A broad understanding of motor control has been achieved through research performed on upper extremity reaching, walking on level ground, and static balance. Though invaluable insights have been achieved under these testing paradigms, inherent limitations result in less being known regarding functional movement in weight-bearing. Gait studies require large numbers of consecutive steps to achieve high reliability, static balance is limited to the goal of no movement, and upper extremity reaching lacks insights into feedback from the vestibular system. Here we describe (and provide a supplemental video of) a system for testing and training the performance of a weight-bearing, visuomotor task in the form of a mini-squat according to a sinusoidal trace on a screen. In this work, we determined that by altering both task movement rate and resistance at the knee, a hierarchy of difficulty was achieved at all ages. As age increases, there is a velocity-error tradeoff; speed of movement is attempted to be maintained while error is sacrifieced. When introducing an unexpected force perturbation (rapid release of the resistance of the squat for less than a second), older adults who are least able to match the frequency of the task experience the greatest error and velocity rates during the perturbation. This exposes a possible deficit in the feedback control system of even healthy older adults, where future studies may determine if early intervention to prevent such changes may prevent future injury and disability. When older and younger adults learned to perform the visuomotor task while performing a simultaneous cognitive task, learning was slowed as complexity of the cognitive task increased. In older adults, a difficult cognitive task inhibited acquisition of the squatting task with no apparent improvement in trial error nor coherence. Upon retesting of the motor task, there was no difference between dual-task and single-task trained ability to consolidate the motor task in both age groups, though those that trained under a dual-task condition were more able to automate the motor task as measured by a smaller dual-task cost. This may indicate that dual-task training leads to freeing cognitive resources from attending to a functional movement so that they may attend to other tasks such as what may be happening in the environment. Finally, executive function as measured by the Flanker Test, explained 80% of the variability of final day visuomotor error, being a possible prognostic factor for dual-task interventions. Future directions will determine if increased automaticity of a mini-squat will lead improvement to overall improved functional mobility and reduced lower extremity injuries when functioning in a busy community.

Perceptual speech and voice analysis is an essential skill for all speech-language pathologists, but it is a difficult skill to teach. Even the reliability for experienced experts is variable. Some training literature and practices in speech-language pathology suggest that imitating pathological voices may be useful for developing perceptual judgment. Evidence from other fields suggests that motor experience influences perception. Until now the link between production and perception of voice quality has not been addressed. The purpose of this pilot study is to test the hypothesis that imitating pathological voice samples would improve the perceptual discrimination abilities of naïve, inexperienced listeners. Three expert listeners rated 25 voice samples using a perceptual voice evaluation scale, the Grade, Instability, Roughness, Breathiness, Asthenia, Strain Scale (GIRBAS) (Dejonckere et al., 1996), and identified anchor samples for the training protocol. These expert ratings were used to develop summary expert ratings that served as a comparison for the naïve listener ratings. Two groups of naïve undergraduate listeners received training in evaluating voice quality and in administering the GIRBAS. They completed a pretest, a training session, a homework session, and a post-test. During each activity, they rated 6 voices and provided a confidence rating for their scores. The experimental group imitated the voice samples during the study, and the control group completed the training without supplemental motor experience. It was hypothesized that both listener groups would have improved accuracy and confidence levels between the pretest and post-test, with a larger improvement for the experimental group. Data suggested that training improved naïve listener accuracy and confidence levels and that this improvement was maintained for at least seven days after the initial training. Post-test accuracy for both groups was approximately the same. Imitation did not improve the accuracy of ratings, although those subjects had higher confidence levels. The data supported previous research that found that training improved the accuracy of perceptual voice evaluations. However, the hypothesis that imitation could improve perceptual ratings was not supported by this study and bears further investigation due to the small sample size.

&ldquo / Developmental robotics&rdquo / proposes that, instead of trying to build a robot that shows intelligence once and for all, what one must do is to build robots that can develop. A robot should go through cognitive development just like an animal baby does. These robots should be equipped with behaviors that are simple but enough to bootstrap the system. Then, as the robot interacts with its environment, it should display increasingly complex behaviors. Studies in developmental psychology and neurophysiology provide support for the view that, the animals start with innate simple behaviors, and develop more complex behaviors through the differentiation, sequencing, and combination of these primitive behaviors. In this thesis, we propose such a development scheme for a mobile robot. J.J. Gibson&#039 / s concept of &ldquo / affordances&rdquo / provides the basis of this development scheme, and we use a formalization of affordances to make the robot learn about the dynamics of its interactions with its environment. We show that an autonomous robot can start with pre-coded primitive behaviors, and as it executes its behaviors randomly in an environment, it can learn the affordance relations between the environment and its behaviors. We then present two ways of using these learned structures, in achieving more complex, voluntary behaviors. In the first case, the robot still uses its pre-coded primitive behaviors only, but the sequencing of these are such that new more complex behaviors emerge. In the second case, the robot uses its pre-coded primitive behaviors to create new behaviors.

