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PubMed2006

Perceptions of teachers' general and informational feedback and intrinsic motivation in physical education: two-year effects.

Relative change or stability of perceived positive general feedback and perceived informational feedback and their influence on students' intrinsic motivation in physical education over two years were examined. 302 students, ages 11 to 15 years, responded to the Perception of Teacher's Feedback questionnaire. Two years later, these students filled out the questionnaire again, along with a modified version of the Sport Motivation Scale. Analysis showed that both types of perceived feedback exhibited moderate stability over the two years. Perceived positive general feedback demonstrated a significant direct effect on students' intrinsic motivation measured concurrently in physical education. Further, fixing to zero the effect of perceived positive general feedback on intrinsic motivation measured concurrently, an effect emerged over the two years.

Adolescent↗
PubMed1992

Noncontingent positive and negative feedback during maximal exercise.

A closed skill, maximal effort on a bicycle ergometer was used to study the effects of noncontingent external feedback on performance, perceived effort, and the subject's assessment of the quality and accuracy of the feedback. The 47 subjects included elite athletes as well as physical education majors. They were asked to perform a series of 5 60-sec. trials of maximal effort, trials which included positive, negative, positive and negative, and no-feedback conditions. Although there were no significant effects on performance for the various feedback conditions, subjects judged the positive feedback favourably and as accurate, but negative feedback was judged unfavourably and considered to be inaccurate. This result is seen as supportive of the 1982 McCarrey, et al. supposition that successful athletes may have less need to internalize attributions of effect.

Adult↗
PubMed1996

The horizontal vertical illusion: evidence for strategic factors in feedback-induced illusion decrement.

This study assessed whether feedback would improve performance on a horizontal vertical illusion task and whether such improvement would transfer to different forms of the illusion. Subjects shortened the extended vertical line of small, medium, and large inverted-T figures to be equal in length to the horizontal line before and after being shown a correctly adjusted medium-sized figure (visual feedback). Next, they were tested on three alternate forms of the illusion; a production task (drawing 1-in. lines in the horizontal and vertical planes), an adjustment task using L figures, and a task requiring them to choose which of several sailboat drawings had mast height equal to hull length. Prior to feedback, vertical lines were adjusted shorter than the horizontal lines on each size inverted-T figure. After feedback on the medium-size figure, experimental subjects were more accurate than the controls on each size inverted-T figure. The results suggest that transfer of illusion decrement was also obtained for the boat-selection and, to a lesser extent, the L-figure adjustment tasks but not to the line-production task. These findings are consistent with the notion that improvement after feedback is not due to structural changes in visual processing or to simple feedback-induced compensation in performance but involves some strategic or cognitive change in judging line length.

Adult↗
PubMed1998

Quantitative electroencephalogram of posterior cortical areas of fluent and stuttering participants during reading with normal and altered auditory feedback.

In the left and right hemisphere, posterior quantitative electroencephalogram Beta band activity (13.5-25.5 Hz) of seven adult participants who stutter and seven age-matched normal controls was obtained while subjects read text under three experimental conditions of normal auditory feedback, delayed auditory feedback, and frequency-altered feedback. Data were obtained from surface electrodes affixed to the scalp using a commercial electrode cap. Electroencephalogram activity was amplified, band-pass analog-filtered, and then digitized. During nonaltered auditory feedback, stuttering participants displayed Beta band hyperreactivity, with the right temporal-parietal lobe region showing the greatest activity. Under conditions of delayed auditory feedback and frequency-altered auditory feedback, the stuttering participants displayed a decrease in stuttering behavior accompanied by a strong reduction in Beta activity for the posterior-temporal-parietal electrode sites, and the left hemisphere posterior sites evidenced a larger area of reactivity. Such findings suggest than an alteration in the electrical fields of the cortex occurred in the stuttering participants under both conditions, possibly reflecting changes in neurogenerator status or current dipole activity. Further, one could propose that stuttering reflects an anomaly of the sensory-linguistic motor integration wherein each hemisphere generates competing linguistic messages at hyperreactive amplitudes.

