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Results for “augmented feedback”

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PubMed2005

Augmented, pulsating tactile feedback facilitates simulator training of clinical breast examinations.

Haptic training devices can facilitate tactile skill development by providing repeatable exposures to rare stimuli. Extant haptic training simulator research primarily emphasizes realistic stimuli representation; however, the experiments reported herein suggest that providing augmented feedback can improve training effectiveness, even when the feedback is not natural. A novel clinical breast examination training device uses inflated balloons embedded in silicone to simulate breast lumps. Oscillating the balloon water pressure makes the lumps pulsate. The pulsating lumps are easier to detect than the static lumps used in current simulators, and this manipulation seems to effectively introduce trainees to small, deep lumps that are initially difficult to perceive. A study of 48 medical students indicates that training with the dynamic breast model increased the number of lumps detected, F(1, 47) = 9.34, p = .004, decreased the number of false positives, F(1, 47) = 5.78, p = .020, and improved intersimulator skill transfer, F(1, 47) = 26.56, p < .001. The results suggest that at least in this case, augmented, tactile feedback increases training effectiveness, despite the fact that the feedback does not attempt to mimic any physical phenomenon present in the natural stimulus. Applications of this research include training techniques and tools for improved detection of palpable cancers.

Adult↗

PubMed1991

Knowledge of results and motor learning--implications for physical therapy.

Relevant to this special series on movement science, a brief overview of research in the field of motor learning is provided. A distinction between learning and performance is emphasized with respect to experimental design and the evaluation of laboratory and clinical intervention techniques. Intrinsic and extrinsic feedback are defined. Basic principles of motor learning pertaining to the use of augmented feedback or knowledge of results (KR) are reviewed. Particular emphasis is placed on recent research regarding the effects of selected KR variations (KR relative frequency, bandwidth KR, and KR delay) on motor performance and learning in healthy young adults. Results are discussed in terms of short-lasting temporary performance effects and relatively long-lasting learning effects. Theoretical and practical implications from this research are discussed. It is suggested that it is appropriate to use the principles obtained through laboratory experimentation as guidelines rather than as exact recommendations when applying basic research findings to clinical practice.

Feedback↗

PubMed1989

Standing balance training: effect on balance and locomotion in hemiparetic adults.

The effects of balance retraining on standing balance and locomotor performance were examined in postacute hemiparetic adults. Balance during habitual and instructed-even standing, as well as locomotor performance, were measured before and after a three- to four-week treatment period. Two groups of 21 matched subjects participated in physical therapy. One group received standing balance training with a specially designed feedback device that provided dynamic visual information about relative weight distribution over the paretic and nonparetic limb. Subjects trained with the feedback device showed significantly better static standing symmetry than did subjects who did not receive augmented feedback, p less than .05. Although both groups improved significantly in gait velocity, cadence, stride length, and cycle time, p less than .01, the initially identified asymmetrical locomotor pattern appeared to be only minimally affected by the standing balance training. Results indicated that although standing balance and locomotor control mechanisms may be highly interrelated, a reduction in standing balance asymmetry does not necessarily lead to a concomitant reduction in the asymmetrical limb movement patterns associated with hemiparetic locomotion.

Arm↗

PubMed1995

Subject-controlled performance feedback and learning of a closed motor skill.

Research on knowledge of results and knowledge of performance has been directed toward identification of the optimal schedule for administering feedback. The purpose of this investigation was to assess whether a schedule based on performance feedback controlled by the learner would be a more effective means of delivering feedback than any predetermined or random schedule. Participants were randomly assigned to one of five conditions: (a) control group receiving no performance feedback, (b) 50% relative performance feedback, (c) summary performance feedback, (d) subject-controlled performance feedback, and (e) yoked control group. Data were collected during an acquisition phase (four blocks of 10 trials) and a retention phase (two block of 10 trials) in which subjects performed an underhand ball toss. Repeated-measures analyses indicated significant main effects for the absolute error (AE). Participants in the subject-controlled performance feedback condition performed significantly better on both retention trials than the other groups. Analysis suggests that a feedback schedule which is controlled by the learner may be a more effective means of delivering augmented feedback than other schedules which have been examined.

Adult↗

PubMed2002

Feedback withdrawal and changing compliance during manual hyperinflation.

