Mazur J E, Kralik J D
Psychology Department, Southern Connecticut State University, New Haven 06515.
J Exp Anal Behav. 1990 Jan;53(1):175-87. doi: 10.1901/jeab.1990.53-175.
This experiment measured pigeons' choices between delayed reinforcers and fixed-ratio schedules in which a force of approximately 0.48 N was needed to operate the response key. In ratio-delay conditions, subjects chose between a fixed-ratio schedule and an adjusting delay. The delay was increased or decreased several times a session in order to estimate an indifference point--a delay duration at which the two alternatives were chosen about equally often. Each ratio-delay condition was followed by a delay-delay condition in which subjects chose between the adjusting delay and a variable-time schedule, with the components of this schedule selected to match the ratio completion times of the preceding ratio-delay condition. The adjusting delays at the indifference point were longer when the alternative was a fixed-ratio schedule than when it was a matched variable-time schedule, which indicated a preference for the matched variable-time schedules over the fixed-ratio schedules. This preference increased in a nonlinear manner with increasing ratio size. This nonlinearity was inconsistent with a theory that states that indifference points for both time and ratio schedules can be predicted by multiplying the choice response-reinforcer intervals of the two types of schedules by different multiplicative constants. Two other theories, which predict nonlinear increases in preference for the matched variable-time schedules, are discussed.
本实验测量了鸽子在延迟强化物与固定比率程序之间的选择，在固定比率程序中，操作反应键需要大约0.48牛的力。在比率-延迟条件下，实验对象在固定比率程序和调整延迟之间进行选择。每次实验中延迟会增加或减少几次，以估计一个无差异点——即两种选择被选择的频率大致相等时的延迟时长。每个比率-延迟条件之后是一个延迟-延迟条件，在此条件下，实验对象在调整延迟和可变时程序之间进行选择，该程序的组成部分被选定为与前一个比率-延迟条件下的比率完成时间相匹配。当选择是固定比率程序时，无差异点处的调整延迟比当选择是匹配的可变时程序时更长，这表明相比于固定比率程序，实验对象更偏好匹配的可变时程序。随着比率大小的增加，这种偏好以非线性方式增强。这种非线性与一种理论不一致，该理论认为时间和比率程序的无差异点可以通过将两种类型程序的选择反应-强化物间隔乘以不同的乘法常数来预测。本文还讨论了另外两种预测对匹配的可变时程序偏好呈非线性增加的理论。
