Effects of the discriminability of alternatives in three-alternative concurrent-schedule performance

Six pigeons were trained on two- and three-alternative concurrent schedules in which the alternatives were signaled by different wavelengths of light on the main pecking key. The schedules were arranged according to a switching-key procedure in which pecks on a white side key produced a 3-s blackout and, intermittently, a change in the variable-interval schedule of food programmed on the main (center) key after the blackout. In Part 1, a two-alternative concurrent variable-interval schedule was arranged in which the alternatives were signaled by 560 nm and 630 nm. Parts 2 and 3 arranged three-alternative concurrent variable-interval schedules with the alternatives signaled by 560 nm, 600 nm, and 630 nm (Part 2) and 560 nm, 623 nm, and 630 nm (Part 3). Within each part, the relative rate of food reinforcers available on the alternatives was varied across a wide range. In all parts of the experiment, the ratios of responses emitted between pairs of alternatives were more extreme than the ratios of reinforcers obtained on the pairs of alternatives, a result termed overmatching. In Parts 2 and 3, generalized matching sensitivities between pairs of alternatives were found to be higher when the reinforcer rate on the third alternative was low than when it was high—an apparent failure of the constant-ratio rule. The data were well described by an extension of the Davison and Jenkins (1985) model, which assumes differing discriminabilities between concurrent-schedule alternatives in combination with a punishing effect of blackout following changeovers.     

Apocalyptic relevance

In their book, Relevance, Sperber and Wilson make an important contribution towards constructing a credible theory of this unforthcoming notion. All is not clear sailing, however. If it is accepted as a condition on the adequacy of any account of relevance that it not be derivable either that nothing is relevant to anything or that everything is relevant to everything, it can be shown that Sperber and Wilson come close to violating the condition.     

Protoalgebraic Gentzen Systems and the Cut Rule

In this paper we show that, in Gentzen systems, there is a close relation between two of the main characters in algebraic logic and proof theory respectively: protoalgebraicity and the cut rule. We give certain conditions under which a Gentzen system is protoalgebraic if and only if it possesses the cut rule. To obtain this equivalence, we limit our discussion to what we call regular sequent calculi, which are those comprising some of the structural rules and some logical rules, in a sense we make precise. We note that this restricted set of rules includes all the usual rules in the literature. We also stress the difference between the case of two-sided sequents and the case of many-sided sequents, in which more conditions are needed.     

小学儿童亲社会价值取向发展的实验研究

本研究采用问卷法对小学二年级、四年级和六年级学生共337人进行研究.结果表明,小学二、四、六年级儿童的亲社会价值取向在某些情境中存在差异.男女儿童的价值取向存在显著差异,女性比男性更加明确自己的价值取向,更愿意对受难者给予直接的关怀和帮助.不同价值取向的儿童在教师评价中表现出显著的亲社会行为差异.     

公民情感的法律确认:立法伦理的应有视域

公民情感的法律确认是基于公民行为选择中两难困境的应对之策。这一立法实践有其学理和历史的依据。将公民情感的法律确认纳入立法伦理的视域,将不仅有助于良法的创制,而且还因其逻辑地排除了司法活动的情感障碍和为公民奠定了守法的情感基础而有利于良法的有效实现。     

决策过程中的记忆可提取性效用

记忆的可提取性效用是人们在评估过往事件时所感受到的愉悦或满意程度, 这种评估建立在人们从记忆中提取出的信息基础上。研究发现, 人们对过往事件进行评估时会出现违反效用最大化原则的决策, 主要表现在三个实验现象上：峰终律、时长忽视和违背单调叠加性。研究者多从原型判断的角度去理解这些现象, 但可提取性效用是否还有其他内在机制仍然有待进一步研究。     

Counting to Infinity: Does Learning the Syntax of the Count List Predict Knowledge That Numbers Are Infinite?

By around the age of 5½, many children in the United States judge that numbers never end, and that it is always possible to add 1 to a set. These same children also generally perform well when asked to label the quantity of a set after one object is added (e.g., judging that a set labeled “five” should now be “six”). These findings suggest that children have implicit knowledge of the “successor function”: Every natural number, n, has a successor, n + 1. Here, we explored how children discover this recursive function, and whether it might be related to discovering productive morphological rules that govern language-specific counting routines (e.g., the rules in English that represent base-10 structure). We tested 4- and 5-year-old children’s knowledge of counting with three tasks, which we then related to (a) children’s belief that 1 can always be added to any number (the successor function) and (b) their belief that numbers never end (infinity). Children who exhibited knowledge of a productive counting rule were significantly more likely to believe that numbers are infinite (i.e., there is no largest number), though such counting knowledge was not directly linked to knowledge of the successor function, per se. Also, our findings suggest that children as young as 4 years of age are able to implement rules defined over their verbal count list to generate number words beyond their spontaneous counting range, an insight which may support reasoning over their acquired verbal count sequence to infer that numbers never end.     

Children's knowledge of deceptive gaze cues and its relation to their actual lying behavior

Eye gaze plays a pivotal role during communication. When interacting deceptively, it is commonly believed that the deceiver will break eye contact and look downward. We examined whether children’s gaze behavior when lying is consistent with this belief. In our study, 7- to 15-year-olds and adults answered questions truthfully (Truth questions) or untruthfully (Lie questions) or answered questions that required thinking (Think questions). Younger participants (7- and 9-year-olds) broke eye contact significantly more when lying compared with other conditions. Also, their averted gaze when lying differed significantly from their gaze display in other conditions. In contrast, older participants did not differ in their durations of eye contact or averted gaze across conditions. Participants’ knowledge about eye gaze and deception increased with age. This knowledge significantly predicted their actual gaze behavior when lying. These findings suggest that with increased age, participants became increasingly sophisticated in their use of display rule knowledge to conceal their deception.