BACKGROUND AND PURPOSE: The performance of manual hyperinflation by physiotherapists can be improved by the availability of a pressure manometer. The present study aimed to test whether these benefits could be maintained when the manometer is withdrawn and whether the availability of a manometer affects the pressures delivered under changing respiratory compliances. METHOD: Manual hyperinflation breaths were delivered to a test lung by student physiotherapists, with a target peak airway pressure of 30 cm H2O under control, feedback and feedback-withdrawal conditions. The breaths were delivered for three trials under each testing condition at each of three respiratory compliance settings. RESULTS: The availability of augmented feedback increased the accuracy and reduced the variability of performance; however, these improvements were not maintained when feedback was withdrawn. Changing respiratory compliance significantly affected the accuracy and variability during the control and withdrawal conditions, but the availability of a manometer negated these differences. CONCLUSIONS: The availability of a pressure manometer negates the influence of respiratory compliance on the achievement of target peak airway pressures during manual hyperinflation in the laboratory environment, however these benefits are not retained when feedback is withdrawn. Therefore, it is recommended that a pressure manometer should be routinely available during manual hyperinflation in clinical practice to optimize treatment safety and effectiveness.

Adult↗

PubMed2000

Augmentation of SR Ca(2+) release by rapamycin and FK506 causes K(+)-channel activation and membrane hyperpolarization in bladder smooth muscle.

1. The immunosuppressants rapamycin and FK506 are known to relax smooth muscle despite facilitating Ca(2+) release through ryanodine-receptors of the sarcoplasmic reticulum (SR). The apparent contradiction was studied in isolated guinea-pig urinary bladder myocytes. 2. Modulation of spontaneous SR Ca(2+) release was monitored by means of spontaneous transient outward currents (or STOCs) in isolated smooth muscle cells voltage-clamped to -20 mV. Rapamycin (10 microM, n=18) significantly increased amplitude (50+/-12%, mean+/-s.d.), life time (77+/-19%), and time integral of STOCs (113+/-22%), and it reduced the interval between STOCs (20+/-7%). FK506 (20 microM, n=24) increased amplitude (15+/-7%), life time (50+/-7%), time integral (104+/-26%). Cyclosporin A (20 microM, n=18) had no significant effects on STOCs. 3. The basal cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) measured by Indo1-fluorescence was insensitive to rapamycin or FK506. Pretreatment with rapamycin (20 microM, 2 min) did not impair the SR Ca(2+) load as can be concluded from caffeine-induced Ca(2+)-transients. 4. As it was expected from the enhanced STOC activity, the non-clamped membrane was hyperpolarized by rapamycin (15+/-2 mV) or by FK506 (15+/-3 mV). 5. The data are consistent with the idea that rapamycin and FK506 augment spontaneous SR Ca(2+) release by removal of FK-binding proteins from the RyR-complex. Smooth muscle relaxation is interpreted as negative Ca(2+) feedback: augmented Ca(2+) activation of STOCs induces membrane hyperpolarization that reduces Ca(2+) influx through voltage gated channels.

Animals↗

PubMed1994

Motor skill acquisition and retention as a function of average feedback, summary feedback, and performance variability.

Summary feedback involves withholding feedback from subjects until the last trial in a block is completed, and then presenting feedback about each trial. A variation of this method, called average feedback (Young & Schmidt, 1992), presents subjects with only the mean of the trial block. We investigated whether these methods have similar effects on acquisition and retention of a simple motor skill. Five groups of subjects (n = 16 per group) performed 60 acquisition trials of an aiming task involving both spatial and temporal accuracy. We presented average and summary feedback based on either 5-trial blocks or 15-trial blocks and compared these schedules with every-trial feedback. During acquisition, all groups improved with practice, with a slight tendency for the every-trial condition to have less absolute error than the longer summary and average conditions. Analysis of delayed no-feedback retention tests, however, revealed a strong advantage for the 5-trial summary and average conditions compared with the every-trial condition. In addition, we found that for long blocks of acquisition trials without augmented feedback, the performance variability of those trials was associated with retention performance. Results are discussed in terms of how these different manipulations may make feedback less useful during acquisition, but foster the use of certain information processing activities that enhance overall learning.

Journal Article↗

PubMed1976

On the self-regulation of the occipital alpha rhythm: control strategies, states of consciousness, and the role of physiological feedback.

