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PubMed1973

The effects of experimenter's instructions, feedback, and praise on teacher praise and student attending behavior.

Systematic use of experimenter's instructions, feedback, and feedback plus social praise was used to increase teacher praise for student attending behavior of three elementary school teachers. Experimenter's verbal interactions with teachers, teacher's verbal praise for student behaviors, and pupil attending behavior were recorded during baseline conditions. As the three successive experimental conditions were introduced first with Teacher A, then with Teacher B, in a multiple baseline design, behaviors of the experimenter, the two teachers, and eight students were measured and recorded. In the cases of Teachers A and B, experimental condition one (Instructions) and experimental condition two (Feedback) produced inconclusive results. Experimental condition three (Feedback Plus Social Praise) produced more teacher praise for student attending behavior. The entire "Package" of Experimenter's Instructions, Feedback, and Feedback Plus Social Praise was introduced to Teacher C in a single experimental condition. As in the cases of Teachers A and B, behaviors measured were: (1) the experimenter's verbal interactions, (2) the teacher's praise of students, and (3) the student's attending behavior. Introduction of the "Package" also produced more teacher praise for student attending behavior.

Journal Article↗
PubMed1978

Modification of combined migraine-muscle contraction headaches using BVP and EMG feedback.

The effect of blood volume pulse (BVP) and frontalis muscle action potential (EMG) feedback on control of vasoconstriction of the temporal artery and frontalis muscle activity in combined migraine-muscle tension subjects was investigated in a multiple baseline design (across subjects and responses). The data indicated: (a) both subjects obtained an ability to control BVP during BVP feedback and EMG during EMG feedback; (b) there were decreases in frequency of migraine headaches during BVP feedback and decreases in muscle contraction headaches during EMG feedback. The results of this study supported the theoretical explanation of two pain mechanisms involved in combined muscle contraction-migraine headaches as well as the effectiveness of bio-feedback procedures that target directly the specific pain mechanism in the elimination of the two types of head pain.

Adult↗
PubMed1983

Feedback interventions and driving speed: A parametric and comparative analysis.

Five experiments were conducted to assess the effects of several variables on the efficacy of feedback in reducing driving speed. Experiment 1 systematically varied the criterion used to define speeding, and results showed that the use of a lenient criterion (20 km/hr over the speed limit), which allowed for the posting of high percentages of drivers not speeding, was more effective in reducing speeding than the use of a stringent criterion (10 km/hr over the speed limit). In Experiment 2 an analysis revealed that posting feedback reduced speeding on a limited access highway and the effects persisted to some degree up to 6 km. Experiments 3 and 4 compared the effectiveness of an unmanned parked police vehicle (Experiment 3) and a police air patrol speeding program (Experiment 4) with the feedback sign and determined whether the presence of either of these enforcement variables could potentiate the efficacy of the sign. The results of both experiments demonstrated that although the two enforcement programs initially produced larger effects than the feedback sign, the magnitude of their effect attenuated over time. Experiment 5 compared the effectiveness of a traditional enforcement program with a warning program which included handing out a flier providing feedback on the number and types of accidents occuring on the road during the past year. This experiment demonstrated that the warning program produced a marked reduction in speeding and the traditional enforcement program did not. Furthermore, the warning program and a feedback sign together produced an even greater reduction in speeding than either alone.

Journal Article↗
PubMed1980

Skin temperature regulation: the effects of suggestion and feedback.

This study focuses on the effects of visual digital feedback and verbal suggestions on an individual's ability to increase hand skin temperature. In this 2 x 2 factorial design, thirty-eight college students were assigned to conditions receiving feedback or no feedback and suggestions or no suggestions. Subjects receiving suggestions heard a tape recorded imagery phrase related to increasing hand temperature; subjects in the no-suggestion condition received neutral phrases of electronic definitions. All subjects participated in three training sessions. Analysis of the third session indicated an interaction effect; post hoc analysis indicated a significant difference between subjects receiving feedback with suggestion and subjects receiving feedback and no suggestion. The results suggest that the ability to increase skin temperature may require the concomitant use of feedback and suggestion.

Biofeedback, Psychology↗
PubMed2006

Innovative approaches to obtaining community feedback in the Witness for Wellness experience.

