Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Grossman Center for the Statistics of Mind, Columbia University, New York, NY 10027, USA.
Neuron. 2023 Aug 16;111(16):2601-2613.e5. doi: 10.1016/j.neuron.2023.05.028. Epub 2023 Jun 22.
The brain makes decisions by accumulating evidence until there is enough to stop and choose. Neural mechanisms of evidence accumulation are established in association cortex, but the site and mechanism of termination are unknown. Here, we show that the superior colliculus (SC) plays a causal role in terminating decisions, and we provide evidence for a mechanism by which this occurs. We recorded simultaneously from neurons in the lateral intraparietal area (LIP) and SC while monkeys made perceptual decisions. Despite similar trial-averaged activity, we found distinct single-trial dynamics in the two areas: LIP displayed drift-diffusion dynamics and SC displayed bursting dynamics. We hypothesized that the bursts manifest a threshold mechanism applied to signals represented in LIP to terminate the decision. Consistent with this hypothesis, SC inactivation produced behavioral effects diagnostic of an impaired threshold sensor and prolonged the buildup of activity in LIP. The results reveal the transformation from deliberation to commitment.
大脑通过积累证据来做出决策，直到有足够的证据停止并做出选择。证据积累的神经机制是在联合皮层中建立的，但终止的位置和机制尚不清楚。在这里，我们表明上丘（SC）在终止决策中起着因果作用，并提供了这种情况发生的机制的证据。当猴子做出知觉决策时，我们同时从外侧顶内区（LIP）和 SC 的神经元中记录。尽管平均活动相似，但我们在两个区域中发现了不同的单次试验动态：LIP 显示漂移扩散动态，而 SC 显示爆发动态。我们假设爆发表现出应用于 LIP 中表示的信号的阈值机制，以终止决策。与该假设一致，SC 失活导致行为效应可诊断为阈值传感器受损，并延长了 LIP 中活动的积累。结果揭示了从深思熟虑到承诺的转变。
