McDevitt Margaret A, Pisklak Jeffrey M, Spetch Marcia, Dunn Roger
Department of Psychology, McDaniel College, 2 College Hill, Westminster, MD, 21157, United States.
University of Alberta, Canada.
Behav Processes. 2018 Dec;157:279-285. doi: 10.1016/j.beproc.2018.10.008. Epub 2018 Oct 28.
Under certain conditions pigeons will choose an option that provides less probable food over one that provides more probable food. This suboptimal choice behavior occurs when the outcomes are delayed and stimuli during the delay differentially signal the upcoming outcomes on the suboptimal alternative, but not the optimal alternative. The present study assessed whether duration of the outcome delay affects pigeons' suboptimal preference. Pigeons chose between a suboptimal alternative that provided food 20% of the time and an optimal alternative that provided food 80% of the time. Stimuli presented during the delays signaled the outcomes on the suboptimal alternative, but not on the optimal alternative. The outcome delays were 5 s in some conditions and 20 s in others. The results of two experiments demonstrate that behavior is generally more suboptimal when the outcome delays are longer but tends to stay relatively suboptimal if subjects experience the long delay condition before the short delay condition. The finding that behavior is more suboptimal with longer delays to the outcomes is consistent with the view that pigeons' suboptimal choice is influenced by both conditioned and primary reinforcement and is inconsistent with the view that suboptimal choice is influenced solely by signal value.
在某些条件下，鸽子会选择获得食物可能性较小的选项，而不是选择获得食物可能性较大的选项。当结果延迟出现，且延迟期间的刺激能以不同方式预示次优选项（而非最优选项）即将出现的结果时，就会出现这种次优选择行为。本研究评估了结果延迟的时长是否会影响鸽子的次优偏好。鸽子需要在一个次优选项（20%的时间能获得食物）和一个最优选项（80%的时间能获得食物）之间做出选择。延迟期间呈现的刺激预示了次优选项的结果，但没有预示最优选项的结果。在某些条件下，结果延迟为5秒，在其他条件下为20秒。两项实验的结果表明，当结果延迟较长时，行为通常更偏向次优，但如果受试者先经历长延迟条件，再经历短延迟条件，行为往往会保持相对次优。结果延迟较长时行为更偏向次优这一发现，与鸽子的次优选择受条件强化和初级强化共同影响的观点一致，而与次优选择仅受信号值影响的观点不一致。
