A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power

Positive health outcomes of mindfulness-based interventions for cancer patients and survivors: A systematic review and meta-analysis

Mindfulness-based interventions (MBIs) are commonly used for cancer patients and survivors to reduce symptoms, but little is known about effects on positive health outcomes. We conducted a systematic review and meta-analysis to determine the effects of MBIs on positive health outcomes (mindfulness skills, self-compassion, positive affect, coping, social support, well-being, personal growth, and spirituality) in cancer patients and survivors. Four databases (PubMed, PsycINFO, Web of Science, and CINAH) were searched (grey literature was not included), abstracts and full texts were screened, and MBI quality and risk of bias were assessed. Effect sizes were calculated and data was analyzed using a frequentist analytical strategy. Eligible studies were randomized controlled trials (RCTs) evaluating the effect of MBIs compared to any type of control on positive health outcomes in cancer patients or survivors. Based on 46 RCTs eligible for meta-analysis, statistical significant effects were observed for all positive health outcomes at post-treatment. Effect sizes ranged from small (positive affect; Hedges's g = 0.26) to large (spirituality, g = 0.91). At follow-up, mindfulness skills, self-compassion, personal growth, and spirituality reached statistical significance, with effect sizes ranging from small (positive affect; g = 0.07) to medium (spirituality; g = 0.61) and large (post-traumatic growth; g = 1.40). Taken together, significant effects of MBIs were found for several positive outcomes in cancer patients and survivors, with the strongest evidence found for mindfulness skills. MBIs may play a key role in improving well-being in this population.

Introducing ART: A new method for testing auditory memory with circular reproduction tasks

Theories of visual working memory have seen significant progress through the use of continuous reproduction tasks. However, these tasks have mainly focused on studying visual features, with limited examples existing in the auditory domain. Therefore, it is unknown to what extent newly developed memory models reflect domain-general limitations or are specific to the visual domain. To address this gap, we developed a novel methodology: the Auditory Reproduction Task (ART). This task utilizes Shepard tones, which create an infinite rising or falling tone illusion by dissecting pitch chroma and height, to create a 1-360° auditory circular space. In Experiment 1, we validated the perceptual circularity and uniformity of this auditory stimulus space. In Experiment 2, we demonstrated that auditory working memory shows similar set size effects to visual working memory-report error increased at a set size of 2 relative to 1, caused by swap errors. In Experiment 3, we tested the validity of ART by correlating reproduction errors with commonly used auditory and visual working memory tasks. Analyses revealed that ART errors were significantly correlated with performance in both auditory and visual working memory tasks, albeit with a stronger correlation observed with auditory working memory. While these experiments have only scratched the surface of the theoretical and computational constraints on auditory working memory, they provide a valuable proof of concept for ART. Further research with ART has the potential to deepen our understanding of auditory working memory, as well as to explore the extent to which existing models are tapping into domain-general constraints.

Efficacy of eHealth Versus In-Person Cognitive Behavioral Therapy for Insomnia: Systematic Review and Meta-Analysis of Equivalence

BACKGROUND

Insomnia is a prevalent condition with significant health, societal, and economic impacts. Cognitive behavioral therapy for insomnia (CBTI) is recommended as the first-line treatment. With limited accessibility to in-person-delivered CBTI (ipCBTI), electronically delivered eHealth CBTI (eCBTI), ranging from telephone- and videoconference-delivered interventions to fully automated web-based programs and mobile apps, has emerged as an alternative. However, the relative efficacy of eCBTI compared to ipCBTI has not been conclusively determined.

OBJECTIVE

This study aims to test the comparability of eCBTI and ipCBTI through a systematic review and meta-analysis of equivalence based on randomized controlled trials directly comparing the 2 delivery formats.

METHODS

A comprehensive search across multiple databases was conducted, leading to the identification and analysis of 15 unique randomized head-to-head comparisons of ipCBTI and eCBTI. Data on sleep and nonsleep outcomes were extracted and subjected to both conventional meta-analytical methods and equivalence testing based on predetermined equivalence margins derived from previously suggested minimal important differences. Supplementary Bayesian analyses were conducted to determine the strength of the available evidence.

RESULTS

The meta-analysis included 15 studies with a total of 1083 participants. Conventional comparisons generally favored ipCBTI. However, the effect sizes were small, and the 2 delivery formats were statistically significantly equivalent (P<.05) for most sleep and nonsleep outcomes. Additional within-group analyses showed that both formats led to statistically significant improvements (P<.05) in insomnia severity; sleep quality; and secondary outcomes such as fatigue, anxiety, and depression. Heterogeneity analyses highlighted the role of treatment duration and dropout rates as potential moderators of the differences in treatment efficacy.

CONCLUSIONS

eCBTI and ipCBTI were found to be statistically significantly equivalent for treating insomnia for most examined outcomes, indicating eCBTI as a clinically relevant alternative to ipCBTI. This supports the expansion of eCBTI as a viable option to increase accessibility to effective insomnia treatment. Nonetheless, further research is needed to address the limitations noted, including the high risk of bias in some studies and the potential impact of treatment duration and dropout rates on efficacy.

TRIAL REGISTRATION

PROSPERO CRD42023390811; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=390811.

Kneel, stand, prostrate: The psychology of prayer postures in three world religions

Most people practice a religion, often multiple times daily. Among the most visible aspects of these practices are body postures, which according to embodiment theories, likely shape the psychological experience of religion. In a preregistered study, we test this idea among Christians, Muslims, and Hindus in the United States, Turkey, and India (N = 2,458). In a repeated-measures experimental design, participants imagined praying in various typical postures, then reported their affective experiences, perceived relationship with deity, and prayer content for each posture. Compared to downward and constrictive postures, expansive and upward postures led to more positive emotions, dominance, and praise-focused prayers, yet fewer introspective or intercessory prayers. Interestingly, these effects varied based on religious context (e.g., many Hindus found upward and expansive postures offensive, causing no positive affect). We further explored whether these effects varied based on posture familiarity, religiosity, interoceptive sensibility, and personality traits. This research provides unique data on embodied processes shaping affect and cognition in religious practices.

Bodies in action: Do contractive and expansive postures facilitate adaptive behavior?

The present study investigated the effects of expansive and contractive body displays on adaptive behavior and affective outcomes. Addressing limitations in past research, the effects were investigated in two different contexts (i.e., fear context and sadness context), compared with two types of control conditions and the moderating effects of motivational traits and symptoms of psychopathology were accounted for. A sample of 186 adults completed a fear experiment involving a mock job interview and a sadness experiment involving sad mood induction. For each experiment, participants were randomly assigned to one of four body manipulations: (1) expansive; (2) contractive; (3) active control (i.e., running in place); or 4) passive control (i.e., doing nothing). The primary outcome was adaptive behavior (i.e., appropriate job-interview behavior and positive recall bias). Secondary affective outcomes were emotions, action tendencies, and appraisals. Results revealed small, non-significant effects of body displays on primary outcomes (ds = 0.19-0.28). For secondary outcomes, significant effects were identified for positive emotions (ds = 0.33). Across secondary outcomes, pairwise comparisons revealed that expansive displays led to more favorable outcomes than contractive displays. For participants with the highest levels of depression, body display conditions led to less favorable affective outcomes than control conditions. The results suggest that body displays do not influence adaptive behavior within the investigated contexts. When compared to contractive displays, expansive displays were found to yield more favorable affective changes. Lastly, the findings indicate that further investigations into body manipulations in the context of psychopathology are warranted.

The association between empathy and burnout in medical students: a systematic review and meta-analysis

BACKGROUND

Burnout levels in medical students are higher than in other student groups. Empathy is an increasingly desired outcome of medical schools. Empathy is negatively associated with burnout in physicians. Our objective was to quantitatively review the available literature on associations between empathy and burnout in medical students, and to explore associations between specific empathy aspects (cognitive and affective) and burnout sub-dimensions (emotional exhaustion, depersonalization and personal accomplishment).

