Yawns Are Cool

Although we yawn each and every day, most people have little understanding of why we do it. In fact, the function of yawning has remained mysterious for centuries, even among scientists, and this has only changed quite recently. Contrary to what people have believed for a long time, it is now understood that yawns have nothing to do with breathing or the amount of oxygen we are taking in. Instead, new and growing research has revealed that yawns serve as a brain cooling mechanism. This new perspective on yawning as a response to elevated brain temperature has transformed our understanding of this commonly overlooked and misinterpreted behavior. This information might be useful for treating and diagnosing medical conditions that are accompanied by frequent yawning and for monitoring and improving our brain’s performance throughout the day

Winner and Loser Effects in Major League Baseball Double Headers

Across the animal kingdom it has been observed that outcomes of conflicts are influenced by past experiences, whereby previous winners are likely to keep winning and losers are likely to lose again. These so-called “winner and loser effects” are hypothesized to result from factors such as information acquisition and endocrine responses following the initial bouts. This paper applies the understanding of this phenomenon to a novel domain: patterns of winning and losing in Major League Baseball (MLB) double headers. By accessing archival data available from www.espn.com, we report on the incidence of a single team winning both games (sweeps) versus each team winning one game (splits) in MLB double headers over the last 13 years. Consistent with previous research on winner and loser effects, we show that sweeps are significantly more common than splits and that there is a home field advantage in this context. Results indicate that disparity in opponent quality or skill, as measured by the difference in team records outside the double header match, was not a significant predictor of whether the outcome resulted in a split or a sweep. In contrast to our hypotheses, there was no difference in the margin of victory in games between sweeps and splits. Overall these results add to the existing literature on winner and loser effects, provide a framework for pursuing further research in MLB, and suggest that winner and loser effects may be present across a variety of other forms of human social interaction

Acetaminophen Potentiates Fear Processing: A Comparison Between Ancestral and Modern Threats

The painkilling medication acetaminophen produces a variety of unintended psychological effects. In particular, it has been shown to diminish varied forms of psychological distress by attenuating neural activity in the cerebral cortex and enhancing the signaling of serotonin. As a result, this over-the-counter medication appears to dampen overall affective processing and has been termed “an all-purpose emotion reliever.” However, this drug may not necessarily modify all emotions in the same manner. Specifically, fear processing occurs rapidly within the amygdala and is governed by serotonin. Thus, by blunting cortical activity and facilitating serotonergic action, acetaminophen could in fact potentiate reactions to threatening stimuli. This study intersects with the fields of evolutionary psychology and psychopharmacology by investigating whether acetaminophen modulates responses to fear-inducing stimuli that vary in ancestral relevance. We hypothesized that the more subcortical and prewired mechanisms controlling responses to recurring ancestral threats (snakes and spiders) would be more affected by this drug compared to learned threats of modern environments (handguns and hypodermic needles). In a double-blind placebo-controlled design (N = 94), acetaminophen significantly enhanced participants’ evaluations and emotional reactions to threatening stimuli. In addition, ancestral threats were rated as both significantly more negative and emotionally arousing compared to modern threats. Contrary to our predictions, however, acetaminophen altered affective responses to ancestral and modern threats in a highly similar manner. We conclude that acetaminophen does not blunt overall affective processing, and call for further evolutionary-based research examining the various psychoactive effects of this commonly consumed over-the-counter painkiller

The Successful Exploitation of Urban Environments by the Golden Silk Spider, Nephila clavipes (Araneae, Nephilidae)

Urbanization typically leads to habitat destruction producing negative effects for native species, but some species may exploit these settings. This concept was investigated in the golden silk spider (Nephila clavipes), a large, formidable spider that commonly inhabits forest edges as well as open spaces in urban environments throughout its vast geographic range. Here, we compared variation of N. clavipes success as measured by body size, web size and web positioning along an urban–rural gradient in southern Florida. From morphological measurements collected in the field, urban spiders had 60% longer legs and 35% longer bodies than both park and rural spiders. Furthermore, webs of urban spiders were considerably larger and constructed significantly further from the ground than those of park and rural habitats. The combined observations of body size, web measurements and prominent web placement suggest that N. clavipesare successful exploiters of urban environments relative to park and rural settings in southern Florida. Although previous research has generally focused on the negative aspects of urbanization on animal welfare, this study provides evidence suggesting N. clavipes might benefit from these environmental changes

Acetaminophen Does Not Alter the Early Processing of Emotional Facial Expressions: An Eye-tracking Study

A growing body of research has uncovered that acetaminophen, the most commonly used over-the-counter painkilling drug in the United States, produces a number of unintended psychological effects. In particular, recent studies show that acetaminophen blunts a variety of adaptive affective and cognitive processes, including our sensitivity to painful social experiences and subjective responses to emotional stimuli. Using a double-blind placebo-controlled study, here we examined whether acetaminophen alters the early visual processing of emotional facial expressions. Participants consumed 1000 mg of acetaminophen, or a matched placebo, prior to performing a delayed disengagement task with different facial expressions. Specifically, we used eye-tracking software to assess the latency to look away from neutral, happy, and angry faces. Based on prior research, we hypothesized that acetaminophen would reduce the typical delay in disengaging from emotional expressions. Our findings showed a significant main effect of facial expression, with happy faces producing the greatest delay, but there was no difference in response between the acetaminophen and placebo conditions. These results indicate that acetaminophen does not alter our initial assessment of emotional facial expressions, but we suggest further research be conducted to examine how this widely consumed drug may alter the detection and perception of emotions in others

