Jackson K, Hackenberg T D
Department of Psychology, University of Florida, Gainesville 32611, USA.
J Exp Anal Behav. 1996 Jul;66(1):29-49. doi: 10.1901/jeab.1996.66-29.
Pigeons were exposed to self-control procedures that involved illumination of light-emitting diodes (LEDs) as a form of token reinforcement. In a discrete-trials arrangement, subjects chose between one and three LEDs; each LED was exchangeable for 2-s access to food during distinct posttrial exchange periods. In Experiment 1, subjects generally preferred the immediate presentation of a single LED over the delayed presentation of three LEDs, but differences in the delay to the exchange period between the two options prevented a clear assessment of the relative influence of LED delay and exchange-period delay as determinants of choice. In Experiment 2, in which delays to the exchange period from either alternative were equal in most conditions, all subjects preferred the delayed three LEDs more often than in Experiment-1. In Experiment 3, subjects preferred the option that resulted in a greater amount of food more often if the choices also produced LEDs than if they did not. In Experiment 4, preference for the delayed three LEDs was obtained when delays to the exchange period were equal, but reversed in favor of an immediate single LED when the latter choice also resulted in quicker access to exchange periods. The overall pattern of results suggests that (a) delay to the exchange period is a more critical determinant of choice than is delay to token presentation; (b) tokens may function as conditioned reinforcers, although their discriminative properties may be responsible for the self-control that occurs under token reinforcer arrangements; and (c) previously reported differences in the self-control choices of humans and pigeons may have resulted at least in part from the procedural conventions of using token reinforcers with human subjects and food reinforcers with pigeon subjects.
鸽子接受了自我控制程序，该程序涉及将发光二极管（LED）点亮作为一种代币强化形式。在离散试验安排中，受试者在一个和三个LED之间进行选择；在不同的试验后交换期，每个LED可兑换2秒的食物获取时间。在实验1中，受试者通常更喜欢立即呈现单个LED，而不是延迟呈现三个LED，但两种选择在交换期延迟上的差异使得无法清晰评估LED延迟和交换期延迟作为选择决定因素的相对影响。在实验2中，在大多数情况下，来自任一选项的交换期延迟相等，所有受试者比在实验1中更频繁地选择延迟的三个LED。在实验3中，如果选择也产生LED，受试者比不产生LED时更频繁地选择能获得更多食物的选项。在实验4中，当交换期延迟相等时，获得了对延迟的三个LED的偏好，但当后一种选择也导致更快进入交换期时，偏好反转，转而支持立即呈现的单个LED。结果的总体模式表明：（a）交换期延迟比代币呈现延迟是更关键的选择决定因素；（b）代币可能起到条件强化物的作用，尽管它们的辨别特性可能是代币强化物安排下出现自我控制的原因；（c）先前报道的人类和鸽子在自我控制选择上的差异可能至少部分是由于对人类受试者使用代币强化物和对鸽子受试者使用食物强化物的程序惯例所致。
