Knutson J F
J Exp Anal Behav. 1970 Mar;13(2):221-31. doi: 10.1901/jeab.1970.13-221.
Pigeons were trained to key peck for food on multiple reinforcement schedules including components of continuous and fixed-ratio reinforcement and extinction. At the end of the chamber opposite the response key was a restrained target pigeon. The target restraining equipment was designed to record automatically blows struck against the target. When the experimental pigeons were paired with restrained target pigeons they attacked the target. Attack occurred during extinction after both continuous and fixed-ratio reinforcement. Attack also occurred occasionally during fixed-ratio 25 and fixed-ratio 40 and frequently during fixed-ratio 60 and fixed-ratio 120. No attack occurred during fixed-ratio 15 and continuous reinforcement. After a history of stable responding without a target bird present, the introduction of a target bird resulted in severely strained key-peck responding characterized by long periods of neither key pecking nor aggressing.
鸽子在多种强化程序下接受训练，通过啄键获取食物，这些强化程序包括连续强化、固定比率强化以及消退等部分。在与反应键相对的实验箱末端，有一只被束缚的目标鸽子。目标束缚装置旨在自动记录对目标的攻击次数。当实验鸽子与被束缚的目标鸽子配对时，它们会攻击目标。攻击行为在连续强化和固定比率强化后的消退阶段出现。在固定比率25和固定比率40时偶尔也会出现攻击行为，而在固定比率60和固定比率120时则频繁出现。在固定比率15和连续强化期间未出现攻击行为。在没有目标鸟的情况下经历了稳定反应的阶段后，引入目标鸟会导致严重紧张的啄键反应，其特征是长时间既不啄键也不攻击。
