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Anhedonia is associated with computational impairments in reward and effort learning in young people with depression symptoms
No full textBackground: Anhedonia and depression symptoms have been linked to potential deficits in reward learning. However, how anhedonia impacts the ability to adjust and learn about the effort required to obtain rewards remains unclear.
Methods: We examined young people (N = 155, 16 to 25 years) with a range of depression and anhedonia symptoms using a probabilistic instrumental reward and effort learning task. Participants were asked to learn which option to choose to maximize reward or minimise effort for reward. We compared the exerted effort (button pressing speed) for high (puppy images) vs low (dog images) rewards and collected subjective reports of “liking”, “wanting” and “willingness to exert effort”. Computational models were fit to the learning data and estimated parameter values were correlated with depression and anhedonia symptoms.
Results: As depression symptoms and consummatory anhedonia increased, reward liking decreased, and as anticipatory anhedonia increased, liking, wanting and willingness to exert effort for reward decreased.
Participants exerted more effort for high rewards than for low rewards, but anticipatory anhedonia diminished this difference.
Higher consummatory anhedonia was associated with poorer reward and effort learning, and with increased temperature parameter values for both learning types, indicating a higher tendency to make exploratory choices. Higher depression symptoms were associated with lower reward learning accuracy.
Conclusion: We provide novel evidence that anhedonia is associated with difficulties in modulating effort as a function of reward value. Regarding the computational mechanisms underpinning learning in anhedonia, we demonstrate that anhedonia is associated with the underexploitation of low effort and high reward options. We suggest that addressing the impairments in exploration/exploitation behaviours in anhedonic young people could be a novel target for intervention
Knowledge, attitudes, and perceptions toward dairy fat and consumption of dairy fat in Mexico, Chile, and Argentina
No full textThe objective of this research paper was to assess consumer knowledge, attitudes, and perceptions towards dairy fat. Adult participants completed a web-based survey collected from November 2022 to February 2023, across Mexico, Chile, and Argentina. In total, 1,204 respondents completed the survey. Most respondents were between 18 and 39 years old, female, educated, and employed. Results indicated that for both women (χ²=13.7, df4, p<0.01) and men (χ²=26.7, df4, p<0.01), the percentage of people who consume dairy products at least once a day increases with age. However, neither gender nor age affected the consumption of milk, yogurt, butter, cheese, and cream. An effect of country (χ²= 330.2, df18, p<0.01), age (χ²= 69.2, df36, p<0.01), and gender (χ²= 69.2, df36, p<0.01) was observed with respect to the type of milk consumed. In Mexico, whole milk garnered the highest consumption rates, while semi-skimmed milk was favored in Chile, and skimmed milk was preferred in Argentina. Results also show that whole milk consumption was higher in men, however, skimmed and light milk were preferred by women. Moreover, an effect of country (χ²=30.4, df14, p<0.01) and age (χ²=70.1, df28, p<0.01) was observed in relation to the type of fat that people consider most important. More respondents (48%) considered milk fat to be “healthy” or “very healthy” while no dependence was observed between countries and the relationship between the milk fat content and health. The best-known milk fat component in Argentina was omega-6 while Chilean consumers were less familiar with this component. Mexican consumers, on the other hand, gave greater importance to mono-unsaturated fats. Knowledge of other dairy fat groups and nutrients was similar across countries. This study benchmarks consumer knowledge and perceptions of dairy fat in Latin America, offering valuable insights for academia, industry, and consumers in the dairy sector
Quantitative susceptibility mapping in adults with persistent postconcussion symptoms after mild traumatic brain injury: an exploratory study
No full textBACKGROUND AND PURPOSE: It is estimated that 18%–30% of patients with concussion experience symptoms lasting more than 1 month, known as persistent post-concussion symptoms (PPCS). Symptoms can be debilitating, and include headache, dizziness, nausea, problems with memory and concentration, sleep and mood disruption, and exercise intolerance. Previous studies have used quantitative susceptibility mapping (QSM) to show altered tissue susceptibility levels in adults acutely following concussion, however this finding has yet to be investigated in participants with PPCS.
MATERIALS AND METHODS: In this exploratory case-controlled study, we measured tissue susceptibility using QSM in 24 participants with PPCS after mild traumatic brain injury (mTBI) and 23 healthy controls with no history of concussion. We compute tissue susceptibility for 7 white matter tracts and 3 deep gray matter regions and compare tissue susceptibility between groups using ANCOVA models controlling for age and sex. We also assess the relationship between regional tissue susceptibility and symptoms.
