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PubMed1997

P3B and positive slow wave following real and dummy feedback on arithmetic rule-learning and perceptuomotor tasks.

Event-related Potentials (ERPs) were recorded to feedback during a cognitively demanding, arithmetic rule-learning task and a relatively simple, skill-oriented, perceptuomotor task. For both tasks, a compound feedback display was employed. It consisted of numeric feedback information presented simultaneously with a red or green light (50% each) which indicated whether the numeric information was real (valid) or dummy (invalid). The task and feedback-validity manipulations showed a functional dissociation between the P3b (350-450 msec.) and a Positive Slow Wave (600-900-msec.). P3b was larger for real than for dummy feedback; Positive Slow Wave was larger for rule-learning than for perceptuomotor tasks.

Adolescent↗
PubMed2002

Jaw and finger movement accuracy under visual and nonvisual feedback conditions.

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 anl other disciplines. Furthermore, the results contribute to our understanding of the role of various modalities of feedback during motor execution.

Adolescent↗
PubMed2003

Survey of preferences for feedback style in high school athletes.

This study asked high school athletes what kinds of desirable traits or styles they would like to see in coaches when they provided correct feedback. High school athletes (M age=14.5 yr., SD=2.1), 43 girls and 70 boys, in both individual and team sports were recruited from 2 junior high and 2 senior high schools. A questionnaire measuring preferences for feedback style was developed with 12 9-point Likert scale items. Each item dealt with one aspect of feedback style. The survey covered several characteristics of feedback style: character, timing, frequency, precision, intent, informational style versus controlling style, descriptive versus prescriptive, and context. Analyses of variance, performed on responses to each question to assess the effects of sex, age, and sport, indicated high uniformity in responses to the qualities of feedback style, with no significant differences for sex, age, or sport.

Adolescent↗
PubMed2004

Does augmented feedback from pedometers increase adults' walking behavior?

This study investigated whether feedback from pedometers motivated adults to increase their walking behavior. Participants (n =26) were enrolled in one of two 8-wk. "Walking for Fitness" classes. The study used a crossover design, such that Group 1 wore pedometers for the first 3 weeks (Feedback Condition) and sealed "disguised" pedometers for the last 3 weeks (No-feedback Condition). The order of feedback was reversed for Group 2. Analysis indicated that (a) neither group increased their walking behavior significantly over time and, (b) interactions between groups were not significant at Week 3 or 6, indicating that groups did not respond differently to feedback from the pedometers. If a motivational effect from pedometers exists, it may be small, dissipate before 3 wk., only work in combination with goal setting, or only motivate certain types of individuals.

Adult↗
PubMed2000

Effect of feedback expectancy on NEO-Five Factor Inventory scores.

Although Costa and McCrae have indicated that respondents can strategically self-present on the NEO-Five Factor Inventory when instructed to do so, little research has examined the situational factors related to the motivation to self-present. This study examined feedback expectancy concerning test performance as one variable that might have relevance to strategic self-presentation on the NEO-Five Factor Inventory. Participants (N = 108) completed the inventory under one of three feedback expectancy conditions: public feedback, private feedback, or a control condition. Multiple analyses of variance indicated no significant differences on the inventory's domain scores among conditions, suggesting that feedback expectancy was not related to performance.

Adolescent↗
PubMed2002

Effects of generalized self-efficacy and negative social comparison feedback on specific self-efficacy and performance.

The effects of social comparison feedback on specific self-efficacy and performance of high generalized self-efficacy participants and low generalized self-efficacy participants were examined with the help of 20 participants with high generalized self-efficacy and 20 participants with low generalized self-efficacy. Half of the participants in each generalized self-efficacy group received negative social comparison feedback after each of four trials of an experimental task while the other half received no feedback. Two kinds of specific self-efficacy-performance-based and normative-based--were measured once before the task and four times after the trials of the task. After the task, the High generalized self-efficacy/Feedback group rated performance-based specific self-efficacy higher and performed better than the Low generalized self-efficacy/Feedback group. No significant difference was observed between the High generalized self-efficacy/No feedback group and Low generalized self-efficacy/No feedback group. There were no significant effects with regard to normative-based specific self-efficacy.

Achievement↗
PubMed1996

Modeling ruminant feed intake with protein, chemostatic, and distention feedbacks.