In an experiment investigating the self-control of occipital alpha strength, a factorial design was employed with two levels of feedback (available or non-available), three levels of instruction (Cognitive, Oculomotor, and none), and two levels of lighting (on and off), except that the no-feedback-no-instruction group was not run. The Cognitive instructions were based on the strategies reported in the literature: To generate alpha, persons were instructed to relax, "let go", try to feel pleasant and serene, and allow themselves to review pleasant personal experiences; to suppress alpha, persons were instructed to concentrate, try hard, exert themselves mentally, and try to fell anxious or frustrated. The Oculomotor instructions to generate alpha were to visually blur and not focus, and to suppress alpha were to "look" and focus. The results led to the following conclusions: (a) Feedback-augmented enhancement and suppression of occipital alpha strength is always mediated by learned control of oculomotor processes, although sometimes persons are not aware that they are employing this strategy, especially in the case of alpha enhancement; alpha feedback trainees learn to "not look" in order to enhance alpha strength. (b) Whenever Cognitive strategies are successful in producing alpha strength changes, this is due to the fact that they can be efficient mediators of changes in oculomotor processes. (c) Feedback together with simple Oculomotor instructions leads to more successful alpha control than either alone. (d) High or enhanced levels of occipital alpha strength are not invariably accompanied by the "alpha experience", in fact, if a person is not led to expect it, the alpha experience will usually not occur during occipital alpha enhancement feedback. (e) States of nonsensory awareness, such as an absorption in thoughts and feelings, are reliably associated with enhanced occipital alpha strength. This association is what would be expected: Since vision is the dominant sensory modality in humans, it is reasonable that when visual processing is reduced during alpha enhancement feedback that there is also reduced sensory awareness in general and often greater attention to thoughts and feelings. (f) Alpha feedback per se is neither necessary for nor especially facilitative of the achievement of the alpha experience. Thus, if the alpha experience is more likely to occur with alpha feedback than without it, this is due to the special circumstances that make up the feedback situation and not due to alpha feedback per se.

Alpha Rhythm↗

PubMed2005

Head control: volitional aspects of rehabilitation training in patients with multiple sclerosis compared with healthy subjects.

OBJECTIVE: To investigate the role of voluntary mechanisms and motor learning in head stability and the impact of longitudinal biofeedback training in head control. DESIGN: Crossover trial and single-subject research design. SETTING: Neurorehabilitation research institute. PARTICIPANTS: Head stability during treadmill gait was measured in healthy subjects and patients with multiple sclerosis (MS). INTERVENTION: The experimental condition in which subjects walked on the treadmill was compared with that in which the head was voluntarily stabilized. In another experimental condition, augmented feedback of head displacement was provided by means of a laser mounted on the head that projected a laser beam on a screen. The motor learning was investigated with biofeedback training sessions. Positional feedback was represented by the laser beam, with subjects having to stabilize the beam while walking on the treadmill. MAIN OUTCOME MEASURE: Head angular oscillation in the sagittal and frontal planes. RESULTS: Results showed that on verbal request, healthy subjects and patients further stabilized the head during gait, especially in the sagittal plane. Short-term feedback of head displacement was no better than self-stabilization at improving head control. Conversely, the motor learning was evident in the rehabilitation protocol: after 10 to 15 training sessions, patients with MS showed a clinically relevant decrease of head angular oscillations. CONCLUSIONS: Voluntary mechanisms play a role in head stabilization during gait. Augmented biofeedback of head displacement may be effective in reducing head oscillations.

Adaptation, Physiological↗

PubMed1998

The metabotropic glutamate receptors of the vestibular organs.

This research sought to test the presence and function of metabotropic excitatory amino acid receptors (mGluR) in the frog semicircular canal (SCC). The mGluR agonist +/- 1-aminocyclopentane-trans-1,3-dicarboxylate (ACPD) produced an increase in afferent firing rates of the ampullar nerve of the intact posterior canal. This increase was not due to a stimulation of cholinergic efferent terminals or the acetylcholine (ACh) receptor, since atropine, in concentrations which blocked the response to exogenous acetylcholine, did not affect the response to ACPD. Likewise, ACPD effects were not due to stimulation of postsynaptic NMDA receptors, since the NMDA antagonist D(-)-2-amino-5-phosphonopentanoate (AP-5) did not affect the response to ACPD, reinforcing the reported selectivity of ACPD for mGluRs. When the SCC was superfused with artificial perilymph known to inhibit hair cell transmitter release (i.e. low Ca-high Mg), ACPD failed to increase afferent firing. This suggests that the receptor activated by ACPD is located on the hair cell. Pharmacological evidence suggested that the mGluRs involved in afferent facilitation belong to Group I (i.e. subtypes 1 and 5). In fact, the Group III agonist AP-4 had no effect, and the ACPD facilitatory effect was blocked by the Group I mGluR antagonists (S)-4-carboxyphenylglycine (CPG) and (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA). Additional pharmacological evidence supported the presence of Group I mGluRs. Interestingly, the mGluR antagonists, AIDA and 4CPG, by themselves did not affect the resting firing rates of ampullar afferents. This may suggest that the mGluRs are not involved in resting activity but perhaps only in evoked activity (as suggested in Guth et al. (1991) Hear. Res. 56, 69-78). In addition, the mRNA for the mGluR1 has been detected in hair cells of both SCC, utricle, and saccule. In summary, the evidence points to an mGluR localized to the hair cell (i.e. an autoreceptor) which may be activated to produce a positive feedback augmentation of evoked but not resting transmitter release and thus affect afferent activity.

