A Bayesian inference model can predict the effects of attention on the serial dependence in heading estimation from optic flow

It has been demonstrated that observers can accurately estimate their self-motion direction (i.e., heading) from optic flow, which can be affected by attention. However, it remains unclear how attention affects the serial dependence in the estimation. In the current study, participants conducted two experiments. The results showed that the estimation accuracy decreased when attentional resources allocated to the heading estimation task were reduced. Additionally, the estimates of currently presented headings were biased toward the headings of previously seen headings, showing serial dependence. Especially, this effect decreased (increased) when the attentional resources allocated to the previously (currently) seen headings were reduced. Furthermore, importantly, we developed a Bayesian inference model, which incorporated attention-modulated likelihoods and qualitatively predicted changes in the estimation accuracy and serial dependence. In summary, the current study shows that attention affects the serial dependence in heading estimation from optic flow and reveals the Bayesian computational mechanism behind the heading estimation.

Size adaptation: Do you know it when you see it?

The visual system adapts to a wide range of visual features, from lower-level features like color and motion to higher-level features like causality and, perhaps, number. According to some, adaptation is a strictly perceptual phenomenon, such that the presence of adaptation licenses the claim that a feature is truly perceptual in nature. Given the theoretical importance of claims about adaptation, then, it is important to understand exactly when the visual system does and does not exhibit adaptation. Here, we take as a case study one specific kind of adaptation: visual adaptation to size. Supported by evidence from four experiments, we argue that, despite robust effects of size adaptation in the lab, (1) size adaptation effects are phenomenologically underwhelming (in some cases, hardly appreciable at all), (2) some effects of size adaptation appear contradictory, and difficult to explain given current theories of size adaptation, and (3) prior studies on size adaptation may have failed to isolate size as the adapted dimension. Ultimately, we argue that while there is evidence to license the claim that size adaptation is genuine, size adaptation is a puzzling and poorly understood phenomenon.

Conflicts between short- and long-term experiences affect visual perception through modulating sensory or motor response systems: Evidence from Bayesian inference models

The independent effects of short- and long-term experiences on visual perception have been discussed for decades. However, no study has investigated whether and how these experiences simultaneously affect our visual perception. To address this question, we asked participants to estimate their self-motion directions (i.e., headings) simulated from optic flow, in which a long-term experience learned in everyday life (i.e., straight-forward motion being more common than lateral motion) plays an important role. The headings were selected from three distributions that resembled a peak, a hill, and a flat line, creating different short-term experiences. Importantly, the proportions of headings deviating from the straight-forward motion gradually increased in the peak, hill, and flat distributions, leading to a greater conflict between long- and short-term experiences. The results showed that participants biased their heading estimates towards the straight-ahead direction and previously seen headings, which increased with the growing experience conflict. This suggests that both long- and short-term experiences simultaneously affect visual perception. Finally, we developed two Bayesian models (Model 1 vs. Model 2) based on two assumptions that the experience conflict altered the likelihood distribution of sensory representation or the motor response system. The results showed that both models accurately predicted participants' estimation biases. However, Model 1 predicted a higher variance of serial dependence compared to Model 2, while Model 2 predicted a higher variance of the bias towards the straight-ahead direction compared to Model 1. This suggests that the experience conflict can influence visual perception by affecting both sensory and motor response systems. Taken together, the current study systematically revealed the effects of long- and short-term experiences on visual perception and the underlying Bayesian processing mechanisms.

Motivation and prediction-driven processing of social memoranda

Social semantic memory guides many aspects of behavior. Individuals rely on acquired and inferred knowledge about personal characteristics and group membership to predict the behavior and character of social targets. These predictions then determine the expectations from, the behavior in, and the interpretations of social interactions. According to predictive processing accounts, mnemonic and attentional mechanisms should enhance the processing of prediction-violating events. However, empirical findings suggest that prediction-consistent social events are often better remembered. This mini-review integrates recent evidence from social and non-social memory research to highlight the role of motivation in explaining these discrepancies. A particular emphasis is given to the continuous nature of prediction-(in)consistency, the epistemic tendency of perceivers to maintain or update their knowledge, and the dynamic influences of motivation on multiple steps in prediction-driven social memory. The suggested framework provides a coherent outlook of existing work and offers promising future directions to better understand the ebb and flow of social memoranda.