Little progress has been made in modeling intake regulation in spite of the many mechanisms identified as important. A model with relatively simple inputs was developed that included compartments for protein, soluble carbohydrate, digestible fiber, and very slowly digesting fiber. Distention and chemostatic feedbacks were combined using a previously published equation. The ratio of current ruminal fill to a modulating parameter for ruminal fill represented distention feedback. The ratio of the current flow of available energy to a modulating parameter for chemostatic demand represented chemostatic feedback. The modulating parameter for ruminal fill was based on literature reports of ruminal contents. Intake was adjusted based on current fill and energy flow relative to modulating parameters for fill and chemostatic feedback. The effect of the digestible organic matter (DOM) to CP ratio on DOM intake was modeled to adjust rates of digestion, rates of passage, and the chemostatic feedback. The model tested an integrated concept of intake regulation with only CP, IVDMD, and NDF as inputs. In spite of relatively simple inputs, the model behavior in response to variation in protein, digestibility, and fiber was similar to observations of animal responses.

Animals↗
PubMed1996

Use of an instrumented treadmill for real-time gait symmetry evaluation and feedback in normal and trans-tibial amputee subjects.

The purpose of this research was to evaluate a newly developed system for assessing and providing feedback of gait symmetry information in real time to subjects walking on a motorised treadmill (the CCF Treadmill). The advantages of the system are that it allows the rapid collection and comparison of temporal and kinetic parameters of gait for multiple successive strides, at a constant known speed, without forcing subjects to target their footsteps. Gait asymmetries of six normal (mean age 42.7 years) and six unilateral transtibial amputee subjects (mean age 41.7, and average 6.0 years using a prosthesis) were quantified. The amputee group was the reevaluated after receiving five minutes of training with each of three different types of real-time visual feedback (RTVF). Asymmetries in the measured parameters before feedback were 4.6 times greater in the amputee population than in the normal group, and were consistent with the finding of previous authors. Significant decreases in gait asymmetry were demonstrated for all forms of feedback after amputees received feedback training. Results, however, indicated that gait asymmetries for different variables are not necessarily related, and that more work needs to be done to identify those variables for which attaining a more symmetrical gait pattern is most beneficial. Further work also needs to be done to determine the long term effects of such RTVF training. The CCF Treadmill and RTVF were shown to be potentially useful tools both for defining rehabilitation targets and for quantifying patients' progress towards those goals.

Adult↗
PubMed1987

[The effects of self-evaluative responses with feedback in learning].

This study was designed to investigate the effects of self-evaluative responses with feedback in a nonsense syllable recognition task (Experiment I) and a concept learning task (Experiment II). Subjects were 143 fifth graders who were first asked to identify each item in the task before being exposed to the experimental procedures. Following the actual learning trials, all subjects were given the post-test. The experimental procedures were as follows: SF--in the process of identification, subjects evaluated their answers and feedback was provided on their evaluations. EF--in the process of identification, subjects were given feedback on their answers. NF--subjects evaluated their answers but no feedback was provided. PF--EF and NF procedures alternated from trial to trial. In both experiments, SF and EF groups learned more effectively than NF and PF groups. In contrast to experiment I, many subjects in SF group were successful in the concept learning task. These results suggested that self-evaluative responses with feedback had positive effects on learning, especially on concept learning.

Child↗
PubMed1988

[Sex difference in susceptibility to delayed auditory feedback in oral reading tasks].

Sex difference in susceptibility to DAF (delayed auditory feedback) in oral reading of texts was investigated. Forty adults, 20 males and 20 females with normal speech and hearing abilities, read aloud two kinds of texts, one easy to read and the other difficult, under two conditions, NAF (normal auditory feedback) and DAF. Delays were 150, 200, 300, 400 and 500 ms and the feedback intensity was 90 dB in SPL at maximum. Susceptibility to DAF was defined as max magnitude of DAF Index under five DAF conditions (DAF Index = 1-CMR(tau)/CMR(0), where CMR was correct mora rate per second and tau the delay). As the results, the susceptibility was significantly higher in males than in females for easy texts. Sex difference of the feedback mechanism for articulation was clearer in easy texts than in difficult ones. It was suggested that the articulatory movement was more cognitively controlled by the route of auditory feedback in males than in females.

Adolescent↗
PubMed1999

Feedback processing as parallel task in P300 conditioning.

Previous reports on conditioning P300 amplitude indicated that downtraining produced a stronger effect than uptraining. This asymmetry can be due to the effect of drain on processing resources of the brain produced by the attempts to use feedback information (parallel task effect). Such a drain should reduce P300 amplitude regardless of the direction of training. The aim of the experiment was to demonstrate this effect. Event-related potentials (ERPs) evoked by light stimuli in a standard odd-ball procedure were recorded from Fz, Cz and Pz scalp sites. Subjects were instructed to enlarge or to reduce the P300 amplitude. The first 30 presentations of the target stimulus were analyzed during which the effect of learning should be negligible and processing of feedback information should be intensive. ERPs recorded during uptraining and downtraining were compared with the no-feedback recordings. As predicted, downtraining significantly reduced the P300 amplitude even in the first session of learning. Unexpectedly, uptraining recordings did not differ from no-feedback ERPs but differed significantly from downtraining waves. Such results support the prediction that feedback procedures involve a number of processes that alter the P300 amplitude even before the effects of learning can be expected. But if the hypothesis of the parallel task is to be accepted there must be another instantaneous process that compensates for P300 amplitude reduction during uptraining.

