scholarly journals Efeito da associação de prática imagética e física na aprendizagem motora em crianças

2019 ◽  
Vol 20 (5) ◽  
pp. 363-372
Author(s):  
Patrícia Sayuri Takazono ◽  
Luis Augusto Teixeira
Keyword(s):  
Motor Learning ◽  
Sensory Feedback ◽  
Movement Time ◽  
Performance Gain ◽  
Physical Practice ◽  
Reaching Task ◽  
Manual Task ◽  
Imagery Training ◽  
Task Component ◽  
Performance Gains

Imagery training has been shown to induce motor learning in adults, but similar evidence in children is scarce. In this experiment, we aimed to evaluate the effect of association between imagery and physical practice compared to pure physical practice in the learning of a manual task in 9-10 year-old children. The task consisted of transporting a block and fitting it into a support with speed and steadiness, assessing movement time to complete the “reaching” and “transport” task components. The children were assigned to one of three groups: (a) physical practice (PHYS) (240 trials), (b) combination (COMB) of imagery (180 trials) and physical (60 trials) practice, and (c) control (CON), associating visual rotation (180 trials) and physical practice (60 trials). Performance was evaluated immediately and 24 h after practice. Results indicated that the PHYS group achieved a persistent performance gain in the “transport”, but not in the “reaching” task component, while the COMB group achieved persistent performance gains in both movement components; no significant differences were found for the CON group. Our results suggest that imagery training improves the task mental representation in children, while physical practice provides sensory feedback on the performed movements. As a conclusion, the results suggest that combination of imagery and physical practice can be more effective than pure physical practice for children’s motor learning.

scholarly journals Joint speed feedback improves myoelectric prosthesis adaptation after perturbed reaches in non amputees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eric J. Earley ◽  
Reva E. Johnson ◽  
Jonathon W. Sensinger ◽  
Levi J. Hargrove
Keyword(s):  
Sensory Feedback ◽  
Feedforward Control ◽  
Feedback System ◽  
Augmented Feedback ◽  
Myoelectric Prosthesis ◽  
Reaching Task ◽  
Prosthesis Control ◽  
High Uncertainty ◽  
Relevant Factors ◽  
Positional Control

AbstractAccurate control of human limbs involves both feedforward and feedback signals. For prosthetic arms, feedforward control is commonly accomplished by recording myoelectric signals from the residual limb to predict the user’s intent, but augmented feedback signals are not explicitly provided in commercial devices. Previous studies have demonstrated inconsistent results when artificial feedback was provided in the presence of vision; some studies showed benefits, while others did not. We hypothesized that negligible benefits in past studies may have been due to artificial feedback with low precision compared to vision, which results in heavy reliance on vision during reaching tasks. Furthermore, we anticipated more reliable benefits from artificial feedback when providing information that vision estimates with high uncertainty (e.g. joint speed). In this study, we test an artificial sensory feedback system providing joint speed information and how it impacts performance and adaptation during a hybrid positional-and-myoelectric ballistic reaching task. We found that overall reaching errors were reduced after perturbed control, but did not significantly improve steady-state reaches. Furthermore, we found that feedback about the joint speed of the myoelectric prosthesis control improved the adaptation rate of biological limb movements, which may have resulted from high prosthesis control noise and strategic overreaching with the positional control and underreaching with the myoelectric control. These results provide insights into the relevant factors influencing the improvements conferred by artificial sensory feedback.

scholarly journals Aging Does Not Affect Beta Modulation during Reaching Movements

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Serena Ricci ◽  
Ramtin Mehraram ◽  
Elisa Tatti ◽  
Aaron B. Nelson ◽  
Martina Bossini-Baroggi ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Movement Time ◽  
Peak Latency ◽  
Reaching Movements ◽  
Performance Indices ◽  
Reaching Task ◽  
Beta Power ◽  
Total Movement ◽  
Older Subjects ◽  
Highly Correlated