METHODS

A comprehensive search of the literature published up until January 2024 was undertaken in the PubMed, EMBASE, CINAHL, The Cochrane Library, and PsycINFO databases. Two independent reviewers screened 498 records and quality-rated and extracted data from eligible studies. The effect size correlations (ESr) were pooled using a random-effects model and between-study variation explored with meta-regression. The review was preregistered with PROSPERO (#CRD42023467670) and reported following the PRISMA guidelines.

RESULTS

Twenty-one studies including a total of 27,129 medical students published between 2010 and 2023 were included. Overall, empathy and burnout were negatively and statistically significantly associated (ESr: -0.15, 95%CI [-0.21; -0.10], p < .001). When analyzing sub-dimensions, cognitive empathy was negatively associated with emotional exhaustion (ESr: -0.10, 95%CI [-0.17; -0.03], p = .006) and depersonalization (ESr: -0.15, 95%CI [-0.24; 0.05], p = .003), and positively associated with personal accomplishment (ESr: 0.21, 95%CI [0.12; 0.30], p < .001). Affective empathy was not statistically significantly associated with emotional exhaustion, depersonalization or personal accomplishment. Supplementary Bayesian analysis indicated the strongest evidence for the positive association between cognitive empathy and personal accomplishment. Response rate and gender moderated the relationship so that higher response rates and more male respondents strengthen the negative association between empathy and burnout.

CONCLUSION

Greater empathy, in particular cognitive empathy, is associated with lower burnout levels in medical students. This appears to be primarily driven by cognitive empathy's positive association with personal accomplishment.

PROTOCOL REGISTRATION

#CRD42023467670.

Creatine supplementation for optimization of physical function in the patient at risk of functional disability: A systematic review and meta-analysis

BACKGROUND

The efficacy of creatine replacement through supplementation for the optimization of physical function in the population at risk of functional disability is unclear.

METHODS

We conducted a systematic literature search of MEDLINE, EMBASE, the Cochrane Library, and CINAHL from inception to November 2022. Studies included were randomized controlled trials (RCTs) comparing creatine supplementation with placebos in older adults and adults with chronic disease. The primary outcome was physical function measured by the sit-to-stand test after pooling data using random-effects modeling. We also performed a Bayesian meta-analysis to describe the treatment effect in probability terms. Secondary outcomes included other measures of physical function, muscle function, and body composition. The risk of bias was assessed using the Cochrane risk-of-bias tool.

RESULTS

We identified 33 RCTs, comprising 1076 participants. From six trials reporting the primary outcome, the pooled standardized mean difference (SMD) was 0.51 (95% confidence interval [CI]: 0.01-1.00; I2 = 62%; P = 0.04); using weakly informative priors, the posterior probability that creatine supplementation improves physical function was 66.7%. Upper-body muscle strength (SMD: 0.25; 95% CI: 0.06-0.44; I2 = 0%; P = 0.01), handgrip strength (SMD 0.23; 95% CI: 0.01-0.45; I2 = 0%; P = 0.04), and lean tissue mass (MD 1.08 kg; 95% CI: 0.77-1.38; I2 = 26%; P < 0.01) improved with creatine supplementation. The quality of evidence for all outcomes was low or very low because of a high risk of bias.

CONCLUSION

Creatine supplementation improves sit-to-stand performance, muscle function, and lean tissue mass. It is crucial to conduct high-quality prospective RCTs to confirm these hypotheses (PROSPERO number, CRD42023354929).

Interventions for insomnia in cancer patients and survivors-a comprehensive systematic review and meta-analysis

BACKGROUND

Considering the persistent nature and higher prevalence of insomnia in cancer patients and survivors compared with the general population, there is a need for effective management strategies. This systematic review and meta-analysis aimed to comprehensively evaluate the available evidence for the efficacy of pharmacological and nonpharmacological interventions for insomnia in adult cancer patients and survivors.

METHODS

Following the PRISMA guidelines, we analyzed data from 61 randomized controlled trials involving 6528 participants. Interventions included pharmacological, physical, and psychological treatments, with a focus on insomnia severity and secondary sleep and non-sleep outcomes. Frequentist and Bayesian analytical strategies were employed for data synthesis and interpretation.

RESULTS

Cognitive-Behavioral Therapy for Insomnia (CBT-I) emerged as the most efficacious intervention for reducing insomnia severity in cancer survivors and further demonstrated significant improvements in fatigue, depressive symptoms, and anxiety. CBT-I showed a large postintervention effect (g = 0.86; 95% confidence interval [CI] = 0.57 to 1.15) and a medium effect at follow-up (g = 0.55; 95% CI = 0.18 to 0.92). Other interventions such as bright white light therapy, sleep medication, melatonin, exercise, mind-body therapies, and mindfulness-based therapies showed benefits, but the evidence for their efficacy was less convincing compared with CBT-I. Brief Behavioral Therapy for Insomnia showed promise as a less burdensome alternative for patients in active cancer treatment.

CONCLUSIONS

CBT-I is supported as a first-line treatment for insomnia in cancer survivors, with significant benefits observed across sleep and non-sleep outcomes. The findings also highlight the potential of less intensive alternatives. The research contributes valuable insights for clinical practice and underscores the need for further exploration into the complexities of sleep disturbances in cancer patients and survivors.

The effect of experimental emotion induction on experimental pain: a systematic review and meta-analysis

ABSTRACT

The idea that emotions can influence pain is generally recognized. However, a synthesis of the numerous individual experimental studies on this subject is lacking. The aim of the present systematic review and meta-analysis was to synthesize the existing evidence on the effect of experimental emotion induction on experimental pain in nonclinical adults. PsycInfo and PubMed were searched up until April 10, 2023, for studies assessing differences in self-reported pain between emotion induction groups and/or control groups or between conditions within group. Risk of bias was assessed for the individual studies. The literature search yielded 78 relevant records of 71 independent studies. When compared with control conditions, the pooled results revealed a statistically significant pain-attenuating effect of positive emotion induction (between-group: Hedges g = -0.48, 95% CI: -0.72; -0.25, K = 9; within-group: g = -0.24, 95% CI: -0.32; -0.15, K = 40), and a statistically significant pain-exacerbating effect of negative emotion induction in within-group analyses but not between-group analyses (between-group: g = -0.29, 95% CI: -0.66; 0.07, K = 10; within-group: g = 0.14, 95% CI: 0.06; 0.23, K = 39). Bayesian meta-analysis provided strong support for an effect of positive emotion induction but weak support for an effect of negative emotion induction. Taken together, the findings indicate a pain-attenuating effect of positive emotion induction, while the findings for negative emotion induction are less clear. The findings are discussed with reference to theoretical work emphasizing the role of motivational systems and distraction for pain. Limitations include considerable heterogeneity across studies limiting the generalizability of the findings.

A tutorial on Bayesian model-averaged meta-analysis in JASP

Researchers conduct meta-analyses in order to synthesize information across different studies. Compared to standard meta-analytic methods, Bayesian model-averaged meta-analysis offers several practical advantages including the ability to quantify evidence in favor of the absence of an effect, the ability to monitor evidence as individual studies accumulate indefinitely, and the ability to draw inferences based on multiple models simultaneously. This tutorial introduces the concepts and logic underlying Bayesian model-averaged meta-analysis and illustrates its application using the open-source software JASP. As a running example, we perform a Bayesian meta-analysis on language development in children. We show how to conduct a Bayesian model-averaged meta-analysis and how to interpret the results.