Adult↗
PubMed2000

Use of visual feedback in retraining balance following acute stroke.

BACKGROUND AND PURPOSE: Visual feedback related to weight distribution and center-of-pressure positioning has been shown to be effective in increasing stance symmetry following stroke, although it is not clear whether functional balance ability also improves. This study compared the relative effectiveness of visual feedback training of center-of-gravity (CoG) positioning with conventional physical therapy following acute stroke. SUBJECTS: Forty-six people who had strokes within 80 days before the study, resulting in unilateral hemiparesis, and who were in need of balance retraining participated. METHODS AND MATERIALS: Initially, subjects were randomly assigned to visual feedback or conventional physical therapy groups for balance retraining until 16 subjects per group were recruited. The next 14 subjects were assigned to a control group. All subjects received physical therapy and occupational therapy (regular therapy) 2 hours a day, and subjects in the 2 experimental groups received additional balance training 30 minutes a day until discharge. The visual feedback group received information about their CoG position as they shifted their weight during various activities. The conventional therapy group received verbal and tactile cues to encourage symmetrical stance and weight shifting. Static (postural sway) and activity-based measures of balance (Berg Balance Scale, gait speed, and the Timed "Up & Go" Test) were contrasted across the 3 groups at baseline, at discharge, and at 1 month following discharge using an analysis of variance for repeated measures. RESULTS: All groups demonstrated marked improvement over time for all measures of balance ability, with the greatest improvements occurring in the period from baseline to discharge. No between-group differences were detected in any of the outcome measures. CONCLUSION AND DISCUSSION: Visual feedback or conventional balance training in addition to regular therapy affords no added benefit when offered in the early stages of rehabilitation following stroke.

Acute Disease↗
PubMed2000

Feedback connections from area MT of the squirrel monkey to areas V1 and V2.

Area MT/V5 is reciprocally connected with both V1 and V2; but, despite extensive anatomical and physiological investigations, detailed information on the feedback component of these connections is still not available. The present report uses serial section reconstruction of single axons, labeled by anterograde tracers injected in area MT of squirrel monkeys, to characterize these connections further. As with other feedback systems, MT axons terminating in both areas V1 (n = 9) and V2 (n = 6) are widely divergent. In area V1, MT fields are larger than those from V2 and are about comparable to those from V4 or TEO. Terminations in V1, unlike other feedback connections described so far, terminate in several laminar combinations: only layer 1 (n = 2); only layer 4B (n = 3); layers 1 and 4B (n = 1); and layers 1, 4B, and 6 (n = 3). In V2, they occur mainly in layers 1 and 5 or 6. Terminations have two patterns even within a single axon: strung along collateral segments and grouped within small clusters. There are no apparent differences in the size, shape, or density of terminal specializations in V1 or V2, and, consistently with previous double-labeling experiments (Kennedy and Bullier [1985] J Neurosci 5:2815-2830), some axons can branch to both areas. This result, along with the laminar evidence for subtypes of feedback connections, argues against an exclusively hierarchical organization based on "pairwise" connectivity. For V1 and MT, there may be directly reciprocal loops between feedforward and feedback projecting neurons, but this is less likely to be so for V2 and MT.

Animals↗
PubMed2002

Climate feedbacks at the tundra-taiga interface.

Feedbacks, or internal interactions, play a crucial role in the climate system. Negative feedback will reduce the impact of an external perturbation, a positive feedback will amplify the effect and could lead to an unstable system. Many of the feedbacks found in the climate system are positive; thus, for example, increasing CO2 levels will increase temperature, reduce the snow cover, increase the absorption of radiation and hence increase temperature further. The most obvious feedbacks, such as the snow example quoted above, are already included within our models of the climate and earth system. Others, such as the impact of increasing forest cover due to global warming, are only just being included. Others, such as, the impact of global warming on the northern peatlands and the impact of freshwater flows on the Arctic Ocean are not yet considered. The contrast in surface characteristics between low tundra vegetation to high taiga forest is considerable. The contrast is greatest in the winter, when the tundra is snow covered but the trees of the taiga protrude through the snow pack, and is probably the greatest contrast found on the land surface anywhere. This variation causes massive changes in the energy fluxes at the surface and hence the temperature conditions on the ground and within the atmosphere. There will be large resultant changes in the vegetation development, the carbon fluxes, the permafrost and the hydrology. The Arctic is already experiencing change and it is essential for us to understand the basic processes, and how these interact, to be confident of our predictions of environmental change in the future.

