Affective reactivity in agentic and affiliative extraversion

The affective-reactivity hypothesis holds that extraverts experience greater levels of positive affect in response to rewards than do introverts. This issue is complicated by the fact that extraversion is comprised of two major components of agency and affiliation. Agentic extraversion reflects social dominance, exhibitionism and achievement striving, whilst affiliative extraversion reflects being warm, affectionate, and valuing close relationships with others. Both components of extraversion have been found to be associated with particular forms of affective reactivity: agentic extraversion predicts positive activation in response to appetitive rewards, whilst affilaitve extraversion predicts warmth-affection in response to affiliative rewards. The aim of this thesis was to test affective reactivity in agentic and affiliative extraversion. Additional issues such as the role of cognitive appraisals in affective reactivity, and whether individual differences in reward sensitivity are also observable in physiological markers of emotion were also examined. Affective-reactivity was tested in response to social behaviours, mental imagery and film clips. It was predicted that agentic extraversion would predict positive activation in response to appetitive situations and that affiliative extraversion would predict warmth-affection and pleasure in response to affiliative situations. There was no support for the predictions regarding agentic extraversion, and affiliative extraversion was only found to predict pleasure and warmth-affection following affiliative mental imagery. The relationships between affiliative extraversion and affect were also found to be mediated by cognitive appraisals, and there was some evidence that affiliative extraversion is associated with zygomaticus activation in response to an affiliative film clip. In sum, support for the affective reactivity hypothesis in agentic and affiliative extraversion was limited. Issues for future researchers to consider include how different experimental methods differentially induce emotion, and how agentic and affiliative extraversion should be conceptualised and measured.The affective-reactivity hypothesis holds that extraverts experience greater levels of positive affect in response to rewards than do introverts. This issue is complicated by the fact that extraversion is comprised of two major components of agency and affiliation. Agentic extraversion reflects social dominance, exhibitionism and achievement striving, whilst affiliative extraversion reflects being warm, affectionate, and valuing close relationships with others. Both components of extraversion have been found to be associated with particular forms of affective reactivity: agentic extraversion predicts positive activation in response to appetitive rewards, whilst affilaitve extraversion predicts warmth-affection in response to affiliative rewards. The aim of this thesis was to test affective reactivity in agentic and affiliative extraversion. Additional issues such as the role of cognitive appraisals in affective reactivity, and whether individual differences in reward sensitivity are also observable in physiological markers of emotion were also examined. Affective-reactivity was tested in response to social behaviours, mental imagery and film clips. It was predicted that agentic extraversion would predict positive activation in response to appetitive situations and that affiliative extraversion would predict warmth-affection and pleasure in response to affiliative situations. There was no support for the predictions regarding agentic extraversion, and affiliative extraversion was only found to predict pleasure and warmth-affection following affiliative mental imagery. The relationships between affiliative extraversion and affect were also found to be mediated by cognitive appraisals, and there was some evidence that affiliative extraversion is associated with zygomaticus activation in response to an affiliative film clip. In sum, support for the affective reactivity hypothesis in agentic and affiliative extraversion was limited. Issues for future researchers to consider include how different experimental methods differentially induce emotion, and how agentic and affiliative extraversion should be conceptualised and measured