Afferent Pathways↗

PubMed1993

Acquiring bimanual skills: contrasting forms of information feedback for interlimb decoupling.

The present experiments addressed the learner's capability to perform different upper-limb actions simultaneously with the help of various sources of information feedback. An elbow flexion movement was made in the left limb together with a flexion-extension-flexion movement in the right limb. Interlimb interactions were assessed at the structural as well as the metrical level of movement specification during acquisition and retention. Despite a strong initial tendency for the limbs to be synchronized, findings revealed that Ss became gradually more successful in interlimb decoupling as a result of practice with augmented feedback. However, detailed knowledge of movement kinematics was no more effective than global outcome information for interlimb decoupling, indicating that knowledge of results may have more potential for acquiring multiple degree-of-freedom tasks than previously believed. Finally, the data support the general notion that learning new coordination tasks involves the suppression of preexisting preferred coordination tendencies, which is often a prerequisite for building new coordination modes.

Adolescent↗

PubMed1991

Visual tasks in helicopter shipboard landing.

The purpose of this research was to identify visual scene content important in helicopter shipboard landings, particularly in the hover phase, for further study in a research simulator. A second purpose was to illustrate the use of a methodology (Protocol Analysis) which may hold promise for many areas of human factors research. Discussions with pilots, reviews of relevant Naval Aviation Training and Operational Procedures (NATOPS) manuals and observation of simulated helicopter shipboard landings suggested that the visual elements required in helicopter shipboard landings may depend upon whether experienced or inexperienced pilots are flying, a simulator or an aircraft is flown, the environment is day or night, or the pilot seeks to acquire or maintain a skill level. A scenario involving an experienced pilot flying dusk/night approaches in a simulator was intensively studied. As he flew each approach, the pilot dictated real-time verbal protocols of his visual and control activities. These protocols were subsequently partitioned by the authors into nine phases defined in terms of range or altitude from the ship, and the visual tasks required in each segment were described. An outcome of this analysis was a list of visual cue augmentations that may be useful for providing augmented feedback in training.

Aircraft↗

PubMed1984

The mechanism of inhibition and "reversal" of mitogen-induced lymphocyte activation in a model of purine-nucleoside phosphorylase deficiency.

Purine-nucleoside phosphorylase (PNP) is a purine degradative enzyme that catalyzes the phosphorolysis of (deoxy) inosine or (deoxy) guanosine to their respective bases and (deoxy) ribose 1-phosphate. A severe T-cell immune deficiency syndrome with hypouricemia is associated with impaired PNP function. To study the biochemical basis for this syndrome we created an in vitro model of PNP deficiency in mitogen (phytohemagglutinin)-stimulated normal human peripheral blood lymphocytes using guanosine to competitively inhibit deoxyguanosine phosphorolysis. Guanosine-induced guanine toxicity was reversed by adenine. Under these conditions, deoxyguanosine (5-45 microM) diminished mitogen stimulation to 30% of control while increasing the deoxyguanosine triphosphate pool (dGTP) by over 20-fold. Deoxycytidine reversed deoxyguanosine toxicity with a diminution of dGTP accumulation, but no significant change in the deoxycytidine triphosphate pool. Thymidine reversed the deoxyguanosine toxicity, repleted the thymidine triphosphate (dTTP) pool, and caused an even further increase in the accumulation of dGTP. These data support a model of lymphotoxicity in PNP deficiency based on dGTP accumulation with inhibition of ribonucleotide reductase and depletion of the thymidine triphosphate pool. Thymidine triphosphate depletion is reversed by either deoxycytidine or thymidine; however, the former diminishes dGTP accumulation (probably by competition for phosphorylation) and the latter potentiates dGTP accumulation (probably through feedback augmentation of guanosine diphosphate (GDP) reduction by ribonucleotide reductase secondary to an increased dTTP pool).

Deoxyribonucleosides↗

PubMed2002

The relationship between knowledge of results and motor learning in Parkinsonian patients.