Air↗
PubMed2005

Improving management of hypertension in general practice: a randomised controlled trial of feedback derived from electronic patient data.

BACKGROUND: Although absolute risk of death associated with raised blood pressure increases with age, the benefits of treatment are greater in older patients. However, fewer patients in this group are identified, treated, and controlled. AIM: To evaluate the impact of the provision of different levels of feedback on identification, treatment, and control of older patients with hypertension. DESIGN OF STUDY: Randomised controlled trial. SETTING: Fifty-two Scottish general practices. METHOD: Practices were randomly allocated to either control (n = 19), audit only feedback (n = 16), or audit plus risk feedback, prioritising patients by absolute risk (n = 17). Electronic data were extracted from practice computer systems annually from 1999 to 2001 and used to develop feedback. Data were collected for 30 345 patients aged 65-79 years. RESULTS: The majority of known patients with hypertension in each group had an initial blood pressure recorded (control = 89.6%; audit = 80.4%; risk = 96.1%) and this increased over the study period (control = 92.3%; audit = 86.0%; risk = 96.6%). Initially, more than 80% of patients in each group were treated but many were uncontrolled (blood pressure >/=160/ >/=90 mmHg) (control = 41.5%; audit = 41.3%; risk = 36.1%). The numbers of untreated and uncontrolled patients in each group reduced (control = 32.3%; audit = 38.3%; risk = 32.6%). There was some evidence of a significant difference in mean systolic pressure between the audit plus risk and audit only groups: (149.6 versus 152.7 mmHg; P = 0.019) and of significantly greater control in the audit plus risk group compared with the other groups 49.4% (versus audit only = 35.4%; versus control = 46.5%; odds ratio = 1.72 [95% confidence interval = 1.09 to 2.70]; P = 0.019). CONCLUSIONS: Levels of identification, treatment, and control improved in each group. Although there were still significant numbers of patients with uncontrolled hypertension, there is some evidence to suggest that providing patient-specific feedback may have a positive impact on identification and management of hypertension in older people and produce an increase in control.

Aged↗
PubMed2005

Using feedback to raise the quality of primary care computer data: a literature review.

BACKGROUND: Primary care is recognised as a medical specialty and its unique information needs justify the existence of its own health informatics sub-specialty: primary care informatics (PCI). A challenge for PCI is how to raise the standard of computerised medical records so that meaningful conclusions can be drawn from them. In the UK the Primary Care Data Quality (PCDQ) programme has eight years experience of using feedback in an educational context to improve data quality. OBJECTIVE: This literature review set out to define the characteristics of a feedback process most likely to achieve change; the principles of which could be applied to PCDQ or to other data quality initiatives. METHOD: A literature review of the major medical bibliographical databases, and the websites and working groups of the international medical informatics associations. RESULTS: There are generalisable lessons for primary care derived from the literature about implementing best evidence, feedback and the theory of diffusion of innovation. The principles identified are: (1) Engage and support local innovators - i.e. those most likely to adopt change, demonstrate the evidence-base for the intervention and the form of feedback most acceptable to them (2) Model the clinical context in which quality improvement is required; (3) Develop an understanding of the health system, its culture and management system; and, (4) Identify and address technical issues relating to computer use and coding. CONCLUSIONS: Feedback is most effective when: clinically relevant, educationally orientated, given by peers, and sensitive to the socio-technical context.

Feedback↗
PubMed1992

Endothelial vasoactive influence simulated by exponential feedback.

We hypothesized that results from rabbit carotid sinus wall and baroreceptors could be simulated using exponential feedback in a viscoelastic model. Wall and baroreceptor were each modeled by second order differential equations. Coefficients for viscosity, elasticity and feedback were estimated from experimental data. Feedback of model wall distension (y1) on viscosity (C) was expressed by the transfer function: C/y1 = RW/(s tau W + 1). With gain (RW) = 52.5E6 N(s)/m2 and tau W = 34 sec, this feedback resulted in simulation of wall response for sinuses with intact endothelium. Model receptor required no (or negative gain) feedback to simulate baroreceptors.

Animals↗
PubMed1990

Effects of case manager feedback on the quality of individual habilitation plan objectives.

The functional relation between feedback by a case manager and improved writing of Individual Habilitation Plan (IHP) objectives in adult service agencies was assessed. Feedback on seven features of IHP objectives was delivered by the local case manager to program staff of four agencies providing residential or vocational support to adults with moderate to severe disabilities. The results demonstrate that each of the four agencies improved the quality of their written objectives after receiving feedback from the case manager and maintained those gains 18 months after feedback was terminated. Implications for case managers as feedback agents were discussed.

Community Mental Health Services↗