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Results for “augmented feedback”

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At least 55 records · Page 3Linked to original sources
PubMed2002

Age-related differences and the role of augmented visual feedback in learning a bimanual coordination pattern.

The purpose of this study was to investigate the effects of aging and the role of augmented visual information in the acquisition of a new bimanual coordination pattern, namely a 90 degrees relative phase pattern. In a pilot study, younger and older adults received augmented visual feedback in the form of a real-time orthogonal display of both limb movements after every fifth trial. Younger adults acquired this task over three days of practice and retained the task well over periods of one week and one month of no practice while the older adults showed no improvement at all on the task. It was hypothesized that the amount of augmented information was not sufficient for the older adults to overcome the strong tendency to perform natural, intrinsically stable coordination patterns, which consequently prevented them from learning the task. The present study evaluated the age-related role of augmented visual feedback for learning the new pattern. Participants were randomly assigned within age groups to receive either concurrent or terminal visual feedback after every trial in acquisition. In contrast to the pilot study, all of the older adults learned the pattern, although not to the same level as the younger adults. Both younger and older adults benefitted from concurrent visual feedback, but the older adults gained more from the concurrent feedback than the younger adults, relative to terminal feedback conditions. The results suggest that when learning bimanual coordination patterns, older adults are more sensitive to the structure of the practice conditions, particularly the availability of concurrent visual information. This greater sensitivity to the learning environment may reflect a diminished capacity for inhibitory control and a decreased ability to focus attention on the salient aspects of learning the task.

Adult↗
PubMed1978

Use of augmented sensory feedback to achieve symmetrical standing.

Ambulatory patients with hemiparesis were given auditory feedback of weight bearing on the involved leg in order to achieve symmetrical standing. A device for augmented sensory feedback, the Limb Load Monitor, was used for the training. Patients who could correct their limb loading pattern during the first treatment session learned to achieve symmetrical standing. Results are also related to the magnitude of weight bearing on the involved limb and the side on which the lesion occurs. These findings suggest that the patients utilized the feedback signal to control an inherent activity.

Adult↗
PubMed2004

Augmented visual feedback increases finger tremor during postural pointing.

Physiological tremor in the upper limb of eight adults was examined during the performance of a unilateral pointing task under conditions where the visual feedback, limb used and target size were altered. All subjects were required to aim a hand-held laser pointer at a circular target 5.5 m away with the goal of keeping the laser emission within the centre of the target. Visual feedback was defined as either normal vision (NV) of their limb tremor, where the laser was switched off, or augmented vision (AV) where the laser was switched on. Postural tremor from the segments of the upper limb, forearm muscle EMG activity, and target accuracy measures were recorded and analysed in the time and frequency domains. Accuracy-tremor relations were assessed using cross correlation and linear regression. Results revealed a high degree of similarity in the general pattern of the tremor output seen for each limb segment across conditions with only scalar (amplitude) changes being seen as a function of the different constraints imposed. For any single condition the tremor amplitude increased from proximal to distal segments. The frequency profile for the tremor in any segment displayed two prominent frequency peaks (at 2-4 Hz and 8-12 Hz). A third, higher frequency peak (18-22 Hz) was observed in the index fingers only. Across all conditions significant coupling relations were observed only between the hand-finger and forearm-upper arm segment pairs. Altering the visual feedback was shown to have the greatest effect on limb tremor with increased tremor and EMG activity and decreased coupling being seen under AV conditions. In trying to reduce tremor output when the augmented feedback was provided novice subjects instead increased muscle activity which resulted in increased tremor. Overall these results indicate that the physiological tremor output observed in neurologically normal subjects is not simply the product of intrinsic oscillations but is influenced by the nature of the task being performed.

Adult↗
PubMed1994

Effects of physical guidance and knowledge of results on motor learning: support for the guidance hypothesis.

The guidance hypothesis (Schmidt, 1991) predicts that the guiding properties of augmented feedback are beneficial for motor learning when used to reduce error, but detrimental when relied upon. Therefore, a heavily guiding form of feedback might be detrimental for learning. In addition, the guidance hypothesis predicts that practice with a high relative frequency of augmented feedback would be detrimental for learning. An experiment is described that crossed two forms of feedback with two levels of relative frequency. Subjects practiced movements to a target with either physical guidance or knowledge of results, and with either a high or faded relative frequency. The high frequency physical guidance condition resulted in the poorest retention, and both high frequency feedback conditions resulted in the least accuracy in transfer. These results provide support for the guidance hypothesis and suggest consideration of the combined effects on learning of the type and relative frequency of augmented feedback and acquisition-test conditions.

Adult↗
PubMed1985

Augmented auditory information in the control of upper-limb prostheses.

