近日，美国加州大学洛杉矶分校Michele A. Basso及其研究小组揭示灵长类动物上丘在计算知觉决策证据中的因果作用。2021年6月28日，国际知名学术期刊《自然—神经科学》在线发表了这一成果。

在脑干区域（上丘SC，参与准备眼球运动）的单侧可逆的失活前后，受过训练的猴子执行了一项两项选择的感知决策任务，并报告了动态玻璃图案的感知方向。研究人员发现单侧SC失活产生了显著的决策偏差和反应时间的变化，这与灵长类SC在感知决策中的因果作用一致。

将信号检测理论和顺序采样模型与数据拟合表明，SC失活导致对侧决策的相对证据减少，就好像为同侧选择的时变证据信号添加了一个恒定的偏移量。结果为感知决策的具身认知模型提供了因果证据，并提供了令人信服的证据，证明灵长类动物的SC（脑干结构）在如何计算决策证据方面发挥因果作用——这一过程通常归因于前脑。 

附：英文原文

Title: Causal role for the primate superior colliculus in the computation of evidence for perceptual decisions

Author: Elizabeth J. Jun, Alex R. Bautista, Michael D. Nunez, Daicia C. Allen, Jung H. Tak, Eduardo Alvarez, Michele A. Basso

Issue&Volume: 2021-06-28

Abstract: Trained monkeys performed a two-choice perceptual decision-making task in which they reported the perceived orientation of a dynamic Glass pattern, before and after unilateral, reversible, inactivation of a brainstem area—the superior colliculus (SC)—involved in preparing eye movements. We found that unilateral SC inactivation produced significant decision biases and changes in reaction times consistent with a causal role for the primate SC in perceptual decision-making. Fitting signal detection theory and sequential sampling models to the data showed that SC inactivation produced a decrease in the relative evidence for contralateral decisions, as if adding a constant offset to a time-varying evidence signal for the ipsilateral choice. The results provide causal evidence for an embodied cognition model of perceptual decision-making and provide compelling evidence that the SC of primates (a brainstem structure) plays a causal role in how evidence is computed for decisions—a process usually attributed to the forebrain.

DOI: 10.1038/s41593-021-00878-6

Source: https://www.nature.com/articles/s41593-021-00878-6