Reinforcement learning of adaptive control strategies

Humans can up- or downregulate the degree to which they rely on task information for goal-directed behaviour, a process often referred to as cognitive control. Adjustments in cognitive control are traditionally studied in response to experienced or expected task-rule conflict. However, recent theories suggest that people can also learn to adapt control settings through reinforcement. Across three preregistered task switching experiments (n = 415), we selectively rewarded correct performance on trials with either more (incongruent) or less (congruent) task-rule conflict. Results confirmed the hypothesis that people rewarded more on incongruent trials showed smaller task-rule congruency effects, thus optimally adapting their control settings to the reward scheme. Using drift diffusion modelling, we further show that this reinforcement of cognitive control may occur through conflict-dependent within-trial adjustments of response thresholds after conflict detection. Together, our findings suggest that, while people remain more efficient at learning stimulus-response associations through reinforcement, they can similarly learn cognitive control strategies through reinforcement.

Examining the efficacy of treatments for arm lymphedema in breast cancer survivors: an overview of systematic reviews with meta-analyses

Background

Lymphedema affects one in six breast cancer survivors making it a global healthcare challenge. There is considerable debate about the efficacy of different treatments for lymphedema. We aimed to summarize the current evidence for treatments for lymphedema in breast cancer survivors.

Methods

In this overview of systematic reviews with meta-analyses (SRMAs), five databases were searched for SRMAs of randomised controlled trials (RCTs) reporting effects of medications, surgery, exercise, laser therapy, acupuncture, kinesio taping, or complex decongestive physiotherapy (CDP) for breast cancer-related lymphedema published from database inception up to March 7, 2023. Data extraction was performed for the SRMAs and RCTs, and SRMAs were appraised with AMSTAR2. Random effects meta-analyses of the RCTs provided estimates of the pooled effects sizes (Hedges' g) for each treatment modality. This study is registered with PROSPERO, CRD42020184813.

Findings

1569 studies were identified by the search and eighteen SRMAs with 51 RCTs were included, investigating manual lymphatic drainage (MLD), compression pump, exercise, kinesio taping, laser, and acupuncture. Overall, the methodological quality of the SRMAs was low. SRMAs reached different conclusions for all treatment modalities, except for kinesio taping where the two SRMAs found no effect. The analysis of 40 RCTs with 1970 participants revealed a small effect across all interventions compared to any control (g = 0.20, p = 0.047, I2 = 0.79), corresponding to volume reductions of 119.7 ml (95% CI 135-104) and 88.0 ml (95% CI 99-77) in the intervention and control groups, respectively, and a small effect of exercise (g = 0.26, p = 0.022, I2 = 0.44). The between-group differences in volume reduction were small and did not reach statistical significance for any one treatment modality.

Interpretation

Based on the available data, there is no evidence of superiority of any one treatment on volume reduction nor any solid research refuting these treatments. Thus, definitive conclusions to inform clinical practice about the efficacy of these treatments cannot be drawn. Due to poor-quality evidence, more research is needed to untangle the efficacy of each treatment component for different stages of lymphedema.

Funding

Danish Cancer Society.

Attentional blur and blink: Effects of adaptive attentional scaling on visual awareness

Attentional scaling is a crucial mechanism that enables us to flexibly allocate our attention to larger or smaller regions in the visual field. Although previous studies have demonstrated the critical role of attentional scaling in visual processing, its impact on modulating visual awareness is not yet fully understood. This study investigates the adaptive control of attentional scaling and its influence on visual awareness in an attentional blink paradigm. Participants were required to attend to the first target's location, which was manipulated either session-wise, trial-wise, or such that it could be learned across a block of trials. Discrete, all-or-none, awareness was expected when attention was allocated to a narrow area, while gradual awareness was expected when attention was allocated to a larger area. We used mixture modeling to assess second target awareness across these different attentional scales. The results revealed that participants could adaptively control their attentional scale both across stable sessions, and through (implicit) statistical learning in blocks of successive trials. This produced gradual perceptual awareness when the participants adopted a broad attentional scale, causing an attentional "blur". However, trial-wise cues did not allow for attentional scaling, resulting in more discrete target perception overall, and an attentional "blink". We conclude that the attentional scale is to some extent under adaptive control during the attentional blink/blur, where it can produce qualitatively different modes of perceptual awareness.

Meta-analyses in psychology often overestimate evidence for and size of effects

Adjusting for publication bias is essential when drawing meta-analytic inferences. However, most methods that adjust for publication bias do not perform well across a range of research conditions, such as the degree of heterogeneity in effect sizes across studies. Sladekova et al. 2022 (Estimating the change in meta-analytic effect size estimates after the application of publication bias adjustment methods. Psychol. Methods) tried to circumvent this complication by selecting the methods that are most appropriate for a given set of conditions, and concluded that publication bias on average causes only minimal over-estimation of effect sizes in psychology. However, this approach suffers from a 'Catch-22' problem-to know the underlying research conditions, one needs to have adjusted for publication bias correctly, but to correctly adjust for publication bias, one needs to know the underlying research conditions. To alleviate this problem, we conduct an alternative analysis, robust Bayesian meta-analysis (RoBMA), which is not based on model-selection but on model-averaging. In RoBMA, models that predict the observed results better are given correspondingly larger weights. A RoBMA reanalysis of Sladekova et al.'s dataset reveals that more than 60% of meta-analyses in psychology notably overestimate the evidence for the presence of the meta-analytic effect and more than 50% overestimate its magnitude.

Feeling Small or Standing Tall? Height Manipulation Affects Speech Anxiety and Arousal in Virtual Reality

Social performance situations often constitute one of the most challenging communication tasks across different cultures. In today's work environments, giving presentations and performing in front of others are often essential and expected. Therefore, public speaking anxiety can have a serious impact on an individual's job performance, career choice, and prospects. Contemporary consumer virtual reality hardware has made it possible to practice public speaking anywhere in a safe and private virtual reality environment (VRE). As VREs offer the means to practice real-life scenarios, they also make it possible to go beyond what is "real"; to replace simulations with more dynamic and innovative training environments. Furthermore, with occupational life undergoing a significant shift toward technology-mediated working conditions, innovative tools and methods could also be used during virtually implemented real-time social interactions. This research aimed to study the ways in which an illusion of height, that is, perceived tallness versus perceived shortness, without any visible virtual body or representation, influences state speech anxiety and emotional responses of participants during simulation of a stressful speech task. The experiment followed a strictly controlled between-subject procedure, and both self-reported and psychophysiological data were collected. Results indicate that participants perceiving the illusion of tallness felt less anxious and had lower self-reported arousal compared with participants with the illusion of shortness. This implies that even simple, visual, first-person perspective manipulation of the VRE could help individuals to reduce their stress responses during a task-oriented situation.

Comparing the efficacy of mindfulness-based therapy and cognitive-behavioral therapy for depression in head-to-head randomized controlled trials: A systematic review and meta-analysis of equivalence

BACKGROUND

While Cognitive Behavioral Therapy (CBT) is recommended as first-line treatment for depression, a significant minority do not show an adequate treatment response. Despite evidence for the efficacy of Mindfulness-Based Therapies (MBT) both in treating current depression and preventing relapse, it remains unknown whether MBT and CBT are equivalent in the treatment of current depression.

METHODS

Five databases were searched for randomized controlled trials (RCTs) directly comparing MBT with CBT and including depression as primary or secondary outcome.

RESULTS

When pooling the results of 30 independent RCTs with a total of 2750 participants, MBT and CBT were statistically significantly equivalent at both post-intervention (Hedges's g = -0.009; p < .001) and follow-up (g = -0.033; p = .001). Supplementary Bayesian analyses provided further support for the alternative hypothesis of no difference between MBT and CBT. When exploring possible sources of heterogeneity, the differences at follow-up were smaller between CBT and mindfulness-based cognitive therapy (MBCT) than between CBT and mindfulness-based stress-reduction (MBSR) (Slope = 0.37;p = .022).

