Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Emotional regulation of fertility decision making: What is the nature and structure of "baby fever"?

Baby fever-a visceral physical and emotional desire to have a baby-is well known in popular culture, but has not been empirically studied in psychology. Different theoretical perspectives suggest that desire for a baby is either superfluous to biological sex drives and maternal instincts, a sociocultural phenomenon unrelated to biological or evolutionary forces, or an evolved adpatation for regulating birth timing, proceptive behavior, and life history trajectories. A series of studies (involving 337 undergraduate participants and 853 participants from a general population Internet sample) found that: (a) a simple scale measure could elicit ratings of desire frequency; (b) these ratings exhibited significant sex differences; (c) this sex difference was distinct from a general desire for sexual activity; and (d) these findings generalize to a more diverse online population. Factor analyses of ratings for desire elicitors/inhibitors identified three primary factors underlying baby fever. Baby fever appears to be a real phenomenon, with an underlying multifactorial structure. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Participant recruitment methods and statistical reasoning performance

Optimal Bayesian reasoning performance has reportedly been elusive, and a variety of explanations have been suggested for this situation. In a series of experiments, it is demonstrated that these difficulties with replication can be accounted for by differences in participant-sampling methodologies. Specifically, the best performances are obtained with students from top-tier, national universities who were paid for their participation. Performance drops significantly as these conditions are altered regarding inducements (e.g., using unpaid participants) or participant source (e.g., using participants from a second-tier, regional university). Honours-programme undergraduates do better than regular undergraduates within the same university, paid participation creates superior performance, and top-tier university students do better than students from lower ranked universities. Pictorial representations (supplementing problem text) usually have a slight facilitative effect across these participant manipulations. These results indicate that studies should take account of these methodological details and focus more on relative levels of performance rather than absolute performance.     

Participant recruitment methods and statistical reasoning performance

Optimal Bayesian reasoning performance has reportedly been elusive, and a variety of explanations have been suggested for this situation. In a series of experiments, it is demonstrated that these difficulties with replication can be accounted for by differences in participant-sampling methodologies. Specifically, the best performances are obtained with students from top-tier, national universities who were paid for their participation. Performance drops significantly as these conditions are altered regarding inducements (e.g., using unpaid participants) or participant source (e.g., using participants from a second-tier, regional university). Honours-programme undergraduates do better than regular undergraduates within the same university, paid participation creates superior performance, and top-tier university students do better than students from lower ranked universities. Pictorial representations (supplementing problem text) usually have a slight facilitative effect across these participant manipulations. These results indicate that studies should take account of these methodological details and focus more on relative levels of performance rather than absolute performance.     

The White–Coat Effect: Physician Attire and Perceived Authority, Friendliness, and Attractiveness

Although previous studies have evaluated the effects of attire on doctor–patient interaction, the common assumption of a tradeoff between perceptions of medical authority/ status versus trustworthiness/openness has not been established. Thirty–eight male and 40 female participants rated their perceptions of same– and opposite–gender models who all were identified as doctors, but who were wearing different attire. The results indicate that authority and trust are not opposing factors and that a white coat and formal attire are clearly superior to casual attire. Additionally, perceptions of attractiveness of same– and opposite–gender doctors were rated, finding gender differences in perceptions different from, but theoretically similar to, prior findings. For females rating male models, perceptions of authority and attractiveness appear to be related.     

Frequency interpretation of ambiguous statistical information facilitates Bayesian reasoning

The idea that naturally sampled frequencies facilitate performance in statistical reasoning tasks because they are a cognitively privileged representational format has been challenged by findings that similarly structured numbers presented as chances similarly facilitate performance, on the basis of the claim that these are technically single-event probabilities. A crucial opinion, however, is that of the research participants, who possibly interpret chances as de facto frequencies. A series of experiments here indicate that not only is performance improved by clearly presented natural frequencies, rather than chances phrasing, but also that participants who interpreted chances as frequencies, rather than as probabilities, were consistently better at statistical reasoning. This result was found across different variations of information presentation and across different populations.     

Which statistical formats facilitate what decisions? The perception and influence of different statistical information formats

Research suggesting both a superiority of frequencies over single‐event probabilities and of smaller reference classes over very large reference classes have utilized tasks that vary in computational complexity. The present research sought to simply and directly evaluate if—apart from simplifying statistical inference tasks—frequencies and small reference classes are clearer than other formats. After eliminating possible computational confounds, simple frequencies (based on small reference classes, e.g. 1/3) and to some extent relative frequencies (percentages, e.g. 33%) were perceived as clearer than absolute frequencies (based on very large reference classes, e.g. 90 million Americans) and single‐event probabilities (e.g. 0.33). Concurrently, these different formats were evaluated in terms of their relative influence. Absolute frequencies were relatively more persuasive for smaller magnitudes (e.g. 2.7 million) but less persuasive for larger magnitudes (e.g. 267 million), as compared to analogous presentations. Single‐event probabilities were judged to minimize the significance of information. Copyright © 2002 John Wiley & Sons, Ltd.     

进化频率表征对统计推理（非）灵活性的影响：认知风格和简要提示不影响贝叶斯推理

当形式操纵有助于贝叶斯推理时会有怎样的加工发生呢？一种观点认为自然取样的频率可以激发在其操作中具有相对特异性的特权表征系统。而与之相对的一种观点则认为,自然取样频率只是引发具有嵌套关系的更为普遍的加工的一种方式。比较两种观点,后者预示着只需要使用相当简要和直接的干预（如简单的指示）就能够促进推理的改善,而前者则意味着更为广泛的干预和/或更有洞见的理解才能改善推理。本研究表明,无论是短暂立即的干预,还是预存的表征偏向,抑或是表征的灵活性都不能促进被试的表现。另一方面,也有证据显示,频率论者的问题解释可以改善统计推理表现,而且有时还会增加其反应的信心。这些结果支持了特权表征系统观     

What Would It Take to Get You into an Electric Car? Consumer Perceptions and Decision Making about Electric Vehicles

Americans buy millions of vehicles every year, but research on how those decisions are made, including personality and individual difference factors, has rarely taken full advantage of psychological insights. This is an increasingly important topic because, for instance, decisions to buy electric vehicles (EVs) rather than gasoline-powered vehicles have environmental and geopolitical consequences. A series of studies reveal the very different perceptions of EVs and gas vehicles. Although vehicle choices at the aggregate level were strongly correlated with economic considerations, individual consumer choices were correlated with delay discounting rates in Study 1 but not Study 2. These studies also did not find significant correlations between EV purchase decisions and a number of other individual difference traits often thought to be factors in such decisions (i.e., social value orientation, political attitudes, environmental attitudes, preference for novel products, or an array of core social values). Regression models indicate that factors which did predict vehicle choices concerns were about the performance and range of EVs, EV prevalence in general, and beliefs about what statements different vehicle types made about their owners and the owners’ values. More attention to the vehicle-associated values and immediate performance/use issues can help to promote EV purchase decisions and subsequent improvements in environmental and political stability.