Reed College, Portland, Oregon 97202, USA.
J Exp Anal Behav. 2009 Sep;92(2):139-59. doi: 10.1901/jeab.2009.92-139.
In most studies of choice under concurrent schedules of reinforcement, two physically identical operanda are provided. In the "real world," however, more than two choice alternatives are often available and biases are common. This paper describes a method for studying choices among an indefinite number of alternatives when large biases are present. Twenty rats were rewarded for choosing among five operanda with reinforcers scheduled probabilistically and concurrently. Large biases were generated by differences among the operanda: two were levers and three were pigeon keys. The results showed that when reinforcer frequencies were systematically varied, an extension of Baum's (1974) Generalized Matching Model, referred to as the Barycentric Matching Model, provided an excellent description of the data, including individual bias values for each of the operanda and a single exponent indicating sensitivity to reinforcer ratios.
在大多数同时强化的选择研究中，会提供两个物理上完全相同的操作数。然而，在“现实世界”中，通常会有两个以上的选择可供选择，并且偏见很常见。本文描述了一种在存在大偏见的情况下研究无限数量选择的方法。当强化物的频率被系统地改变时，20 只老鼠被奖励在五个操作数之间进行选择，这些操作数的强化物是概率性和同时进行的。大偏见是由操作数之间的差异产生的：两个是杠杆，三个是鸽子钥匙。结果表明，当强化物频率被系统地改变时，Baum（1974）的广义匹配模型的扩展，称为重心匹配模型，为数据提供了极好的描述，包括每个操作数的个体偏见值和一个单一的指数，表明对强化物比率的敏感性。