The present study compared the effects of augmented auditory information on the linear positioning performance of individuals with natural or prosthetic limbs. Subjects were ten male volunteers, five of whom had above-elbow amputations and had used their prosthetic devices for an average of 8.3 years. The other five subjects were selected from a volunteer pool. Movements were made and measured on a standard linear slide whose cursor had a pulsing infrared diode attached opposite the subject. An infrared camera and microprocessor translated diode movement into a corresponding change in voltage. The voltage was simultaneously applied to an audio device which supplied the augmented feedback. The movement of the cursor by the subject was paralleled by a linearly-related change in audible frequency (Hz). The subjects performed 15 trials at each of three retentions (immediate, 15-sec filled, and 15 sec unfilled), both with and without the augmented feedback, for a total of 90 trials. The results of group X feedback X retention intervals analysis of variance on absolute and variable error indicated both a group X retention and a group X feedback interaction. Subjects using a prosthetic limb to produce the movement were less accurate and more variable than the "normal" subjects when augmented feedback was not concurrent with response.

Adult↗
PubMed2004

Bimanual directional interference: the effect of normal versus augmented visual information feedback on learning and transfer.

When performing movements with different spatial trajectories in both upper limbs simultaneously, patterns of interference emerge that can be overcome with practice. Even though studies on the role of augmented feedback in motor learning have been abundant, it still remains to be discovered how overcoming such specific patterns of spatial interference can be optimized by instructional intervention. In the present study, one group acquired a bimanual movement with normal vision, whereas a second group received augmented feedback of the obtained trajectories on a computer screen in real time. Findings revealed that, relative to normal vision, the augmented feedback hampered skill learning and transfer to different environmental conditions. These observations are discussed in view of the benefits and pitfalls of augmented feedback in relation to task context and instructional condition.

Adolescent↗
PubMed2003

The effects of augmented kinematic feedback on motor skill learning in rifle shooting.

In this study, we examined the effects of augmented kinematic knowledge of performance (KP) on shooting performance and learning. Knowledge of performance described the aiming trajectory of the rifle barrel. The effects of knowledge of performance were evaluated in terms of shooting accuracy (shooting score), variability of the shooting score (root mean square error) and rifle stability (x- and y-deviation of rifle movement). The participants (n = 40) were randomly assigned to one of four groups: no-KP, 50% KP, 100% KP and a control group. The three experimental groups performed 480 shots during a 4 week acquisition phase in which feedback was provided. No-feedback retention tests were administered at 2 and 10 days after acquisition. There were no differences between groups during acquisition. In the 2 day retention test, the mean shooting score of the group receiving 100% knowledge of performance was significantly higher than that of the other groups. Furthermore, variability in shooting score for the 100% KP group was lower than that for the 50% KP and control groups. No significant differences were found in rifle stability between the experimental groups. In summary, a high frequency of kinematic knowledge of performance improved shooting accuracy, but the effect appeared to be temporal, disappearing in the 10 day retention test. Given that a parallel effect was not found in rifle stability, future research should focus on examining the reasons for this improvement in shooting score.

Adult↗
PubMed2002

Inhibition of apical Na+/H+ exchangers on the macula densa cells augments tubuloglomerular feedback.

NO produced by neuronal NO synthase (nNOS) in the macula densa blunts tubuloglomerular feedback (TGF). nNOS activity is strongly pH-dependent. Increasing luminal NaCl concentration increases nNOS activity, NO production, and apical Na+/H+ exchange. Na+/H+ exchange alkalinizes the macula densa. We hypothesized that inhibiting apical Na+/H+ exchange in macula densa cells would augment TGF by blunting nNOS activation caused by increasing luminal NaCl concentration. Rabbit afferent arterioles and attached macula densas were microperfused in vitro. TGF response was defined as the change in afferent arteriole diameter caused by increasing the NaCl concentration in the macula densa perfusate. 7-Nitroindazole (7-NI; 10 micromol/L) alone in the macula densa lumen increased the TGF response from 2.4+/-0.1 to 3.8+/-0.2 microm (P<0.01). When dimethyl amiloride (100 micromol/L), a Na+/H+ exchange inhibitor, was added to the macula densa lumen, it increased the TGF response from 2.5+/-0.3 to 3.7+/-0.5 microm (P<0.01). In the presence of dimethyl amiloride, 7-NI had no effect on the TGF response (from 2.6+/-0.2 to 2.7+/-0.2 microm). Our data indicate that inhibiting apical Na+/H+ exchange in the macula densa mimics the effect of inhibiting NO production by nNOS in the macula densa on TGF. Thus, it is possible that increased apical Na+/H+ exchange caused by increasing the sodium concentration in the lumen of the macula densa activates macula densa nNOS. The link between nNOS and Na+/H+ exchange may be intracellular pH.

Amiloride↗
PubMed1999

Motor learning after unilateral brain damage.