During movement, modulation of beta power occurs over the sensorimotor areas, with a decrease just before its start (event-related desynchronization, ERD) and a rebound after its end (event-related synchronization, ERS). We have recently found that the depth of ERD-to-ERS modulation increases during practice in a reaching task and the following day decreases to baseline levels. Importantly, the magnitude of the beta modulation increase during practice is highly correlated with the retention of motor skill tested the following day. Together with other evidence, this suggests that the increase of practice-related modulation depth may be the expression of sensorimotor cortex’s plasticity. Here, we determine whether the practice-related increase of beta modulation depth is equally present in a group of younger and a group of older subjects during the performance of a 30-minute block of reaching movements. We focused our analyses on two regions of interest (ROIs): the left sensorimotor and the frontal region. Performance indices were significantly different in the two groups, with the movements of older subjects being slower and less accurate. Importantly, both groups presented a similar increase of the practice-related beta modulation depth in both ROIs in the course of the task. Peak latency analysis revealed a progressive delay of the ERS peak that correlated with the total movement time. Altogether, these findings support the notion that the depth of beta modulation in a reaching movement task does not depend on age and confirm previous findings that only ERS peak latency but not ERS magnitude is related to performance indices.

scholarly journals Mu Suppression Is Sensitive to Observational Practice but Results in Different Patterns of Activation in Comparison with Physical Practice

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Najah Alhajri ◽  
Nicola J. Hodges ◽  
Jill G. Zwicker ◽  
Naznin Virji-Babul
Keyword(s):  
Motor Learning ◽  
Retention Test ◽  
Motor Task ◽  
Mu Rhythm ◽  
Healthy Individuals ◽  
Physical Practice ◽  
Short Term ◽  
Mu Suppression ◽  
Index Changes ◽  
Observational Practice

Research has shown the effectiveness of observational practice for motor learning, but there continues to be debate about the mechanisms underlying effectiveness. Although cortical processes can be moderated during observation, after both physical and observational practice, how these processes change with respect to behavioural measures of learning has not been studied. Here we compared short-term physical and observational practice during the acquisition and retention of a novel motor task to evaluate how each type of practice modulates EEG mu rhythm (8–13 Hz). Thirty healthy individuals were randomly assigned to one of three groups: (1) physical practice (PP), (2) observational practice (OP), and (3) no practice (NP) control. There were four testing stages: baseline EEG, practice, postpractice observation, and delayed retention. There was significant bilateral suppression of mu rhythm during PP but only left lateralized mu suppression during OP. In the postpractice observation phase, mu suppression was bilateral and larger after PP compared to that after OP. NP control showed no evidence of suppression and was significantly different to both the OP and PP groups. When comparing the three groups in retention, the groups did not differ with respect to tracing times, but the PP group showed fewer errors, especially in comparison to the NP group. Therefore, although the neurophysiological measures index changes in the OP group, which are similar but moderated in comparison to PP, changes in these processes are not manifest in observational practice outcomes when assessed in a delayed retention test.

THE INFLUENCE OF TDCS INTENSITY ON DECISION-MAKING TRAINING AND TRANSFER OUTCOMES

2020 ◽  
Author(s):  
Shane E Ehrhardt ◽  
Hannah L. Filmer ◽  
Yohan Wards ◽  
Jason B Mattingley ◽  
Paul E Dux
Keyword(s):  
Dual Task ◽  
Reaction Times ◽  
Performance Outcomes ◽  
Single Task ◽  
Training Performance ◽  
Dual Task Performance ◽  
Task Component ◽  
Task Practice ◽  
Task Training ◽  
Performance Gains

Transcranial direct current stimulation (tDCS) has been shown to improve single- and dual-task performance in healthy participants and enhance transferable training gains following multiple sessions of combined stimulation and task-practice. However, it has yet to be determined what the optimal stimulation dose is for facilitating such outcomes. We aimed to test the effects of different tDCS intensities, with a commonly used electrode montage, on performance outcomes in a multi-session single/dual-task training and transfer protocol. In a pre-registered study, 123 participants, who were pseudorandomised across four groups, each completed six sessions (pre- and post-training sessions and four combined tDCS and training sessions) and received 20 minutes of prefrontal anodal tDCS at 0.7 mA, 1.0 mA, 2.0 mA, or 15-second sham stimulation. Response time and accuracy were assessed in trained and untrained tasks. The 1.0 mA group showed substantial improvements in single-task reaction time and dual-task accuracy, with additional evidence for improvements in dual-task reaction times, relative to sham performance. This group also showed near transfer to the single-task component of an untrained multitasking paradigm. The 0.7 mA and 2.0 mA intensities varied in which performance measures they improved on the trained task, but in sum, the effects were less robust than for the 1.0 mA group and there was no evidence for the transfer of performance. Our study highlights that training performance gains are augmented by tDCS, but their magnitude and nature are not uniform across stimulation intensity.