Sex differences in the neural control of muscle

Sex-differences in muscle strength have been linked to differences in muscle size, involved limb, and daily activities. Early work has shown that sex-differences are greater in the upper compared to lower limb, making the upper limb an ideal model to investigate the best statistical approaches for sex comparison. Large differences in the upper limb reveals how biomechanical factors may impact neural control. Since males and females are more comparable with respect to strength in the lower limb, it allows for a determination of whether potential sex-differences in neural control exist without large differences in biomechanics. Understanding sex-differences allows for prescription of rehabilitation and training modalities, taking into account potential specificities in sex-related neuromuscular and musculoskeletal factors. The overall purpose was to examine neural and biomechanical differences that would account for sex-differences in neural control of muscle. Manuscript 1 examined normalization versus an ANCOVA to assess sex-differences. Sex-differences were seen in elbow flexor strength and rate of force development (RFD). Normalization by either maximum strength or neural factors couldn’t account for all sex-differences in RFD, resulting in an ambiguous interpretation. In contrast, both variables were able to be incorporated in an ANCOVA to determine their relative contribution. Manuscript 2 examined the effect of task familiarization and the contribution of maximum strength, twitch contraction time, muscle fiber condition velocity, and rate of muscle activation to sex-differences in the RFD during dorsiflexion. There were no significant differences between the sexes in muscle properties, but there were differences in neural control. Additionally, across days females exhibited a neural adaptation leading to an improvement in the RFD. Manuscript 3 directly assessed potential sex-differences in neural control during force gradation by recording motor unit activity during maximal and submaximal contractions. Females had less force steadiness (FS), which may have resulted from neural compensation for a less optimal pennation angle or a tendency towards greater joint laxity. Higher motor unit discharge rates and incidence of doublets may increase twitch force summation leading to a reduction in FS. Thus, biomechanical, not inherent sex-differences in neural drive led to neural compensation strategies manifesting as a difference in FS

Poverty and mental health : policy, practice and research implications

This article examines the relationship between poverty and mental health problems. We draw on the experience of Glasgow, our home city, which contains some of Western Europe's areas of greatest concentrated poverty and poorest health outcomes. We highlight how mental health problems are related directly to poverty, which in turn underlies wider health inequalities. We then outline implications for psychiatry

Credibility of subgroup analyses by socioeconomic status in public health intervention evaluations:An underappreciated problem?

There is increasing interest amongst researchers and policy makers in identifying the effect of public health interventions on health inequalities by socioeconomic status (SES). This issue is typically addressed in evaluation studies through subgroup analyses, where researchers test whether the effect of an intervention differs according to the socioeconomic status of participants. The credibility of such analyses is therefore crucial when making judgements about how an intervention is likely to affect health inequalities, although this issue appears to be rarely considered within public health. The aim of this study was therefore to assess the credibility of subgroup analyses in published evaluations of public health interventions. An established set of 10 credibility criteria for subgroup analyses was applied to a purposively sampled set of 21 evaluation studies, the majority of which focussed on healthy eating interventions, which reported differential intervention effects by SES. While the majority of these studies were found to be otherwise of relatively high quality methodologically, only 8 of the 21 studies met at least 6 of the 10 credibility criteria for subgroup analysis. These findings suggest that the credibility of subgroup analyses conducted within evaluations of public health interventions’ impact on health inequalities may be an underappreciated problem. Keywords: Health inequalities, Health inequities, Equity and public health interventions, Policy impact by socioeconomic statu

Reliability of the biceps brachii M-wave

BACKGROUND: The peak-to-peak (P-P) amplitude of the maximum M-wave and the area of the negative phase of the curve are important measures that serve as methodological controls in H-reflex studies, motor unit number estimation (MUNE) procedures, and normalization factors for voluntary electromyographic (EMG) activity. These methodologies assume, with little evidence, that M-wave variability is minimal. This study therefore examined the intraclass reliability of these measures for the biceps brachii. METHODS: Twenty-two healthy adults (4 males and 18 females) participated in 5 separate days of electrical stimulation of the musculocutaneous nerve supplying the biceps brachii muscle. A total of 10 stimulations were recorded on each of the 5 test sessions: a total of fifty trials were used for analysis. A two-factor repeated measures analysis of variance (ANOVA) evaluated the stability of the group means across test sessions. The consistency of scores within individuals was determined by calculating the intraclass correlation coefficient (ICC). The variance ratio (VR) was then used to assess the reproducibility of the shape of the maximum M-wave within individual subjects. RESULTS: The P-P amplitude means ranged from 12.62 ± 4.33 mV to 13.45 ± 4.07 mV across test sessions. The group means were highly stable. ICC analysis also revealed that the scores were very consistent (ICC = 0.98). The group means for the area of the negative phase of the maximum M-wave were also stable (117 to 126 mV·ms). The ICC analysis also indicated a high degree of consistency (ICC = 0.96). The VR for the sample was 0.244 ± 0.169, which suggests that the biceps brachii maximum M-wave shape was in general very reproducible for each subject. CONCLUSION: The results support the use of P-P amplitude of the maximum M-wave as a methodological control in H-reflex studies, and as a normalization factor for voluntary EMG. The area of the negative phase of the maximum M-wave is both stable and consistent, and the shape of the entire waveform is highly reproducible and may be used for MUNE procedures