Predictive cues elicit a liminal confirmation bias in the moral evaluation of real-world images

Previous research suggested that predictive cues enhance the preference and reduce the response time for congruent targets during bivalent food evaluation, indicating a confirmation bias. Less is known about how prior processing affects subjective moral evaluation. Here, we used three different types of predictive cues to elicit directional vs. non-predictive prior processing and then asked the participants to perform moral evaluations on a continuous scale from -10 ("very immoral") to +10 ("very moral") with a diverse set of real-world images. Our experimental image database balanced the morality of image content and the volatility of the ratings based on the means and standard deviations in a preliminary study. Ratings, response times, and gaze positions were measured to examine the effects of predictive cues on the moral evaluation of real-world images. We found that the moral ratings were in line with the expectations induced by the cues. Compared to the non-predictive condition, the moral evaluation in the directional conditions was more polarized. For neutral images, the predictive cues tilted the evaluations to positive vs. negative, indicating a decisive liminal influence. High-volatility images were impacted more than low-volatility images in ratings as well as response times. Furthermore, the gaze positions during the interval between the predictive cue and the image showed a spatial displacement in line with the cue instruction, indicating a response bias. Together, the results show that predictive cues elicit a liminal confirmation bias in moral image evaluation, much in the same way as in bivalent food evaluation.

Highly dangerous road hazards are not immune from the low prevalence effect

The low prevalence effect (LPE) is a cognitive limitation commonly found in visual search tasks, in which observers miss rare targets. Drivers looking for road hazards are also subject to the LPE. However, not all road hazards are equal; a paper bag floating down the road is much less dangerous than a rampaging moose. Here, we asked whether perceived hazardousness modulated the LPE. To examine this, we took a dataset in which 48 raters assessed the perceived dangerousness of hazards in recorded road videos (Song et al. in Behav Res Methods, 2023. https://doi.org/10.3758/s13428-023-02299-8 ) and correlated the ratings with data from a hazard detection task using the same stimuli with varying hazard prevalence rates (Kosovicheva et al. in Psychon Bull Rev 30(1):212-223, 2023. https://doi.org/10.3758/s13423-022-02159-0 ). We found that while hazard detectability increased monotonically with hazardousness ratings, the LPE was comparable across perceived hazardousness levels. Our findings are consistent with the decision criterion account of the LPE, in which target rarity induces a conservative shift in criterion. Importantly, feedback was necessary for a large and consistent LPE; when participants were not given feedback about their accuracy, the most dangerous hazards showed a non-significant LPE. However, eliminating feedback was not enough to induce the opposite of the LPE-prevalence induced concept change (Levari et al. in Science 360(6396):1465-1467, 2018. https://doi.org/10.1126/science.aap8731 ), in which participants adopt a more liberal criterion when instances of a category become rare. Our results suggest that the road hazard LPE may be somewhat affected by the inherent variability of driving situations, but is still observed for highly dangerous hazards.

'Concept creep' in perceptions of mental illness - an experimental examination of prevalence-induced concept change

The perception of what constitutes mental illness is influenced by various social and medical developments. Prevalence-induced concept change is a phenomenon where decreasing the prevalence of a category leads people to expand their judgment of that concept. In this study, we tested whether changing the prevalence of statements describing mental illness results in a change in the concept of mental illness. Based on a population survey (n = 1031), we created a validated set of 273 brief statements depicting either clear symptoms of mental illness, clear examples of healthy behaviour, or ambiguous situations. We presented a subset of statements to 138 students, asking them to judge whether each statement represented mental illness, or not. After 96 statements, we reduced the prevalence of clearly mentally ill statements in one group, while the proportion of statements denoting clear mental illness remained the same in the other group. In the group where the proportion of clearly mentally ill statements was reduced during the experiment, a concept change of mental illness evolved: participants were more likely to identify a statement as denoting a mental illness. The results indicate that the perceived prevalence of symptoms of mental illness is important for conceptualizing mental illness and that decreasing prevalence broadens the concept of mental illness. These findings add a novel perspective to current debates around diagnostic thresholds, the treatment-prevalence paradox, the medicalization of emotions, and the focus of anti-stigma campaigns.