scholarly journals Plastic Changes in Hand Proprioception Following Force-Field Motor Learning

2010 ◽  
Vol 104 (3) ◽  
pp. 1213-1215 ◽  
Author(s):  
Daniel J. Goble ◽  
Joaquin A. Anguera
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Recent Work ◽  
Recent Article ◽  
Sensory Feedback ◽  
Motor Output ◽  
Feedback Processing ◽  
Plastic Changes ◽  
Proprioceptive Function ◽  
New Evidence

Motor neurophysiologists are placing greater emphasis on sensory feedback processing than ever before. In line with this shift, a recent article by Ostry and colleagues provided timely new evidence that force-field motor learning influences not only motor output, but also proprioceptive sense. In this Neuro Forum, the merits and limitations of Ostry and colleagues are explored in the context of recent work on proprioceptive function, including several recent studies from this journal.

Modeling the Performance of Biaxially-Textured Silicon Solar Cells

2014 ◽  
Vol 1670 ◽  
Author(s):  
Joel B. Li ◽  
Bruce M. Clemens
Keyword(s):  
Grain Size ◽  
Solar Cells ◽  
Polycrystalline Silicon ◽  
Silicon Solar Cells ◽  
Device Performance ◽  
Performance Gain ◽  
Carrier Recombination ◽  
Out Of Plane ◽  
Performance Gains ◽  
Tcad Sentaurus

ABSTRACTGrain boundaries (GBs) in polycrystalline silicon (poly-Si) thin film solar cells are frequently found to be detrimental for device performance. Biaxiallytextured silicon with grains that are well-aligned in-plane and out-of-plane can possess fewer GB defects. In this work, we use TCAD Sentaurus device simulator and known experimental work to investigate and quantify the potential performance gains of biaxially-textured silicon. Simulation shows there can be performance gain from well-aligned grains when GB defects dominate carrier recombination or when grains are small. On the other hand, when intra-grain defects dominate recombination and grains are large, well-aligned grains do not lead to much performance gain. Another important result from our simulation is when intra-grain and GB defects are few, Jsc is almost independent of grain size while Voc drops with decreasing grain size.

A mental route to motor learning: Improving trajectorial kinematics through imagery training

1998 ◽  
Vol 90 (1) ◽  
pp. 95-106 ◽  
Author(s):  
L Yágüez ◽  
D Nagel ◽  
H Hoffman ◽  
A.G.M Canavan ◽  
E Wist ◽  
...  
Keyword(s):  
Motor Learning ◽  
Imagery Training

The Effects of Visual and Proprioceptive Feedback on Motor Learning

1975 ◽  
Vol 19 (2) ◽  
pp. 162-165 ◽  
Author(s):  
Jack A. Adams ◽  
Daniel Gopher ◽  
Gavan Lintern
Keyword(s):  
Motor Learning ◽  
Visual Feedback ◽  
Sensory Feedback ◽  
Closed Loop ◽  
Motor Program ◽  
Absolute Error ◽  
Proprioceptive Feedback ◽  
Knowledge Of Results ◽  
And Performance ◽  
Effective Source

A self paced linear positioning task was used to study the effects of visual and proprioceptive feedback on learning and performance. Subjects were trained with knowledge of results (KR) and tested without it. The analysis of the absolute error scores of the no-KR trials is discussed in this paper. Visual feedback was the more effective source of sensory feedback, but proprioceptive feedback was also effective. An observation that the response did not become independent of sensory feedback as a result of learning, was interpreted as supporting Adams closed loop theory of motor learning in preference to the motor program hypothesis. Other data showed that the presence of visual feedback during learning could inhibit the later effectiveness of proprioceptive feedback.

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

2021 ◽  
Vol 15 ◽  
Author(s):  
Marleen J. Schoenfeld ◽  
Ioana-Florentina Grigoras ◽  
Charlotte J. Stagg ◽  
Catharina Zich
Keyword(s):  
Phase Shift ◽  
Motor Learning ◽  
Movement Time ◽  
Peak Frequency ◽  
Learning Task ◽  
Double Blind Study ◽  
The Novel ◽  
Bimanual Interaction ◽  
Healthy Participants ◽  
Different Levels

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.

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