Right Here Right Now (RHRN) pilot study: testing a method of near-real-time data collection on the social determinants of health

Background: Informing policy and practice with up-to-date evidence on the social determinants of health is an ongoing challenge. One limitation of traditional approaches is the time-lag between identification of a policy or practice need and availability of results. The Right Here Right Now (RHRN) study piloted a near-real-time data-collection process to investigate whether this gap could be bridged. Methods: A website was developed to facilitate the issue of questions, data capture and presentation of findings. Respondents were recruited using two distinct methods – a clustered random probability sample, and a quota sample from street stalls. Weekly four-part questions were issued by email, Short Messaging Service (SMS or text) or post. Quantitative data were descriptively summarised, qualitative data thematically analysed, and a summary report circulated two weeks after each question was issued. The pilot spanned 26 weeks. Results: It proved possible to recruit and retain a panel of respondents providing quantitative and qualitative data on a range of issues. The samples were subject to similar recruitment and response biases as more traditional data-collection approaches. Participants valued the potential to influence change, and stakeholders were enthusiastic about the findings generated, despite reservations about the lack of sample representativeness. Stakeholders acknowledged that decision-making processes are not flexible enough to respond to weekly evidence. Conclusion: RHRN produced a process for collecting near-real-time data for policy-relevant topics, although obtaining and maintaining representative samples was problematic. Adaptations were identified to inform a more sustainable model of near-real-time data collection and dissemination in the future

Health inequality implications from a qualitative study of experiences of poverty stigma in Scotland

Rationale: Individuals living in Scotland's most deprived communities experience a higher burden of morbidity and early mortality than those living in more affluent areas. Experiences of poverty-based stigma may be one psychosocial mechanism through which socioeconomic position influences health, although there is little available data on this issue from a Scottish perspective. Objective: The aim of this study was to identify which aspects of poverty stigma are particularly salient to individuals with lived experience of poverty, and may therefore contribute to health inequalities. Methods: Five focus groups were conducted with 39 individuals with experience of living on low incomes in Scotland in order to explore their experiences and perceptions of poverty stigma. Results: Five main themes were identified, reflecting aspects of poverty stigma operating at various structural, public and individual levels: media representations of poverty; negative encounters with social security systems; perceived public attitudes regarding poverty in Scotland; lowered self-esteem and internalisation of negative attitudes, and; emotional responses to stigma. Conclusion: These dimensions of stigma potentially influence public health and health inequalities in Scotland, although future research will be necessary to quantify these and estimate their relationships with health outcomes

Poverty stigma, mental health, and well-being : a rapid review and synthesis of quantitative and qualitative research

Poverty is associated with higher rates of mental illness and lower levels of well-being. Poverty affects mental health and well-being through a range of mechanisms, one of which may be experiences of stigma associated with living in poverty or accessing services designed to assist individuals on low incomes (including social security). The aim of this study was to synthesise published research on the relationship between individuals' experiences of poverty stigma and aspects of mental health and well-being. A rapid review was undertaken of quantitative and qualitative research published between January 2005 and February 2021. In total, 22 (5 quantitative and 17 qualitative or mixed methods) studies met the inclusion criteria, the findings of which were extracted and analysed using thematic synthesis. Experiences of poverty stigma were found to be associated with four broad aspects of mental health and well-being: negative self-evaluations, diminished social well-being, negative affect, and mental ill-health. Several forms of poverty stigma, including self, received, perceived, anticipated, and endorsed stigma were implicated in these associations. Poverty stigma may contribute to inequalities in mental illness and well-being, although further quantitative and longitudinal research is required to test its impact on mental health