Category Flexibility in Emotion Learning

Learners flexibly update category boundaries to adjust to the range of experiences they encounter. However, little is known about whether the degree of flexibility is consistent across domains. We examined whether categorization of social input, specifically emotions, is afforded more flexibility as compared to other biological input. To address this question, children (6-12 years; 32 female, 37 male; 7 Hispanic or Latino, 62 not Hispanic or Latino; 8 Black or African American, 14 multiracial, 46 White, 1 selected "other") categorized faces morphed from calm to upset and animals morphed from a horse to a cow across task phases that differed in the distribution of stimuli presented. Learners flexibly adjusted both emotion and animal category boundaries according to distributional information, yet children showed more flexibility when updating their category boundaries for emotions. These results provide support for the idea that children-who must adjust to the vast and varied emotional signals of their social partners-respond to social signals dynamically in order to make predictions about the internal states and future behaviors of others.

Clinical Validation Benchmark Dataset and Expert Performance Baseline for Colorectal Polyp Localization Methods

Colorectal cancer is one of the leading death causes worldwide, but, fortunately, early detection highly increases survival rates, with the adenoma detection rate being one surrogate marker for colonoscopy quality. Artificial intelligence and deep learning methods have been applied with great success to improve polyp detection and localization and, therefore, the adenoma detection rate. In this regard, a comparison with clinical experts is required to prove the added value of the systems. Nevertheless, there is no standardized comparison in a laboratory setting before their clinical validation. The ClinExpPICCOLO comprises 65 unedited endoscopic images that represent the clinical setting. They include white light imaging and narrow band imaging, with one third of the images containing a lesion but, differently to another public datasets, the lesion does not appear well-centered in the image. Together with the dataset, an expert clinical performance baseline has been established with the performance of 146 gastroenterologists, who were required to locate the lesions in the selected images. Results shows statistically significant differences between experience groups. Expert gastroenterologists' accuracy was 77.74, while sensitivity and specificity were 86.47 and 74.33, respectively. These values can be established as minimum values for a DL method before performing a clinical trial in the hospital setting.

Taking prevalence effects on the road: Rare hazards are often missed

Previous work has shown that, in many visual search and detection tasks, observers frequently miss rare but important targets, like weapons in bags or abnormalities in radiological images. These prior studies of the low-prevalence effect (LPE) use static stimuli and typically permitted observers to search at will. In contrast, many real-world tasks, like looking for dangerous behavior on the road, only afford observers a brief glimpse of a complex, changing scene before they must make a decision. Can the LPE be a factor in in dynamic, time-limited moments of real driving? To test this, we developed a novel hazard-detection task that preserves much of the perceptual richness and complexity of hazard detection in the real world, while allowing for experimental control over event prevalence. Observers viewed brief video clips of road scenes recorded from dashboard cameras and reported whether they saw a hazardous event. In separate sessions, the prevalence of these events was either high (50% of videos) or low (4%). Under low prevalence, observers missed hazards at more than twice the rate observed in the high-prevalence condition. Follow-up experiments demonstrate that this elevation of miss rate at low prevalence persists when participants were allowed to correct their responses, increases as hazards become increasingly rare (down to 1% prevalence) and is resistant to simple cognitive intervention (participant prebriefing). Together, our results demonstrate that the LPE generalizes to complex perceptual decisions in dynamic natural scenes, such as driving, where observers must monitor and respond to rare hazards.

A review of attentional bias modification trainings for depression

Negative attentional bias is a basic character of depression. The attentional bias modification training (ABMT), being a highly promising and easy-to-use depression intervention technique, has attracted much attention to alleviate depressive symptoms in recent years. However, the effectiveness of ABMT programs was mixed across studies, since it remained unclear the underlying mechanisms of ABMT on alleviating depressive symptoms. We systematically analyzed the main ABMT paradigms to clarify possible mechanisms of effective training and reasons of ineffective training. Valid ABMT programs might alleviate depressive symptoms through regulating self-related rumination or two subcomponents of attentional bias: facilitated attention and impaired attentional disengagement. The reasons for the invalidity of ABMT mainly included the suboptimal design of training procedures, mixed effects of participants' personal characteristics, and the unclear relationship between attentional bias and depression. The ABMT is promising for alleviating depressive symptoms, but training procedures are required to be improved to obtain stable training effects.

