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861.
862.
The metaphor of the behavior stream provides a framework for studying the effects of response-independent food presentations intruded into an environment in which operant responding of pigeons was maintained by variable-interval schedules. In the first two experiments, response rates were reduced when response-independent food was intruded during the variable-interval schedule according to a concomitantly present fixed-time schedule. These reductions were not always an orderly function of the percentage of response-dependent food. Negatively accelerated patterns of key pecking across the fixed-time period occurred in Experiment 1 under the concomitant fixed-time variable-interval schedules. In Experiment 2, positively and negatively accelerated and linear response patterns occurred even though the schedules were similar to those used in Experiment 1. The variable findings in the first two experiments led to three subsequent experiments that were designed to further illuminate the controlling variables of the effects of intruded response-independent events. When the fixed and variable schedules were correlated with distinct operanda by employing a concurrent fixed-interval variable-interval schedule (Experiment 3) or with distinct discriminative stimuli (Experiments 4 and 5), negatively accelerated response patterns were obtained. Even in these latter cases, however, the response patterns were a joint function of the physical separation of the two schedules and the ratio of fixed-time or fixed-interval to variable-interval schedule food presentations. The results of the five experiments are discussed in terms of the contributions of both reinforcement variables and discriminative stimuli in determining the effects of intruding response-independent food into a stream of operant behavior. 相似文献
863.
864.
In this target article the following hypotheses are discussed: (1) Colour is autonomous: a perceptuolinguistic and behavioural universal. (2) It is completely described by three independent attributes: hue, brightness, and saturation: (3) Phenomenologically and psychophysically there are four unique hues: red, green, blue, and yellow; (4) The unique hues are underpinned by two opponent psychophysical and/or neuronal channels: red/green, blue/yellow. The relevant literature is reviewed. We conclude: (i) Psychophysics and neurophysiology fail to set nontrivial constraints on colour categorization. (ii) Linguistic evidence provides no grounds for the universality of basic colour categories. (iii) Neither the opponent hues red/green, blue/yellow nor hue, brightness, and saturation are intrinsic to a universal concept of colour. (iv) Colour is not autonomous. 相似文献
865.
866.
古突厥碑铭中提到的中国和吐蕃沃尔夫冈—埃克哈特·夏利普著欣慰译古突厥碑铭大体上写于8世纪初和9世纪中叶之间,是一种突厥语的最初证明,碑文包括占统治地位的突厥人[1]和后来的回纥人———他们也说突厥语———与居住在他们的el———即他们的草原帝国———... 相似文献
867.
为健康服务的植物生物技术罗杰·贝希伊丽莎白·谢尔-弗里德里克约瑟夫·谢尔著乔亚译为科学技术方法辨护穷国越来越穷,富国越来越富,这是一句口头禅。迄今的事实向我们说明,依靠人类的团结来解决这样的困境,不啻幻想。但这是一个实际而急迫的大问题。发达世界依仗其... 相似文献
868.
870.
对中西医结合的思考福建中医学院中医系(福州350003)陈峰指导老师戴春福1中西医结合方法的精髓———考察中医建立理论的方法,研究其至今仍具有生命力的原因中医仅用阴阳气血津液以及五脏六腑等几个基本概念,就可以达到对人体这个极其复杂有机体总体上的正确... 相似文献