The purpose of this research is to examine the gender differences that exist when male and female participants complete the mirror-tracing task. This task was chosen because it requires both spatial and psychomotor abilities and is unusual in the sense that it has a far higher correlation with standard spatial ability measures than do most other psychomotor tests. This research will focus on looking at gender differences in speed, accuracy, and practice effects. It will also investigate two personality traits that correlate with performance on the task: introversion and anxiety. Data will be collected from three studies: Experiment 2 of Ackerman&Cianciolo's (1999) study, Experiment 3 of Ackerman&Cianciolo's (2000) study, and Experiment 1 of Field's (1998) study. The results are expected to show that males complete the mirror-tracing task quicker than females during initial, intermediate, and final assessments; however, females will exhibit greater practice effects than males. The results are also anticipated to show there is no significant gender difference in the number of errors made during initial, intermediate, or final assessment. Finally, the number of errors made during initial assessment on the mirror-tracing task is expected to be negatively correlated with introversion and positively correlated with anxiety.

I outline a framework for researching the effects of practice schedule on skill acquisition, based upon stage theories of information processing and stage theories of skill acquisition. Skilled performance requires stimulus identification, response selection, and response execution. I hypothesize that practice schedule affects learning in two types of information processing stages: stimulus-oriented and response-oriented stages. The loci of these effects differ based on the stage. In stimulus-oriented stages, practice schedule affects concept and categorization learning via contiguity of exemplars and feature saliency. In response-oriented stages, practice schedule affects the efficiency with which individuals produce a response by affecting response preparation. I evaluated this framework and theory with 4 experiments that manipulated practice schedule and amount of practice, in 2 domains with different information processing demands. Experiments~1~and~2 focused on response-oriented stages via a task that required participants to execute a multisegment movement according to a target time. Experiments~3~and~4 focused on stimulus-oriented stages via a task that required participants to categorize football play diagrams. Within the 2 task domains the amount of acquisition practice was manipulated to test whether different durations of acquisition training changed how practice schedules affected retention and transfer performance. The practice schedule manipulation had reliable effects on performance and learning when task performance involved either response preparation or induction of categorization rules. Practice schedule did not affect performance or learning when task performance involved categorization decisions, after the rules had been learned. Additionally, I report a novel method for quantifying amount of practice that allows comparisons across task domains.

Chronic neck pain is a widespread problem that causes individual suffering as well as large costs for the society. The knowledge about the pathophysiology is poor and therefore specific diagnosis and causal treatment are rare. Important knowledge for characterization of the disorders has been gained from research on sensorimotor functions in people with neck pain. Moreover, rehabilitation regimes including sensorimotor exercises indicate promising results. The main objectives of this thesis were to extend the knowledge on sensorimotor dysfunctions in chronic neck pain, and to develop a new exercise method for improving sensorimotor functions of the neck. The studies focused on aspects of postural control and movements of the arm and neck. These are vital functions for many activities of daily living. People with chronic (>3 months) neck pain were compared to healthy controls (CON). Neck pain related to trauma was referred to as whiplash associated disorders (WAD), while neck pain without association to trauma was referred to as non-specific (NS). Arm-functioning was assessed in a pointing task. WAD and NS had reduced pointing precision compared to CON. The reduced precision was associated with self-rated difficulties performing neck movements, physical functioning, and in WAD, also pain and balance disturbances. Postural control was assessed in quiet standing on a force platform without vision. The center of pressure signal was decomposed into it’s slow and fast components. WAD and NS were compared to CON. The results revealed an effect of age on the magnitude of the fast sway component, but no effect of group. The magnitude of the slow component was elevated in both WAD and NS. This increase was associated with self-rated balance disturbance, arm-functioning, difficulties to run and sensory alterations in WAD, while in NS, the increase in the slow sway component was associated with concurrent low back pain. Neck movements were assessed in a cervical axial rotation test with maximal speed. In total 8 variables representing basic kinematics, including variables reflecting movement smoothness and conjunct motions were calculated. NS were compared to CON. Linear discriminant modelling indicated Peak Speed and conjunct motions as significant classification variables that together had a sensitivity of 76.3% and specificity of 77.6%. Retest reliability was good for Peak Speed but poor for the measure of conjunct motions. Peak Speed was slower in NS compared to CON, and even slower in a sub-group of NS with concurrent low back pain. Reduced Peak Speed was associated with self-rated difficulties performing neck movements, car driving, running, sleeping disturbances and pain. The clinical applicability of a novel method for neck coordination exercise was assessed in a pilot study on persons with NS. The results supported the applicability and indicated positive effects of the exercise: reduced postural sway in quiet standing and increased smoothness in cervical rotations. Indications on improvement in self-rated disability and fear of movement were seen at six months follow up. In conclusion, sensorimotor functions can be altered in chronic neck pain, particularly in neck disorders with concurrent low back pain and WAD. The discriminative ability and clinical validity displayed in pointing precision, postural sway and cervical axial rotation speed imply that such tests can be valuable tools in the assessment of chronic neck pain patients, and for selecting and evaluating treatment interventions. Indications of improvements seen in the pilot-study support a future RCT.

