Mortimer Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, 10027, USA.
Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
Nat Commun. 2020 Jul 10;11(1):3466. doi: 10.1038/s41467-020-17058-y.
Value-based decision-making requires different variables-including offer value, choice, expected outcome, and recent history-at different times in the decision process. Orbitofrontal cortex (OFC) is implicated in value-based decision-making, but it is unclear how downstream circuits read out complex OFC responses into separate representations of the relevant variables to support distinct functions at specific times. We recorded from single OFC neurons while macaque monkeys made cost-benefit decisions. Using a novel analysis, we find separable neural dimensions that selectively represent the value, choice, and expected reward of the present and previous offers. The representations are generally stable during periods of behavioral relevance, then transition abruptly at key task events and between trials. Applying new statistical methods, we show that the sensitivity, specificity and stability of the representations are greater than expected from the population's low-level features-dimensionality and temporal smoothness-alone. The separability and stability suggest a mechanism-linear summation over static synaptic weights-by which downstream circuits can select for specific variables at specific times.
基于价值的决策需要不同的变量——包括提议的价值、选择、预期结果和最近的历史——在决策过程的不同时间。眶额皮层(OFC)参与基于价值的决策,但尚不清楚下游电路如何将复杂的 OFC 反应解读为相关变量的单独表示,以在特定时间支持不同的功能。我们在猕猴进行成本效益决策时记录了单个 OFC 神经元的活动。使用一种新的分析方法,我们发现了可分离的神经维度,这些维度分别选择性地表示当前和先前提议的价值、选择和预期奖励。这些表示在与行为相关的时期内通常是稳定的,然后在关键任务事件和试验之间突然转变。应用新的统计方法,我们表明表示的敏感性、特异性和稳定性大于从群体的低水平特征(维度和时间平滑度)中预期的。可分离性和稳定性表明,下游电路可以通过静态突触权重的线性求和,在特定时间选择特定变量。