Jaw and Finger Movement Accuracy under Visual and Nonvisual Feedback Conditions

2002 ◽  
Vol 95 (3_suppl) ◽  
pp. 1129-1140 ◽  
Author(s):  
Luc F. De Nil ◽  
Sophie J. Lafaille
Keyword(s):  
Visual Feedback ◽  
Target Position ◽  
Clinical Intervention ◽  
Finger Movements ◽  
Jaw Movements ◽  
Beneficial Effects ◽  
Movement Error ◽  
Language Pathology ◽  
On Line ◽  
Speed Accuracy

The present study revisited the issue whether the presence of added visual feedback differentially affects the accuracy of finger and jaw movements. 15 men were instructed to move either the index finger on the dominant (right) hand, or the jaw, to a predefined target position with the highest precision possible. During execution of the task, on-line visual feedback of the moving articulator was either present or removed In contrast to previous findings, significant improvement was observed for both finger and jaw movements in the visual feedback condition. Movement error in the nonvisual condition was proportionally greater for finger than for jaw movements which may have reflected a speed-accuracy trade-off because finger movements in the nonvisual condition were executed significantly faster than those of the jaw. The present findings support the beneficial effects of adding visual feedback during dynamic oral and finger movements that require a high spatial precision. Such findings support current methods of clinical intervention in speech-language pathology and other disciplines. Furthermore, the results contribute to our understanding of the role of various modalities of feedback during motor execution.

scholarly journals Effects of Motor Training on Accuracy and Precision of Jaw and Finger Movements

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yinan Chen ◽  
Song Wu ◽  
Zhengting Tang ◽  
Jinglu Zhang ◽  
Lin Wang ◽  
...  
Keyword(s):  
Visual Feedback ◽  
Target Position ◽  
Trigeminal System ◽  
Control Mechanisms ◽  
Finger Movements ◽  
Fixed Target ◽  
Accuracy And Precision ◽  
Jaw Opening ◽  
Before And After ◽  
Lifting Task

Objective. To compare the effects of training of jaw and finger movements with and without visual feedback on precision and accuracy. Method. Twenty healthy participants (10 men and 10 women; mean age 24.6±0.8 years) performed two tasks: a jaw open-close movement and a finger lifting task with and without visual feedback before and after 3-day training. Individually determined target positions for the jaw corresponded to 50% of the maximal jaw opening position, and a fixed target position of 20 mm was set for the finger. Movements were repeated 10 times each. The variability in the amplitude of the movements was expressed as percentage in relation to the target position (Daccu—accuracy) and as coefficient of variation (CVprec—precision). Result. Daccu and CVprec were significantly influenced by visual feedback (P=0.001 and P<0.001, respectively) and reduced after training jaw and finger movements (P<0.001). Daccu (P=0.004) and CVprec (P=0.019) were significantly different between jaw and finger movements. The relative changes in Daccu (P=0.017) and CVprec (P=0.027) were different from pretraining to posttraining between jaw and finger movements. Conclusion. The accuracy and precision of standardized jaw and finger movements are dependent on visual feedback and appears to improve more by training in the trigeminal system possibly reflecting significant neuroplasticity in motor control mechanisms.

Specificity of Learning in Adults with and Without Down Syndrome

2003 ◽  
Vol 22 (3) ◽  
pp. 237-252 ◽  
Author(s):  
Steve Hansen ◽  
Bridget Sheahan ◽  
Melinda Wu ◽  
James Lyons ◽  
Timothy N. Welsh ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Developmental Delay ◽  
Visual Feedback ◽  
Feedforward Control ◽  
Peak Velocity ◽  
Kinesthetic Feedback ◽  
On Line ◽  
Time Required ◽  
Specificity Of Learning ◽  
Sensory Condition

Adults with Down syndrome (DS), an undifferentiated developmental delay (UnD) and no developmental delay practiced a manual target aiming task either with or without on-line visual feedback. Following acquisition, participants performed a retention test involving the same sensory condition available during practice, followed by a transfer test under the other sensory condition. Although the participants with UnD were highly dependent on visual feedback for movement accuracy, participants with DS relied more on either kinesthetic feedback or feedforward control for spatial precision. Participants in all three groups improved their movement times with practice. This improvement was associated both with an increase in peak velocity and a reduction in the time required to decelerate their aiming movements. Contrary to our expectations, improvements in performance were not specific to the sensory conditions available during practice.

