Herrnstein R J, Loveland D H
J Exp Anal Behav. 1972 Nov;18(3):369-83. doi: 10.1901/jeab.1972.18-369.
Twenty-three pigeons were subjected to a series of procedures in which the key-peck's effects ranged from immediate, differential food reinforcement, through delayed reinforcement, the production of stimulus changes with and without probable secondary reinforcement, the prevention of food presentation ("food-avoidance"), to extinction. Neither primary nor secondary food reinforcement appeared to be essential for the maintenance or acquisition of key pecking. The food-avoidance contingency failed to suppress responding in any subject. Only complete extinction, when pecking produced neither food nor stimulus changes, eliminated all pecking for most subjects. A combination of stimulus-change reinforcement and food reinforcement appeared to account for the results, but only if it could be assumed that the presence of food in a procedure enhanced the reinforcing power of stimulus change, whether or not the food was also dependent upon responding. Such an interaction between reinforcers may be involved in the phenomenon of autoshaping.
对23只鸽子进行了一系列实验程序，其中啄键的效果范围从即时的、有差异的食物强化，到延迟强化，有无可能的二级强化时刺激变化的产生，食物呈现的阻止（“食物回避”），再到消退。一级和二级食物强化对于啄键行为的维持或习得似乎都不是必需的。食物回避条件在任何实验对象中都未能抑制反应。只有当啄键既不产生食物也不引起刺激变化的完全消退，才消除了大多数实验对象的所有啄键行为。刺激变化强化和食物强化的结合似乎可以解释实验结果，但前提是可以假定在一个程序中食物的存在增强了刺激变化的强化能力，无论食物是否也依赖于反应。强化物之间的这种相互作用可能与自动成型现象有关。
