Humans are able to overcome sensory perturbations imposed on their movements through motor learning. One of the key mechanisms to accomplish this is sensorimotor adaptation, an implicit, error-driven learning mechanis...Humans are able to overcome sensory perturbations imposed on their movements through motor learning. One of the key mechanisms to accomplish this is sensorimotor adaptation, an implicit, error-driven learning mechanism. Past work on sensorimotor adaptation focused mainly on adaptation to rotated visual feedback—A paradigm known as visuomotor rotation. Recent studies have shown that sensorimotor adaptation can also occur under mirror-reversed visual feedback. In visuomotor rotation, sensorimotor adaptation can be driven by both endpoint and online feedback [1] [2]. However, it’s not been clear whether both kinds of feedback can similarly drive adaptation under a mirror reversed perturbation. We performed a study to establish what kinds of feedback can drive adaptation under mirror reversal. In the first two conditions, the participants were asked to ignore visual feedback. In the first condition, we provided mirror reversed online feedback and endpoint feedback. We reproduced previous findings showing that online feedback elicited adaptation under mirror reversal. In a second condition, we provided mirror reversed endpoint feedback. However, in the second condition, we found that endpoint feedback alone failed to elicit adaptation. In a third condition, we provided both types of feedback at the same time, but in a conflicting way: endpoint feedback was non-reversed while online feedback was mirror reversed. The participants were asked to ignore online visual feedback and try to hit the target with help from veridical endpoint feedback. In the third condition, in which veridical endpoint feedback and mirror reversed online feedback were provided, adaptation still occurred. Our results showed that endpoint feedback did not elicit adaptation under mirror reversal but online feedback did. This dissociation between effects of endpoint feedback and online feedback on adaptation under mirror reversal suggests that adaptation under these different kinds of feedback might in fact operate via distinct mechanisms.展开更多
Introduction: Mental exercise using the mirror therapy (MT) improves the retention of newly acquired skills and the performance of sequential motor skills in subjects with post-stroke hemiparesis. Objectives: The stud...Introduction: Mental exercise using the mirror therapy (MT) improves the retention of newly acquired skills and the performance of sequential motor skills in subjects with post-stroke hemiparesis. Objectives: The study aimed to analyze the mirror therapy effect on the range of motion and the lower limb functionality in post-stroke hemiparesis subjects. Materials and Methods: Eleven participants with hemiparesis in the lower limb were subjected to the 10 sessions of a MT protocol. The interventions were three times per week per 30 minutes each day. Evaluation of active and passive ankle goniometry (dorsiflexion and eversion movements);Ascent and Descent Ladder Rate (ADLR);Time Up and Go test (TUG test);EFEI scale;and FAAM scale were performed. The data were collected before and after the intervention using MT, and then statistically compared. Results: The MT improved significantly (p < 0.01) the range of motion of the paretic lower limb both evaluated by active and passive ankle goniometry. An increase in the speed of gait and other functional tasks related to the paretic lower limbs were found through the TUG and ADLR tests. It also demonstrated a positive influence on the functionality of the paretic lower limb motor control through the analysis of the scores in the FAAM and EFEI scales. Conclusion: It is concluded that the MT therapy can help the patients with post-stroke hemiparesis in the improvement of several functions. Probably, the mirror therapy would aid in the repair of the injuries in the cortical areas.展开更多