BACKGROUND: Awareness of the need for innovative approaches to obtaining feedback in community-based participatory research (CBPR) is increasing. These innovative approaches should incorporate the core principles of CBPR, including equity and co-learning. Additionally, the methods should be culturally appropriate and inclusive of the community and academic partners. OBJECTIVE: To develop and implement two separate methods of obtaining community feedback for two activities in a CBPR initiative: 1) discussion of three work-group plans during a leadership council meeting; and 2) feedback from the work groups to the target community in a public setting. METHODS: In order to facilitate a feedback process for the discussion of 3 separate group action plans, an adapted version of the modified Delphi technique was used during which 42 community and academic partners voted and evaluated each plan both before and after group discussion. Results were immediately posted on a projection screen for the group to process. The second community feedback method incorporated the use of an audience response system (ARS) in order to obtain responses from 187 community participants after hearing summaries of the Witness for Wellness work-group action plans. More than 60% of the respondents added that the use of the handheld device made research seem more relevant and less intimidating. CONCLUSIONS: Both the use of the adapted modified Delphi process and ARS were effective in capturing community feedback related to two group activities in the Witness for Wellness initiative. Both methods also allowed participants to understand the role of research in a community setting.

Black or African American↗
PubMed2002

Roles of positive and negative feedback in biological systems.

We discuss the influence of positive and negative feedback on the stability of a system, which is not clear-cut, and involves complex, mathematical problems. We show in particular that positive feedback can have a stabilising effect on some systems. We also point out the role that positive feedback plays in the digital treatment of signals required by cellular signalling, drawing on analogies from electronics, and the role that negative feedback plays in making a system robust against alteration of its parameters. Both positive and negative feedback can be seen as important enhancers of the properties of biological systems.

Animals↗
PubMed2006

Multiple feedback loop design in the tryptophan regulatory network of Escherichia coli suggests a paradigm for robust regulation of processes in series.

Biological networks have evolved through adaptation in uncertain environments. Of the different possible design paradigms, some may offer functional advantages over others. These designs can be quantified by the structure of the network resulting from molecular interactions and the parameter values. One may, therefore, like to identify the design motif present in the evolved network that makes it preferable over other alternatives. In this work, we focus on the regulatory networks characterized by serially arranged processes, which are regulated by multiple feedback loops. Specifically, we consider the tryptophan system present in Escherichia coli, which may be conceptualized as three processes in series, namely transcription, translation and tryptophan synthesis. The multiple feedback loop motif results from three distinct negative feedback loops, namely genetic repression, mRNA attenuation and enzyme inhibition. A framework is introduced to identify the key design components of this network responsible for its physiological performance. We demonstrate that the multiple feedback loop motif, as seen in the tryptophan system, enables robust performance to variations in system parameters while maintaining a rapid response to achieve homeostasis. Superior performance, if arising from a design principle, is intrinsic and, therefore, inherent to any similarly designed system, either natural or engineered. An experimental engineering implementation of the multiple feedback loop design on a two-tank system supports the generality of the robust attributes offered by the design.

Escherichia coli↗
PubMed2026

Webcam-Based Real-Time Visual Feedback During Baduanjin Practice in Older Adults: 6-Week Pilot Randomized Study.

