Department of Psychology, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
J Exp Anal Behav. 2012 Jan;97(1):51-70. doi: 10.1901/jeab.2012.97-51.
Four pigeons were trained in a series of two-component multiple schedules. Reinforcers were scheduled with random-interval schedules. The ratio of arranged reinforcer rates in the two components was varied over 4 log units, a much wider range than previously studied. When performance appeared stable, prefeeding tests were conducted to assess resistance to change. Contrary to the generalized matching law, logarithms of response ratios in the two components were not a linear function of log reinforcer ratios, implying a failure of parameter invariance. Over a 2 log unit range, the function appeared linear and indicated undermatching, but in conditions with more extreme reinforcer ratios, approximate matching was observed. A model suggested by McLean (1991), originally for local contrast, predicts these changes in sensitivity to reinforcer ratios somewhat better than models by Herrnstein (1970) and by Williams and Wixted (1986). Prefeeding tests of resistance to change were conducted at each reinforcer ratio, and relative resistance to change was also a nonlinear function of log reinforcer ratios, again contrary to conclusions from previous work. Instead, the function suggests that resistance to change in a component may be determined partly by the rate of reinforcement and partly by the ratio of reinforcers to responses.
四只鸽子在一系列的双成分多项程序中接受训练。强化物是根据随机间隔程序安排的。两个成分中安排的强化物率的比例在 4 个对数单位内变化，这比以前研究的范围要宽得多。当表现似乎稳定时，进行预喂食测试以评估对变化的抵抗力。与广义匹配律相反，两个成分中的反应比率的对数不是强化物比率对数的线性函数，这意味着参数不变性失败。在 2 个对数单位的范围内，该函数呈线性且表示低估匹配，但在更极端的强化物比率条件下，观察到了近似匹配。麦克林（McLean，1991）提出的一个模型，最初用于局部对比，比 Herrnstein（1970）和 Williams 和 Wixted（1986）的模型更能预测这些对强化物比率敏感性的变化。在每个强化物比率下进行了对变化的抵抗力的预喂食测试，对变化的相对抵抗力也是强化物比率对数的非线性函数，这再次与之前的工作结论相悖。相反，该函数表明，对一个成分中变化的抵抗力可能部分取决于强化的速度，部分取决于强化物与反应的比率。