RESULTS: There were no significant differences between tissue susceptibility in participants with PPCS compared with control subjects in any of the evaluated regions. However, we show lower tissue susceptibility across 4 white matter tracts was generally associated with worse symptoms in the PPCS group. Specifically, we saw relationships between white matter susceptibility and headache (p = .006), time since injury (p = .03), depressive symptoms (p = .021), and daytime fatigue (p = .01) in participants with PPCS.
CONCLUSIONS: These results provide evidence in support of persistent changes in the brain months to years after injury and highlight the need to further understand the pathophysiology of PPCS, to determine effective prevention and treatment options
Two new Globicornis Latreille species from eastern Mediterranean (Coleoptera: Dermestidae: Megatominae)
Get PDFTwo new species, Globicornis (Globicornis) busei Holloway and Herrmann and Globicornis (Globicornis) lienemanni Holloway and Herrmann (Coleoptera: Dermestidae: Megatominae) from eastern Mediterranean are described and compared with G. picta (Küster, 1851), the most likely confounding species
because of geographical overlap and external similarity. Images of the habitus, ventrites, antenna, aedeagus,
and sternite IX are presented. Ten Globicornis (Globicornis) Latreille, 1829 species are now known from the eastern Mediterranean
Landscapes of (re)conquest: frontier dynamics in medieval Iberia and Occitania
No full textFrontiers were an integral feature of every medieval polity, and their spaces were defined by opposing spheres of influence, contact and connectivity. As these polities expanded and contracted, often as a result of military conquest and territorial annexation, their permeable edges became defined by transformative cultural landscapes. Here, the encounters between native or resident and incoming populations, from small elite groups through to larger numbers of migrants from diverse social backgrounds, resulted in varying degrees of cultural hybridity. This came to define frontier societies, and left an enduring impact even as borderlands continued to move. They also saw the reconfiguration of political, economic and religious landscapes as frontier authorities invested in both old and new centers, with varying degrees of continuity. Today, the remains of their fortified residences represent the most striking monuments associated with former frontiers. They remain at the center of public narratives regarding state formation and cultural conflict.
Adopting the definition of frontiers as both the spaces at the edges of polities and the composite societies resulting from their territorial expansion, this book presents a multi-disciplinary study of their dynamics. Focusing on the western Mediterranean, it draws on case studies of cultural landscapes shaped by two contrasting periods of conquest, regime change and state formation: the Castilian and Aragonese conquests of al-Andalus (Islamic Iberia) and the French annexation of Occitania following the Albigensian Crusade. Integrating perspectives from settlement and landscape archaeology, geoarchaeology, zooarchaeology, archaeobotany, archaeometallurgy and isotopic analyses, this book provides a new framework for the study of the transformative spaces of medieval frontier societies
Formal and informal sources of social support and their differential associations with intervention outcomes for depressive and anxiety symptoms among older adults
Get PDFBackground
Previous studies have highlighted social support as an important protective factor for depression and anxiety. Yet, little is known about how different dimensions of social support would be differentially associated with the prognosis of intervention outcomes.
Objective
We examined the influences of different sources of emotional support and the quantity of emotional and instrumental support pre-intervention on the prognosis of depressive and anxiety symptoms among older adults.
Methods
Data were prospectively collected from 4002 adults aged ≥60 years from a collaborative stepped-care intervention programme for depressive symptoms in Hong Kong. Source of emotional support and quantity of emotional and instrumental support were assessed pre-intervention. Depressive and anxiety symptoms were assessed using Patient Health Questionnaire–9-item (PHQ-9) and Generalized Anxiety Disorder–7-item (GAD-7) pre- and post-intervention. Linear mixed models were used to examine the prognostic effects of social support on mental health symptoms, adjusting for loneliness, living status, and sociodemographics.
Results
Preference for formal support was associated with greater reductions in depressive symptoms (b = −0.52, CI = −1.05–0.01), whereas preferences for informal family and community support was associated with greater reductions in anxiety symptoms (b = −0.51, CI = −0.94 to −0.07; b = −0.46, CI = −0.91 to −0.0004, respectively). More instrumental support pre-intervention was associated with a greater magnitude of increase in both depressive and anxiety symptoms.