CONCLUSION

The currently available evidence suggests that that MBT and CBT are equally efficacious in treating current adult depression. It remains unclear whether the similar effects of the two intervention types are due to different mechanisms or common factors.

Chemsex and chemsex associated substance use among men who have sex with men in Asia: A systematic review and meta-analysis

BACKGROUND

The prevalence of chemsex has been reported by multiple systematic reviews among men who have sex with men (MSM) focussing predominantly on the Global North. An Asian perspective with meta-analytical evidence is missing. This meta-analysis summarised the prevalence of substance use associated with chemsex, and chemsex activity among MSM and MSM sub-populations in Asia, as well as the likelihood for chemsex among MSM living with or without HIV.

METHODS

We utilized PubMed, Web of Science and medRxiv to search for literature describing chemsex and its associated substance use among MSM and MSM sub-populations in Asia from January 1, 2010 to November 1, 2021 to conduct three meta-analyses with both frequentist and Bayesian approaches.

RESULTS

We identified 219 studies and included 23 in the meta-analysis. Based on the frequentist models, methamphetamine was the default substance associated with chemsex among MSM in Asia (prevalence = 0.16, 95 %CI:0.09-0.22), followed by GHB/GBL (prevalence = 0.15, 95 %CI:0.03-0.27) and ketamine (prevalence = 0.08, 95 %CI:0.04-0.12), but hardly any cocaine (prevalence = 0.01, 95 %CI:0.00-0.03). Compared to a general MSM population (prevalence = 0.19, 95 %CI:0.15-0.23), MSM engaging in transactional sex showed a higher prevalence of chemsex (MSM sex work clients [prevalence = 0.28, 95 %CI:0.11-0.45]; MSM sex worker [prevalence = 0.28, 95 %CI:0.17-0.26]). MSM living with HIV also showed higher odds of chemsex activity (OR = 3.35, 95 %CI:1.57-7.10), compared to MSM living without HIV. Both meta-analytic models converged, indicating robust evidence.

CONCLUSIONS

Our meta-analyses showed that chemsex is not uncommon among MSM, and MSM engaging in transactional sex in Asia. We confirmed that MSM living with HIV have a higher likelihood of engaging in chemsex, too. Chemsex prevention and management strategies in Asia should be adjusted accordingly.

Robust Bayesian meta-analysis: Model-averaging across complementary publication bias adjustment methods

Publication bias is a ubiquitous threat to the validity of meta-analysis and the accumulation of scientific evidence. In order to estimate and counteract the impact of publication bias, multiple methods have been developed; however, recent simulation studies have shown the methods' performance to depend on the true data generating process, and no method consistently outperforms the others across a wide range of conditions. Unfortunately, when different methods lead to contradicting conclusions, researchers can choose those methods that lead to a desired outcome. To avoid the condition-dependent, all-or-none choice between competing methods and conflicting results, we extend robust Bayesian meta-analysis and model-average across two prominent approaches of adjusting for publication bias: (1) selection models of p-values and (2) models adjusting for small-study effects. The resulting model ensemble weights the estimates and the evidence for the absence/presence of the effect from the competing approaches with the support they receive from the data. Applications, simulations, and comparisons to preregistered, multi-lab replications demonstrate the benefits of Bayesian model-averaging of complementary publication bias adjustment methods.

Greater volumes of a callosal sub-region terminating in posterior language-related areas predict a stronger degree of language lateralization: A tractography study

Language lateralization is the most intriguing trait of functional asymmetry for cognitive functions. Nowadays, ontogenetic determinants of this trait are largely unknown, but there are efforts to find its anatomical correlates. In particular, a white matter interhemispheric connection-the corpus callosum-has been proposed as such. In the present study, we aimed to find the association between the degree of language lateralization and metrics of the callosal sub-regions. We applied a sentence completion fMRI task to measure the degree of language lateralization in a group of healthy participants balanced for handedness. We obtained the volumes and microstructural properties of callosal sub-regions with two tractography techniques, diffusion tensor imaging (DTI) and constrained spherical deconvolution (CSD). The analysis of DTI-based metrics did not reveal any significant associations with language lateralization. In contrast, CSD-based analysis revealed that the volumes of a callosal sub-region terminating in the core posterior language-related areas predict a stronger degree of language lateralization. This finding supports the specific inhibitory model implemented through the callosal fibers projecting into the core posterior language-related areas in the degree of language lateralization, with no relevant contribution of other callosal sub-regions.

Breast-Conserving Surgery or Mastectomy?: Impact on Survival

The early randomized controlled trials revealed no differences in survival between breast-conserving surgery (BCS) and mastectomy. However, breast cancer treatment has undergone changes, and the results of recent population-based registry studies suggest superior long-term survival after BCS. To explore the current evidence, a systematic review and meta-ana lysis of population-based observational studies from 2010 and onward was conducted.

Methods

A literature search was conducted in the PubMed, Embase, and Cochrane databases to identify relevant literature. Keywords included "mastectomy," "breast conserving surgery," and "survival." The identified studies were narratively reviewed and effect sizes (hazard ratios [HRs]) for overall (OS) and breast cancer-specific survival (BCSS) were combined with random-effects models.

Results

A total of 30 reports were included in the review, and results from 25 studies were included in the meta-analyses. Compared with mastectomy, BCS was associated with better OS (HR = 1.34 [1.20-1.51]; N = 1,311,600) and BCSS (HR = 1.38 [1.29-1.47]; N = 494,267). Selected subgroups of patients, based on lymph node status, age (<50 years/≥50 years), and radiation therapy after mastectomy (±), all showed better overall survival after BCS. The number (range 4-12) and type of prognostic variables adjusted for in the survival analyses of the studies did not statistically significantly moderate the differences in survival between BCS and mastectomy.

Conclusions

The combined findings from large population-based studies indicate that BCS is associated with survival benefit compared with mastectomy, suggesting that BCS be the recommended treatment of early breast cancer (T1-2N0-1M0) if a radical lumpectomy can be performed.

Bodily feedback: expansive and upward posture facilitates the experience of positive affect

Most emotion theories recognise the importance of the body in expressing and constructing emotions. Focusing beyond the face, the present research adds needed empirical data on the effect of static full body postures on positive/negative affect. In Studies 1 (N = 110) and 2 (N = 79), using a bodily feedback paradigm, we manipulated postures to test causal effects on affective and physiological responses to emotionally ambiguous music. Across both studies among U.S. participants, we find the strongest support for an effect of bodily postures that are expansive and oriented upward on positive affect. In addition, an expansive and upward pose also led to greater cardiac vagal reactivity but these changes in parasympathetic activity were not related to affective changes (Study 2). In line with embodied theories, these results provide additional support for the role of postural input in constructing affect. Discussion highlights the relevance of these findings for the study of religious practices during which the postures studied are often adopted.

Informed Bayesian survival analysis

BACKGROUND

We provide an overview of Bayesian estimation, hypothesis testing, and model-averaging and illustrate how they benefit parametric survival analysis. We contrast the Bayesian framework to the currently dominant frequentist approach and highlight advantages, such as seamless incorporation of historical data, continuous monitoring of evidence, and incorporating uncertainty about the true data generating process.

METHODS

We illustrate the application of the outlined Bayesian approaches on an example data set, retrospective re-analyzing a colon cancer trial. We assess the performance of Bayesian parametric survival analysis and maximum likelihood survival models with AIC/BIC model selection in fixed-n and sequential designs with a simulation study.