Heading perception from optic flow is affected by heading distribution

Recent studies have revealed a central tendency in the perception of physical features. That is, the perceived feature was biased toward the mean of recently experienced features (i.e., previous feature distribution). However, no study explored whether the central tendency was in heading perception or not. In this study, we conducted three experiments to answer this question. The results showed that the perceived heading was not biased toward the mean of the previous heading distribution, suggesting that the central tendency was not in heading perception. However, the perceived headings were overall biased toward the left side, where headings rarely appeared in the right-heavied distribution (Experiment 3), suggesting that heading perception from optic flow was affected by previously seen headings. It indicated that the participants learned the heading distributions and used them to adjust their heading perception. Our study revealed that heading perception from optic flow was not purely perceptual and that postperceptual stages (e.g., attention and working memory) might be involved in the heading perception from optic flow.

Human ageing is associated with more rigid concept spaces

Prevalence-induced concept change describes a cognitive mechanism by which someone's definition of a concept shifts as the prevalence of instances of that concept changes. While this phenomenon has been established in young adults, it is unclear how it affects older adults. In this study, we explore how prevalence-induced concept change affects older adults' lower-level, perceptual, and higher-order, ethical judgements. We find that older adults are less sensitive to prevalence-induced concept change than younger adults across both domains. Using computational modeling, we demonstrate that these age-related changes in judgements reflect more cautious and deliberate responding in older adults. Based on these findings, we argue that while overly cautious responding by older adults may be maladaptive in some cognitive domains, in the case of prevalence-induced concept change, it might be protective against biased judgements.

Changes in the Prevalence of Thin Bodies Bias Young Women's Judgments About Body Size

Body dissatisfaction is pervasive among young women in Western countries. Among the many forces that contribute to body dissatisfaction, the overrepresentation of thin bodies in visual media has received notable attention. In this study, we proposed that prevalence-induced concept change may be one of the cognitive mechanisms that explain how beauty standards shift. We conducted a preregistered online experiment with young women (N = 419) and found that when the prevalence of thin bodies in the environment increased, the concept of being overweight expanded to include bodies that would otherwise be judged as "normal." Exploratory analyses revealed significant individual differences in sensitivity to this effect, in terms of women's judgments about other bodies as well as their own. These results suggest that women's judgments about other women's bodies are biased by an overrepresentation of thinness and lend initial support to policies designed to increase size-inclusive representation in the media.

'Diagnostic downshift': clinical and system consequences of extrapolating secondary care testing tactics to primary care

Numerous drivers push specialist diagnostic approaches down to primary care ('diagnostic downshift'), intuitively welcomed by clinicians and patients. However, primary care's different population and processes result in under-recognised, unintended consequences. Testing performs poorer in primary care, with indication creep due to earlier, more undifferentiated presentation and reduced accuracy due to spectrum bias and the 'false-positive paradox'. In low-prevalence settings, tests without near-100% specificity have their useful yield eclipsed by greater incidental or false-positive findings. Ensuing cascades and multiplier effects can generate clinician workload, patient anxiety, further low-value tests, referrals, treatments and a potentially nocebic population 'disease' burden of unclear benefit. Increased diagnostics earlier in pathways can burden patients and stretch general practice (GP) workloads, inducing downstream service utilisation and unintended 'market failure' effects. Evidence is tenuous for reducing secondary care referrals, providing patient reassurance or meaningfully improving clinical outcomes. Subsequently, inflated investment in per capita testing, at a lower level in a healthcare system, may deliver diminishing or even negative economic returns. Test cost poorly represents 'value', neglecting under-recognised downstream consequences, which must be balanced against therapeutic yield. With lower positive predictive values, more tests are required per true diagnosis and cost-effectiveness is rarely robust. With fixed secondary care capacity, novel primary care testing is an added cost pressure, rarely reducing hospital activity. GP testing strategies require real-world evaluation, in primary care populations, of all downstream consequences. Test formularies should be scrutinised in view of the setting of care, with interventions to focus rational testing towards those with higher pretest probabilities, while improving interpretation and communication of results.

