Thresholds for movement direction: Two directions are less detectable than one

Thresholds for detecting movement direction were measured for two different types of dynamic dot display; first, one in which all dots moved upwards, and secondly, one in which half the dots moved upwards and half moved downwards. Direction sensitivity was found to be worse for the stimulus containing two simultaneous directions of motion than for the stimulus in one direction. These data are taken as evidence of some form of competition, or AND-NOT gating, between the outputs of direction-specific analysers during threshold determination.     

Incentive learning following reinforcer devaluation is not conditional upon the motivational state during re-exposure

Three experiments analysed the effect of re-exposure to the reinforcer following aversion conditioning on instrumental performance. In the first experiment, groups of hungry and thirsty rats were trained to press a lever for sucrose, which was then followed by a single injection of lithium chloride (LiCl). On the following day, half the animals in each motivational condition received re-exposure to the sucrose solution; the remaining animals were not re-exposed. In a subsequent extinction test animals that had received re-exposure to the sucrose pressed less than animals that were not re-exposed. Moreover, the effect of re-exposure to the sucrose solution was similar following training under hunger and thirst. In the remaining studies, animals were trained to lever-press for sucrose while either hungry or thirsty. They were then injected with LiCl and re-exposed to the sucrose while either hungry or thirsty, i.e. in the same or different motivational state employed during training, or they were not re-exposed. Lever pressing was then tested in extinction in the training motivational state. As in the first experiment, re-exposure to the reinforcer after aversion conditioning enhanced the magnitude of the reinforcer devaluation effect. More importantly, re-exposure to the sucrose produced a comparable effect on instrumental performance, whether re-exposure was given under the same or different motivational state to that employed during training. These results suggest that the instrumental reinforcer devaluation effect depends upon a process of incentive learning, but that this process is not conditional upon the current motivational state of the animal.     

Antibiotic Use and the Demise of Husbandry

Numerous ethical issues have emerged from the industrialization of animal agriculture. Those issues ultimately rest in large measure upon overuse of antibiotics. How this has occurred is discussed in detail in this paper.     

Lefort as a reader of Machiavelli and Marx

This essay begins with the contention that phenomenology has taken a “hermeneutic turn,” “the things themselves” are always already interpreted. Philosophers often elaborate their own positions through a “reading” of the works of other philosophers. This is the case for Claude Lefort. Through his interpretive reading of the works of Machiavelli one sees the origin of Lefort’s idea of the autonomy and the anonymity of the political and thus his notion of political modernity. In tracing the evolution of Lefort’s relationship to Marx, we witness the process by which he disengages himself from his early “enchantment” with the works of Marx and the idea of the proletariat as a class bearing universal interest. Ultimately he criticizes Marx for his attempt to derive the political from the dimension of the social. This issues in his theory of totalitarianism as the attempt of a regime to close in on itself, thus denying any gesture to the dimension of the other.     

Japanese preschoolers’ evaluation of circular and non-circular arguments

Observational and experimental data have revealed that preschoolers possess some argumentation skills, both in the production and the evaluation of arguments. However, these skills might have been fostered by the particular cultural context of Western middle- and upper-classes families, to which most children studied belong. Some data suggests that children in other cultures possess at least some of these skills, but no experimental data had been gathered in Eastern cultures. These cultures are supposed to frown on argumentation, and might thus be less conducive to the early development of argumentation skills. We test the emergence of argument evaluation skills in Japanese 5-year-olds by presenting them with a choice between endorsing a strong, perceptual argument, and a weak, circular argument. A first experiment revealed a trend in the direction of the strong argument. A second experiment that addresses some methodological concerns of the first demonstrates a significant tendency to follow the strong argument. These results are similar to those previously gathered in two other cultures (Swiss and Maya), and suggest that some basic argumentation skills are early developing across cultures.     

Double effect,all over again: The case of Sister Margaret McBride

As media reports have made widely known, in November 2009, the ethics committee of St. Joseph’s Hospital in Phoenix, Arizona, permitted the abortion of an eleven-week-old fetus in order to save the life of its mother. This woman was suffering from acute pulmonary hypertension, which her doctors judged would prove fatal for both her and her previable child. The ethics committee believed abortion to be permitted in this case under the so-called principle of double effect, but Thomas J. Olmsted, the bishop of Phoenix, disagreed with the committee and pronounced its chair, Sister Margaret McBride, excommunicated latae sententiae, “by the very commission of the act.” In this article, I take the much discussed Phoenix case as an occasion to subject the principle of double effect to another round of philosophical scrutiny. In particular, I examine the third condition of the principle in its textbook formulation, namely, that the evil effect in question may not be the means to the good effect. My argument, in brief, is that the textbook formulation of the principle does not withstand philosophical scrutiny. Nevertheless, in the end, I do not claim that we should then “do away” with the principle altogether. Instead, we do well to understand it within the context of casuistry, the tradition of moral reasoning from which it issued.