RESULTS

In the retrospective re-analysis of the example data set, the Bayesian framework provided evidence for the absence of a positive treatment effect of adding Cetuximab to FOLFOX6 regimen on disease-free survival in patients with resected stage III colon cancer. Furthermore, the Bayesian sequential analysis would have terminated the trial 10.3 months earlier than the standard frequentist analysis. In a simulation study with sequential designs, the Bayesian framework on average reached a decision in almost half the time required by the frequentist counterparts, while maintaining the same power, and an appropriate false-positive rate. Under model misspecification, the Bayesian framework resulted in higher false-negative rate compared to the frequentist counterparts, which resulted in a higher proportion of undecided trials. In fixed-n designs, the Bayesian framework showed slightly higher power, slightly elevated error rates, and lower bias and RMSE when estimating treatment effects in small samples. We found no noticeable differences for survival predictions. We have made the analytic approach readily available to other researchers in the RoBSA R package.

CONCLUSIONS

The outlined Bayesian framework provides several benefits when applied to parametric survival analyses. It uses data more efficiently, is capable of considerably shortening the length of clinical trials, and provides a richer set of inferences.

A Bayesian perspective on severity: risky predictions and specific hypotheses

A tradition that goes back to Sir Karl R. Popper assesses the value of a statistical test primarily by its severity: was there an honest and stringent attempt to prove the tested hypothesis wrong? For "error statisticians" such as Mayo (1996, 2018), and frequentists more generally, severity is a key virtue in hypothesis tests. Conversely, failure to incorporate severity into statistical inference, as allegedly happens in Bayesian inference, counts as a major methodological shortcoming. Our paper pursues a double goal: First, we argue that the error-statistical explication of severity has substantive drawbacks; specifically, the neglect of research context and the specificity of the predictions of the hypothesis. Second, we argue that severity matters for Bayesian inference via the value of specific, risky predictions: severity boosts the expected evidential value of a Bayesian hypothesis test. We illustrate severity-based reasoning in Bayesian statistics by means of a practical example and discuss its advantages and potential drawbacks.

Adjusting for Publication Bias in JASP and R: Selection Models, PET-PEESE, and Robust Bayesian Meta-Analysis

Meta-analyses are essential for cumulative science, but their validity can be compromised by publication bias. To mitigate the impact of publication bias, one may apply publication-bias-adjustment techniques such as precision-effect test and precision-effect estimate with standard errors (PET-PEESE) and selection models. These methods, implemented in JASP and R, allow researchers without programming experience to conduct state-of-the-art publication-bias-adjusted meta-analysis. In this tutorial, we demonstrate how to conduct a publication-bias-adjusted meta-analysis in JASP and R and interpret the results. First, we explain two frequentist bias-correction methods: PET-PEESE and selection models. Second, we introduce robust Bayesian meta-analysis, a Bayesian approach that simultaneously considers both PET-PEESE and selection models. We illustrate the methodology on an example data set, provide an instructional video ( https://bit.ly/pubbias ) and an R-markdown script ( https://osf.io/uhaew/ ), and discuss the interpretation of the results. Finally, we include concrete guidance on reporting the meta-analytic results in an academic article.

The Impact of Sample Size Misestimations on the Interpretation of ARDS Trials: Systematic Review and Meta-analysis

BACKGROUND

Indeterminate randomized controlled trials (RCTs) in ARDS may arise from sample size misspecification, leading to abandonment of efficacious therapies.

RESEARCH QUESTIONS

If evidence exists for sample size misspecification in ARDS RCTs, has this led to rejection of potentially beneficial therapies? Does evidence exist for prognostic enrichment in RCTs using mortality as a primary outcome?

STUDY DESIGN AND METHODS

We identified 150 ARDS RCTs commencing recruitment after the 1994 American European Consensus Conference ARDS definition and published before October 31, 2020. We examined predicted-observed sample size, predicted-observed control event rate (CER), predicted-observed average treatment effect (ATE), and the relationship between observed CER and observed ATE for RCTs with mortality and nonmortality primary outcome measures. To quantify the strength of evidence, we used Bayesian-averaged meta-analysis, trial sequential analysis, and Bayes factors.

RESULTS

Only 84 of 150 RCTs (56.0%) reported sample size estimations. In RCTs with mortality as the primary outcome, CER was overestimated in 16 of 28 RCTs (57.1%). To achieve predicted ATE, interventions needed to prevent 40.8% of all deaths, compared with the original prediction of 29.3%. Absolute reduction in mortality ≥ 10% was observed in 5 of 28 RCTs (17.9%), but predicted in 21 of 28 RCTs (75%). For RCTs with mortality as the primary outcome, no association was found between observed CER and observed ATE (pooled OR: β = -0.04; 95% credible interval, -0.18 to 0.09). We identified three interventions that are not currently standard of care with a Bayesian-averaged effect size of > 0.20 and moderate strength of existing evidence: corticosteroids, airway pressure release ventilation, and noninvasive ventilation.

INTERPRETATION

Reporting of sample size estimations was inconsistent in ARDS RCTs, and misspecification of CER and ATE was common. Prognostic enrichment strategies in ARDS RCTs based on all-cause mortality are unlikely to be successful. Bayesian methods can be used to prioritize interventions for future effectiveness RCTs.

Power-Posing Robots: The Influence of a Humanoid Robot’s Posture and Size on its Perceived Dominance, Competence, Eeriness, and Threat

When interacting with sophisticated digital technologies, people often fall back on the same interaction scripts they apply to the communication with other humans—especially if the technology in question provides strong anthropomorphic cues (e.g., a human-like embodiment). Accordingly, research indicates that observers tend to interpret the body language of social robots in the same way as they would with another human being. Backed by initial evidence, we assumed that a humanoid robot will be considered as more dominant and competent, but also as more eerie and threatening once it strikes a so-called power pose. Moreover, we pursued the research question whether these effects might be accentuated by the robot’s body size. To this end, the current study presented 204 participants with pictures of the robot NAO in different poses (expansive vs. constrictive), while also manipulating its height (child-sized vs. adult-sized). Our results show that NAO’s posture indeed exerted strong effects on perceptions of dominance and competence. Conversely, participants’ threat and eeriness ratings remained statistically independent of the robot’s depicted body language. Further, we found that the machine’s size did not affect any of the measured interpersonal perceptions in a notable way. The study findings are discussed considering limitations and future research directions.

Sleep During Oncological Treatment - A Systematic Review and Meta-Analysis of Associations With Treatment Response, Time to Progression and Survival

Introduction

Disrupted sleep and sleep-wake activity are frequently observed in cancer patients undergoing oncological treatment. These disruptions are often associated with aggravated symptom burden and diminished health-related quality of life that in turn may compromise treatment adherence and, thus, effectiveness. In addition, disrupted sleep has been linked to carcinogenic processes, which ultimately could result in worse prognostic outcomes.

Aims

Our aim was to systematically review and conduct a meta-analysis of studies examining the associations between sleep and sleep-wake activity and prognostic outcomes in cancer patients undergoing oncological treatment.

Methods

A comprehensive systematic search of English language papers was undertaken in June 2020 using PubMed, The Cochrane Library, and CINAHL. Two reviewers independently screened 4,879 abstracts. A total of 26 papers were included in the narrative review. Thirteen papers reporting hazard ratios reflecting associations between a dichotomized predictor variable (sleep) and prognostic outcomes were subjected to meta-analysis.

Results

Nineteen of the 26 eligible studies on a total of 7,092 cancer patients reported associations between poorer sleep and poorer response to treatment, shorter time to progression, and/or reduced overall survival, but were highly heterogeneous with respect to the sleep and outcome parameters investigated. Meta-analysis revealed statistically significant associations between poor self-reported sleep and reduced overall survival (HR = 1.33 [95% CI 1.09-1.62], k = 11), and shorter time to progression (HR = 1.40 [95% CI 1.23-1.59], k = 3) and between poor objectively assessed sleep and reduced overall survival (HR = 1.74 [95% CI 1.05-2.88], k = 4).

