5,018 research outputs found

    Investigating Different Levels of Bimanual Interaction With a Novel Motor Learning Task: A Behavioural and Transcranial Alternating Current Stimulation Study

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    Many tasks require the skilled interaction of both hands, such as eating with knife and fork or keyboard typing. However, our understanding of the behavioural and neurophysiological mechanisms underpinning bimanual motor learning is still sparse. Here, we aimed to address this by first characterising learning-related changes of different levels of bimanual interaction and second investigating how beta tACS modulates these learning-related changes. To explore early bimanual motor learning, we designed a novel bimanual motor learning task. In the task, a force grip device held in each hand (controlling x- and y-axis separately) was used to move a cursor along a path of streets at different angles (0°, 22.5°, 45°, 67.5°, and 90°). Each street corresponded to specific force ratios between hands, which resulted in different levels of hand interaction, i.e., unimanual (Uni, i.e., 0°, 90°), bimanual with equal force (Bieq, 45°), and bimanual with unequal force (Biuneq 22.5°, 67.5°). In experiment 1, 40 healthy participants performed the task for 45 min with a minimum of 100 trials. We found that the novel task induced improvements in movement time and error, with no trade-off between movement time and error, and with distinct patterns for the three levels of bimanual interaction. In experiment 2, we performed a between-subjects, double-blind study in 54 healthy participants to explore the effect of phase synchrony between both sensorimotor cortices using tACS at the individual’s beta peak frequency. The individual’s beta peak frequency was quantified using electroencephalography. 20 min of 2 mA peak-to-peak amplitude tACS was applied during task performance (40 min). Participants either received in-phase (0° phase shift), out-of-phase (90° phase shift), or sham (3 s of stimulation) tACS. We replicated the behavioural results of experiment 1, however, beta tACS did not modulate motor learning. Overall, the novel bimanual motor task allows to characterise bimanual motor learning with different levels of bimanual interaction. This should pave the way for future neuroimaging studies to further investigate the underlying mechanism of bimanual motor learning

    Motor learning induced neuroplasticity in minimally invasive surgery

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    Technical skills in surgery have become more complex and challenging to acquire since the introduction of technological aids, particularly in the arena of Minimally Invasive Surgery. Additional challenges posed by reforms to surgical careers and increased public scrutiny, have propelled identification of methods to assess and acquire MIS technical skills. Although validated objective assessments have been developed to assess motor skills requisite for MIS, they poorly understand the development of expertise. Motor skills learning, is indirectly observable, an internal process leading to relative permanent changes in the central nervous system. Advances in functional neuroimaging permit direct interrogation of evolving patterns of brain function associated with motor learning due to the property of neuroplasticity and has been used on surgeons to identify the neural correlates for technical skills acquisition and the impact of new technology. However significant gaps exist in understanding neuroplasticity underlying learning complex bimanual MIS skills. In this thesis the available evidence on applying functional neuroimaging towards assessment and enhancing operative performance in the field of surgery has been synthesized. The purpose of this thesis was to evaluate frontal lobe neuroplasticity associated with learning a complex bimanual MIS skill using functional near-infrared spectroscopy an indirect neuroimaging technique. Laparoscopic suturing and knot-tying a technically challenging bimanual skill is selected to demonstrate learning related reorganisation of cortical behaviour within the frontal lobe by shifts in activation from the prefrontal cortex (PFC) subserving attention to primary and secondary motor centres (premotor cortex, supplementary motor area and primary motor cortex) in which motor sequences are encoded and executed. In the cross-sectional study, participants of varying expertise demonstrate frontal lobe neuroplasticity commensurate with motor learning. The longitudinal study involves tracking evolution in cortical behaviour of novices in response to receipt of eight hours distributed training over a fortnight. Despite novices achieving expert like performance and stabilisation on the technical task, this study demonstrates that novices displayed persistent PFC activity. This study establishes for complex bimanual tasks, that improvements in technical performance do not accompany a reduced reliance in attention to support performance. Finally, least-squares support vector machine is used to classify expertise based on frontal lobe functional connectivity. Findings of this thesis demonstrate the value of interrogating cortical behaviour towards assessing MIS skills development and credentialing.Open Acces

    Are There Brain-Based Predictors of the Ability to Learn a New Skill in Healthy Ageing and Can They Help in the Design of Effective Therapy after Stroke?