Broadened Concepts of Harm Appear Less Serious

Harm-related concepts have progressively broadened their meanings to include less severe phenomena, but the implications of this expansion are unclear. Across five studies involving 1,819 American participants recruited on MTurk or Prolific, we manipulated whether participants learned about marginal, prototypical (severe), or mixed examples of workplace bullying (Studies 1 and 3a), trauma (Studies 2 and 3b), or sexual harassment (Study 4). We hypothesized that exposure to marginal examples of a concept would lead participants to view the harm associated with it as less serious than those exposed to prototypical examples ( trivialization hypothesis). We also predicted that mixing marginal examples with prototypical examples would disproportionately reduce perceived seriousness ( threshold shift hypothesis). All studies supported the trivialization hypothesis, but threshold shift was not consistently supported. Our findings suggest that broadened concepts of harm may dilute the perceived severity and urgency of the harms they identify.

How one block of trials influences the next: persistent effects of disease prevalence and feedback on decisions about images of skin lesions in a large online study

Using an online, medical image labeling app, 803 individuals rated images of skin lesions as either "melanoma" (skin cancer) or "nevus" (a skin mole). Each block consisted of 80 images. Blocks could have high (50%) or low (20%) target prevalence and could provide full, accurate feedback or no feedback. As in prior work, with feedback, decision criteria were more conservative at low prevalence than at high prevalence and resulted in more miss errors. Without feedback, this low prevalence effect was reversed (albeit, not significantly). Participants could participate in up to four different conditions a day on each of 6 days. Our main interest was in the effect of Block N on Block N + 1. Low prevalence with feedback made participants more conservative on a subsequent block. High prevalence with feedback made participants more liberal on a subsequent block. Conditions with no feedback had no significant impact on the subsequent block. The delay between Blocks 1 and 2 had no significant effect. The effect on the second half of Block 2 was just as large as on the first half. Medical expertise (over the range available in the study) had no impact on these effects, though medical students were better at the task than other groups. Overall, these seem to be robust effects where feedback may be 'teaching' participants how to respond in the future. This might have application in, for example, training or re-training situations.

Justice and Inclusion Mutually Cause Each Other

Justice should increase inclusion because just treatment conveys acceptance and enables social exchanges that build cohesion. Inclusion should increase justice because people can use inclusion as a convenient fairness cue. Prior research touches on these causal associations but relies on a thin conception of inclusion and neglects within-person effects. We analyze whether justice causes inclusion at the within-person level. Five waves of data were gathered from 235 college students in 38 entrepreneurial teams. Teams were similar in size, work experience, deadlines, and goals. General cross-lagged panel models indicated that justice and inclusion had a reciprocal influence on each other. A robustness check with random-intercept cross-lagged models supported the results. In the long run, reversion to the mean occurred after an effect decayed, suggesting that virtuous or vicious cycles are unlikely. The results imply that maintaining overall justice at the peer-to-peer level may lead to inclusion.

Pessimistic health and optimistic wealth distributions perceptions in Germany and the UK: evidence from an online-survey

Background

Inequalities in health and wealth distributions are becoming pressing societal problems in many countries. How these inequalities are perceived and to what degree perceptions are aligned with actual distributions, is important for trust in public health services, social and economic policies, and policymakers. This study aims to assess perceived and desired levels of inequality in health and wealth in Germany and the UK.

Methods

The online-survey was filled out by 769 volunteers (322 from Germany, 447 from the UK), recruited from an existing commercial panel (Prolific Academic) or via Facebook advertisements in 2019. Perceived and ideal national health and wealth distributions were assessed and compared to actual health indicators (i.e. days absent from work, number of visits to general practitioners (GPs) and self-rated health), and actual wealth distributions with t-tests.

Results

A pronounced gap emerged between the estimated, ideal and actual inequality. Both samples strikingly underestimated the proportion of (very) good health in the national distribution by a factor of ~ 2.3 (participants estimated that 34% of the German and 36% of the UK population respectively are very healthy or healthy, while the actual proportion in the population was 75% in Germany and 84% in the UK, P < 0.001 for all). Moreover, actual health distributions were much closer to the desired than the perceived health distributions (78% of German and 72% of UK participants ideally being very healthy or healthy). A reversed pattern of results emerged for wealth in both samples, with wealth inequality being strikingly worse than desired and inequality being underestimated by a factor ~ 1.7 (P < 0.001 for all). Results were consistent across demographic groups.

