A study on how concurrent visual feedback affects motor learning of adjustability of grasping force in younger and older adults.

In this study, we investigated the differences of the effectiveness from concurrent visual feedback among younger and older adults in learning tasks that require adjustability of grasping force (AGF), as well as the functions related to AGF in each generation. The younger and older adult groups were evaluated for simple visual reaction time as visual-motor speed (VMS) and a 100 g AGF task that reflected the difference between desired performance and actual performance. The main learning task was then practiced using concurrent visual feedback and tested without feedback. The VMS of older adults was slower than that of the younger, and the error in the 100 g AGF task was larger in older adults than in the younger adults. Performance improved from pre-test to retention test in both groups, but the older adult group failed to reach the level of the younger adult group. The results of this study show that concurrent visual feedback is effective for learning the tasks that require AGF in both groups. Indicatively, improvement in performance during practice is insufficient in older people for whom there is a large difference between desired performance and actual performance, or whose VMS is slow.

Association between the Effects of Positive Social-Comparative Feedback and Learners' Competitiveness.

This study examined the effects of positive social-comparative feedback on learners' intrinsic motivation on a motor learning task, as well as its association with learners' competitiveness. The participants, who performed a balance task in a positive social-comparative feedback and a control group, were assessed for performance outcome, perceived competence, and competitiveness. The positive social-comparative feedback group demonstrated more effective balance performance than the control group on the retention test. In addition, the participants in the positive social-comparative feedback group reported significantly higher perceived competence than the participants in the control group after practice. Further, a subscale of learners' competitiveness-instrumental competitiveness-predicted the performance on a retention test in the positive social-comparative feedback group, but not in the control group. Our results suggest that positive social-comparative feedback is not beneficial to all learners, and may even be less effective for learners with lower competitiveness.

Magnetorheological Fluids with Surface-Modified Iron Oxide Magnetic Particles with Controlled Size and Shape.

This study is focused on surface-modified Fe3O4@SiO2 particles with precisely controlled sizes and shapes applied in magnetorheological (MR) fluids. After the preparation of the monodisperse spindle-shaped and cubic Fe3O4@SiO2 particles, surface modification with dodecyltrimethoxysilane (DTM) was carried out via a silane coupling reaction to increase the dispersion stability of the particles. Afterward, MR fluids were prepared by mixing the DTM-modified Fe3O4@SiO2 particles with silicon oil. Transmission electron microscopy observations demonstrated that spindle-shaped Fe3O4@SiO2 particles could form a more stable chain-like structure than cubic Fe3O4@SiO2 particles upon application of an external magnetic field. The rheological measurements of MR fluids also indicated that the surface modification with DTM, the introduction of anisotropic shapes, and the increase in the particle size all played positive roles in the improvement in MR properties.

How does physical guidance affect motor learning and learner's workload?

[Purpose] Physical guidance is routinely used in clinical practices such as rehabilitation to facilitate motor learning. Physical guidance would facilitate motor learning and reduce the workload; however, this relationship is unknown. Thus, we aimed to investigate this relationship using a physical guidance device. [Participants and Methods] Twenty-seven healthy young adults were randomly assigned to three groups and underwent varying practice conditions. The participants used a physical guidance device during practice for 2 days, did not use the device during practice for 2 days, or used the device on the first but not the second practice day. Motor learning was assessed by measuring the instability generated by the participants while maintaining a standing position on the Biodex Balance System. Psychological status was evaluated by analyzing the participants' responses to the National Aeronautics and Space Administration-Task Load Index. [Results] Improved performance was noted in all participants; however, those who used a physical guidance device during practice for 2 days exhibited poor motor learning compared with those assigned to the other two conditions. Frustration was significantly lower in participants who used a physical guidance device during practice than those who did not. [Conclusion] The use of physical guidance during practice can reduce participant frustration, but excessive physical guidance during practice reduces learning efficiency.

Relationship between correcting error and smoothness of movement in the process of motor learning.

