speeds compared to PNS. For tests of interference, a significant interaction for reaction time and sequence duration revealed that PNS’ performance reached a relative plateau while PWS’ performance continued to show improvement. The third study in this dissertation investigated the extent to which individual differences in motor learning are associated with differences in stuttering treatment outcome. PWS participating in an intensive fluency treatment program were assessed for their working memory ability and their motor iii learning performance on a syllable reading and finger tapping task. Treatment success was measured at pre-treatment, post-treatment and six months follow-up using percent syllables stuttered, introspective clinical characteristics (OASES; Yaruss, 2010) and fluency effort. The relationship between motor learning and treatment outcome was examined using multiple regression analyses. Results did not support the hypothesis that the ability to learn a simple speech and nonspeech motor task is predictive of treatment outcome. Although treatment proved successful as evidenced by percent syllables stuttered and OASES scores, scores of fluency effort indicated that participants had not automated their newly learned fluency skills when speaking in everyday conversations. Together, these studies do not support the hypothesis of a motor learning deficit in PWS but rather support the assumption of limited motor abilities. Limited motor abilities are discussed as having implications to stuttering treatment outcome.

Simulation has not been extensively studied for teaching rehabilitation practitioners technical skills. The purpose of this study is to test the efficacy of an artificial hand as a teaching tool for orthosis-making. Thirty-four participants were randomized into three groups. The first group made five orthoses on a human hand, the second made five orthoses on a model hand, and the third made one orthosis on a human hand. A one-week transfer test consisted of all participants making one orthosis on a human hand. Their performance and orthoses were evaluated using a validated checklist and global rating scale. No differences were found between groups for process-related measures. The model hand group did better on final product measures and had a larger movement time than the other two groups. Practicing on artificial hands is a useful way of learning to make orthoses. Additionally, higher practice volume did not lead to better performance.

Simulation has not been extensively studied for teaching rehabilitation practitioners technical skills. The purpose of this study is to test the efficacy of an artificial hand as a teaching tool for orthosis-making. Thirty-four participants were randomized into three groups. The first group made five orthoses on a human hand, the second made five orthoses on a model hand, and the third made one orthosis on a human hand. A one-week transfer test consisted of all participants making one orthosis on a human hand. Their performance and orthoses were evaluated using a validated checklist and global rating scale. No differences were found between groups for process-related measures. The model hand group did better on final product measures and had a larger movement time than the other two groups. Practicing on artificial hands is a useful way of learning to make orthoses. Additionally, higher practice volume did not lead to better performance.

The brain undergoes structural changes in response to new experiences like learning a new skill. Skilled motor movements depend greatly on the primary motor cortex for their execution. Recent studies describe rat strain differences in motor performance related to differential synaptic efficacy in the motor cortex of rats. Previous studies identified differences in motor performance related to differential dendritic morphology and strain related differences in synaptic function in the motor cortex. Strain differences are one way of investigating anatomical organization and behaviour of the motor system. The object of this research was to examine strain related differences in dendritic morphology in layer II / III pyramidal cells of the forelimb area of the sensory motor cortex in both Long-Evans and Fischer 344 rats after reach training. This research also examined whether changes in reaching behaviour could be attributed to changes in dendritic morphology. Rats were trained once a day for 30 days to reach for a food pellet through a slot in a reaching box. Pyramidal cells in the motor sensory forelimb (MSF) cortex were stained with the Golgi Cox method. Subsequent analysis of Sholl and branch order data of cell drawings determined that there were no significant differences in any measure of dendritic length or dendritic length at branch order 3, 4, 5 of pyramidal cells in layer II/III of the MSF cortex between the Long Evans and Fischer 344 rat strain. The only significant strain related difference was that the Fischer 344 strain exhibited fewer reaches for each food pellet obtained, demonstrating greater reaching proficiency than similarly trained Long-Evans rats. These findings suggest that further research examining strain comparisons is required to understand the neural mechanisms underlying the differences in motor behaviour observed in these rat strains. / October 2006