Conclusions

Respondents in both Germany and the UK have profoundly negative misperceptions regarding the distribution of health, which contrasts with starkly positive misperceptions regarding the distribution of wealth, indicating that the public is healthier but poorer than they think. More importantly, from a public health perspective, a high level of consensus emerged, with both healthy and wealthy participants misperceiving health and wealth distributions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11355-x.

Feedback moderates the effect of prevalence on perceptual decisions

How does the prevalence of a target influence how it is perceived and categorized? A substantial body of work, mostly in visual search, shows that a higher proportion of targets are missed when prevalence is low. This classic low prevalence effect (LPE) involves a shift to a more conservative decision criterion that makes it less likely that observers will call an ambiguous item a target. In contrast, Levari et al. (Science, 360[6396], 1465-1467, 2018) recently reported the opposite effect in a simple categorization task. In their hands, at low prevalence, observers adopted a more liberal criterion, making observers more likely to label ambiguous dots on a blue-purple continuum "blue." They called this "prevalence-induced concept change" (PICC). Here, we report that the presence or absence of feedback is critical. With feedback, observers become more conservative at low prevalence, as in the LPE. Without feedback, they become more liberal, identifying a wider range of stimuli as targets, as in Levari's PICC studies. Stimuli from a shape continuum ranging from rounded ("Bouba") to bumpy ("Kiki") shapes produced similar results. Other variables: response type (2AFC vs. go/no-go), color (blue-purple vs. red-green), and stimuli type (solid color vs. texture) did not influence the criterion shifts. Understanding these effects of prevalence and ways they can be controlled illuminates the context-specific nature of perceptual decisions and may be useful in socially important, low prevalence tasks like cancer screening, airport security, and disease diagnosis in pathology.

Categorization of Vocal Emotion Cues Depends on Distributions of Input

Learners use the distributional properties of stimuli to identify environmentally relevant categories in a range of perceptual domains, including words, shapes, faces, and colors. We examined whether similar processes may also operate on affective information conveyed through the voice. In Experiment 1, we tested how adults (18–22-year-olds) and children (8–10-year-olds) categorized affective states communicated by vocalizations varying continuously from “calm” to “upset.” We found that the threshold for categorizing both verbal (i.e., spoken word) and nonverbal (i.e., a yell) vocalizations as “upset” depended on the statistical distribution of the stimuli participants encountered. In Experiment 2, we replicated and extended these findings in adults using vocalizations that conveyed multiple negative affect states. These results suggest perceivers’ flexibly and rapidly update their interpretation of affective vocal cues based upon context.

When experience does not promote expertise: security professionals fail to detect low prevalence fake IDs

Professional screeners frequently verify photograph IDs in such industries as professional security, bar tending, and sales of age-restricted materials. Moreover, security screening is a vital tool for law enforcement in the search for missing or wanted persons. Nevertheless, previous research demonstrates that novice participants fail to spot fake IDs when they are rare (i.e., the low prevalence effect; LPE). To address whether this phenomenon also occurs with professional screeners, we conducted three experiments. Experiment 1 compared security professional and non-professionals. Experiment 2 compared bar-security professionals, access-security professionals, and non-professionals. Finally, Experiment 3 added a newly created Professional Identity Training Questionnaire to determine whether and how aspects of professionals’ employment predict ID-matching accuracy. Across all three experiments, all participants were susceptible to the LPE regardless of professional status. Neither length/type of professional experience nor length/type of training experience affected ID verification performance. We discuss task performance and survey responses with aims to acknowledge and address this potential problem in real-world screening scenarios.

Now you see them, and now you don't: An evolutionarily informed model of environmental influences on human sex differences

The contributions of evolutionary processes to human sex differences are vigorously debated. One counterargument is that the magnitude of many sex differences fluctuates from one context to the next, implying an environment origin. Sexual selection provides a framework for integrating evolutionary processes and environmental influences on the origin and magnitude of sex differences. The dynamics of sexual selection involve competition for mates and discriminative mate choices. The associated traits are typically exaggerated and condition-dependent, that is, their development and expression are very sensitive to social and ecological conditions. The magnitude of sex differences in sexually selected traits should then be largest under optimal social and ecological conditions and shrink as conditions deteriorate. The basics of this framework are described, and its utility is illustrated with discussion of fluctuations in the magnitude of human physical, behavioral, and cognitive sex differences.