Adolescent↗
PubMed2004

Error detection in text: do feedback and familiarity help?

In the present study, the authors examined the extent to which familiarity and feedback (auditory and/or articulatory) might be beneficial to proofreading. Participants proofread unfamiliar and familiar (repeated) passages while (a) concurrently reading either aloud or silently, (b) concurrently listening to the passages being read to them, or (c) reading without either auditory or articulatory feedback. Errors were one-letter changes that transformed function words into contextually inappropriate words. Familiarity improved reading times largely irrespective of feedback, and it enhanced error detection only when auditory feedback was available to participants. Proofreaders' enhanced error detection in familiar text reflected a change in their sensitivity to errors rather than any change in the placement of the response criterion for reporting errors. These findings suggest that familiarity can produce two kinds of functional fluency, one involving speed of processing, which is largely independent of feedback, and the other concerned with accuracy of processing, which relies on feedback.

Adult↗
PubMed2005

Optimal classifier feedback improves cost-benefit but not base-rate decision criterion learning in perceptual categorization.

Unequal payoffs engender separate reward- and accuracy-maximizing decision criteria; unequal base rates do not. When payoffs are unequal, observers place greater emphasis on accuracy than is optimal. This study compares objective classifier (the objectively correct response) with optimal classifier feedback (the optimal classifier's response) when payoffs or base rates are unequal. It provides a critical test of Maddox and Bohil's (1998) competition between reward and accuracy maximization (COBRA) hypothesis, comparing it with a competition between reward and probability matching (COBRM) and a competition between reward and equal response frequencies (COBRE) hypothesis. The COBRA prediction that optimal classifier feedback leads to better decision criterion leaning relative to objective classifier feedback when payoffs are unequal, but not when base rates are unequal, was supported. Model-based analyses suggested that the weight placed on accuracy was reduced for optimal classifier feedback relative to objective classifier feedback. In addition, delayed feedback affected learning of the reward-maximizing decision criterion.

Decision Making↗
PubMed2004

Disrupting feedback processing interferes with rule-based but not information-integration category learning.

The effect of a sequentially presented memory scanning task on rule-based and information-integration category learning was investigated. On each trial in the short feedback-processing time condition, memory scanning immediately followed categorization. On each trial in the long feedback-processing time condition, categorization was followed by a 2.5-sec delay and then memory scanning. In the control condition, no memory scanning was required. Rule-based category learning was significantly worse in the short feedback-processing time condition than in the long feedback-processing time condition or control condition, whereas information-integration category learning was equivalent across conditions. In the rule-based condition, a smaller proportion of observers learned the task in the short feedback-processing time condition, and those who learned took longer to reach the performance criterion than did those in the long feedback-processing time or control condition. No differences were observed in the information integration task. These results provide support for a multiple-systems approach to category learning and argue against the validity of single-system approaches.

Feedback↗
PubMed2003

Response stability and variability induced in humans by different feedback contingencies.

In two experiments, the behavioral effects of different response-feedback contingencies were examined with a task requiring human subjects to repeatedly type three-key sequences on a computer keyboard. In Experiment 1, the subjects first received positive feedback for response variability, followed by no feedback, or vice versa In Experiment 2, the subjects first received positive feedback for response variability, followed by response-independent positive feedback, or vice versa. Response stability and variability were examined using different measures, such as percentage of trials meeting the variability criteria, frequency of use of the different response alternatives, and autocorrelations as an index of response randomness. The subjects' behavior in the first phase in each condition came to reflect the current feedback contingency. Depending on the measure examined, responding after each contingency change was characterized by both response stability and decreases or increases in response variability. The collective results are discussed in the framework of previous animal and human studies on behavioral stability and variability.

Adult↗
PubMed2006

A role for MAPK in feedback inhibition of Tcrb recombination.

