J Exp Anal Behav. 1969 May;12(3):451-61. doi: 10.1901/jeab.1969.12-451.
Two experiments studied the effects of reinforcement schedules on generalization gradients. In Exp. 1, after pigeons' responding to a vertical line was reinforced, the pigeons were tested with 10 lines differing in orientation. Reconditioning and the redetermination of generalization gradients were repeated from 8 to 11 times with the schedule of reinforcement varied in the reconditioning phase. Stable gradients could not be observed because the successive reconditionings and tests steepened the gradients and reduced responding. Experiment 2 over-came these effects by first training the birds to respond to all of the stimuli. Then, brief periods of reinforced responding to the stimulus correlated with reinforcement alternated with the presentation of the 10 lines in extinction. The development of stimulus control was studied eight times with each bird, twice with each of four schedules of reinforcement. Gradients were similar each time a schedule was imposed; the degree of control by the stimulus correlated with reinforcement varied with particular schedules. Behavioral contrast occurred when periods of reinforcement and extinction alternated and was more durable with fixed-interval, variable-interval, and variable-ratio schedules than with fixed-ratio or differential-reinforcement-of-low-rate schedules.
两项实验研究了强化程序对概括梯度的影响。在实验 1 中，当鸽子对一条垂直线的反应得到强化后，用 10 条方向不同的线对其进行测试。在重新训练阶段，改变强化程序，重复了 8 到 11 次重新训练和重新确定概括梯度。由于连续的重新训练和测试使梯度变陡，反应减少，因此无法观察到稳定的梯度。实验 2 通过首先训练鸟类对所有刺激做出反应来克服这些影响。然后，在强化与刺激相关的短暂反应期与在消退中呈现 10 条线交替出现。用每种鸟进行了 8 次，每种强化程序进行了 2 次，研究了刺激控制的发展。每次实施一个程序时，梯度都相似；刺激的控制程度与特定的程序有关。当强化和消退交替出现时，出现了行为对比，且在固定间隔、可变间隔和可变比率程序中比在固定比率或低比率差别强化程序中更为持久。
