Jensen Greg, Neuringer Allen
Psychology Department, Reed College, Portland, OR 97202, USA.
J Exp Psychol Anim Behav Process. 2008 Oct;34(4):437-60. doi: 10.1037/0097-7403.34.4.437.
Two procedures commonly used to study choice are concurrent reinforcement and probability learning. Under concurrent-reinforcement procedures, once a reinforcer is scheduled, it remains available indefinitely until collected. Therefore reinforcement becomes increasingly likely with passage of time or responses on other operanda. Under probability learning, reinforcer probabilities are constant and independent of passage of time or responses. Therefore a particular reinforcer is gained or not, on the basis of a single response, and potential reinforcers are not retained, as when betting at a roulette wheel. In the "real" world, continued availability of reinforcers often lies between these two extremes, with potential reinforcers being lost owing to competition, maturation, decay, and random scatter. The authors parametrically manipulated the likelihood of continued reinforcer availability, defined as hold, and examined the effects on pigeons' choices. Choices varied as power functions of obtained reinforcers under all values of hold. Stochastic models provided generally good descriptions of choice emissions with deviations from stochasticity systematically related to hold. Thus, a single set of principles accounted for choices across hold values that represent a wide range of real-world conditions.
两种常用于研究选择的程序是并发强化和概率学习。在并发强化程序中，一旦安排了强化物，它会一直可用，直到被获取。因此，随着时间的推移或在其他操作上的反应，强化变得越来越有可能。在概率学习中，强化物的概率是恒定的，与时间的推移或反应无关。因此，基于单次反应，特定的强化物要么获得，要么未获得，并且潜在的强化物不会像在轮盘赌下注时那样被保留。在“现实”世界中，强化物的持续可用性通常介于这两个极端之间，由于竞争、成熟、衰退和随机分散，潜在的强化物会丢失。作者对持续强化物可用性的可能性（定义为持有）进行了参数化操作，并研究了其对鸽子选择的影响。在所有持有值下，选择随着获得的强化物的幂函数而变化。随机模型通常能很好地描述选择发出情况，与随机性的偏差与持有系统相关。因此，一组单一的原则解释了跨越代表广泛现实世界条件的持有值的选择。