BACKGROUND: Baduanjin qigong is a traditional mind-body exercise used to support balance and physical health in older adults. Age-related changes in proprioception may make accurate self-directed performance difficult without external guidance. OBJECTIVE: The aim of this study is to explore whether webcam-based real-time visual feedback delivered during supervised laboratory sessions was associated with differences in webcam-derived 2D pose discrepancy and movement consistency during Baduanjin practice in older adults. METHODS: A total of 31 older adults were enrolled, and 28 participants with complete analyzable records were included in this complete-case dataset (feedback group, n=14; nonfeedback group, n=14). All sessions were conducted face-to-face in a supervised motion-analysis laboratory. Weekly 2D pose-discrepancy values were analyzed using a linear mixed-effects model with fixed effects for group, categorical week, and the group-by-week interaction and a participant-specific random intercept. Joint- and movement-specific participant-level 6-week means were analyzed exploratorily using Welch independent-samples t tests. Holm correction was applied across 24 exploratory contrasts (6 week-specific, 8 joint-specific, and 10 movement-specific comparisons), and Hedges g and 95% CIs were reported. Participant-specific weekly slopes and within-participant variability were additionally examined to directly assess longitudinal error drift. RESULTS: The linear mixed-effects model showed no significant group-by-week interaction (Wald χ25=1.09; P=.96) and no significant overall week effect (Wald χ25=6.40; P=.27). Averaged across 6 weeks, the feedback group had an estimated mean 2D pose discrepancy 1.20° lower than the nonfeedback group (95% CI -2.38° to -0.02°; P=.046), although this marginal pilot finding was sensitive to an analytic approach. No week-specific contrast remained significant after Holm adjustment. Nominal right elbow, right shoulder, and right knee differences did not survive global Holm correction. Form 3 showed a lower mean discrepancy in the feedback group (mean difference -3.70°, 95% CI -5.86° to -1.54°; Hedges g=-1.30; unadjusted P=.002; Holm-adjusted P=.04). Direct analyses of participant-specific slopes and within-participant SDs did not support a significant between-group difference in longitudinal error drift. CONCLUSIONS: In this small exploratory pilot study conducted under supervised laboratory conditions, the 6-week trajectories did not differ significantly between groups. A marginally lower average 2D pose discrepancy was observed in the feedback group across the 6 weeks, but no individual week- or joint-specific comparison remained significant after multiplicity adjustment. Form 3 was the only exploratory contrast that remained significant after global Holm correction. Direct longitudinal analyses did not demonstrate prevention of error drift. Larger studies using validated reference measurements, prespecified outcomes, and adequately powered longitudinal designs are required.

Humans↗
PubMed2001

Improving quality improvement using achievable benchmarks for physician feedback: a randomized controlled trial.

CONTEXT: Performance feedback and benchmarking, common tools for health care improvement, are rarely studied in randomized trials. Achievable Benchmarks of Care (ABCs) are standards of excellence attained by top performers in a peer group and are easily and reproducibly calculated from existing performance data. OBJECTIVE: To evaluate the effectiveness of using achievable benchmarks to enhance typical physician performance feedback and improve care. DESIGN: Group-randomized controlled trial conducted in December 1996, with follow-up through 1998. SETTING AND PARTICIPANTS: Seventy community physicians and 2978 fee-for-service Medicare patients with diabetes mellitus who were part of the Ambulatory Care Quality Improvement Project in Alabama. INTERVENTION: Physicians were randomly assigned to receive a multimodal improvement intervention, including chart review and physician-specific feedback (comparison group; n = 35) or an identical intervention plus achievable benchmark feedback (experimental group; n = 35). MAIN OUTCOME MEASURE: Preintervention (1994-1995) to postintervention (1997-1998) changes in the proportion of patients receiving influenza vaccination; foot examination; and each of 3 blood tests measuring glucose control, cholesterol level, and triglyceride level, compared between the 2 groups. RESULTS: The proportion of patients who received influenza vaccine improved from 40% to 58% in the experimental group (P<.001) vs from 40% to 46% in the comparison group (P =.02). Odds ratios (ORs) for patients of achievable benchmark physicians vs comparison physicians who received appropriate care after the intervention, adjusted for preintervention care and nesting of patients within physicians, were 1.57 (95% confidence interval [CI], 1.26-1.96) for influenza vaccination, 1.33 (95% CI, 1.05-1.69) for foot examination, and 1.33 (95% CI, 1.04-1.69) for long-term glucose control measurement. For serum cholesterol and triglycerides, the achievable benchmark effect was statistically significant only after additional adjustment for physician characteristics (OR, 1.40 [95% CI, 1.08-1.82] and OR, 1.40 [95% CI, 1.09-1.79], respectively). CONCLUSION: Use of achievable benchmarks significantly enhances the effectiveness of physician performance feedback in the setting of a multimodal quality improvement intervention.

Aged↗
PubMed1988

The Barnum effect in couples: effects of intimacy, involvement, and sex on acceptance of generalized personality feedback.