A Thermal Window for Yawning in Humans: Yawning as a Brain Cooling Mechanism

The thermoregulatory theory of yawning posits that yawns function to cool the brain in part due to counter-current heat exchange with the deep inhalation of ambient air. Consequently, yawning should be constrained to an optimal thermal zone or range of temperature, i.e., a thermal window, in which we should expect a lower frequency at extreme temperatures. Previous research shows that yawn frequency diminishes as ambient temperatures rise and approach body temperature, but a lower bound to the thermal window has not been demonstrated. To test this, a total of 120 pedestrians were sampled for susceptibly to self-reported yawn contagion during distinct temperature ranges and seasons (winter: 1.4 °C, n = 60; summer: 19.4 °C, n = 60). As predicted, the proportion of pedestrians reporting yawning was significantly lower during winter than in summer (18.3% vs. 41.7%), with temperature being the only significant predictor of these differences across seasons. The underlying mechanism for yawning in humans, both spontaneous and contagious, appears to be involved in brain thermoregulation

Bacterial cooperation through horizontal gene transfer

Cooperation exists across all scales of biological organization, from genetic elements to complex human societies. Bacteria cooperate by secreting molecules that benefit all individuals in the population (i.e., public goods). Genes associated with cooperation can spread among strains through horizontal gene transfer (HGT). We discuss recent findings on how HGT mediated by mobile genetic elements promotes bacterial cooperation, how cooperation in turn can facilitate more frequent HGT, and how the act of HGT itself may be considered as a form of cooperation. We propose that HGT is an important enforcement mechanism in bacterial populations, thus creating a positive feedback loop that further maintains cooperation. To enforce cooperation, HGT serves as a homogenizing force by transferring the cooperative trait, effectively eliminating cheaters

Protocol for an agent-based model of recombination in bacteria playing a public goods game

Agent-based models are composed of individual agents coded for traits, such as cooperation and cheating, that interact in a virtual world based on defined rules. Here, we describe the use of an agent-based model of homologous recombination in bacteria playing a public goods game. We describe steps for software installation, setting model parameters, running and testing models, and visualization and statistical analysis. This protocol is useful in analyses of horizontal gene transfer, bacterial sociobiology, and game theory. For complete details on the use and execution of this protocol, please refer to Lee et al.

People that score high on psychopathic traits are less likely to yawn contagiously

Considerable variation exists in the contagiousness of yawning, and numerous studies have been conducted to investigate the proximate mechanisms involved in this response. Yet, findings within the psychological literature are mixed, with many studies conducted on relatively small and homogeneous samples. Here, we aimed to replicate and extend upon research suggesting a negative relationship between psychopathic traits and yawn contagion in community samples. In the largest study of contagious yawning to date (N = 458), which included both university students and community members from across 50 nationalities, participants completed an online study in which they self-reported on their yawn contagion to a video stimulus and completed four measures of psychopathy: the primary and secondary psychopathy scales from the Levenson Self-Report Psychopathy Scale (LSRPS), the psychopathy construct from the Dirty Dozen, and the Psychopathic Personality Traits Scale (PPTS). Results support previous findings in that participants that yawned contagiously tended to score lower on the combined and primary measures of psychopathy. That said, tiredness was the strongest predictor across all models. These findings align with functional accounts of spontaneous and contagious yawning and a generalized impairment in overall patterns of behavioral contagion and biobehavioral synchrony among people high in psychopathic traits

A presença em Cabo Verde de objectos adquiridos no exterior pela diáspora – Visão dos emigrantes residentes em Portugal

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Antropologia – Cultura Material e ConsumosTrata-se aqui de abordar os impactos da presença em Cabo Verde de objectos adquiridos no exterior pela diáspora, na modificação, criação, assim como na difusão da cultura de consumo, procurando evidenciar algumas características que demonstram tratar de assuntos relevantes no campo dos estudos antropológicos. Para tal, escolhi como objecto de estudo a comunidade cabo-verdiana residente na cidade de Lisboa, reconhecendo-a como uma das comunidades de emigrantes com uma permanência mais prolongada em Portugal, mas que mantém ainda contactos com os seus familiares e traços culturais de origem muito acentuados. Este trabalho nasce da necessidade de aperfeiçoar os estudos ligados à cultura material e consumo na nova forma de produção acelerada, ligada a uma sociedade cada vez mais consumista. A partir delas, os indivíduos comunicam e sentem-se incluídos no colectivo. O acto de possuir ou desejar bens torna-os distintos ou iguais aos demais membros de seu grupo sociocultural. Pretende-se compreender a existência de uma relação de interdependência complexa entre contextos culturais e práticas de consumo. O porquê da valorização dos produtos levados do estrangeiro através da diáspora constitui um tema complexo e que traz um número elevado de questões em torno de consumo na nova conjuntura industrial, que torna-se cada vez mais globalizada, criando diferenças entre classes, grupos e a sociedade em geral. Este estudo procura também explicar até que ponto a cultura de consumo é significativa para definir a identidade de cada indivíduo, ligando a questão do “ter” à questão do “ser”. Estas interrogações, e muitas outras, estiveram na base de uma primeira reflexão sobre o objecto da investigação que está na base desta dissertação