IDIBAPS, Rosselló 149, 08036, Barcelona, Spain.
Center for Brain and Cognition, Universitat Pompeu Fabra, Ramón Trias Fargas, 25, 08018, Barcelona, Spain.
Nat Commun. 2021 Dec 8;12(1):7148. doi: 10.1038/s41467-021-27302-8.
Standard models of perceptual decision-making postulate that a response is triggered in reaction to stimulus presentation when the accumulated stimulus evidence reaches a decision threshold. This framework excludes however the possibility that informed responses are generated proactively at a time independent of stimulus. Here, we find that, in a free reaction time auditory task in rats, reactive and proactive responses coexist, suggesting that choice selection and motor initiation, commonly viewed as serial processes, are decoupled in general. We capture this behavior by a novel model in which proactive and reactive responses are triggered whenever either of two competing processes, respectively Action Initiation or Evidence Accumulation, reaches a bound. In both types of response, the choice is ultimately informed by the Evidence Accumulation process. The Action Initiation process readily explains premature responses, contributes to urgency effects at long reaction times and mediates the slowing of the responses as animals get satiated and tired during sessions. Moreover, it successfully predicts reaction time distributions when the stimulus was either delayed, advanced or omitted. Overall, these results fundamentally extend standard models of evidence accumulation in decision making by showing that proactive and reactive processes compete for the generation of responses.
传统的感知决策模型假定，当累积的刺激证据达到决策阈值时，反应会在刺激呈现时触发。然而，该框架排除了在不受刺激影响的情况下，主动生成知情反应的可能性。在这里，我们发现，在大鼠的自由反应时间听觉任务中，反应性和主动性反应同时存在，这表明通常被视为串行过程的选择选择和运动启动是解耦的。我们通过一种新的模型来捕捉这种行为，该模型在两种竞争过程（分别是动作启动或证据积累）中的任意一个达到界限时，都会触发主动和被动反应。在这两种类型的反应中，最终的选择都是由证据积累过程来决定的。动作启动过程很容易解释过早的反应，对长反应时间的紧急效应有贡献，并在动物在会议期间感到厌倦和疲劳时，调节反应的减慢。此外，当刺激被延迟、提前或省略时，它还可以成功地预测反应时间分布。总的来说，这些结果通过表明主动和被动过程竞争生成反应，从根本上扩展了决策中证据积累的标准模型。