The impact of the Syrian conflict on population well-being

The United Nations described the Syrian conflict as the worst man-made disaster since World War II. We adopted a global perspective in examining the impact of the Syrian conflict on Syrians’ physical, mental, and social well-being using the Gallup World Poll. Face-to-face interview data of 11,452 Syrian participants from 2008 to 2015 show that Syrians’ physical (e.g., access to shelter), mental (e.g., life satisfaction), and social (e.g., social support) well-being decline substantially. Syrians who reported being exposed to the conflict are similarly affected compared to those without direct exposure, suggesting country-wide spillover effects. Global data covering 1.7 million participants across 163 countries from 2006 to 2016 show during the conflict, Syria’s precipitous decline in well-being is unparalleled in the world, even when compared to countries similarly experiencing war, protests, and disasters. Our findings reinforce the vital importance of an accelerated peace process to restore well-being in Syria.

The current Syrian conflict is considered a major humanitarian crisis. Here, the authors show a decline in population well-being with the onset of the conflict, and show how this decline compares to other populations experiencing wars, civil unrest or natural disasters.

Reactions to male-favouring versus female-favouring sex differences: A pre-registered experiment and Southeast Asian replication

Two studies investigated (1) how people react to research describing a sex difference, depending on whether that difference favours males or females, and (2) how accurately people can predict how the average man and woman will react. In Study 1, Western participants (N = 492) viewed a fictional popular-science article describing either a male-favouring or a female-favouring sex difference (i.e., men/women draw better; women/men lie more). Both sexes reacted less positively to the male-favouring differences, judging the findings to be less important, less credible, and more offensive, harmful, and upsetting. Participants predicted that the average man and woman would react more positively to sex differences favouring their own sex. This was true of the average woman, although the level of own-sex favouritism was lower than participants predicted. It was not true, however, of the average man, who - like the average woman - reacted more positively to the female-favouring differences. Study 2 replicated these findings in a Southeast Asian sample (N = 336). Our results are consistent with the idea that both sexes are more protective of women than men, but that both exaggerate the level of same-sex favouritism within each sex - a misconception that could potentially harm relations between the sexes.

Positive Treatment Expectancies Reduce Clinical Pain and Perceived Limitations in Movement Ability Despite Increased Experimental Pain: A Randomized Controlled Trial on Sham Opioid Infusion in Patients with Chronic Back Pain

BACKGROUND

Increasing evidence for the efficacy of analgesic placebo effects in laboratory studies with healthy persons raises the question whether placebos could be used to improve the treatment of pain patients. Expectancies play a central role in shaping analgesic placebo but also nocebo effects.

OBJECTIVES

We investigated to what extent a sham opioid infusion (saline solution) produces sustained clinically relevant placebo and nocebo effects in chronic back pain patients.

METHODS

Fifty-nine patients received the sham opioid infusion applied via a large drain dressing and were compared to 14 control patients without intervention (natural history, NH) while experimental pain stimuli were applied. All subjects were told that the infusion would decrease pain although in rare cases pain increase would be possible (induction of expectancy). In addition, conditioning was introduced where the participants either experienced a decrease in experimental pain (n = 17; placebo conditioning), an increase (n = 21; nocebo conditioning), or no change (n = 21, no conditioning).

RESULTS

Compared to the NH group, all infusion groups showed positive treatment expectancies and significantly (p < 0.001) reduced clinical back pain (primary outcome) and pain-related disability (secondary outcome, assessed by self-reported functional capacity and perceived impairment of mobility). Even the nocebo conditioned group experiencing increased experimental pain developed positive treatment expectancies followed by reduced pain experience. Positive treatment expectancies and relief in clinical back pain were significantly positively correlated (r = 0.72, p < 0.01).

CONCLUSIONS

These findings suggest that it may be beneficial to explicitly shape and integrate treatment expectancies into clinical pain management.