Conclusion

The current findings indicate that disturbed sleep during treatment may be a relevant behavioral marker of poor cancer prognosis. The limited number of studies, the common use of single item sleep measures, and potential publication bias highlight the need for further high quality and longitudinal studies.

Psychosocial Intervention in Chronic Obstructive Pulmonary Disease: Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Many patients with chronic obstructive pulmonary disease (COPD) experience persistent interrelated psychological and physical symptoms despite optimal treatment. Several studies of psychosocial intervention in COPD have been published in recent years. The present study aimed to conduct a quantitative summary of the efficacy of such interventions on psychological and physical outcomes.

METHODS

Two independent raters screened PubMed, PsycINFO, Embase, Web of Science, Cochrane Library, and CINAHL for eligible studies. In all, 35 independent, randomized controlled trials with a total of 3,120 patients with COPD were included, assessed for their methodological quality, and subjected to meta-analytic evaluation.

RESULTS

Meta-analyses revealed small, statistically significant effects of psychosocial intervention on combined psychological (Hedges's g = 0.28; 95%CI: 0.16-0.41) and physical outcomes (g = 0.21; 95%CI: 0.07-0.35) with no indications of publication bias. Supplementary Bayesian meta-analyses provided strong evidence for a non-zero overall effect on psychological outcomes (Bayes factor (BF) = 305) and moderate support for physical outcomes (BF = 6.1). Exploring sources of heterogeneity with meta-regression indicated that older age of patients and longer duration of interventions were associated with smaller effects on psychological outcomes.

CONCLUSIONS

The results support psychosocial intervention as an additional, useful tool in multidisciplinary respiratory care with the potential to improve both psychological and physical outcomes. Future studies are recommended to monitor adverse effects, apply blinding of active control conditions, and determine sample sizes with a priori power calculations.

REGISTRATION

Registered with Prospero (www.crd.york.ac.uk/prospero/) prior to initiation of the literature search (Reg. ID: CRD42020170083).

The mystery remains: breadth of attention in Flanker and Navon tasks unaffected by affective states induced by an appraisal manipulation

Affective effects on breadth of attention have been related to aspects of different components of affective states such as the arousal and valence of affective experience and the motivational intensity of action tendency. As none of these explanations fully aligns with existing evidence, we hypothesised that affective effects on breadth of attention may arise from the appraisal component of affective states. Based on this reconceptualisation, we tested the effects of conduciveness and power appraisals on two measures of breadth of attention. In two web-based experiments, we manipulated these appraisals in a 2 × 2 design using a game-like arithmetic task where participants could (1) gain or lose rewards (goal conducive vs. obstructive) based on (2) either their action or the actions of a "robot" (high vs. low power). Breadth of attention was assessed using the flanker task (Experiment 1; n = 236) and the Navon task (Experiment 2; n = 215). We found that appraisals did not directly influence breadth of attention even though high power appraisal significantly improved the overall performance in both experiments indicating successful appraisal manipulation. We discuss ways in which these findings inform future efforts to explain the origins of affective effects on attentional breadth.

Neuroticism Drives Associations Between Repetitive Behaviors and Depression in Autistic Adults

Depression is more prevalent among autistic adults than neurotypical adults, yet risk factors are incompletely understood in this population. Some research groups have focused on relationships between negative repetitive thinking and depression in the autistic population, which may explain elevated prevalence rates in line with general population findings on rumination and internalizing disorders. Little is known about associations between depression and more prototypical repetitive cognitions and/or behaviors characteristic of autism (i.e., insistence on sameness [IS] and repetitive sensorimotor [RSM] behaviors). Therefore, the present study aimed to examine associations between IS, RSM behaviors, and depressive symptoms in 762 autistic adults, and whether observed effects are confounded by additional factors (e.g., demographic factors, trait neuroticism). To test if greater IS scores were associated with greater depressive symptoms on the BDI-II, a Bayesian linear regression was conducted with BDI-II scores (dependent variable) regressed on age, gender, educational level, RSM scores, and IS scores (independent variables). To test the effects of neuroticism on observed relationships, a second regression was conducted that included all predictors from the baseline model and neuroticism. Standardized regression coefficients were tested against an interval null hypothesis of [-0.1, 0.1] to assess for practical significance. Results indicated that IS exhibited a moderate positive relationship with depressive symptoms, while RSM behaviors provided only a slight increase in predictive ability. However in the second model, neuroticism exhibited a strong positive relationship with depressive symptoms, completely attenuating the effect of IS. Associations between RSM behaviors and depressive symptoms did not meet our criteria for practical significance, particularly when neuroticism was added to the model. Neither RSM nor IS moderated the effect of neuroticism on depression. The findings from this study add to the literature on risk factors in the pathway to depression in autism, and suggest opportunities for clinical translation to screening and intervention efforts. Screening for IS in autistic individuals is a common diagnostic practice in clinical and research settings that may be leveraged to also identify those at higher risk for depression, and increasing flexibility in daily life may promote emotional regulation and distress tolerance.

Bayesian model-averaged meta-analysis in medicine

We outline a Bayesian model-averaged (BMA) meta-analysis for standardized mean differences in order to quantify evidence for both treatment effectiveness δ and across-study heterogeneity τ . We construct four competing models by orthogonally combining two present-absent assumptions, one for the treatment effect and one for across-study heterogeneity. To inform the choice of prior distributions for the model parameters, we used 50% of the Cochrane Database of Systematic Reviews to specify rival prior distributions for δ and τ . The relative predictive performance of the competing models and rival prior distributions was assessed using the remaining 50% of the Cochrane Database. On average, ℋ 1 r -the model that assumes the presence of a treatment effect as well as across-study heterogeneity-outpredicted the other models, but not by a large margin. Within ℋ 1 r , predictive adequacy was relatively constant across the rival prior distributions. We propose specific empirical prior distributions, both for the field in general and for each of 46 specific medical subdisciplines. An example from oral health demonstrates how the proposed prior distributions can be used to conduct a BMA meta-analysis in the open-source software R and JASP. The preregistered analysis plan is available at https://osf.io/zs3df/.

Comparing the evidential strength for psychotropic drugs: a Bayesian meta-analysis

Approval and prescription of psychotropic drugs should be informed by the strength of evidence for efficacy. Using a Bayesian framework, we examined (1) whether psychotropic drugs are supported by substantial evidence (at the time of approval by the Food and Drug Administration), and (2) whether there are systematic differences across drug groups. Data from short-term, placebo-controlled phase II/III clinical trials for 15 antipsychotics, 16 antidepressants for depression, nine antidepressants for anxiety, and 20 drugs for attention deficit hyperactivity disorder (ADHD) were extracted from FDA reviews. Bayesian model-averaged meta-analysis was performed and strength of evidence was quantified (i.e. BFBMA). Strength of evidence and trialling varied between drugs. Median evidential strength was extreme for ADHD medication (BFBMA = 1820.4), moderate for antipsychotics (BFBMA = 365.4), and considerably lower and more frequently classified as weak or moderate for antidepressants for depression (BFBMA = 94.2) and anxiety (BFBMA = 49.8). Varying median effect sizes (ESschizophrenia = 0.45, ESdepression = 0.30, ESanxiety = 0.37, ESADHD = 0.72), sample sizes (Nschizophrenia = 324, Ndepression = 218, Nanxiety = 254, NADHD = 189.5), and numbers of trials (kschizophrenia = 3, kdepression = 5.5, kanxiety = 3, kADHD = 2) might account for differences. Although most drugs were supported by strong evidence at the time of approval, some only had moderate or ambiguous evidence. These results show the need for more systematic quantification and classification of statistical evidence for psychotropic drugs. Evidential strength should be communicated transparently and clearly towards clinical decision makers.

A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect

We conducted a preregistered multilaboratory project (k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result (d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect (d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.

