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 spatiotemporal dynamics of ongoing beta band (15-30 Hz) cortical oscillations and the modulation of this neural activity by tactile input and movement provide insight into how the brain achieves proper sensorimotor processing. Earlier studies have shown that the synchrony of the cortical beta rhythms within and between central and peripheral neuronal populations is modulated during and following somatosensation or movement, and correlated with effective motor control. In addition, abnormal levels of beta oscillations in the basal ganglia are correlated with motor dysfunction in Parkinson’s disease. Numerous functional roles for the beta rhythm have been proposed – ranging from inhibition to the facilitation of long-range communication. However, the neural network that generates the sensorimotor beta rhythm and the functional significance of this activity have not been fully specified. Thus, I used magnetoencephalography to complete three studies of the beta rhythm in healthy right-handed adults. In the first study, I hypothesized that finger vibration at beta frequencies would generate stimulus-coherent neuronal firing in the neural network that generates the beta rhythm – thus revealing the nodes of this network. Data were analyzed for nineteen subjects (10 females). The coherent activity was revealed using a novel analysis technique that generated whole-brain maps of inter-trial synchrony during passive repetitive finger vibration at 23 Hz. These maps identified contralateral primary somatosensory cortex (SI), posterior parietal cortex, supplementary motor area and primary motor cortex (MI), and ipsilateral brainstem as nodes in the network. In the second study, I correlated changes in focused attention with modulations in beta band cortical responses to specify the functional significance of this activity. Data were analyzed for twelve subjects (7 females). With increased focused attention to the stimulus, I hypothesized that the beta band responses to finger vibration would be enhanced in areas involved in somatosensory processing. A transient increase in the magnitude of beta oscillations in MI (event-related synchronization) following vibration offset was significantly enhanced by attention, as compared to passive stimulation. In addition, attention caused the suppression of beta oscillations (event-related desynchronization, ERD) in ipsilateral SI beginning 1 second prior to vibration offset. Strong attention-modulation of the beta rhythm outside of contralateral SI implies that these changes are indicative of higher-order processing of afferent information. In the third study, I tested the hypothesis that synchrony between beta rhythms in contralateral MI and the relevant muscle supports effective neuronal communication. I correlated changes in task performance with corticomuscular coherence (CMC) during the sustained application of force to match a visually-presented target. Data were analyzed for eighteen subjects (9 females). As predicted, CMC in MI was significantly increased during improved performance in this task. This suggests that central-peripheral synchrony plays an important functional role in sustaining isometric muscle control. Concurrent beta ERD in bilateral SI and primary visual cortices during the contraction indicates the importance of afferent feedback in this task. Gender-related effects were not investigated in these studies. Beta band neuromagnetic responses to movement and somatosensation identify a pervasive neural network that is involved in processing the relevant properties of somatic input and regulating sustained motor output.

It is widely thought that emotional stimuli receive privileged neural status compared to their non-affective counterparts. This prioritization, however, comes at a cost, as the neural capacity of the human brain is finite; the prioritization of any one object comes at the expense of other concurrent objects in the visual array competing for awareness (Desimone & Duncan, 1995). Despite this reality, little work has examined the functional benefit derived from the perceptual prioritization of affective information. Why do we preferentially attend to emotional faces? According to evolutionary accounts, emotions originated as adaptations towards action, helping to prepare the organism for movement (Darwin, 1872; Frijda, 1986). The current dissertation examines this from the perceptive of visual neuroscience and motor cognition. Chapters 1 and 2 examine the mechanisms involved during the perceptual prioritization of emotional content in the context of action system modulation. Chapters 3 and 4 then directly examine emotions effect on oculomotor action output. Results across the studies are discussed in the context of evolutionary theories related to biological origins of emotional expression.

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

Damage to motor areas of the brain, caused by stroke, can produce devastating motor deficits, including aberrant control of force. After stroke, reorganization of the brain’s motor system has been identified as one of the fundamental mechanisms involved in recovery of motor control after stroke. Yet, few studies have investigated how force production and modulation are encoded in the brain after stroke and how this relates to motor outcome. Thus, the purpose of this study was to (1) understand how past neuroimaging literature has contributed to establishing common patterns of brain reorganization during both relative and absolute force production after stroke, (2) examine how brain function is reorganized during force production and modulation in individuals with stroke, and (3) relate this task-related reorganization of brain function to the amount of paretic arm use after stroke. In the second chapter, we systematically reviewed all relevant literature examining brain activation during force production after stroke. The following chapters (chapters 3 and 4) applied functional magnetic resonance imaging (fMRI) to examine the neural correlates of force production and modulation after stroke. Chapter 2 supports differences in task-related brain activation dependent on features of stroke, such as severity and chronicity, as well as influence of rehabilitation. In addition, results suggest that activation of common motor areas of the brain during force production can be identified in relation to functional outcome after stroke. Results from the subsequent two chapters (3 and 4), demonstrate that brain function reorganizes in terms of absolute, and not relative force production after stroke. Specifically, stroke participants exhibit greater activation of motor areas than healthy controls when matched for absolute force production. Moreover, there is a relationship between paretic arm usage and brain activation, where stroke participants having less paretic arm use, as measured using wrist accelerometers, exhibit higher brain activation. Results of this thesis suggest that during absolute force production, brain activation may approach near maximal levels in stroke participants at lower forces than healthy controls. Furthermore, this effect may be amplified even further in subjects with less paretic arm usage, as increased activation in motor areas occurs in participants with less arm use after stroke. Ultimately, the results from this thesis will contribute to research relevant to brain reorganization in individuals with stroke and may lead to the development of new, beneficial therapeutic interventions that optimize brain reorganization and improve functional recovery after stroke.