The Tcrb locus is subject to a host of regulatory mechanisms that impart a strict cell and developmental stage-specific order to variable (V), diversity (D), and joining (J) gene segment recombination. The Tcrb locus is also regulated by allelic exclusion mechanisms, which restrict functional rearrangements to a single allele. The production of a functional rearrangement in CD4-CD8- double-negative (DN) thymocytes leads to the assembly of a pre-TCR and initiates signaling cascades that allow for DN to CD4+CD8+ double-positive (DP) differentiation, proliferation, and feedback inhibition of further Vbeta to DJbeta rearrangement. Feedback inhibition is believed to be controlled, in part, by the loss of Vbeta gene segment accessibility during the DN to DP transition. However, the pre-TCR signaling pathways that lead to the inactivation of Vbeta chromatin have not been determined. Because activation of the MAPK pathway is documented to promote DP differentiation in the absence of allelic exclusion, we characterized the properties of Vbeta chromatin within DP thymocytes generated by a constitutively active Raf1 (Raf-CAAX) transgene. Consistent with previous reports, we show that the Raf-CAAX transgene does not inhibit Tcrb recombination in DN thymocytes. Nevertheless, DP thymocytes generated by Raf-CAAX signals display normal down-regulation of Vbeta segment accessibility and normal feedback inhibition of the Vbeta to DJbeta rearrangement. Therefore, our results emphasize the distinct requirements for feedback inhibition in the DN and DP compartments. Although MAPK activation cannot impose feedback in DN thymocytes, it contributes to feedback inhibition through developmental changes that are tightly linked to DN to DP differentiation.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Confidential prescriber feedback and education to improve antibiotic use in primary care: a controlled trial.

BACKGROUND: Antibiotics are a medication class for which inappropriate prescribing is frequently described. We sought to assess the effectiveness of a mailed intervention combining confidential prescribing feedback with targeted educational bulletins in increasing the use of less expensive, first-line antibiotics by practising physicians. METHODS: The participants were 251 randomly selected primary care physicians from southern Ontario who consented to participate (135 in the feedback group and 116 in the control group). Prescribing data were obtained from the claims database of the Ontario Drug Benefit program, which covers all Ontarians over age 65 years for drugs selected from a minimally restrictive formulary. Confidentially prepared profiles of antibiotic prescriptions coupled with guidelines-based educational bulletins were mailed to the intervention group every 2 months for 6 months. The control group received no intervention until after completion of the study. The main outcome measures were change from baseline in physician's median antibiotic cost and proportion of episodes of care in which a prespecified first-line antibiotic was used first. RESULTS: The median prescription cost of about $11 remained constant in the feedback group but rose in the control group (change of $0.05 v. $3.37, p < 0.002). First-line drug use increased in the feedback group but decreased in the control group (change of 2.6% v. -1.7%, p < 0.01). In a mailed survey of 100 feedback recipients (response rate 76%), 82% indicated that they would participate readily in another, similar program. INTERPRETATION: A simple program of confidential feedback and educational materials blunted cost increases, increased the use of first-line antibiotics and was highly acceptable to Ontario primary care physicians.

Adult↗
PubMed2000

Cortical feedback controls the frequency and synchrony of oscillations in the visual thalamus.

Thalamic circuits have an intrinsic capacity to generate state-dependent oscillations of different frequency and degrees of synchrony, but little is known of how synchronized oscillation is controlled in the intact brain or what function it may serve. The influence of cortical feedback was examined using slice preparations of the visual thalamus and computational models. Cortical feedback was mimicked by stimulating corticothalamic axons, triggered by the activity of relay neurons. This artificially coupled network had the capacity to self-organize and to generate qualitatively different rhythmical activities according to the strength of corticothalamic feedback stimuli. Weak feedback (one to three shocks at 100-150 Hz) phase-locked the spontaneous spindle oscillations (6-10 Hz) in geniculate and perigeniculate nuclei. However, strong feedback (four to eight shocks at 100-150 Hz) led to a more synchronized oscillation, slower in frequency (2-4 Hz) and dependent on GABA(B) receptors. This increase in synchrony was essentially attributable to a redistribution of the timing of action potential generation in lateral geniculate nucleus cells, resulting in an increased output of relay cells toward the cortex. Corticothalamic feedback is thus capable of inducing highly synchronous slow oscillations in physiologically intact thalamic circuits. This modulation may have implications for a better understanding of the descending control of thalamic nuclei by the cortex, and the genesis of pathological rhythmical activity, such as absence seizures.

