Rayburn-Reeves Rebecca M, Zentall Thomas R
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA.
Learn Behav. 2013 Jun;41(2):138-47. doi: 10.3758/s13420-012-0091-5.
We studied behavioral flexibility, or the ability to modify one's behavior in accordance with the changing environment, in pigeons using a reversal-learning paradigm. In two experiments, each session consisted of a series of five-trial sequences involving a simple simultaneous color discrimination in which a reversal could occur during each sequence. The ideal strategy would be to start each sequence with a choice of S1 (the first correct stimulus) until it was no longer correct, and then to switch to S2 (the second correct stimulus), thus utilizing cues provided by local reinforcement (feedback from the preceding trial). In both experiments, subjects showed little evidence of using local reinforcement cues, but instead used the mean probabilities of reinforcement for S1 and S2 on each trial within each sequence. That is, subjects showed remarkably similar behavior, regardless of where (or, in Exp. 2, whether) a reversal occurred during a given sequence. Therefore, subjects appeared to be relatively insensitive to the consequences of responses (local feedback) and were not able to maximize reinforcement. The fact that pigeons did not use the more optimal feedback afforded by recent reinforcement contingencies to maximize their reinforcement has implications for their use of flexible response strategies under reversal-learning conditions.
我们使用反转学习范式，在鸽子身上研究了行为灵活性，即根据不断变化的环境改变自身行为的能力。在两个实验中，每个实验环节都由一系列五次试验的序列组成，这些序列涉及简单的同时颜色辨别任务，每个序列中都可能出现反转。理想的策略是在每个序列开始时选择S1（第一个正确刺激），直到它不再正确，然后切换到S2（第二个正确刺激），从而利用局部强化提供的线索（前一次试验的反馈）。在两个实验中，受试者几乎没有表现出使用局部强化线索的迹象，而是使用了每个序列中每次试验S1和S2的平均强化概率。也就是说，无论在给定序列中反转发生在哪里（或者，在实验2中，是否发生反转），受试者都表现出非常相似的行为。因此，受试者似乎对反应的后果（局部反馈）相对不敏感，并且无法使强化最大化。鸽子没有利用近期强化意外情况提供的更优反馈来最大化强化这一事实，对它们在反转学习条件下使用灵活反应策略具有启示意义。