A simple timing movement was used to investigate augmented feedback on motor learning in Parkinson's disease (PD) patients and controls. During acquisition, participants received knowledge of results (KR) about their errors after every trial (100%) or every fifth trial (20%). Participants then performed a retention test without KR. Controls performed better on the retention test after having had 20% KR during acquisition. PDs showed superior retention with 100% KR. This suggests that the PD patients are more reliant on KR for learning motor skills; a difference that may be attributable to reduced proprioceptive acuity in PD patients.

Aged↗

PubMed2002

Generation of bimanual trajectories of disparate eccentricity: levels of interference and spontaneous changes over practice.

The authors examined intermanual interactions of 2 hands that were required to concurrently follow trajectories that differed in eccentricity. Ten healthy participants attempted to learn to trace 2 figures, a circle and an ellipse, with bilaterally isochronous (1:1) timing demands. Initial unimanual trials were followed by bilateral practice comprising 750 movement cycles. Two objectives were addressed: The authors' primary aim was to determine if kinematic interlimb interference is evident independent of spatial and temporal interference and to observe the potential practice-related changes in the nature of that interference. That test was afforded by participants' natural tendency to draw a circle with a relatively constant tangential velocity and an ellipse with a systematically varying velocity. A second aim was to observe the nature of spontaneous changes in the performance of each individual effector, and in the relationship between effectors, across practice. Those objectives were specifically addressed in a context in which augmented feedback was not available to direct the learners' attention to a particular feature of performance. The results suggested that interlimb assimilation of spatial features is the primary source of interference for that task and that apparent effects at the kinematic level are the secondary, indirect product of spatial coupling. Those results were found across blocks of practice. With respect to nondirected performance changes, substantially less improvement was evident in the performance of each individual effector than in the reduction of interlimb interference. Specifically, no practice-related changes in temporal variability or velocity bias, and minimal changes in trajectory smoothness, were evident in individual limbs. Conversely, significant reductions were observed in the variability of relative phase between limbs and in the magnitude of interlimb phase lag.

Adolescent↗

PubMedDate not supplied

A model of women's sexual arousal.

A model of female sexual arousal shows the composite emotion of subjective sexual arousal, which results from conscious appraisal of sexual stimuli and their context in the presence of positive affective and cognitive feedback. Genital feedback augments the subjective arousal to a variable degree. Genital congestion can be triggered by sexual stimuli in the absence of subjective arousal. Then the congestion either is ignored or not interpreted as sexual. An anhedonic or even a dysphoric response to the sensations of genital congestion are further possibilities. This model allows for various subtypes of arousal disorder and thus facilitates a choice of therapeutic intervention.

Autonomic Nervous System↗

PubMed2003

Schema theory: critical review and implications for the role of cognition in a new theory of motor learning.

This paper is based on a symposium celebrating the 26th anniversary of the publication of "A Schema Theory of Discrete Motor Skill Learning" (Schmidt, 1975) held at the annual conference of the North American Society for the Psychology of Sport and Physical Activity in June 2001. We provide a brief historical context for schema theory and a review of the development of the mechanistic approach to motor learning in general. We explore recent findings in mental practice, observational learning, augmented feedback presentation, and the variability of practice that are inconsistent with schema theory and provide a rationale for the importance of cognitive activity in motor learning.

Child↗

PubMed1989

Preferred tempo in the learning of a gross cyclical action.

Seventy-five subjects, randomly assigned to one of five training conditions, were required to learn to make large-amplitude, high-tempo, fluent movements on a so-called ski-simulator over a period of four days. Subjects trained under different tempo conditions. In four of the conditions the tempo was prescribed ("preferred", high, low, or increasing), augmented feedback being provided to enable subjects to stay on "target". "Preferred" tempo was based on the weight of the subject and was derived from a regression equation based on previous empirical research. In a fifth condition, subjects trained on "discovery learning" principles, i.e. without the tempo being prescribed. The results obtained on the three parameters (amplitude, frequency, and fluency) during the daily test sessions (in which the tempo was not prescribed) formed the data for the analyses. A learning effect was apparent on all three parameters over the four-day training period. Subjects who trained under the high or the low prescribed tempos, however, were shown to produce significantly smaller amplitude movements than subjects who trained under the other three conditions. Training under the low-tempo condition was also shown to have disadvantageous effects on the parameters tempo and fluency. It was concluded that, for these kinds of action, training at a high or a low tempo--and particularly the latter--has undesirable effects. Such disadvantageous effects, however, were shown to be avoidable if training is begun with the "preferred" tempo of the subject and increased successively by 7% over days.

Adolescent↗