Spetch M L, Dunn R
J Exp Anal Behav. 1987 Jan;47(1):57-72. doi: 10.1901/jeab.1987.47-57.
Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement.
采用并发链程序研究了鸽子在混合强化程序中对提供不同强化百分比的选项之间的选择。在实验1中，选项是终端链程序，其强化延迟和强化幅度相等，但提供不同的强化百分比，其中一个程序提供强化的可靠性是另一个程序的两倍。所有鸽子都更喜欢更可靠的程序，它们的偏好水平并没有受到绝对百分比值变化或强化幅度变化的系统性影响。在实验2中，随着终端链持续时间的增加，对提供100%强化的程序相对于提供33%强化的程序的偏好系统性增加。相反，随着初始链持续时间的增加，偏好系统性降低。实验3研究了在强化百分比相等但强化延迟不等的情况下的选择。对较短强化延迟的偏好并没有受到强化绝对百分比变化的系统性影响。结果的总体模式支持了基于将延迟减少假设扩展到涉及百分比强化混合程序的选择程序的预测。