Action Potentials↗
PubMed2001

Getting 360 degrees feedback right.

Over the past decade, 360-degree feedback has revolutionized performance management. But one of its components--peer appraisal--consistently stymies executives and can exacerbate bureaucracy, heighten political tensions, and consume lots of time. For ten years, Maury Peiperl has studied 360-degree feedback and has asked: under what circumstances does peer appraisal improve performance? Why does peer appraisal sometimes work well and sometimes fail? And how can executives make these programs less anxiety provoking for participants and more productive for organizations? Peiperl discusses four paradoxes inherent to peer appraisal: In the Paradox of Roles, colleagues juggle being both peer and judge. The Paradox of Group Performance navigates between assessing individual feedback and the reality that much of today's work is done by groups. The Measurement Paradox arises because simple, straightforward rating systems would seem to generate the most useful appraisals--but they don't. Customized, qualitative feedback, though more difficult and time consuming to generate, is more helpful in improving performance. During evaluations, most people focus almost exclusively on reward outcomes and ignore the constructive feedback generated by peer appraisal. Ironically, it is precisely this overlooked feedback that helps improve performance--thus, the Paradox of Rewards. These paradoxes do not have neat solutions, but managers who understand them can better use peer appraisal to improve their organizations.

Benchmarking↗
PubMed2001

Modeling circadian oscillations with interlocking positive and negative feedback loops.

Both positive and negative feedback loops of transcriptional regulation have been proposed to be important for the generation of circadian rhythms. To test the sufficiency of the proposed mechanisms, two differential equation-based models were constructed to describe the Neurospora crassa and Drosophila melanogaster circadian oscillators. In the model of the Neurospora oscillator, FRQ suppresses frq transcription by binding to a complex of the transcriptional activators WC-1 and WC-2, thus yielding negative feedback. FRQ also activates synthesis of WC-1, which in turn activates frq transcription, yielding positive feedback. In the model of the Drosophila oscillator, PER and TIM are represented by a "lumped" variable, "PER." PER suppresses its own transcription by binding to the transcriptional regulator dCLOCK, thus yielding negative feedback. PER also binds to dCLOCK to de-repress dclock, and dCLOCK in turn activates per transcription, yielding positive feedback. Both models displayed circadian oscillations that were robust to parameter variations and to noise and that entrained to simulated light/dark cycles. Circadian oscillations were only obtained if time delays were included to represent processes not modeled in detail (e.g., transcription and translation). In both models, oscillations were preserved when positive feedback was removed.

Animals↗
PubMed1976

On the evocability of a positive oestrogen feedback action on LH secretion in transsexual men and women.

In transsexual men with homosexual behaviour and intact testicular function, as well as in homosexual men with normal gender identity, following a negative oestrogen feedback effect a delayed positive oestrogen feedback action on LH secretion was evoked. By contrast, in transsexual men with hypo- or asexuality and intact testes or hypergonadotrophic hypo- or agonadism, as well as in heterosexual men with normal gender identity, a negative oestrogen feedback effect was not followed by a positive feedback action on LH release. In transsexual women with homosexual behaviour and oligo- and/or hypomenorrhoea, only a weak or at best moderate positive oestrogen feedback action on LH release was evocable, similarly as in castrated and oestrogen-primed heterosexual men. By contrast, in a transsexual woman with bisexual behaviour and eumenorrhoea, a strong positive oestrogen feedback action on LH secretion was evocable, as well as in heterosexual women with normal gender identity.

Brain↗
PubMed2003

A neural basis for auditory feedback control of vocal pitch.

