Landon Jason, Davison Michael, Elliffe Douglas
Department of Psychology, University of Auckland, New Zealand.
J Exp Anal Behav. 2002 May;77(3):257-71. doi: 10.1901/jeab.2002.77-257.
Five pigeons were trained on concurrent variable-interval schedules in a switching-key procedure. The overall rate of reinforcement was constant in all conditions, and the ratios of reinforcers obtainable on the two alternatives were varied over seven levels. Each condition remained in effect for 65 sessions, and the last 50 sessions of data from each condition were analyzed. The most recently obtained reinforcer had the largest effect on current preference, but each of the eight previously obtained reinforcers had a small measurable effect. These effects were larger when the reinforcer ratio was more extreme. A longer term effect of reinforcement was also evident, which changed as a function of the reinforcer ratio arranged. More local analyses showed regularities at a reinforcer-by-reinforcer level and large transient movements in preference toward the just-reinforced alternative immediately following reinforcers, followed by a return to stable levels that were related to the reinforcer ratio in effect. The present data suggest that the variables that control choice have both short- and long-term effects and that the short-term effects increased when the reinforcer ratios arranged were more extreme.
五只鸽子在一个切换键程序中接受了并发可变间隔时间表的训练。在所有条件下，总体强化率是恒定的，并且在两个选项上可获得的强化物比例在七个水平上变化。每个条件持续65个时段，并对每个条件下最后50个时段的数据进行分析。最近获得的强化物对当前偏好的影响最大，但之前获得的八个强化物中的每一个都有一个小的可测量影响。当强化物比例更极端时，这些影响更大。强化的长期影响也很明显，它随着所安排的强化物比例而变化。更局部的分析显示了在逐个强化物水平上的规律性，以及强化后立即对刚强化的选项的偏好出现大的瞬时变化，随后回到与有效强化物比例相关的稳定水平。目前的数据表明，控制选择的变量具有短期和长期影响，并且当所安排的强化物比例更极端时，短期影响会增加。