将被动时间反转镜(PTRM)技术与双向判决反馈均衡器(DFE)相结合,设计并实现了高可靠性的单载波水声通信解码方案。接收端采用PTRM压缩信道多途结构,聚焦信号能量;利用双向DFE将传统DFE和反向DFE输出结果合并,进一步降低错误判决的概率,...将被动时间反转镜(PTRM)技术与双向判决反馈均衡器(DFE)相结合,设计并实现了高可靠性的单载波水声通信解码方案。接收端采用PTRM压缩信道多途结构,聚焦信号能量;利用双向DFE将传统DFE和反向DFE输出结果合并,进一步降低错误判决的概率,提高系统稳健性。在时不变浅海水声信道环境中,开展的水声通信试验数据处理结果表明:与传统DFE相比,双向DFE能够获得一定的处理增益,5 km、7 km和10 km通信距离上的均衡后输出信噪比分别提高了2.74 d B、2.36 d B和1.54 d B,有效改善了解码性能。展开更多
文摘Humans are able to overcome sensory perturbations imposed on their movements through motor learning. One of the key mechanisms to accomplish this is sensorimotor adaptation, an implicit, error-driven learning mechanism. Past work on sensorimotor adaptation focused mainly on adaptation to rotated visual feedback—A paradigm known as visuomotor rotation. Recent studies have shown that sensorimotor adaptation can also occur under mirror-reversed visual feedback. In visuomotor rotation, sensorimotor adaptation can be driven by both endpoint and online feedback [1] [2]. However, it’s not been clear whether both kinds of feedback can similarly drive adaptation under a mirror reversed perturbation. We performed a study to establish what kinds of feedback can drive adaptation under mirror reversal. In the first two conditions, the participants were asked to ignore visual feedback. In the first condition, we provided mirror reversed online feedback and endpoint feedback. We reproduced previous findings showing that online feedback elicited adaptation under mirror reversal. In a second condition, we provided mirror reversed endpoint feedback. However, in the second condition, we found that endpoint feedback alone failed to elicit adaptation. In a third condition, we provided both types of feedback at the same time, but in a conflicting way: endpoint feedback was non-reversed while online feedback was mirror reversed. The participants were asked to ignore online visual feedback and try to hit the target with help from veridical endpoint feedback. In the third condition, in which veridical endpoint feedback and mirror reversed online feedback were provided, adaptation still occurred. Our results showed that endpoint feedback did not elicit adaptation under mirror reversal but online feedback did. This dissociation between effects of endpoint feedback and online feedback on adaptation under mirror reversal suggests that adaptation under these different kinds of feedback might in fact operate via distinct mechanisms.
文摘Introduction: Mental exercise using the mirror therapy (MT) improves the retention of newly acquired skills and the performance of sequential motor skills in subjects with post-stroke hemiparesis. Objectives: The study aimed to analyze the mirror therapy effect on the range of motion and the lower limb functionality in post-stroke hemiparesis subjects. Materials and Methods: Eleven participants with hemiparesis in the lower limb were subjected to the 10 sessions of a MT protocol. The interventions were three times per week per 30 minutes each day. Evaluation of active and passive ankle goniometry (dorsiflexion and eversion movements);Ascent and Descent Ladder Rate (ADLR);Time Up and Go test (TUG test);EFEI scale;and FAAM scale were performed. The data were collected before and after the intervention using MT, and then statistically compared. Results: The MT improved significantly (p < 0.01) the range of motion of the paretic lower limb both evaluated by active and passive ankle goniometry. An increase in the speed of gait and other functional tasks related to the paretic lower limbs were found through the TUG and ADLR tests. It also demonstrated a positive influence on the functionality of the paretic lower limb motor control through the analysis of the scores in the FAAM and EFEI scales. Conclusion: It is concluded that the MT therapy can help the patients with post-stroke hemiparesis in the improvement of several functions. Probably, the mirror therapy would aid in the repair of the injuries in the cortical areas.
文摘将被动时间反转镜(PTRM)技术与双向判决反馈均衡器(DFE)相结合,设计并实现了高可靠性的单载波水声通信解码方案。接收端采用PTRM压缩信道多途结构,聚焦信号能量;利用双向DFE将传统DFE和反向DFE输出结果合并,进一步降低错误判决的概率,提高系统稳健性。在时不变浅海水声信道环境中,开展的水声通信试验数据处理结果表明:与传统DFE相比,双向DFE能够获得一定的处理增益,5 km、7 km和10 km通信距离上的均衡后输出信噪比分别提高了2.74 d B、2.36 d B和1.54 d B,有效改善了解码性能。