[Purpose] Improvement in the smoothness of movement is a motor learning outcome. This study sought to clarify the relationship between motor skills and smoothness of movement in motor learning. [Participants and Methods] We subjected 12 healthy adults to a task in which they had to learn the sensation of a load while standing up and sitting down. We attached triaxial accelerometers to the seventh cervical spine and the third lumbar spinous process of the participants prior to measurement. We took the measurements over two successive days and used absolute error and variable error as indicators of motor learning outcomes. In addition, we used entropy, calculated from the results of the power spectrum analysis of acceleration changes, as an indicator of the smoothness of the movement. [Results] In the test sessions, absolute and variable errors showed a significant reduction. Entropy also showed a similarly significant decrease, although the change in errors and entropy showed different transitions. [Conclusion] Qualitative indicators of motor learning captured an aspect of motor learning that one cannot capture by quantitative indicators. In the future, qualitative indicators will be necessary to judge the outcomes of motor learning.

The effects of feedback timing and frequency on the acquisition of cardiopulmonary resuscitation skills of health sciences undergraduate students: A 2 x 2 factorial quasi randomized study.

BACKGROUND: High-quality training is required to improve the cardiopulmonary resuscitation (CPR) skills. Although it has been reported that the use of a feedback device is effective, the effects of feedback timing and frequency on CPR training have not been investigated. The aim of this study was to clarify the influence of feedback frequency and timing on the acquisition of CPR skills. METHODS: Sixty-eight undergraduates were first divided into female (n = 32) and male (n = 36) groups, and randomly assigned to one of four groups for each sex: concurrent-100%, concurrent-50%, terminal-100%, and terminal-50% feedback groups. The randomization was performed using a lottery method. This study consisted of a pre-test, practice sessions, a post-test, and a follow-up test. In the practice sessions, the participants performed six 2-minute CPR sessions in accordance with the condition assigned using mannequins and feedback devices. The post-test was conducted 24 hours after the completion of the practice sessions and the follow-up test was conducted 3 months after the completion of the practice sessions. The primary outcome of the study was the overall score at the follow-up test. RESULTS: The results of the overall score at the follow-up test for each group were 88.2 ± 9.6% for concurrent-100%, 92.2 ± 6.4% for concurrent-50%, 82.6 ± 16.4% for terminal-100%, and 85.2 ± 16.9% for terminal-50%. We did not find any statistically significant difference for the overall score at the follow-up test among the four groups (p = 0.173). The ANOVA for the test sessions revealed that there were no significant main effects of feedback timing (p = 0.135) or frequency (p = 0.765), and no significant interaction between timing and frequency (p = 0.997). CONCLUSION: The present study reveals that the use of feedback devices is an important factor for higher quality CPR training, regardless of the timing and frequency with which they are used.

Dynamic balance assessment using an unstable board in community-dwelling elderly people.

[Purpose] A new method for measuring dynamic balance was developed. The aim of this study was to describe the use of a novel "unstable board" to evaluate the balance ability of community-dwelling elderly individuals. [Participants and Methods] The following balance outcomes were evaluated in 59 community-dwelling elderly people: anteroposterior and mediolateral stability indexes on the unstable board, Mini-Balance Evaluation Systems Test score, the Functional Reach Test score, Timed Up-and-Go time, and the Figure-8 Walk Test time. [Results] With respect to the relationship between the stability indexes and functional balance scales, the anteroposterior stability index significantly correlated with the anticipatory postural adjustment component (r=-0.422), stability in the gait component (r=-0.274), and total score of the Mini-Balance Evaluation Systems Test (r=-0.316); timed up-and-go time (r=0.320); and figure-8 walk test time (r=0.340). No correlation was found between the mediolateral stability index and the functional balance scale scores. [Conclusion] The anteroposterior stability index correlated with the declines in postural adjustments and performance in the dynamic balance assessments. Therefore, the anteroposterior stability index, evaluated on an unstable board, could provide an efficient tool for predicting changes in dynamic balance capacity, which could not be identified using the most commonly used balance assessment tools.