The study assessed the impact of test feedback about one partner on both members of male-female couples. Twenty-four males and 24 females ("participants") took an inkblot test and received a standard personality interpretation-purportedly derived from the test-in the presence of a partner (the "observer"). Half the pairs were strangers; the other half defined themselves as intimate friends. Intimate couples rated the feedback as more accurate, remembered more of the feedback, reported more faith in psychological tests, and rated experimenter skill higher than did strangers. Male participants rated the feedback as more accurate than did male observers. Males may be more receptive of feedback in couples when they themselves have taken the test.

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↗
PubMed2002

Positive and negative feedback: striking a balance between necessary antagonists.

Most biological regulation systems comprise feedback circuits as crucial components. Negative feedback circuits have been well understood for a very long time; indeed, their understanding has been the basis for the engineering of cybernetic machines exhibiting stable behaviour. The importance of positive feedback circuits, considered as "vicious circles", has however been underestimated. In this article, we give a demonstration based on degree theory for vector fields of the conjecture, made by René Thomas, that the presence of positive feedback circuits is a necessary condition for autonomous differential systems, covering a wide class of biologically relevant systems, to possess multiple steady states. We also show ways to derive constraints on the weights of positive and negative feedback circuits. These qualitative and quantitative results provide, respectively, structural constraints (i.e. related to the interaction graph) and numerical constraints (i.e. related to the magnitudes of the interactions) on systems exhibiting complex behaviours, and should make it easier to reverse-engineer the interaction networks animating those systems on the basis of partial, sometimes unreliable, experimental data. We illustrate these concepts on a model multistable switch, in the context of cellular differentiation, showing a requirement for sufficient cooperativity. Further developments are expected in the discovery and modelling of regulatory networks in general, and in the interpretation of bio-array hybridization and proteomics experiments in particular.

Animals↗
PubMed1996

Learning combined feedback and feedforward control of a musculoskeletal system.

The goal of this paper is the learning of neuromuscular control, given the following necessary conditions: (1) time delays in the control loop, (2) non-linear muscle characteristics, (3) learning of feedforward and feedback control, (4) possibility of feedback gain modulation during a task. A control system and learning methodology that satisfy those conditions is given. The control system contains a neural network, comprising both feedforward and feedback control. The learning method is backpropagation through time with an explicit sensitivity model. Results will be given for a one degree of freedom arm with two muscles. Good control results are achieved which compare well with experimental data. Analysis of the controller shows that significant differences in controller characteristics are found if the loop delays are neglected. During a control task the system shows feedback gain modulation, similar to experimentally found reflex gain modulation during rapid voluntary contraction. If only limited feedback information is available to the controller the system learns to co-contract the antagonistic muscle pair. In this way joint stiffness increases and stable control is more easily maintained.

Cybernetics↗
PubMed1985

A discrete mathematical model of unlabelled granulocyte kinetics. A preliminary study of feedback control.

The equations used in formulating the continuous model of granulocyte kinetics developed by O'Fallon et al. (1971) were analyzed to see if they could be altered to simulate a feedback mechanism operating on the production and development of granulocytes. After extensive study and modification of the continuous model, it was found that a discrete model based on a Leslie matrix procedure was more effective for simulating the feedback system. This discrete model was used to show experimentally, from a mathematical view point, that a feedback mechanism of some kind must be operating on the production and development of granulocytes. Further, the discrete model was subjected to preliminary tests (simultaneous and cascading feedback) to demonstrate that it has the capability of responding to feedback control.

Animals↗
PubMed1985

Differences between visually triggered human forearm movements with visual and auditory relevant feedback.

The effects of visual and auditory relevant feedback on human forearm movements elicited by random position signal sequences were examined. Forearm movements were performed with four feedback conditions. We observed the reaction time, the holding time, and the adjustment error sequences when the arm moved briskly and accurately to the target position. As the results, the reaction times for auditory relevant feedback were shorter than those for the others (visual or no feedback). The holding times for auditory relevant feedback were longer than those for the others. And the subjects had about one adjustment error to terminate on the target zone.

Acoustic Stimulation↗
PubMed1977

Inhibitory effect of methylxanthines on feedback control of glomerular filtration rate in the rat kidney.

