Ito M, Nakamura K
Department of Psychology, Osaka City University, Japan.
J Exp Anal Behav. 1998 Jan;69(1):87-102. doi: 10.1901/jeab.1998.69-87.
Human subjects were exposed to a concurrent-chains schedule in which reinforcer amounts, delays, or both were varied in the terminal links, and consummatory responses were required to receive points that were later exchangeable for money. Two independent variable-interval 30-s schedules were in effect during the initial links, and delay periods were defined by fixed-time schedules. In Experiment 1, subjects were exposed to three different pairs of reinforcer amounts and delays, and sensitivity to reinforcer amount and delay was determined based on the generalized matching law. The relative responding (choice) of most subjects was more sensitive to reinforcer amount than to reinforcer delay. In Experiment 2, subjects chose between immediate smaller reinforcers and delayed larger reinforcers in five conditions with and without timeout periods that followed a shorter delay, in which reinforcer amounts and delays were combined to make different predictions based on local reinforcement density (i.e., points per delay) or overall reinforcement density (i.e., points per total time). In most conditions, subjects' choices were qualitatively in accord with the predictions from the overall reinforcement density calculated by the ratio of reinforcer amount and total time. Therefore, the overall reinforcement density appears to influence the preference of humans in the present self-control choice situation.
人类被试接受了一种并发链程序，其中强化物数量、延迟或两者在终端链中都有所变化，并且需要做出 consummatory 反应才能获得积分，这些积分随后可兑换成金钱。在初始链中，两个独立的 30 秒可变间隔程序生效，延迟期由固定时间程序定义。在实验 1 中，被试接触了三对不同的强化物数量和延迟，并根据广义匹配定律确定了对强化物数量和延迟的敏感性。大多数被试的相对反应（选择）对强化物数量比对强化物延迟更敏感。在实验 2 中，被试在即时较小强化物和延迟较大强化物之间进行选择，有五种条件，包括有和没有在较短延迟后出现的超时时段，其中强化物数量和延迟相结合，根据局部强化密度（即每延迟的积分）或整体强化密度（即每总时间的积分）做出不同预测。在大多数条件下，被试的选择在质量上符合通过强化物数量与总时间的比率计算出的整体强化密度的预测。因此，在当前的自我控制选择情境中，整体强化密度似乎会影响人类的偏好。
