Economic substitutability of electrical brain stimulation, food, and water.

Concurrent variable-ratio schedules of electrical brain stimulation, food, and water were paired in various combinations as reinforcement of rats' lever presses. Relative prices of the concurrent reinforcers were varied by changing the ratio of the response requirements on the two levers. Economic substitutability, measured by the sensitivity of response ratio to changes in relative price, was highest with brain stimulation reinforcement of presses on both levers and lowest with food reinforcement of presses on one lever and water reinforcement of presses on the other. Substitutability with brain stimulation reinforcement of presses on one lever and either food or water reinforcement for presses on the other was about as high as with brain stimulation for presses on both levers. Electrical brain stimulation for rats may thus serve as an economic substitute for two reinforcers, neither of which is substitutable for the other.     

Testing whether independent treatment groups have equal medians

The paper suggests new methods for comparing the medians corresponding to independent treatment groups. The procedures are based on the Harrell-Davis estimator in conjunction with a slight modification and extension of the bootstrap calibration technique suggested by Loh. Alternatives to the Harrell-Davis estimator are briefly discussed. For the special case of two treatment groups, the proposed procedure always had more power than the Fligner-Rust solution, as well as the procedure examined by Wilcox and Charlin. Included is an illustration, using real data, that comparing medians, rather than means, can yield a substantially different conclusion as to whether two distributions differ in terms of some measure of central location.     

Foraging in a simulated natural environment: There's a rat loose in the lab

Rats were required to earn their food in a large room having nine boxes placed in it, each of which contained food buried in sand. In different phases of the experiment the amount of time allowed for foraging, the amount of food available in each food patch, and the location of the different available amounts were varied. The rats exhaustively sampled all patches each session but seemed to have fairly strong preferences for certain locations over others. If position preferences were for patches containing small amounts of food, the sensitivity to amount available was increased so that when location was compensated for, a pattern of optimal foraging was evident. The importance of environmental constraints in producing optimal behavior and the relation of the observed behavior to laboratory findings are discussed.     

Effects of food deprivation and reinforcement magnitude on conditioned suppression

In Experiment I, the responding of rats lever pressing on a variable-interval schedule for sucrose solution was partially suppressed by a variable duration conditioned stimulus followed by shock. When food deprivation was increased, response rates during and before the conditioned stimulus increased monotonically. Varying the concentration of sucrose across blocks of sessions or from session to session in a semi-random sequence had little effect on response rates either before or during the conditioned stimulus. With a fixed sequence of increasing concentrations across a five-session block, increased concentration produced much more rapid increases in response rates before than during the conditioned stimulus. In Experiment II, rats were presented with the same sequence of increasing concentrations across a five-session block. When tested at 80% body weight, response rates increased rapidly as concentration increased, but at 100%, body-weight rates increased only slightly. The effect of a change in body weight in Experiment II thus mimicked the effect of the conditioned stimulus in the latter part of Experiment I. These findings support the view that the effect of a pre-aversive conditioned stimulus is similar to that of a change in food deprivation, but unlike that of a change in reinforcement magnitude.     

Food deprivation induces conspecific pup-killing in mice

Periods of 24 to 48 hours of food deprivation reliably induced pup-killing in 30–50% of non-killer male mice. The behavior was prevented by previous experience with young and did not perseverate to non-deprived states. Castrated males and intact females also exhibited pup-killing following food deprivation, suggesting that the behavior is neither sexdependent nor related to the presence of testosterone. The findings are discussed in terms of their relationship to predatory behaviors and population dynamics.     

Sweet Necessities: Food, Sex, and Saint Augustine

Central to Augustine's understanding of rightly ordered sexuality is his belief that the pleasure of the act should not be separated from its good (procreation). It is useful to observe that he reasons in a similar way about eating: that the pleasure of eating should not be separated from its good (nourishment). Inadequacies in his understanding of the purpose of food and eating may be instructive when we think about inadequacies in his understanding of sex. If there is more to food than he imagines, the same may be true of sex. Correcting for such inadequacies may also help correct for the (inadvertent) way in which his understanding of the purpose of sex may seem to legitimize technologies of assisted reproduction.     

