Dept. of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.
J Exp Anal Behav. 2009 Nov;92(3):345-65. doi: 10.1901/jeab.2009.92-345.
The present research used pigeons in a three-key operant chamber and varied procedural features pertaining to both initial and terminal links of concurrent chains. The initial links randomly alternated on the side keys during a session, while the terminal links always appeared on the center key. Both equal and unequal initial-link schedules were employed, with either differential or nondifferential terminal-link stimuli across conditions. The research was designed to neutralize initial- and terminal-link spatial cues in order to gain a clearer understanding of the roles of conditioned reinforcement and delayed primary reinforcement in choice. With both equal and unequal initial links and with differential terminal-link stimuli, all pigeons reliably preferred the chain with the shorter terminal link. However, with equal initial links and nondifferential stimuli, all pigeons were indifferent. With unequal initial links and nondifferential stimuli, some pigeons were also indifferent, while others actually reversed and preferred the chain with the shorter initial link, even though it was followed by the longer terminal link. The decrease if not reversal of the previous preferences implies that preferences in concurrent chains are a function of the conditioned reinforcement afforded by terminal-link stimuli, rather than delayed primary reinforcement.
本研究在一个三键操作性条件反射室中使用鸽子，并改变与并行链的初始和终端环节相关的程序特征。在一个会话期间，初始环节随机在侧键之间交替，而终端环节始终出现在中心键上。在不同条件下使用了相等和不相等的初始环节时间表，以及跨条件的差异或非差异终端环节刺激。该研究旨在消除初始和终端环节的空间线索，以便更清楚地了解条件强化和延迟初级强化在选择中的作用。对于相等和不相等的初始环节以及差异的终端环节刺激，所有鸽子都可靠地更喜欢终端环节较短的链条。然而，对于相等的初始环节和非差异刺激，所有鸽子都漠不关心。对于不相等的初始环节和非差异刺激，一些鸽子也漠不关心，而另一些鸽子实际上反转并更喜欢初始环节较短的链条，尽管它后面跟着终端环节较长。以前偏好的减少（如果不是反转）意味着并行链中的偏好是由终端环节刺激提供的条件强化的函数，而不是延迟的初级强化。
