Center for Theoretical Neuroscience, Columbia University, New York, New York 10032, USA.
Department of Neuroscience, Columbia University Medical Center, New York, New York 10032, USA.
Nat Commun. 2016 Oct 27;7:13239. doi: 10.1038/ncomms13239.
Neural populations can change the computation they perform on very short timescales. Although such flexibility is common, the underlying computational strategies at the population level remain unknown. To address this gap, we examined population responses in motor cortex during reach preparation and movement. We found that there exist exclusive and orthogonal population-level subspaces dedicated to preparatory and movement computations. This orthogonality yielded a reorganization in response correlations: the set of neurons with shared response properties changed completely between preparation and movement. Thus, the same neural population acts, at different times, as two separate circuits with very different properties. This finding is not predicted by existing motor cortical models, which predict overlapping preparation-related and movement-related subspaces. Despite orthogonality, responses in the preparatory subspace were lawfully related to subsequent responses in the movement subspace. These results reveal a population-level strategy for performing separate but linked computations.
神经元群体可以在极短的时间内改变它们的计算方式。尽管这种灵活性很常见，但在群体层面上的潜在计算策略仍然未知。为了解决这一差距，我们在运动皮层的准备和运动期间检查了群体反应。我们发现，存在专门用于准备和运动计算的独占且正交的群体级子空间。这种正交性导致了响应相关性的重新组织：在准备和运动之间，具有共享响应特性的神经元集完全改变。因此，同一神经群体在不同时间充当两个具有非常不同特性的独立电路。这一发现与现有的运动皮层模型不一致，后者预测了重叠的与准备相关和与运动相关的子空间。尽管存在正交性，但准备子空间中的反应与随后的运动子空间中的反应之间存在合法的关系。这些结果揭示了一种执行独立但相关计算的群体层面策略。
