Auditory aversive generalization learning prompts threat-specific changes in alpha-band activity

Pairing a neutral stimulus with aversive outcomes prompts neurophysiological and autonomic changes in response to the conditioned stimulus (CS+), compared to cues that signal safety (CS-). One of these changes-selective amplitude reduction of parietal alpha-band oscillations-has been reliably linked to processing of visual CS+. It is, however, unclear to what extent auditory conditioned cues prompt similar changes, how these changes evolve as learning progresses, and how alpha reduction in the auditory domain generalizes to similar stimuli. To address these questions, 55 participants listened to three sine wave tones, with either the highest or lowest pitch (CS+) being associated with a noxious white noise burst. A threat-specific (CS+) reduction in occipital-parietal alpha-band power was observed similar to changes expected for visual stimuli. No evidence for aversive generalization to the tone most similar to the CS+ was observed in terms of alpha-band power changes, aversiveness ratings, or pupil dilation. By-trial analyses found that selective alpha-band changes continued to increase as aversive conditioning continued, beyond when participants reported awareness of the contingencies. The results support a theoretical model in which selective alpha power represents a cross-modal index of continuous aversive learning, accompanied by sustained sensory discrimination of conditioned threat from safety cues.

The Relationship Between Self-Reported Misophonia Symptoms and Auditory Aversive Generalization Leaning: A Preliminary Report

Misophonia is characterized by excessive aversive reactions to specific "trigger" sounds. Although this disorder is increasingly recognized in the literature, its etiological mechanisms and maintaining factors are currently unclear. Several etiological models propose a role of Pavlovian conditioning, an associative learning process heavily researched in similar fear and anxiety-related disorders. In addition, generalization of learned associations has been noted as a potential causal or contributory factor. Building upon this framework, we hypothesized that Misophonia symptoms arise as a consequence of overgeneralized associative learning, in which aversive responses to a noxious event also occur in response to similar events. Alternatively, heightened discrimination between conditioned threat and safety cues may be present in participants high in Misophonia symptoms, as predicted by associative learning models of Misophonia. This preliminary report (n = 34) examines auditory generalization learning using self-reported behavioral (i.e., valence and arousal ratings) and EEG alpha power reduction. Participants listened to three sine tones differing in pitch, with one pitch (i.e., CS+) paired with an aversive loud white noise blast, prompting aversive Pavlovian generalization learning. We assessed the extent to which overgeneralization versus heightened discrimination learning is associated with self-reported Misophonia symptoms, by comparing aversive responses to the CS+ and other tones similar in pitch. Behaviorally, all participants learned the contingencies between CS+ and noxious noise, with individuals endorsing elevated Misophonia showing heightened aversive sensitivity to all stimuli, regardless of conditioning and independent of hyperacusis status. Across participants, parieto-occipital EEG alpha-band power reduction was most pronounced in response to the CS+ tone, and this difference was greater in those with self-reported Misophonia symptoms. The current preliminary findings do not support the notion that overgeneralization is a feature of self-reported emotional experience in Misophonia, but that heightened sensitivity and discrimination learning may be present at the neural level.

A longitudinal study investigating change in BMI z-score in primary school-aged children and the association of child BMI z-score with parent BMI

Background

This paper aims to explore change in BMI z-score through childhood and the association between parent BMI and child BMI z-score. This is important to understand for the development of effective obesity interventions.

Methods

Data from the longitudinal B-ProAct1v study (1837 participants) were analysed. A paired sample t-test examined changes in child BMI z-score between Year 1 and 4. Multivariable linear regression models examined the cross-sectional associations between child BMI z-score and parent BMI in Year 1 and 4. The influence of change in parental BMI between Year 1 and Year 4 on child BMI z-score in Year 4 was explored through regression analyses, adjusted for baseline BMI z-score.

Results

There was a strong association between child BMI z-score at Year 1 and 4. Child mean BMI z-score score increased from 0.198 to 0.330 (p = < 0.005) between these timepoints. For every unit increase in parent BMI, there was an increase in child BMI z-score of 0.047 in Year 1 (p = < 0.005) and of 0.059 in Year 4 (p = < 0.005). Parental BMI change was not significantly associated with Year 4 child BMI z-score.

Conclusion

The key indicator of higher child BMI at Year 4 is high BMI at Year 1. Further studies are needed to explore the impact of parental weight change on child BMI z-score and whether interventions targeted at overweight or obese parents, can improve their child’s BMI z-score.

Development and validation of a questionnaire to evaluate the effectiveness of evidence-based practice teaching

AIM

The aim of this study was to develop and validate a questionnaire to evaluate the effectiveness of evidence-based practice (EBP) teaching.

METHODS

The 152 questionnaires completed by health care professionals with a range of EBP experience were used in this study. Cronbach's alpha for the knowledge and attitude questions indicated a satisfactory level of internal consistency (i.e. >0.60).

RESULTS

The discriminative validity was evidenced by a statistically significant difference in the knowledge and attitude scores of 'novices' (i.e. little or no prior EBP education) compared with 'experts' (i.e. health care professionals and academics currently teaching EBP). Moderate to good (> or =0.4) sensitivity index scores were observed for both knowledge and attitude scores as the result of comparing individuals before and after an EBP intervention.

CONCLUSIONS

The results of this validation study indicate that the developed questionnaire is a satisfactory tool with which to evaluate the effectiveness of EBP teaching interventions.

A preliminary study of the decision-making process within general practice

OBJECTIVE

The aim of the present study was to explore the factors that contribute to the process of decision making within general practice, over and above evidence-based information.

METHODS

A qualitative study was conducted using semi-structured interviews on a purposeful sample of GPs, based in the South West of England. Each interview was tape-recorded and transcribed verbatim.

RESULTS

Five broad categories emerged from the data: practitioner; patient; practitioner-patient relationship; verbal and non-verbal communication; evidence-based medicine; and external factors.

CONCLUSION

The nature of general practice is such that the process of making clinical decisions is complex. In an era when GPs are being overwhelmed by evidence-based information, consideration needs to be given to the implications that the nature of the decision-making process has upon the way 'evidence' is constructed and promoted within general practice.

A systematic review of the effectiveness of critical appraisal skills training for clinicians

The aim of this paper is to undertake a descriptive systematic review of the effectiveness of critical appraisal skills training for clinicians. Of the 10 controlled studies which examined this issue and were found to meet the eligibility criteria of this review, all used a study population of either medical students or doctors in training. The studies used a variety of different intervention 'dosages' and reported a range of outcomes. These included participants' knowledge of epidemiology/biostatistics, their attitudes towards medical literature, their ability to appraise medical literature, and medical literature reading behaviour. An overall improvement in assessed outcomes of 68% was reported after critical appraisal skills training, particularly in knowledge relating to epidemiology and biostatistics. This review appears to provide some evidence of the benefit of teaching critical appraisal skills to clinicians, in terms of both knowledge of methodological/statistical issues in clinical research and attitudes to medical literature. However, these findings should be considered with caution as the methodological quality of studies was generally poor, with only one study employing a randomized controlled design. There is a need for educators within the field of evidence-based health to consider the implications of this review.

Demographic characteristics of the population of Greater Soweto, 1993

"This research note provides information and findings on some aspects of urbanisation in Greater Soweto. It outlines the demographic characteristics of the population, namely the characteristics of households; household preferences for services; perceptions on accommodation; age and gender profiles; education levels; the origin of the inhabitants and mobility in and migration to Greater Soweto. Some findings are particularly important for future planning of services and low-income or subsidised housing."