Nevin J A
J Exp Anal Behav. 1967 May;10(3):251-60. doi: 10.1901/jeab.1967.10-251.
Pigeons were trained on a discrete-trials, simultaneous discrimination procedure, with confusable stimuli such that asymptotic performance was about 85% correct. Trials were terminated if no response occurred within 2 sec of stimulus onset, so that probability of responding was free to vary. The schedule of reinforcement for correct responses was varied, with the following results: (1) there was no relation between frequency of reinforcement and accuracy of responding. (2) In extinction, the probability of responding fell to low levels, but accuracy remained roughly constant. (3) When reinforcement was available after a fixed number of trials or after a fixed number of correct responses, the probability of responding increased with successive trials after reinforcement, but accuracy was generally constant. (4) When every fifth correct response was reinforced, accuracy decreased immediately after reinforcement if the birds were required to respond on every trial.
鸽子接受了离散试验、同时辨别程序的训练，使用的刺激容易混淆，以至于渐近表现的正确率约为85%。如果在刺激开始后2秒内没有反应，试验就会终止，这样反应的概率就可以自由变化。正确反应的强化程序有所不同，结果如下：(1) 强化频率与反应准确性之间没有关系。(2) 在消退过程中，反应概率降至低水平，但准确性大致保持不变。(3) 当在固定次数的试验后或固定次数的正确反应后提供强化时，强化后的连续试验中反应概率会增加，但准确性通常保持不变。(4) 当每五次正确反应得到一次强化时，如果要求鸽子每次试验都做出反应，强化后准确性会立即下降。
