Project description:Promises are crucial for human cooperation because they allow people to enter into voluntary commitments about future behavior. Here we present a novel, fully incentivized paradigm to measure voluntary and costly promise-keeping in the absence of external sanctions. We found across three studies (N = 4,453) that the majority of participants (61%-98%) kept their promises to pay back a specified amount of a monetary endowment, and most justified their decisions by referring to obligations and norms. Varying promise elicitation methods (Study 1a) and manipulating stake sizes (Study 2a) had negligible effects. Simultaneously, when others estimated promise-keeping rates (using two different estimation methods), they systematically underestimated promise-keeping by up to 40% (Studies 1b and 2b). Additional robustness checks to reduce potential reputational concerns and possible demand effects revealed that the majority of people still kept their word (Study 3). Promises have a strong normative power and binding effect on behavior. Nevertheless, people appear to pessimistically underestimate the power of others' promises. This behavior-estimation gap may prevent efficient coordination and cooperation.
Project description:Within the last decade, vitamin D has emerged as a central regulator of host defense against infections. In this regard, vitamin D triggers effective antimicrobial pathways against bacterial, fungal and viral pathogens in cells of the human innate immune system. However, vitamin D also mediates potent tolerogenic effects: it is generally believed that vitamin D attenuates inflammation and acquired immunity, and thus potentially limits collateral tissue damage. Nevertheless, several studies indicate that vitamin D promotes aspects of acquired host defense. Clinically, vitamin D deficiency has been associated with an increased risk for various infectious diseases in epidemiological studies; yet, robust data from controlled trials investigating the use of vitamin D as a preventive or therapeutic agent are missing. In this review, we summarize the current knowledge regarding the effect of vitamin D on innate and acquired host defense, and speculate on the difficulties to translate the available molecular medicine data into practical therapeutic or preventive recommendations.
Project description:Both social and drinking behavior have the potential to modify mood. However, if social drinking enhances positive mood and reduces negative mood, as compared to non-drinking social behavior, then interventions to reinforce non-drinking via sober social activity are undermined. Using multilevel modeling analyses, we compared end-of-day mood on drinking days versus non-drinking days, and on days spent with other people as compared to days spent primarily alone. We evaluated the interaction between drinking/non-drinking and social/solitary behavior and assessed whether the effects of social and drinking behavior extended to mood the next day. Participants were 352 college students (53% female; 55% fraternity/sorority membership; mean age 19.7?years) who completed three automated telephone surveys each day during four 14-day intervals over 1?year. Drinking and being social were associated with higher end-of-day positive mood and significantly lower end-of-day negative mood. However, no positive enhancement or negative attenuation effects of alcohol were observed in interaction analyses. Alcohol provided no improvement in mood over-and-above being social at the end of the day or on the following day. However, drinking the previous day significantly reduced next-day positive mood, whereas being social significantly reduced next-day negative mood. These findings provide support for the reinforcing potential of interventions that increase rewarding social activity in the place of alcohol use.
Project description:Cognitive flexibility is the ability to switch between different concepts or to adapt goal-directed behavior in a changing environment. Although, cognitive research on this ability has long been focused on the individual mind, it is becoming increasingly clear that cognitive flexibility plays a central role in our social life. This is particularly evident in turn-taking in verbal conversation, where cognitive flexibility of the individual becomes part of social flexibility in the dyadic interaction. In this work, we introduce a model that reveals different parameters that explain how people flexibly handle unexpected events in verbal conversation. In order to study hypotheses derived from the model, we use a novel experimental approach in which thirty pairs of participants engaged in a word-by-word interaction by taking turns in generating sentences word by word. Similar to well established individual cognitive tasks, participants needed to adapt their behavior in order to respond to their co-actor's last utterance. With our experimental approach we could manipulate the interaction between participants: Either both participants had to construct a sentence with a common target word (congruent condition) or with distinct target words (incongruent condition). We further studied the relation between the interactive Word-by-Word task measures and classical individual-centered, cognitive tasks, namely the Number-Letter task, the Stop-Signal task, and the GoNogo task. In the Word-by-Word task, we found that participants had faster response times in congruent compared to incongruent trials, which replicates the primary findings of standard cognitive tasks measuring cognitive flexibility. Further, we found a significant correlation between the performance in the Word-by-Word task and the Stop-Signal task indicating that participants with a high cognitive flexibility in the Word-by-Word task also showed high inhibition control.