scholarly journals Experimental dual-mode control of a flexible robotic arm

Robotica ◽  
1992 ◽  
Vol 10 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Woosoon Yim ◽  
Jichun Zuang ◽  
Sahjendra Singh
Keyword(s):  
Target Position ◽  
Terminal State ◽  
Pole Placement ◽  
Robotic Arm ◽  
Dual Mode ◽  
Elastic Mode ◽  
Single Link ◽  
On Line ◽  
Feedforward Controller ◽  
Placement Technique

SUMMARYThis paper focuses on the implementation of a dual-mode controller for the maneuver of a single link flexible robotic arm. The joint angle trajectory tracking is accomplished by a proportional and derivative PD and a feedforward controller. Based on the pole placement technique, a linear stabilizer is designed for elastic mode stabilization. The stabilizer is switched on when the trajectory reaches the vicinity of the terminal state, and the effect of switching time on arm vibration is investigated. An optical deflection sensor is used for on-line measurements of elastic deflections, and also used for the prediction of the static deflection of the arm in the target position. The robustness of the linear stabilizer at varying pay loads is presented.

The impact of concurrent visual feedback on coding of on-line and pre-planned movement sequences

2015 ◽  
Vol 155 ◽  
pp. 92-100 ◽  
Author(s):  
Peter Leinen ◽  
Charles H. Shea ◽  
Stefan Panzer
Keyword(s):  
Visual Feedback ◽  
Movement Sequences ◽  
On Line ◽  
The Impact

scholarly journals Interceptive capturing in large-billed crows: Velocity-dependent weighing of prediction of future target location and visual feedback of current target location

2020 ◽  
Author(s):  
Yusuke Ujihara ◽  
Hiroshi Matsui ◽  
Ei-Ichi Izawa
Keyword(s):  
Visual Feedback ◽  
Target Location ◽  
Target Position ◽  
Head Movements ◽  
Target Velocity ◽  
Moving Target ◽  
Tight Coupling ◽  
Motor Systems ◽  
Feedback Mechanisms ◽  
Behavioural Experiment

AbstractInterception of a moving target is a fundamental behaviour of predators and requires tight coupling between the sensory and motor systems. In the literature of foraging studies, feedback mechanisms based on current target position are frequently reported. However, there have also been recent reports of animals employing feedforward mechanisms, in which prediction of future target location plays an important role. In nature, coordination of these two mechanisms may contribute to intercepting evasive prey. However, how animals weigh these two mechanisms remain poorly understood. Here, we conducted a behavioural experiment involving crows (which show flexible sensorimotor coordination in various domains) capturing a moving target. We changed the velocity of the target to examine how the crows utilised prediction of the target location. The analysis of moment-to-moment head movements and computational simulations revealed that the crows used prediction of future target location when the target velocity was high. In contrast, their interception depended on the current momentary position of the target when the target velocity was slow. These results suggest that crows successfully intercept targets by weighing predictive and visual feedback mechanisms, depending on the target velocity.

scholarly journals Multisensory cueing facilitates naming in aphasia

2020 ◽  
Author(s):  
Klaudia Grechuta ◽  
Belén Rubio Ballester ◽  
Rosa Espín Munné ◽  
Teresa Usabiaga Bernal ◽  
Begoña Molina Hervás ◽  
...  
Keyword(s):  
Language Processing ◽  
Clinical Intervention ◽  
Language Game ◽  
Brain Regions ◽  
Beneficial Effects ◽  
Active Player ◽  
Evaluation Point ◽  
The Times ◽  
The Moment ◽  
Target Words