Forty adults, post-stroke from anterior circulation unilateral cerebrovascular accident (approximately 2 years post onset) and 40 age-matched controls (M = 57 years) practiced a rapid, spatially and temporally constrained programmed action under one of two augmented feedback practice conditions. Participants in the stroke group used the upper limb ipsilateral to the lesion. After an extended practice period (198 trials), acquisition, retention, and reacquisition performance was assessed for accuracy and consistency and compared over trials, between groups and feedback conditions. Both stroke and control groups demonstrated significant improvement in accuracy and consistency over practice with relative persistence of these changes during retention. There were no differences between groups (stroke vs control) in performance patterns across trials for acquisition, retention, or reacquisition phases. In addition, there were no differential effects of the two augmented feedback conditions on performance and no interactions of feedback condition with group. However, independent of feedback condition, the stroke group performed with more error than did the control group during all experimental phases (i.e., acquisition, retention, reacquisition). These results suggest that unilateral stroke-related damage in the sensorimotor areas primarily effects the processes underlying the control and execution of motor skills but not the learning of those skills. Implications of these findings for physical rehabilitation are discussed.

Adult↗
PubMed2002

The effects of augmented sensory feedback precision on the acquisition and retention of a simulated chiropractic task.

OBJECTIVE: To examine the effectiveness of knowledge of results precision in the acquisition and retention of a simulated manipulative procedure. DESIGN: A controlled trial was conducted, with subjects assigned to 1 of 2 interventions by means of a stratified random technique. METHODS: Seventy-one healthy male and female chiropractic student volunteers were asked to control the application of force of a simulated chiropractic manipulative procedure. Two feedback conditions (quantitative and qualitative), 2 performance conditions (light and heavy force levels), and 3 delay intervals (1, 5, and 8 days) were studied. Acquisition trials were divided into 10 blocks of 5 trials for a total of 50 trials. All subjects performed 2 blocks of 10 trials (total of 20 trials) during the no-feedback retention phase. Absolute constant error (/CE/) was analyzed as the measure of performance accuracy, and variable error (VE) was used to determine performance consistency. RESULTS: No significant main effect for the 2 feedback groups was found for /CE/ and VE during the acquisition phase. A significant main effect for force was found for /CE/ and VE, indicating that subjects were more accurate during light conditions than heavy conditions. There was a significant main effect for trial blocks for both /CE/ and VE, indicating that groups became more accurate and consistent as a result of practice. During the retention phase, a significant main effect for retention group conditions was identified for /CE/ but not for VE. This indicates that the retention groups differed in accuracy but were similar in consistency. Post hoc analyses indicated that subjects were less accurate as time between acquisition and retention trials increased. There was a significant main effect for trial blocks for VE but not for /CE/, suggesting that groups became more consistent between trial blocks. A significant group trial block interaction was revealed for /CE/. No other main effects or interactions in the analyses were significant for /CE/ or VE. CONCLUSION: The findings of this study suggest that practice sessions with kinetic devices (simulators) and performance feedback, whether quantitative or qualitative, may be useful when implemented to assist the performance of complex motor skills. There is not enough evidence to support the idea that the training used in this study could generate lasting learning effects.

Adult↗
PubMed2006

Can augmented force feedback facilitate virtual target acquisition tasks?

This study investigates facilitation of a manual target acquisition task by the application of appropriate force feedback through the control device (e.g., mouse, joystick, trackball). Typical manual movements with these devices were measured, and models of such movements were used to predict an intended target location from an initial portion of a trace. Preferred shapes and sizes for feedback force functions to be applied were empirically determined by collecting preference ratings and measuring task completion times. The general experimental task that is typical for an office situation, but findings appear generalizable to some medical and surgical situations (e.g. laparoscopy, catheterization) where a certain target has to be reached whose precise location may be known or unknown.

Computer Peripherals↗
PubMed1999

Effects of instruction in jumping technique and experience jumping on ground reaction forces.

STUDY DESIGN: Randomized, controlled trial. OBJECTIVE: To determine the roles that augmented feedback from instruction in jumping technique and sensory feedback from experience jumping play in assisting individuals to land softly from a jump. BACKGROUND: Jumping and landing activities play a major role in many sports and daily activities. Feedback may assist individuals in decreasing landing forces and thus reduce the chances of sustaining an injury. METHODS AND MEASURES: Nonimpaired subjects (n = 91) were randomly assigned to either an augmented or sensory feedback condition. All subjects were asked to jump from a box 300 mm in height and land as softly as possible on a force plate. Pre-intervention ground reaction forces (GRF) were recorded. Subjects in the augmented feedback condition were then given instructions to focus on hip and knee joint motion as well as a forefoot landing technique for their next jump. Subjects in the sensory feedback condition were asked to use the experience of their first jump to land softly for their next jump. Post-intervention GRFs were recorded and all GRFs were expressed as a multiple of body weight. RESULTS: Those in the augmented condition significantly reduced their GRF scores from pre-(mean = 4.53 +/- 1.51) to post-(mean = 3.57 +/- 1.10) jump, whereas those in the sensory condition did not (mean pre GRF = 4.51 +/- 1.77; mean post GRF = 4.33 +/- 1.54). CONCLUSIONS: High ground reaction forces may be a precipitating factor associated with an injury, where the site of tissue damage would benefit from decreased forces. These findings support the use of instructions related to joint motion to reduce landing forces.

Adolescent↗