Microperfusion experiments were performed in rats to assess the effect of luminal application of theophylline and the more lipophilic 3-isobutyl-1-methylxanthine (IBMX) on feedback regulation of glomerular filtration rate. Elevation of loop of Henle flow from 0 to 40 nl/min caused a 20.3 +/- 4.5% reduction of stop flow pressure (SFP) and a 32.2 +/- 3.7% reduction of early proximal flow rate (EPFR) when the perfusate was a 140 mM NaCl solution. When theophylline was added in a concentration of 5mM SFP fell by only 5.3 +/- 1.8% and EPFR by 7.9 +/- 33%, changes which were significantly smaller than in the control perfusions (P less than 0.01). An identical change of loop of Henle flow in the presence of IBMX in concentration of 1 and 5 mM was associated with a 4.5 +/- 3.9% decrease and a 12.1 +/- 2.7% increase of EPFR. In orthograde perfusion experiments full inhibition of the feedback response was noted at an IBMX concentration of about 1 mM while during retrograde perfusion a concentration of 0.4 mM was sufficient to produce the same effect. This indicates that methylxanthines diffuse out of the loop of Henle to a considerable extent. Methylxanthines reduced absolute and fractional water absorption along the loop of Henle to some extent while Cl absorption rates and early distal Cl concentrations were not significantly altered. Cyclic AMP applied from the luminal side in a concentration of 10 mM did not affect the feedback response of EPFR to flow elevation from 0 to 40 nl/min. Luminal application of dibutyryl cyclic AMP at 10 mM induced a small, but significant reduction of the feedback response when tested by paired t-test (P less than 0.05). Our results show that luminal application of methylxanthines strongly interfere with feedback regulation of glomerular filtration rate. It is unclear at present whether this effect is related to inhibition of cyclic nucleotide phosphodiesterase and a rise in tissue cyclic AMP levels or to interference with a mechanism involving the local action of adenosine or 5'-AMP.

Animals↗
PubMed1989

Tubulo-glomerular feedback response: enhancement in adult spontaneously hypertensive rats and effects of anaesthetics.

Open-loop tubulo-glomerular feedback (TGF) responses were measured in halothane anaesthetized spontaneously hypertensive rats (SHR), in normotensive Wistar Kyoto (WKY) and Sprague-Dawley rats (SPRD), and in inactin anaesthetized SPRD. Proximal intratubular free flow pressures (FFP) (13.8-14.7 mm Hg) and stop-flow pressures (40.0-42.4 mm Hg) were similar in the four groups, but systemic arterial pressure was significantly lower in WKY, and significantly higher in SHR than in SPRD. The turning point (Tp) of the feedback curve was 9.87 nl/min in SHR, significantly lower than the 13.04 nl/min found in WKY. Maximum TGF pressure response was 28.6% greater in SHR than in the normotensive rats (13.3 vs. 9.5 mm Hg; p less than 0.025). The sensitivity, as estimated from the slope of the feedback curve at the Tp [f'(Tp)] was 87% greater in SHR than in WKY. There was no significant difference between these parameters in WKY and SPRD. The TGF pressure response was biphasic in the 3 groups of halothane anaesthetized rats with a steady state level reached in about 2 min after the change in late proximal microperfusion rate. In inactin anaesthetized rats the sensitivity was 41% lower than in the halothane anaesthetized control group of SPRD, the feedback response was lower, and the feedback curve was displaced to the right with the Tp at 15.9 nl/min, significantly higher than in the control group (p less than 0.001). Although the steady state level also was reached within 2 min, the clearly biphasic pattern of the pressure response was less consistent.

Animals↗
PubMed1991

A target feedback device for ventilatory muscle training.

In a previous study, we successfully used a target feedback device, together with an external resistor, to train the ventilatory muscles of patients with chronic obstructive pulmonary disease. In this article, we describe the details of the design and function of the target feedback device. When used in conjunction with an external resistance, the target feedback device provides timing and pressure targets, together with feedback information, on whether these targets are achieved. The target feedback device consists of readily available electronic components and is relatively simple to construct. Adjustment of an external pressure knob permits setting of pressure targets. Adjustment of internal components is possible and allows control of breathing frequency, inspiratory time, and breathing waveform.

Breathing Exercises↗