The Pacified Face: Early Embodiment Processes and the Use of Dummies

Few things affect us as much as facial expressions, as they inform us about others' feelings and intentions, thereby influencing our own emotions and behaviors. A substantial body of literature links the critical abilities of recognizing and understanding emotion displays with facial mimicry, a sensorimotor process involving rapid imitation of perceived expressions. For example, blocking or altering facial mimicry in adults leads to disruptions in judgments in emotion recognition or emotional language processing. The present review focuses on pacifier use in infancy, a common practice that has the potential to interfere with infants' facial movements in ways identical to laboratory paradigms designed to block facial mimicry. Despite this similarity and the widespread use of infant soothers, little is known about their long-term effects. Here we review studies exploring the psychological correlates and implications of pacifier use. In particular, we discuss how soothers may interfere with the development of social skills in infants and present evidence linking pacifier use with disrupted adults' mimicry of facial expressions displayed by infants. Other preliminary findings reveal negative correlations between the use of soothers and children's spontaneous facial mimicry as well as emotional competence of young adults. Such studies, although correlational, suggest that this widespread parenting practice may affect the development of social skills by influencing emotional coordination. We discuss the implications of these findings and propose avenues for future research that can provide insights into the role of embodied processes in the development of emotional competence and adult functioning.

When Small Signs of Change Add Up: The Psychology of Tipping Points

Things change, but the exact point at which they do is often unknown. After how many loveless nights is a relationship “officially” in trouble? After how many happy days has one’s depression “officially” passed? When do recurring patterns in the climate or economy “officially” warrant a response? When is a person’s identity “officially” accepted? Everyday fluctuations in oneself and the social world create ambiguities about when people will diagnose lasting, qualitative change (and therefore act). Recent research documents these tipping points of change as a psychological process, shaped by individual and situational forces. People judge tipping points asymmetrically across valence and asymmetrically across time. Here, I review discoveries and outline future directions in tipping-points research.

Emotional Expressions Reconsidered: Challenges to Inferring Emotion From Human Facial Movements

It is commonly assumed that a person's emotional state can be readily inferred from his or her facial movements, typically called emotional expressions or facial expressions. This assumption influences legal judgments, policy decisions, national security protocols, and educational practices; guides the diagnosis and treatment of psychiatric illness, as well as the development of commercial applications; and pervades everyday social interactions as well as research in other scientific fields such as artificial intelligence, neuroscience, and computer vision. In this article, we survey examples of this widespread assumption, which we refer to as the common view, and we then examine the scientific evidence that tests this view, focusing on the six most popular emotion categories used by consumers of emotion research: anger, disgust, fear, happiness, sadness, and surprise. The available scientific evidence suggests that people do sometimes smile when happy, frown when sad, scowl when angry, and so on, as proposed by the common view, more than what would be expected by chance. Yet how people communicate anger, disgust, fear, happiness, sadness, and surprise varies substantially across cultures, situations, and even across people within a single situation. Furthermore, similar configurations of facial movements variably express instances of more than one emotion category. In fact, a given configuration of facial movements, such as a scowl, often communicates something other than an emotional state. Scientists agree that facial movements convey a range of information and are important for social communication, emotional or otherwise. But our review suggests an urgent need for research that examines how people actually move their faces to express emotions and other social information in the variety of contexts that make up everyday life, as well as careful study of the mechanisms by which people perceive instances of emotion in one another. We make specific research recommendations that will yield a more valid picture of how people move their faces to express emotions and how they infer emotional meaning from facial movements in situations of everyday life. This research is crucial to provide consumers of emotion research with the translational information they require.

Probabilistic learning of emotion categories

Although the configurations of facial muscles that humans perceive vary continuously, we often represent emotions as categories. This suggests that, as in other domains of categorical perception such as speech and color perception, humans become attuned to features of emotion cues that map onto meaningful thresholds for these signals given their environments. However, little is known about the learning processes underlying the representation of these salient social signals. In Experiment 1 we test the role of statistical distributions of facial cues in the maintenance of an emotion category in both children (6-8 years old) and adults (18-22 years old). Children and adults learned the boundary between neutral and angry when provided with explicit feedback (supervised learning). However, after we exposed participants to different statistical distributions of facial cues, they rapidly shifted their category boundaries for each emotion during a testing phase. In Experiments 2 and 3, we replicated this finding and also tested the extent to which learners are able to track statistical distributions for multiple actors. Not only did participants form actor-specific categories, but the distributions of facial cues also influenced participants' trait judgments about the actors. Taken together, these data are consistent with the view that the way humans construe emotion (in this case, anger) is not only flexible, but reflects complex learning about the distributions of the myriad cues individuals experience in their social environments. (PsycINFO Database Record (c) 2019 APA, all rights reserved).