Mazur J E
Psychology Department, Southern Connecticut State University, New Haven, USA.
J Exp Anal Behav. 1998 Mar;69(2):185-97. doi: 10.1901/jeab.1998.69-185.
Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice.
两项实验研究了拖延现象，即鸽子会选择要求更高、延迟时间更长的反应，而不是要求更低、更即时的反应。反应要求是固定间隔时间表，不会立即带来食物强化，但会中断一个55秒的时间段，在此期间食物会在随机时间发放。实验采用了调整延迟程序，在试验过程中改变一个固定间隔要求开始的延迟时间，以估计无差异点——即两个选项被选择的频率大致相同的延迟时间。实验1发现，随着较短固定间隔要求的延迟时间增加，较长固定间隔要求的调整延迟时间也会增加，且增加速率取决于较长固定间隔要求的持续时间。实验2发现，与0秒或20秒的混合延迟相比，鸽子强烈偏好固定间隔要求开始前10秒的固定延迟。这些结果有助于区分不同的方程，这些方程可能描述随着延迟增加反应要求有效性的降低，并且表明延迟强化物和延迟反应要求对选择有对称但相反的影响。