Conclusions
Determining the preferences and availability of various dimensions of social support pre-intervention may provide insights into the potential prognosis of mental health outcomes, and thereby guide clinical decisions in treatment selection. Future studies can further elucidate the mechanisms underlying these associations
Addressing food system determinants of health inequalities in urban environments: learnings from the FoodSEqual and FoodSEqual-Health projects
Get PDFDiet is just one social determinant of health, with obesity and diet-related illness as leading causes of premature deaths and disability in the UK. People living in deprived areas of the UK are more likely to experience poor health outcomes, linked to many social determinants of health such as diet, housing, employment, education, power and discrimination and psycho-social factors such as isolation, quality of social network and perceived level of control. While socio-economic deprivation is a key risk for health inequalities, protected characteristics, vulnerable groups and geographical factors also indicate populations at risk of experiencing health inequalities. In this ‘opinion article’ we draw on our experiences in the Food Systems Equality (FoodSEqual) and FoodSEqual-Health research projects to share our methods of engaging residents from a range of population groups in areas of high deprivation in England, who are often under-represented in studies related to diet and health. We consider the contextual factors that shape the lived experience of residents, the contributions they can make when engaged in research and social development, and advocate for their inclusion in developments designed by voluntary sector organizations, local authorities and central government to improve the food systems they access. Finally, we consider the role of local food strategies and policy actions in developing healthy, sustainable and equitable food systems
A process-based evaluation of biases in extratropical stratosphere–troposphere coupling in subseasonal forecast systems
Get PDFTwo-way coupling between the stratosphere and troposphere is recognized as an important source of subseasonal-to-seasonal (S2S) predictability and can open windows of opportunity for improved forecasts. Model biases can, however, lead to a poor representation of such coupling processes; drifts in a model's circulation related to model biases, resolution, and parameterizations have the potential to feed back on the circulation and affect stratosphere–troposphere coupling. We introduce a set of diagnostics using readily available data that can be used to reveal these biases and then apply these diagnostics to 22 S2S forecast systems.
In the Northern Hemisphere, nearly all S2S forecast systems underestimate the strength of the observed upward coupling from the troposphere to the stratosphere, downward coupling within the stratosphere, and the persistence of lower-stratospheric temperature anomalies. While downward coupling from the lower stratosphere to the near surface is well represented in the multi-model ensemble mean, there is substantial intermodel spread likely related to how well each model represents tropospheric stationary waves.
In the Southern Hemisphere, the stratospheric vortex is oversensitive to upward-propagating wave flux in the forecast systems. Forecast systems generally overestimate the strength of downward coupling from the lower stratosphere to the troposphere, even as most underestimate the radiative persistence in the lower stratosphere. In both hemispheres, models with higher lids and a better representation of tropospheric quasi-stationary waves generally perform better at simulating these coupling processes
In search of an international standardised code of ethics on the use of Generative AI: a social science perspective
No full textVirtual vs human: comparing persuasive factors in influencer marketing campaigns
No full textThis chapter explores the evolving landscape of influencer marketing with the advance of virtual influencers—AI-powered, computer-generated characters designed to emulate human influencers. As traditional advertising faces growing consumer skepticism, social media influencers have emerged as compelling alternatives, with electronic word-of-mouth (e-WOM) playing a central role in shaping consumer behavior. Recently, virtual influencers have garnered attention for their ability to engage audiences, offering brands unprecedented control and consistency in their messaging. However, concerns around their authenticity, credibility, and ethical use remain prevalent. Drawing on empirical research, this chapter investigates how virtual influencers are perceived by social media users, with a specific focus on parasocial interactions and source credibility. Using in-depth interviews analyzed through thematic analysis, the study identifies key factors that make virtual influencers persuasive, including physical and social similarity to the target audience, engaging content, and interactive behaviors. While respondents acknowledge their appeal—especially in contexts such as technology promotion—virtual influencers are seen as less credible than human influencers when promoting products they cannot physically use. Nonetheless, credibility can be enhanced through third-party validation and relevant, high-quality content. The findings highlight that while virtual influencers hold promise, their persuasive power is highly context-dependent and currently falls short of human influencers in terms of perceived authenticity and trustworthiness. The chapter concludes by emphasizing the potential for virtual influencers to gain traction as technology improves and audience expectations evolve