Berkay Dilara, Freestone David, Balcı Fuat
Department of Psychology, Koç University, Rumelifeneri Yolu, 34450, Sarıyer, Istanbul, Turkey.
Department of Psychology, Brown University, Providence, RI, USA.
Anim Cogn. 2016 Nov;19(6):1215-1225. doi: 10.1007/s10071-016-1033-y. Epub 2016 Sep 19.
Endogenous timing uncertainty results in variability in time-based judgments. In many timing tasks, animals need to incorporate their level of endogenous timing uncertainty into their decisions in order to maximize the reward rate. Although animals have been shown to adopt such optimal behavioral strategies in time-based decisions, whether they can optimize their behavior under exogenous noise is an open question. In this study, we tested mice and rats in a task that required them to space their responses for a minimum duration (DRL task) in different task conditions. In one condition, the minimum wait time was fixed, whereas in other conditions minimum wait time was a Gaussian random variable. Although reward maximization entailed waiting longer with added exogenous timing variability, results indicated that both mice and rats became more impulsive and deviated from optimality with increasing levels of exogenous noise. We introduce a reward-rate-dependent sampling function to SET to account for optimal performance in noiseless and suboptimal performance in noisy environments.
内源性时间不确定性导致基于时间的判断存在变异性。在许多计时任务中，动物需要将其内源性时间不确定性水平纳入决策中，以实现奖励率最大化。尽管已证明动物在基于时间的决策中会采用这种最优行为策略，但它们在外源噪声下能否优化自身行为仍是一个悬而未决的问题。在本研究中，我们在一项任务中对小鼠和大鼠进行了测试，该任务要求它们在不同任务条件下将反应间隔至少持续一段时间（DRL任务）。在一种条件下，最短等待时间是固定的，而在其他条件下，最短等待时间是一个高斯随机变量。尽管奖励最大化需要随着外源性时间变异性的增加而等待更长时间，但结果表明，随着外源噪声水平的增加，小鼠和大鼠都变得更加冲动，偏离了最优性。我们引入了一个依赖奖励率的采样函数到SET中，以解释在无噪声环境中的最优表现和在有噪声环境中的次优表现。