Hearing one's own voice is essential for the production of correct vocalization patterns in many birds and mammals, including humans. Bats, for instance, adjust temporal, spectral, and intensity parameters of their echolocation calls by precisely monitoring the characteristics of the returning echo signals. However, neuronal substrates and mechanisms for auditory feedback control of vocalizations are still mostly unknown in any vertebrate. We used echolocating horseshoe bats to investigate the role of the midbrain and hindbrain tegmentum for the control of call frequencies in response to changing auditory feedback. These bats accurately control the frequency of their echolocation calls through auditory feedback both when the bat is at rest [resting frequency (RF)] and when it is flying and compensating for changes in echo frequency caused by flight-induced Doppler shifts [Doppler shift compensation (DSC)]. We iontophoretically injected various GABAergic and glutamatergic transmitter agonists and antagonists into the brainstem tegmentum. We found that within the parabrachial nuclei and the immediately adjacent tegmentum, excitatory effects caused by application of the glutamate agonist AMPA or the GABA(A) antagonist bicuculline raised RF and the frequency of calls emitted during DSC. Bicuculline application routinely blocked DSC altogether. Alternately, inhibitory effects caused by application of either the GABA(A) agonist muscimol or the AMPA antagonist CNQX lowered call frequencies emitted at rest and during DSC. Such an audio-vocal feedback mechanism might share basic aspects with audio-vocal feedback controlling the pitch of vocalizations in other mammals, including the involuntary response to "pitch-shifted feedback" in humans.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed2003

Error monitoring using external feedback: specific roles of the habenular complex, the reward system, and the cingulate motor area revealed by functional magnetic resonance imaging.

The dopaminergic system has been shown to be involved in the processing of rewarding stimuli, specifically of errors in reward prediction, in animal studies as well as in recent neuroimaging studies in humans. Furthermore, a specific role of dopamine in the human homolog of the rostral cingulate motor area (rCMA) was proposed in a recent model of error detection. Negative feedback as well as self-detected errors elicit a negative event-related brain potential probably generated in the rCMA. We performed two experiments using functional magnetic resonance imaging to investigate the brain activity related to negative and positive feedback in a dynamically adaptive motion prediction task. Whereas positive feedback raised hemodynamic activity in the ventral striatum (nucleus accumbens), negative feedback activated the rCMA, the inferior anterior insula, and the epithalamus (habenular complex). These data demonstrate the role of the habenular complex in the control of the human reward system, a function previously hypothesized on the basis of animal research. The rCMA reacted only to errors with negative feedback but not to errors without feedback, which ruled out an influence of response conflict or uncertainty on its role in error detection by external signals.

Adult↗
PubMed1991

Effectiveness of student ratings feedback and consultation for improving instruction in dental school.

The effects of student ratings feedback and consultation on instructional improvement over a four-year time interval were examined. Of the 40 course directors who led the same course over a four-year period, nine sought consultation services after receiving results from their initial student course evaluation. A sample of nine course directors who received student ratings feedback but did not seek consultation were matched to this consultation group, and student ratings comparisons were made over the subsequent three-year period. The consultation group received significantly higher ratings than the ratings only group for six of the nine course rating items. The magnitude of these effect sizes were substantial. When viewed in light of previously reported controlled studies on feedback, the results suggest that consultation is an important adjunct to ratings feedback for improving subsequent instruction in dental education. In response to an attitudinal survey, course directors indicated that students were qualified to rate aspects of instruction and that ratings provided useful feedback for making course improvements. Recommendations for using student ratings feedback are provided.

Analysis of Variance↗
PubMed1990

Feedback of joint angle and EMG in gait of able-bodied subjects.

Recent developments in the ability to identify discrete disturbances in gait patterns have led to the development of a computer-assisted feedback system which can provide continuous visual and auditory feedback to a walking subject concerning some discrete aspect of his gait. The purpose of this study was to determine if able-bodied subjects could use this feedback to modify their gait according to externally imposed targets set for exaggerated joint motions or muscle activity, or for changes in the timing of these movements, or for both parameters together. Two groups of able-bodied older adults were presented with either knee and ankle joint angle feedback or quadriceps electromyographic feedback over four identical sessions. Records were kept of performance relative to the targets set for amplitude, timing, and for both parameters together. Results indicated that able-bodied subjects could modify the amplitude and timing of movements in the presence of feedback; they also suggested that the use of this approach in the reeducation of pathologic gait patients should be explored.

Aged↗