Overweight and prognosis in triple-negative breast cancer patients: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis investigating the association between overweight and outcome in triple-negative breast cancer (TNBC) patients. We searched PubMed and Embase using variations of the search terms triple-negative breast cancer (population), overweight and/or obesity (exposure), and prognosis (outcome). Based on the World Health Organization guidelines for defining overweight, we included longitudinal observational studies, which utilized survival statistics with hazard ratios (HRs) in our analysis. The included studies measured body mass index at the time of diagnosis of TNBC and reported disease-free survival and/or overall survival. Study quality was assessed with the Newcastle-Ottawa Scale and study data were extracted using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) checklist, independently by two authors. Random-effects models were used to combine the effect sizes (HRs), and the results were evaluated and adjusted for possible publication bias. Thirteen studies of 8,944 TNBC patients were included. The meta-analysis showed that overweight was associated with both shorter disease-free survival (HR = 1.26; 95%CI: 1.09–1.46) and shorter overall survival (HR = 1.29; 95%CI: 1.11c1.51) compared to normal-weight. Additionally, our Bayesian meta-analyses suggest that overweight individuals are 7.4 and 9.9 times more likely to have shorter disease-free survival and overall survival, respectively. In conclusion, the available data suggest that overweight is associated with shorter disease-free and overall survival among TNBC patients. The results should be interpreted with caution due to possible publication bias.

A Primer on Bayesian Model-Averaged Meta-Analysis

Meta-analysis is the predominant approach for quantitatively synthesizing a set of studies. If the studies themselves are of high quality, meta-analysis can provide valuable insights into the current scientific state of knowledge about a particular phenomenon. In psychological science, the most common approach is to conduct frequentist meta-analysis. In this primer, we discuss an alternative method, Bayesian model-averaged meta-analysis. This procedure combines the results of four Bayesian meta-analysis models: (a) fixed-effect null hypothesis, (b) fixed-effect alternative hypothesis, (c) random-effects null hypothesis, and (d) random-effects alternative hypothesis. These models are combined according to their plausibilities given the observed data to address the two key questions “Is the overall effect nonzero?” and “Is there between-study variability in effect size?” Bayesian model-averaged meta-analysis therefore avoids the need to select either a fixed-effect or random-effects model and instead takes into account model uncertainty in a principled manner.

Bayesian hypothesis testing and estimation under the marginalized random-effects meta-analysis model

Meta-analysis methods are used to synthesize results of multiple studies on the same topic. The most frequently used statistical model in meta-analysis is the random-effects model containing parameters for the overall effect, between-study variance in primary study’s true effect size, and random effects for the study-specific effects. We propose Bayesian hypothesis testing and estimation methods using the marginalized random-effects meta-analysis (MAREMA) model where the study-specific true effects are regarded as nuisance parameters which are integrated out of the model. We propose using a flat prior distribution on the overall effect size in case of estimation and a proper unit information prior for the overall effect size in case of hypothesis testing. For the between-study variance (which can attain negative values under the MAREMA model), a proper uniform prior is placed on the proportion of total variance that can be attributed to between-study variability. Bayes factors are used for hypothesis testing that allow testing point and one-sided hypotheses. The proposed methodology has several attractive properties. First, the proposed MAREMA model encompasses models with a zero, negative, and positive between-study variance, which enables testing a zero between-study variance as it is not a boundary problem. Second, the methodology is suitable for default Bayesian meta-analyses as it requires no prior information about the unknown parameters. Third, the proposed Bayes factors can even be used in the extreme case when only two studies are available because Bayes factors are not based on large sample theory. We illustrate the developed methods by applying it to two meta-analyses and introduce easy-to-use software in the R package BFpack to compute the proposed Bayes factors.

A tutorial on Bayesian multi-model linear regression with BAS and JASP

Linear regression analyses commonly involve two consecutive stages of statistical inquiry. In the first stage, a single ‘best’ model is defined by a specific selection of relevant predictors; in the second stage, the regression coefficients of the winning model are used for prediction and for inference concerning the importance of the predictors. However, such second-stage inference ignores the model uncertainty from the first stage, resulting in overconfident parameter estimates that generalize poorly. These drawbacks can be overcome by model averaging, a technique that retains all models for inference, weighting each model’s contribution by its posterior probability. Although conceptually straightforward, model averaging is rarely used in applied research, possibly due to the lack of easily accessible software. To bridge the gap between theory and practice, we provide a tutorial on linear regression using Bayesian model averaging in JASP, based on the BAS package in R. Firstly, we provide theoretical background on linear regression, Bayesian inference, and Bayesian model averaging. Secondly, we demonstrate the method on an example data set from the World Happiness Report. Lastly, we discuss limitations of model averaging and directions for dealing with violations of model assumptions.

Saving Science Through Replication Studies

The scientific enterprise has long been based on the presumption of replication, although scientists have recently become aware of various corruptions of the enterprise that have hurt replicability. In this article, we begin by considering three illustrations of research paradigms that have all been subject to intense scrutiny through replications and theoretical concerns. The three paradigms are one for which the corpus of research points to a real finding, one for which the corpus of research points to a significantly attenuated effect, and one for which the debate is ongoing. We then discuss what scientists can learn-and how science can be improved-through replications more generally. From there, we discuss what we believe needs to be done to improve scientific inquiry with regard to replication moving forward. Finally, we conclude by providing readers with several different approaches to replication and how these approaches progress science. The approaches discussed include multilab replications of many effects, multilab replications of specific effects, adversarial collaborations, and stand-alone applications.

A method to adjust a prior distribution in Bayesian second-level fMRI analysis

Previous research has shown the potential value of Bayesian methods in fMRI (functional magnetic resonance imaging) analysis. For instance, the results from Bayes factor-applied second-level fMRI analysis showed a higher hit rate compared with frequentist second-level fMRI analysis, suggesting greater sensitivity. Although the method reported more positives as a result of the higher sensitivity, it was able to maintain a reasonable level of selectivity in term of the false positive rate. Moreover, employment of the multiple comparison correction method to update the default prior distribution significantly improved the performance of Bayesian second-level fMRI analysis. However, previous studies have utilized the default prior distribution and did not consider the nature of each individual study. Thus, in the present study, a method to adjust the Cauchy prior distribution based on a priori information, which can be acquired from the results of relevant previous studies, was proposed and tested. A Cauchy prior distribution was adjusted based on the contrast, noise strength, and proportion of true positives that were estimated from a meta-analysis of relevant previous studies. In the present study, both the simulated images and real contrast images from two previous studies were used to evaluate the performance of the proposed method. The results showed that the employment of the prior adjustment method resulted in improved performance of Bayesian second-level fMRI analysis.

Pooling resources to enhance rigour in psychophysiological research: Insights from open science approaches to meta-analysis

Recent years have witnessed calls for increased rigour and credibility in the cognitive and behavioural sciences, including psychophysiology. Many procedures exist to increase rigour, and among the most important is the need to increase statistical power. Achieving sufficient statistical power, however, is a considerable challenge for resource intensive methodologies, particularly for between-subjects designs. Meta-analysis is one potential solution; yet, the validity of such quantitative review is limited by potential bias in both the primary literature and in meta-analysis itself. Here, we provide a non-technical overview and evaluation of open science methods that could be adopted to increase the transparency of novel meta-analyses. We also contrast post hoc statistical procedures that can be used to correct for publication bias in the primary literature. We suggest that traditional meta-analyses, as applied in ERP research, are exploratory in nature, providing a range of plausible effect sizes without necessarily having the ability to confirm (or disconfirm) existing hypotheses. To complement traditional approaches, we detail how prospective meta-analyses, combined with multisite collaboration, could be used to conduct statistically powerful, confirmatory ERP research.