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    This thesis aimed at looking for neural correlates of motor adaptation as a model of rehabilitation after brain injury. Healthy adults across the lifespan and stroke patients were tested in a force-field learning paradigm. This thesis focuses on EEG analysis and the complex relationship of brain-derived measures with observed behaviour. To describe each domain in detail, the focus was first on finding group differences between older and younger healthy adults in a similar manner as it was later between stroke patients versus healthy controls. The analyses were finalised by looking for relationships between the EEG and motor performance data in a multiple linear regression approach. As candidate EEG biomarkers of motor adaptation, error related event related potential around movement onset in the frontocentral electrodes was chosen in time domain. In the time-frequency domain, the focus was on movement related beta band spectral perturbation, looking at the electrodes over the primary motor cortex and the frontocentral ROI found significant in the time domain. Finally, functional connectivity was analysed focusing first on electrode over the primary motor cortex contralateral to the movement as a seed region, to narrow down the analysis to bilateral motor cortex connectivity and connectivity between primary motor cortex contralateral to the movement and the frontocentral region identified as important in the time domain analysis. The crucial part of the project was analysing the relationship between the neural and kinematic measures. The most important predictor of summed error in motor adaptation was the connectivity between C3 and C4 electrode at the baseline prestimulus period in motor adaptation condition and pinch asymmetry. Higher prestimulus interhemispheric connectivity was associated with bigger deviation from the optimal trajectory. When looking at summed error dynamic derivative as a dependent variable - performance index - it was the ERP at the central error-related ROI that explained the most variance. It can be concluded that higher baseline interhemispheric connectivity can be a reflection of a maladaptive process, perhaps related to increased interhemispheric inhibition. It is important to also note that the same connectivity at different timepoints in the movement can be of different significance - differences between stroke patients and controls were present in the postmovement period. In conclusion, brain information could be helpful for e.g. stratifying patients into different intensity programs based on their predicted potential to recover. Moreover, brain information could be utilised to apply closed-loop systems modulating the intensity of tasks to reach the optimal brain state that facilitates learning. I believe this work will help incorporating brain-derived measures in informing neurorehabilitation programmes in the future

    EEG coherence between the verbal-analytical region (T3) and the motor-planning region (Fz) increases under stress in explicit motor learners but not implicit motor learners

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    This journal supplement contains abstracts of NASPSPA 2010Free Communications - Verbal and Poster: Motor Learning and Controlpublished_or_final_versionThe Annual Conference of the North American Society for the Psychology of Sport and Physical Activity (NASPSPA 2010), Tucson, AZ., 10-12 June 2010. In Journal of Sport and Exercise Psychology, 2010, v. 32 suppl., p. S13

    Postural Sway, EEG and EMG Analysis of Hip and Ankle Muscles during Eight Balance Training Tasks

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    The purpose of this study was to examine postural sway, cortical response and muscle activation of the hip and ankle muscles during eight balance tasks routinely used in sensorimotor training. This was a single group repeated measure study. The postural sway; the power of alpha, beta and sigma wave bands; and the EMG activity of gluteal maximus, gluteal medius, tibialis anterior and medial gastrocnemius were measured in 17 subjects during eight balance tasks with eyes open or closed, feet in tandem or apart and on foam or a firm surface. The results of this study showed that postural sway, EEG power of the beta and sigma wave bands, and EMG activity of the hip and ankle muscles were significantly higher due to the alteration of sensory information in the eight common balance tasks when compared to the control task. The postural sway was affected by the extent of sensory information available for postural control. The recruitment of specific muscles was affected by the context of the tasks rather than the number of sensory factors altered. EEG power of beta and sigma wave bands showed significant increases at the central and parietal area of the brain relative to the control tasks when eyes were open in the tasks. The cortical involvement decreased as the task became more difficult with vision and somatosensory information altered. When the balance task became more challenging with vision, base of support and surface compliance altered, the cortical activity increased significantly again. The postural sway and cortical activity were affected by the amount of sensory information available for postural control. The recruitment of specific muscles was affected by the context of the tasks rather than the numbers of sensory factor altered. Our results suggest that balance training should start with alteration of one sensory factor by first altering the somatosensory input (base of support then the surface compliance), and followed by excluding the visual input. The balance training should then be progressed by altering two then three sensory factors. A balance program should include exercises to strengthen hip and ankle muscles in order to facilitate the postural control in static balance tasks

    Attention and time constraints in performing and learning a table tennis forehand shot

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    This is a section on p. S95 of article 'Verbal and Poster: Motor Development, Motor Learning and Control, and Sport and Exercise Psychology' in Journal of Sport and Exercise Psychology, 2010, v.32, p.S36-S237published_or_final_versio

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 317)

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    This bibliography lists 182 reports, articles and other documents introduced into the NASA scientific and technical information system in November, 1988

    Investigating the Transfer of Learning, Psychological, and Neural Effects in Immersive Virtual Reality

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    Achieving mastery or expertise requires a substantial amount of quality practice. Recent technological developments have introduced a novel approach to practice, virtual reality. Specifically, virtual reality offers a low-cost, customizable opportunity to practice while minimizing the risk of the individual. Given that some types of practice may not lead to the acquisition of a motor skill, or worse, lead to detriments of that skill, understanding the developing science of motor behavior in relation to virtual reality is imperative. The following literature review will begin with a brief historical account of the evolution of virtual reality. Next, some terms of virtual reality will be defined, and the technological characteristics will be introduced. Then, fundamental theories of transfer of learning and important variables which likely contribute to transfer of learning will be discussed. In the following section, the current understanding of virtual reality and motor learning will be explained. Research that has examined transfer of learning within immersive virtual reality will then be examined and discussions of the findings and limitations will be presented. Finally, to address the aforementioned shortcomings, the following project was a two-experimental study to investigate the transfer of learning effects of virtual reality motor skill practice
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