A hallmark of neocortical activity is the presence of low-dimensional fluctuations in firing rate that are coordinated across neurons. However, the impact of these fluctuations on sensory processing remains unclear. Here, we examined fluctuations in populations of orientation-selective neurons from anesthetized macaque primary visual cortex (V1) during stimulus viewing as well as spontaneous activity. We introduce a novel approach termed frequency-separated principal components analysis (FS-PCA) to characterize these fluctuations. This method unveiled a distribution of components with a broad range of frequencies whose eigenvalues and variance followed an approximate power-law. During stimulus viewing, subpopulations of V1 neurons correlated either positively or negatively with low-dimensional fluctuations. These two subpopulations displayed distinct activation properties and noise correlations in response to sensory input. Together, results suggest that slow, low-dimensional fluctuations in V1 population activity shape the response of individual neurons to oriented stimuli and may impact the transmission of sensory information to downstream regions of the primary visual system.

中文翻译：

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皮质种群活动的频率分离主成分分析。

新皮质活动的一个标志是在神经元之间协调的放电率的低维波动的存在。然而，这些波动对感觉处理的影响仍不清楚。在这里，我们检查了来自麻醉猕猴初级视觉皮层 (V1) 的定向选择性神经元群体在刺激观察和自发活动期间的波动。我们引入了一种称为频率分离主成分分析 (FS-PCA) 的新方法来表征这些波动。该方法揭示了具有广泛频率的分量分布，其特征值和方差遵循近似幂律。在刺激观察期间，V1 神经元的亚群与低维波动呈正相关或负相关。这两个亚群响应感官输入显示出不同的激活特性和噪声相关性。总之，结果表明 V1 种群活动的缓慢、低维波动塑造了单个神经元对定向刺激的反应，并可能影响感官信息向初级视觉系统下游区域的传输。