Abstract Background: Impaired naming is a ubiquitous symptom in all types of aphasia, which often adversely impacts independence, quality of life, and recovery of affected individuals. Previous research has demonstrated that naming can be facilitated by phonemic and semantic cueing strategies that are largely incorporated into the treatment of anomic disturbances. Beneficial effects of cueing, whereby naming becomes faster and more accurate, are often attributed to the priming mechanisms occurring within the distributed language network. Objective: We proposed and explored two novel cueing techniques: (1) Silent Visuomotor Cues (SVC), which provided articulatory information of target words presented in the form of silent videos, and (2) Semantic Auditory Cues (SAC), which consisted of acoustic information semantically relevant to target words (ringing for “telephone”). Grounded in neurophysiological evidence, we hypothesized that both SVC and SAC might aid communicative effectiveness possibly by triggering activity in perceptual and semantic language regions, respectively. Methods: Ten participants with chronic non-fluent aphasia were recruited for a longitudinal clinical intervention. Participants were split into dyads (i.e., five pairs of two participants) and required to engage in a turn-based peer-to-peer language game using the Rehabilitation Gaming System for aphasia (RGSa). The objective of the RGSa sessions was to practice communicative acts, such as making a request. We administered SVCs and SACs in a pseudorandomized manner at the moment when the active player selected the object to be requested from the interlocutor. For the analysis, we compared the times from selection to the reception of the desired object between cued and non-cued trials. Results: Naming accuracy, as measured by a standard clinical scale, significantly improved for all stimuli at each evaluation point, including the follow-up. Moreover, the results yielded beneficial effects of both SVC and SAC cues on word naming, especially at the early intervention sessions when the exposure to the target lexicon was infrequent. Conclusions. This study supports the efficacy of the proposed cueing strategies which could be integrated into the clinic or mobile technology to aid naming even at the chronic stages of aphasia. These findings are consistent with sensorimotor accounts of language processing, suggesting a coupling between language, motor, and semantic brain regions. Trial registration: NCT02928822. Registered 30 May 2016

Haemofiltration and haemodiafiltration

2018 ◽  
Author(s):  
Francesco Locatelli ◽  
Celestina Manzoni ◽  
Giuseppe Pontoriero ◽  
Vincenzo La Milia ◽  
Salvatore Di Filippo
Keyword(s):  
Chronic Kidney Disease Stage ◽  
Cost Effective ◽  
Convective Transport ◽  
Disease Stage ◽  
High Flux ◽  
Beneficial Effects ◽  
Positive Effects ◽  
Randomized Controlled ◽  
On Line ◽  
The Impact

Many observational studies have consistently shown that high-flux haemodialysis (hf-HD) has positive effects on the survival and morbidity of uraemic patients when compared with low-flux haemodialysis, and mainly considering the results of Membrane Permeability Outcome (MPO) studies there is evidence favouring high-flux treatments. A further improvement in convective treatments is represented by the on-line modality. On-line preparation from fresh dialysate by a cold-sterilizing filtration process is a cost-effective method of providing large volumes of infusion solution. Randomized, controlled, large-sized trials with long follow-up in haemofiltration (HF) are unfortunately lacking, possibly suggesting the difficulties in performing these trials, mainly in providing the same urea Kt/V considered adequate in HD. On-line haemodiafiltration (HDF) is considered the most efficient technique of using high-flux membranes, and clearances of small solutes like urea are higher in HDF than in HF and of middle solutes like β‎‎‎2-microglobulin are higher than in hf-HD. Thus HDF, as a strategy based on simultaneous diffusive and convective transport, may combine the beneficial effects of diffusive standard HD with the possible advantages of convective HF. Five large, randomized controlled trials just concluded are inconclusive in definitively clarifying the impact of on-line HDF on chronic kidney disease stage 5 patient outcomes.

A Quintic Spline Interpolator for Motion Command Generation of Computer-Controlled Machines

1992 ◽  
Author(s):  
D. C. H. Yang ◽  
Fu-Chung Wang
Keyword(s):  
Quintic Spline ◽  
Motion Trajectories ◽  
Command Generation ◽  
Position Data ◽  
Data Points ◽  
On Line ◽  
Computer Controlled ◽  
Speed Accuracy ◽  
Linear Interpolator ◽  
Accuracy Speed

Abstract This paper presents a new method of motion command generation for computer controlled multi-axis machines. The method is based on a quintic spline interpolator (QSI) which generates motion commands to trace a set of desired discrete position data via a composite quintic spline (CQS). This CQS is nearly arc length parametrized and has both tangents and curvatures continuous at the data points. Consequently, the generated motion trajectories are continuous in both velocity and acceleration throughout the motion. A quick motion command generation scheme is also developed. Compared to the existing linear interpolator (LI), the proposed method takes comparable execution time, but is superior in many other aspects, including position accuracy, speed smoothness, acceleration continuity, torque requirement and jerk reduction. Compared to the existing cubic spline interpolator (CSI), the proposed method is able to maintain a similarly smooth composite profile, but better speed accuracy. On-line implementation of this interpolator is believed very promising.

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