Typical delay determines waiting time on periodic-food schedules: Static and dynamic tests

Pigeons and other animals soon learn to wait (pause) after food delivery on periodic-food schedules before resuming the food-rewarded response. Under most conditions the steady-state duration of the average waiting time, t, is a linear function of the typical interfood interval. We describe three experiments designed to explore the limits of this process. In all experiments, t was associated with one key color and the subsequent food delay, T, with another. In the first experiment, we compared the relation between t (waiting time) and T (food delay) under two conditions: when T was held constant, and when T was an inverse function of t. The pigeons could maximize the rate of food delivery under the first condition by setting t to a consistently short value; optimal behavior under the second condition required a linear relation with unit slope between t and T. Despite this difference in optimal policy, the pigeons in both cases showed the same linear relation, with slope less than one, between t and T. This result was confirmed in a second parametric experiment that added a third condition, in which T + t was held constant. Linear waiting appears to be an obligatory rule for pigeons. In a third experiment we arranged for a multiplicative relation between t and T (positive feedback), and produced either very short or very long waiting times as predicted by a quasi-dynamic model in which waiting time is strongly determined by the just-preceding food delay.     

Effects of alternative reinforcement sources: A reevaluation

The effects of two alternative sources of food delivery on the key-peck responding of pigeons were examined. Pecking was maintained by a variable-interval 3-min schedule. In the presence of this schedule in different conditions, either a variable-time 3-min schedule delivering food independently of responding or an equivalent schedule that required a minimum 2-s pause between a key peck and food delivery (a differential-reinforcement-of-other-behavior schedule) was added. The differential-reinforcement-of-other-behavior schedule reduced response rates more than did the variable-time schedule in most instances. The delay between a key peck and the next reinforcer consistently was longer under the differential-reinforcement-of-other-behavior schedule than under the variable-time schedule. Response rates and median delay between responses and reinforcers were negatively correlated. These results contradict earlier conclusions about the behavioral effects of alternative reinforcement. They suggest that an interpretation in terms of response–reinforcer contiguity is consistent with the data.     

Discrimination learning in a foraging situation

Rats were allowed to forage in a simulated natural environment made up of eight food sources (patches) each containing a fixed number of pellets. Two of the eight contained an extra supply of peanuts. The peanut patches were signaled by an olfactory/visual cue located at the bottom of the ladder leading to the patch. In successive phases the number of sessions per day, height of the patches, and availability of peanuts were manipulated. Subjects showed evidence of discrimination learning under these conditions, although the degree of discriminatory behavior varied as a function of environmental manipulations. Assessment of behavior within foraging sessions showed that subjects systematically changed their patterns of utilization of patches across time. Sampling or exploration, as well as food reinforcement, seem implicated in these results.     

儿童读物中的性别研究——对我国小学语文教材所做的统计分析

每个民族,每种社会都有其特有的传统文化。从人出生的那一天起,这种传统的文化就开始影响他,塑造他。除了家庭和一般的社会环境对儿童的社会化有影响外,学校教育同样是孩子们社会化不可忽视的又一个重要因素。学校教育能够非常系统而又高效率地把社会规范、价值观,道德、知识,技能灌输给学生。这样,学校教育在影响儿童社会化的方向和内容方面的作用便是显而易见的了。对小学课本的     

历史的创造者与历史的推进者

历史的创造者与历史的推进者是两个既有区别又有联系的概念。所谓历史的创造者,指的是引起和推动人类社会运动发展的力量,不管运动的方向是正向的还是逆向的。然而推动人类社会前进的力量,是历史的推进者,而阻碍人类社会前进的力量,便是历史的非推进者。历史的推进者推动历史向前发展,是通过他们在人类社会中创造或协助生产物质财富和精神财富,改进人类社会的面貌实现     

试论马克思主义哲学体系的建构原则

1、实践性原则。强化和发挥马克思主义哲学不仅理论地解释世界而且实践地改变世界的社会功能。在提高哲学理性思维的基础上,从根本上增强和强化人们从事理性批判和理想建构的能力,为人们更加自觉有效地从事实践批判和实践建构提供哲学的工具     

关于人的科学系统

人的问题(确切地说,是一种问题的综合)在现代科学知识中日益被提到首位,是与其发展的前途有关的。“人”的现象的独一无二性,是以自然界和社会的规律的统一性为特征的,这就给人创造了作为科学研究的客体的特殊地位。在这一领域里,把社会科学、自然科学和部分技术科学的兴趣紧密地结合在一起。安纳耶夫已令人信服地指出了这一点。用社会科学来研究,人是任何一个社会系统的主要组成部分,是社会的质的基本的