A systematic review and meta-analysis of the effect of emotion regulation on cortisol

It is generally acknowledged that hormones are implicated in socioemotional behavior, yet little is known about the role of hormones in the context of emotion regulation. The aims of the present review and meta-analysis were to review and synthesize the available evidence pertaining to the effect of emotion regulation instructions on hormones, and to investigate whether this effect varies according to: type of hormone, context (e.g., emotion-induction procedure), emotion regulation characteristics (e.g., emotion regulation strategy), and presence and type of psychiatric disorder. PubMed, PsycINFO, and CINAHL were searched for experimental studies assessing the effect of instructed emotion regulation on levels of hormones (i.e., testosterone, cortisol, oxytocin, estradiol, and vasopressin) in physically healthy adults. The literature search yielded 17 relevant studies, 16 investigating cortisol and one investigating testosterone. Of these, 12 cortisol studies had eligible data for the meta-analysis. The results of the meta-analysis indicated no statistically significant effect of receiving an emotion regulation instruction compared with receiving no instruction on the cortisol response to subsequent emotion induction (g ​= ​−0.05, p ​= ​.48). However, within-person comparisons of change from an unregulated response to a regulated response indicated a significant change in cortisol levels (g ​= ​0.18, p ​= ​.03) consistent with the specified regulation goal (i.e., either up- or downregulation). No statistically significant effects were found in subgroup meta-analyses conducted according to context, emotion regulation characteristics or psychiatric disorders. Taken together, the findings indicate that emotion-induction procedures are associated with increases in cortisol that may subsequently return to equilibrium regardless of emotion-regulation instructions. Based on the large gaps in research (e.g., few studies investigated other hormones than cortisol, few studies included self-report measures of emotions) identified in the present review, we conclude that the effect of emotion regulation on hormones remains poorly understood.

Prospero registration

CRD42020157336.

•

Research on the effect of emotion regulation on hormones has focused on cortisol.

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Emotion regulation does not influence cortisol responses to emotion induction.

•

Psychological confounders have received little attention in the reviewed research.

•

The effect of emotion regulation on hormones remains poorly understood.

Meta-Analysis with Few Studies and Binary Data: A Bayesian Model Averaging Approach

In meta-analysis, the existence of between-sample heterogeneity introduces model uncertainty, which must be incorporated into the inference. We argue that an alternative way to measure this heterogeneity is by clustering the samples and then determining the posterior probability of the cluster models. The meta-inference is obtained as a mixture of all the meta-inferences for the cluster models, where the mixing distribution is the posterior model probabilities. When there are few studies, the number of cluster configurations is manageable, and the meta-inferences can be drawn with BMA techniques. Although this topic has been relatively neglected in the meta-analysis literature, the inference thus obtained accurately reflects the cluster structure of the samples used. In this paper, illustrative examples are given and analysed, using real binary data.

Using bodily postures in the treatment of anorexia nervosa: Effects of power posing on interoception and affective states

OBJECTIVE

Power posing involves the adoption of an expansive bodily posture. This study examined whether power posing could benefit individuals with anorexia nervosa (AN) and women with normal weight in regards to interoceptive ability and affective states.

METHOD

Participants included 50 inpatients and outpatients with AN as well as 51 normal-weight women. Interoceptive accuracy (IAcc), measured by the heartbeat tracking task and interoceptive sensibility (IS), measured by confidence ratings, were assessed at baseline, after a single power posing session and after 1 week of daily training. Also, the short-term effects of power posing on subjective feelings of dominance, pleasantness, and arousal were investigated.

RESULTS

Both groups increased in their IAcc after one power posing session. Also, there was a significant main effect of time on feelings of dominance and pleasantness in the short-term. Women with AN displayed lower levels of IS, dominance, and pleasantness as well as higher levels of arousal than women without AN.

DISCUSSION

These findings suggest that power posing has the potential to increase IAcc, subjective feelings of power and pleasant affect in the short-term. Further research should investigate which mechanisms foster the effectiveness of this intervention to tailor it to the needs of women with AN.

Food-related attentional bias and its associations with appetitive motivation and body weight: A systematic review and meta-analysis

Theoretical models suggest that food-related visual attentional bias (AB) may be related to appetitive motivational states and individual differences in body weight; however, findings in this area are equivocal. We conducted a systematic review and series of meta-analyses to determine if there is a positive association between food-related AB and: (1.) body mass index (BMI) (number of effect sizes (k) = 110), (2.) hunger (k = 98), (3.) subjective craving for food (k = 35), and (4.) food intake (k = 44). Food-related AB was robustly associated with craving (r = 0.134 (95% CI 0.061, 0.208); p < .001), food intake (r = 0.085 (95% CI 0.038, 0.132); p < .001), and hunger (r = 0.048 (95% CI 0.016, 0.079); p = .003), but these correlations were small. Food-related AB was unrelated to BMI (r = 0.008 (95% CI -0.020, 0.035); p = .583) and this result was not moderated by type of food stimuli, method of AB assessment, or the subcomponent of AB that was examined. Furthermore, in a between-groups analysis (k = 22) which directly compared participants with overweight/obesity to healthy-weight control groups, there was no evidence for an effect of weight status on food-related AB (Hedge's g = 0.104, (95% CI -0.050, 0.258); p = .186). Taken together, these findings suggest that food-related AB is sensitive to changes in the motivational value of food, but is unrelated to individual differences in body weight. Our findings question the traditional view of AB as a trait-like index of preoccupation with food and have implications for novel theoretical perspectives on the role of food AB in appetite control and obesity.

Power posing for paranoia: A double-blind randomised controlled experimental test using virtual reality

Paranoia is theorised to build upon feelings of inferior social rank. Power posing has been shown to increase feelings of power, and hence could reduce paranoia. One hundred participants with current paranoia and 50 individuals without paranoia were recruited. Using a double-blind randomised controlled experimental design, participants twice held powerful or neutral postures before entering neutral virtual reality social environments. In the paranoid sample, those who held a powerful pose did not significantly increase in feelings of power by the end of testing in comparison to controls (group difference = 0.67, C.I. = -1.12; 1.46; p = 0.098), or decrease in paranoia (group difference = -0.23, C.I. = -1.17; 0.72; p = 0.634). In the non-paranoid sample, there was a small significant increase in powerful feelings by the end of testing in the powerful group (group difference = 1.13, C.I. = 0.23; 2.02; p = 0.013), but no significant decrease in paranoia (group difference = -0.71, C.I. = -2.16; 0.74; p = 0.338). Paranoia status was not a modifier on the relationship between condition and feelings of power. We conclude that power posing results in only very small changes in self-reported feelings of power and has no subsequent effect on paranoia.

Expansive and Contractive Postures and Movement: A Systematic Review and Meta-Analysis of the Effect of Motor Displays on Affective and Behavioral Responses

This review and meta-analysis explores the experimental effects of expansive and contractive motor displays on affective, hormonal, and behavioral responses. Experimental studies were located through systematic literature searches. Studies had to manipulate motor displays to either expansive or contractive displays and investigate the effect of the displays on affect, hormones, or overt behavior. Meta-analyses were conducted to determine the pooled, standardized mean differences between the effects of motor displays on affective, hormonal, and behavioral responses. From 5,819 unique records, 73 relevant studies were identified. Robust differences between expansive and contractive displays emerged for affective responses and overt behavioral responses across contexts, type of manipulation, and methods of measurement. The results suggest that the effects are driven by the absence of contractive motor displays (contractive vs. neutral displays: Hedges's g = 0.45) rather than the presence of expansive displays (expansive vs. neutral displays: g = 0.06). The findings stand as a corrective to previous research, as they indicate that it is the absence of contractive displays rather than the presence of expansive displays that alters affective and behavioral responding. Future research should include neutral control groups, use different methods to assess hormonal change, and investigate these effects in the context of ideographic goals.