Centre de Recerca Matemàtica, Bellaterra, Spain.
Princeton Neuroscience Institute, Princeton University, Princeton, United States.
Elife. 2023 May 4;12:e84045. doi: 10.7554/eLife.84045.
Making informed decisions in noisy environments requires integrating sensory information over time. However, recent work has suggested that it may be difficult to determine whether an animal's decision-making strategy relies on evidence integration or not. In particular, strategies based on extrema-detection or random snapshots of the evidence stream may be difficult or even impossible to distinguish from classic evidence integration. Moreover, such non-integration strategies might be surprisingly common in experiments that aimed to study decisions based on integration. To determine whether temporal integration is central to perceptual decision-making, we developed a new model-based approach for comparing temporal integration against alternative 'non-integration' strategies for tasks in which the sensory signal is composed of discrete stimulus samples. We applied these methods to behavioral data from monkeys, rats, and humans performing a variety of sensory decision-making tasks. In all species and tasks, we found converging evidence in favor of temporal integration. First, in all observers across studies, the integration model better accounted for standard behavioral statistics such as psychometric curves and psychophysical kernels. Second, we found that sensory samples with large evidence do not contribute disproportionately to subject choices, as predicted by an extrema-detection strategy. Finally, we provide a direct confirmation of temporal integration by showing that the sum of both early and late evidence contributed to observer decisions. Overall, our results provide experimental evidence suggesting that temporal integration is an ubiquitous feature in mammalian perceptual decision-making. Our study also highlights the benefits of using experimental paradigms where the temporal stream of sensory evidence is controlled explicitly by the experimenter, and known precisely by the analyst, to characterize the temporal properties of the decision process.
在嘈杂的环境中做出明智的决策需要随时间整合感官信息。然而，最近的研究表明，可能很难确定动物的决策策略是依赖于证据整合还是其他策略。特别是，基于极值检测或证据流的随机快照的策略可能很难甚至不可能与经典的证据整合区分开来。此外，在旨在研究基于整合的决策的实验中，此类非整合策略可能会出乎意料地普遍。为了确定时间整合是否是感知决策的核心，我们开发了一种新的基于模型的方法，用于比较时间整合与替代的“非整合”策略，用于任务中，其中感官信号由离散的刺激样本组成。我们将这些方法应用于猴子、大鼠和人类执行各种感官决策任务的行为数据。在所有物种和任务中，我们都发现了支持时间整合的趋同证据。首先，在所有研究的观察者中，整合模型更好地解释了标准的行为统计学，如心理测量曲线和心理物理核。其次，我们发现，具有大证据的感官样本不会不成比例地影响主体选择，这与极值检测策略的预测相反。最后，我们通过证明早期和晚期证据的总和都有助于观察者决策，直接证实了时间整合。总的来说，我们的研究结果提供了实验证据，表明时间整合是哺乳动物感知决策中的普遍特征。我们的研究还强调了使用实验范式的好处，其中感官证据的时间流由实验者明确控制，并且分析师可以精确地知道，以描述决策过程的时间特性。
