Zentall Thomas R, Andrews Danielle M, Case Jacob P
University of Kentucky, United States.
University of Kentucky, United States.
Behav Processes. 2017 Dec;145:1-9. doi: 10.1016/j.beproc.2017.09.008. Epub 2017 Sep 20.
Animals choose suboptimally when provided with cues that signal whether reinforcement is coming or not. For example, pigeons do not prefer an alternative that always provides them with a signal for reinforcement over an alternative that provides them with a signal for reinforcement only half of the time and a signal for the absence of reinforcement the rest of the time. In the present research, we tested the hypothesis that if the results of the choice are delayed, pigeons will choose less suboptimally. We tested this hypothesis by forcing pigeons to wait following their choice, requiring them to complete a fixed-interval 20-s schedule prior to receiving the signals for reinforcement. In Experiment 1, we gave the pigeons a choice between (a) a 50% chance of receiving a signal for reinforcement or a 50% chance of receiving a signal for the absence of reinforcement and (b) a 100% chance of receiving a signal for reinforcement. When the signal for reinforcement was delayed, most of the pigeons chose optimally. When it was not delayed, most of the pigeons chose suboptimally. In Experiment 2, we gave the pigeons a choice between (a) a 25% chance of receiving a signal for reinforcement or a 75% chance of receiving a signal for nonreinforcement and (b) a 100% chance of receiving an unreliable signal for reinforcement (predicting reinforcement 75% of the time). When the signal was not delayed, the pigeons showed a strong tendency to choose suboptimally but they chose suboptimally much less when the signal was delayed.
当动物面对提示信号表明强化是否即将到来时，它们的选择并非最优。例如，比起一种仅在一半时间提供强化信号而另一半时间提供无强化信号的选择，鸽子并不偏好总是提供强化信号的选择。在本研究中，我们测试了这样一个假设：如果选择结果被延迟，鸽子的选择将不那么次优。我们通过让鸽子在做出选择后等待来测试这个假设，要求它们在收到强化信号之前完成一个固定间隔20秒的程序。在实验1中，我们让鸽子在以下两种选择之间做出抉择：（a）有50%的机会收到强化信号或有50%的机会收到无强化信号，以及（b）有100%的机会收到强化信号。当强化信号被延迟时，大多数鸽子做出了最优选择。当信号未被延迟时，大多数鸽子做出了次优选择。在实验2中，我们让鸽子在以下两种选择之间做出抉择：（a）有25%的机会收到强化信号或有75%的机会收到无强化信号，以及（b）有100%的机会收到一个不可靠的强化信号（75%的时间预测强化）。当信号未被延迟时，鸽子表现出强烈的次优选择倾向，但当信号被延迟时，它们的次优选择要少得多。