Project description:When Archie Cochrane reproached the medical profession for not having critical summaries of all randomised controlled trials, about 14 reports of trials were being published per day. There are now 75 trials, and 11 systematic reviews of trials, per day and a plateau in growth has not yet been reached. Although trials, reviews, and health technology assessments have undoubtedly had major impacts, the staple of medical literature synthesis remains the non-systematic narrative review. Only a small minority of trial reports are being analysed in up-to-date systematic reviews. Given the constraints, Archie Cochrane's vision will not be achieved without some serious changes in course. To meet the needs of patients, clinicians, and policymakers, unnecessary trials need to be reduced, and systematic reviews need to be prioritised. Streamlining and innovation in methods of systematic reviewing are necessary to enable valid answers to be found for most patient questions. Finally, clinicians and patients require open access to these important resources.
Project description:Previous research has suggested a role of letter location information in familiarity-detection that occurs with word stimuli, but no studies have yet investigated whether certain letter positions are weighted more heavily in the feature-based mechanism behind word familiarity-detection. Based on psycholinguistic research suggesting that first and last letters are weighted more heavily than interior letters when it comes to reading words, we investigated whether first and last letters carry more weight in the mechanism behind word familiarity that results from feature familiarization in a list-learning paradigm. In two experiments, participants studied word fragments (e.g., RA_ _ _ _OP) and later rated the familiarity of complete words (e.g., RAINDROP). We varied whether the first and last or only interior letters were present at study. Participants consistently rated test words whose fragments went unidentified at study as more familiar when the first and last letters had been studied than when only interior letters had been studied. This suggests that first and last letters contribute more strongly to the word familiarity signal than interior letters.
Project description:Media-saturated digital environments seek to influence social media users' behaviour, including through marketing. The World Health Organization has identified food marketing, including advertising for unhealthy items, as detrimental to health, and in many countries, regulation restricts such marketing and advertising to younger children. Yet regulation rarely addresses adolescents and few studies have examined their responses to social media advertising. In two studies, we examined adolescents' attention, memory and social responses to advertising posts, including interactions between product types and source of posts. We hypothesized adolescents would respond more positively to unhealthy food advertising compared to healthy food or non-food advertising, and more positively to ads shared by peers or celebrities than to ads shared by a brand. Outcomes measured were (1a) social responses (likelihood to 'share', attitude to peer); (1b) brand memory (recall, recognition) and (2) attention (eye-tracking fixation duration and count). Participants were 151 adolescent social media users (Study 1: n = 72; 13-14 years; M = 13.56 years, SD = 0.5; Study 2: n = 79, 13-17 years, M = 15.37 years, SD = 1.351). They viewed 36 fictitious Facebook profile feeds created to show age-typical content. In a 3 × 3 factorial design, each contained an advertising post that varied by content (healthy/unhealthy/non-food) and source (peer/celebrity/company). Generalised linear mixed models showed that advertisements for unhealthy food evoked significantly more positive responses, compared to non-food and healthy food, on 5 of 6 measures: adolescents were more likely to wish to 'share' unhealthy posts; rated peers more positively when they had unhealthy posts in their feeds; recalled and recognised a greater number of unhealthy food brands; and viewed unhealthy advertising posts for longer. Interactions with sources (peers, celebrities and companies) were more complex but also favoured unhealthy food advertising. Implications are that regulation of unhealthy food advertising should address adolescents and digital media.
Project description:Dementia is one among the consequences of aging, and amnesia is often one of the most common symptoms. The lack of memory, as a consequence of both "healthy" aging or neurodegenerative conditions, such as in Alzheimer's disease, has a dramatic impact on the patient's lifestyle. In fact, the inability to recall information made by a previous experience could not only alter the interaction with the environment, but also lead to a loss of identity. Mitochondria are key regulators of brain's activity; thanks to their "dynamic organelles" nature they constantly rearrange in the cell body and move along axons and dendrites, changing in dimension, shape, and location, accordingly to the cell's energy requirements. Indeed, the energy they can provide is essential to maintain synaptic plasticity and to ensure transmission through presynaptic terminals and postsynaptic spines. Stressful conditions, like the ones found in neurodegenerative diseases, seriously impair mitochondria bioenergetic, leading to both loss of proper neuronal interaction and of neuron themselves. Here, we highlighted the current knowledge about the role of mitochondria and mitochondrial dynamics in relation to neurodegenerative disorders linked to aging. Furthermore, we discuss the obstacles as well as the future perspectives aimed to enlarge our knowledge about mitochondria as target for new therapeutic strategies to slow down aging and neurodegenerative disease's symptoms.