Muslims and Meat‐Eating

Religious thinking, including among Muslims, connects food and sex, as well as women and animals; both food practices and gender norms are significant for communal identity and boundary construction. Female bodies (properly covered) and animal bodies (properly slaughtered) serve as potent signifiers of Muslim identity, as patriarchal thought sustains the hierarchical cosmologies that affirm male dominance in family and society and allow humans to view animals as legitimately subject to human violence. I argue that Muslims in the industrialized West—especially those concerned with gender justice—ought to be vegetarians and that feminist ethics provides underutilized resources for Muslim thinking about ethics generally and food ethics in particular. Much contemporary Muslim thought about meat is at least as concerned with demonstrating the primacy of “Islamic” identity as with general questions about the formation of virtuous subjects and the development of good societies. This defensive concern with religious authenticity poses a stumbling block to richer thinking. Engagement with non‐Islamic (though not “un‐Islamic”) ethics provides a model for productive dialogue and engagement among parties who disagree about basic presumptions but agree on desirable outcomes, including the development of individuals' ethical sensibilities and the construction of societies conducive to human flourishing.     

规范错觉对外出就餐中食物浪费的影响：心理机制与应对策略

规范错觉是指个体的规范感知与实际存在于群体中的社会规范之间存在差异, 规范错觉影响了社会生活的方方面面。对957份问卷调查的分析显示, 人们普遍高估了他人的食物浪费(行为错觉)以及对浪费的赞同程度(态度错觉), 而这两种错觉又加剧了人们自身的浪费行为。中介效应检验显示, 印象管理中的社交性维度部分中介了两种错觉与浪费行为间的关系。两个随机对照实验进一步检验了描述性(命令性)规范信息对行为(态度)错觉的影响, 结果发现, 描述性规范信息降低了行为错觉, 并通过社交性减少了浪费行为; 而命令性规范信息并不改变态度错觉本身, 但通过降低态度错觉对浪费的影响而减少了浪费行为。上述结果意味着两种规范信息尽管高度相似, 但其作用机制却可能不同, 同时这一发现也为政策制定者提出了两种干预途径。     

中国人限制性饮食和食物渴求的认知神经机制

物质丰富的时代, 如何抵御美味食物线索带来的食物渴求, 并限制饮食从而保持健康成为人们关注的重要话题之一。近年来, 国内学者为了探讨节食成功的原因, 创建中国食物图片库, 考察限制性饮食的认知神经机制, 以及成功和失败限制性饮食者的脑机制差异; 开展了特质食物渴求及中国特色的辣食渴求的认知神经研究。对推进饮食行为研究的理论发展, 也为肥胖、饮食失调等健康干预工作提供重要支持。     

Evaluation of a finger prompt variation in the treatment of pediatric feeding disorders

Children with feeding disorders often engage in refusal behavior to escape or avoid eating. Escape extinction combined with reinforcement is a well-established intervention to treat food refusal. Physical guidance procedures (e.g., jaw prompt, finger prompt) have been shown to increase food acceptance and decrease inappropriate mealtime behavior when more commonly employed escape extinction (e.g., nonremoval of the spoon) procedures are ineffective. The finger prompt, however, has not been extensively evaluated as a treatment adjunct to target food refusal, thus necessitating further examination. The purpose of this prospective study was to assess a variation of a finger prompt procedure to treat food refusal and to assess caregivers' acceptability of the procedure. Three children age 1 to 4 years admitted to an intensive feeding disorders program and their caregivers participated. The finger prompt was effective in increasing bite acceptance across all participants and decreasing or maintaining low levels of inappropriate behavior for 2 participants. The procedure was also acceptable to all caregivers.