Understanding the neural processes underlying motor learning in humans is important to facilitate the acquisition of new motor skills and to aid the relearning of skills lost after neurologic injury. Although it is known that the learning of a new movement is guided by the error feedback received after each repeated attempt to produce the movement, how the central nervous system (CNS) processes individual errors and how it modulates its learning rate in response to the history of errors experienced are issues that remain to be elucidated. To address these issues we studied the generalization of learning and learning decay – the transfer of what has been learned, or unlearned, in a particular movement condition to new movement conditions. Generalization offers a window into the process of error credit assignment during motor learning, since it allows us to measure which actions benefit the most in terms of learning after experiencing an error. We found that the distributions that describe generalization after learning are unimodal and biased towards the motion directions experienced during training, a finding that suggests that the credit for the learning experienced after a particular trial is assigned to the actual motion (motion-referenced learning) and not to the planned motion (plan-referenced learning) as it had previously been assumed in the motor learning literature. In addition, after training the same action along multiple directions, we found that the pattern of learning decay has two distinct components: one that is time-dependent and affects all trained directions, and one that is trial-dependent and affects mostly the direction where decay was induced, generalizing narrowly with a unimodal pattern similar to the one observed for learning generalization. We finally studied the effect that the consistency of the error perturbations in the training environment has on the learning rate adopted by the CNS. We found that learning rate increases when the perturbations experienced in training are consistent, and decreases when these perturbations are inconsistent. Besides increasing our understanding of the mechanisms underlying motor learning, the findings described in the present dissertation will enable the principled design of skill training and rehabilitation protocols that accelerate learning. / Engineering and Applied Sciences

Simulation and Web-based Learning (WBL) are both educational approaches that are increasingly applied in medical education. However, little is known about how these two instructional approaches may be integrated to improve learning outcomes. A prospective three-arm experimental study of different WBL preparation materials was conducted. Thirty undergraduate medical students with no prior experience in central venous catheterization (CVC) were randomly assigned to one of three preparatory interventions: tradition reading materials (TM), observational practice (OP), or OP and educational networking (OPEN). Participants then completed a simulation-based training workshop in CVC and a delayed retention test. Performance was assessed by a task-specific checklist, global rating scale (GRS) and by measuring time to competency. Main findings reveal a significant linear trend across the TM, OP and OPEN groups in time to competency. This exploratory study demonstrates the potential utility of Web-based observational practice and collaborative learning for improving the efficiency of simulation-based training.

Simulation and Web-based Learning (WBL) are both educational approaches that are increasingly applied in medical education. However, little is known about how these two instructional approaches may be integrated to improve learning outcomes. A prospective three-arm experimental study of different WBL preparation materials was conducted. Thirty undergraduate medical students with no prior experience in central venous catheterization (CVC) were randomly assigned to one of three preparatory interventions: tradition reading materials (TM), observational practice (OP), or OP and educational networking (OPEN). Participants then completed a simulation-based training workshop in CVC and a delayed retention test. Performance was assessed by a task-specific checklist, global rating scale (GRS) and by measuring time to competency. Main findings reveal a significant linear trend across the TM, OP and OPEN groups in time to competency. This exploratory study demonstrates the potential utility of Web-based observational practice and collaborative learning for improving the efficiency of simulation-based training.

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