Since the onset of automation, industry has relied on adjustable speed drives to accurately control the speed of motors. Recent advances have increased the number of adjustable speed drives hitting the market. The proper operation of the speed drives requires electrical supply with relatively high power quality which is not the case in most industrial facilities. Power quality problems such as harmonic, sag, swell, flicker, and unbalance can trip the speed drive with a wrong message, which is referred as a premature tripping. Although the power quality problems can be mitigated by using custom power devices, they are bulky and costly. Moreover, they themselves might adversely affect the operation of the adjustable speed drive. A comprehensive study done in this thesis presents the overlooked effect of the custom power devices on the speed drive stability. It is found that the speed drive system might trip due to its interaction with custom power devices. Obviously, it is vital to increase ASD immunity to premature tripping because of poor power quality or custom power. This thesis offers fast, efficient and robust algorithms to achieve this immunity by retrofitting the ASD control unit and integrating the power conditioning function with the adjustable speed drive. Therefore, the power quality problem is mitigated and the drive system performance is significantly enhamced. Such integration requires the modification of the control unit by considering various elements such as envelope tracking, phase-locked loop, symmetrical component extraction, and the controller. Simple but robust and fast algorithms are proposed for such elements based on a newly developed energy operator algorithm. The developed energy operator and the developed algorithms overcome the drawbacks of the existing algorithms.

Motor unit number estimation (MUNE) is an electrodiagnostic procedure used to estimate the number of MUs in a muscle. In this thesis, a new MUNE technique, called Automated MPS, has been developed to overcome the shortcomings of two current techniques, namely MPS and MUESA. This method can be summarized as follows. First, a muscle is stimulated with a train of constant intensity current pulses. Depending on various factors, one to three MUs activate probabilistically after each pulse, and several responses are collected. These collected responses should be divided into up to 2^n clusters, such that each cluster represents one possible combination of n Surface-detected Motor Unit Potentials (SMUPs). After clustering the collected responses, the average response of each cluster is calculated, the outliers are excluded, and similar groups are merged together. Then, depending on the number of response set groups, a decomposition technique is applied to the response clusters to obtain the $n$ constituent SMUPs. To estimate the number of MUs, the aforementioned process is repeated several times until enough SMUPs to calculate a reliable mean-SMUP are acquired. The number of MUs can then be determined by dividing the maximal compound muscle action potential (CMAP) size by the mean-SMUP size. The focus of this thesis was on using pattern recognition techniques to detect n SMUPs from a collected set of waveforms. Several experiments were performed using both simulated and real data to evaluate the ability of Automated MPS in finding the constituent SMUPs of a response set. Our experiments showed that performing Automated MPS needs less experience compared with MPS. Moreover, it can deal with more difficult situations and detect more accurate SMUPs compared with MUESA.

This study described the effect of a non-augmented (Spoken Communication, SC) and two augmented language interventions (Augmented Communication-Input, AC-I or Augmented Communication-Output, AC-O) on the upper-body, gross and fine motor skills of toddlers at the onset and conclusion of the intervention. The data presented are from a longitudinal study by Romski, Sevcik, Adamson, Cheslock, Smith, Barker, & Bakeman (2010). Three standardized assessments and five observational measures examined the participants' motor skills used to activate the speech generating device (SGD), language abilities and outcomes. The AC-O intervention decreased physical prompting, increased error-free symbol activations, and increased developmentally appropriate gross and fine motor use. An augmented intervention that utilizes a SGD may facilitate both language and motor development through the combination of the communicative goals and increased motor learning opportunities when accessing the SGD device.

During centrally orchestrated movements, the nervous system must distinguish between appropriate and inappropriate reflexes. I studied local postural flexion reflexes of the crayfish that are evoked by unexpected touch. An isolated abdomen was used which permitted recording and stimulating of tailfan afferents, nerve cord interneurons, and postural motor neurons. Stimulation of the afferents evoked a postural flexion response of the medium tonic and large phasic motor neurons of the superficial flexor nerve; a flexion motor program was then excited by stimulating descending interneurons. Afferent stimulation evoked a smaller motor response during the motor program than before or after. These results indicate that the postural reflex responses to sensory stimulation are inhibited at a site presynaptic to the motor neurons during the flexion motor program. Application of Picrotoxin (blocked inhibition) to the primary afferent-to-mechanosensory interneuron synapse did not prevent the modulation of the postural flexion reflex during the flexion motor program.

A control system for a BLDC (Brushless Direct Current) motor has been developed in Labview 2009. This report explains how it works, conclusions and some information about things that could have been done differently. This report is also a good introduction to Labview including its advantages and disadvantages. It also explains how a FOC (Field Oriented Control) works. This is the public version of the report which does not include any results or information about the implementation. This information can be found in the original report which only authorized persons have access to.