arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2409.01969q-bio.NCcond-mat.dis-nncs.NE
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非线性递归神经网络的连接结构与动力学

Connectivity structure and dynamics of nonlinear recurrent neural networks

Zuckerman Institute, Columbia University(哥伦比亚大学祖克曼研究所);Kavli Institute for Brain Science, Columbia University(哥伦比亚大学卡弗里脑科学研究所);Center for Brain Science, Harvard University(哈佛大学脑科学中心)

David G. Clark, Owen Marschall, Alexander van Meegen, Ashok Litwin-Kumar

AI总结:

本研究提出理论分析非线性递归神经网络中连接结构(如奇异值谱和模式重叠)对集体动力学的影响,发现活动维度仅由耦合方差和有效秩决定,并在果蝇连接组中验证了结构化重叠的作用。

摘要:

对非线性递归神经网络动力学的研究通常假设耦合是独立同分布的,但大规模连接组学数据表明,生物神经回路表现出显著不同的连接特性。这些特性包括快速衰减的奇异值谱和结构化的奇异向量重叠。在此,我们发展了一种理论来分析这些结构形式如何塑造非线性递归神经网络中的高维集体活动。我们首先引入随机模式模型,这是一种与奇异值分解相关的随机矩阵系综,能够控制谱和左右模式重叠。然后,利用一种新颖的路径积分计算,我们推导出解析表达式,揭示连接结构如何影响集体动力学的特征:活动维度(量化高方差集体活动波动的数量)和时间相关性(表征这些波动的时间尺度)。我们表明,连接结构在单神经元活动中可能不可见,同时却显著塑造集体活动。此外,尽管这些网络具有非线性和高维性质,活动维度仅取决于两个连接参数——耦合的方差和耦合矩阵的有效秩(量化主导秩一连接成分的数量)。我们对比了单神经元异质性和低维连接的影响,并对z分数标准化数据如何影响活动维度做出了预测。最后,我们证明了果蝇连接组中左右模式之间存在结构化重叠,将其纳入理论,并展示它们如何进一步塑造集体动力学。

英文摘要:

Studies of the dynamics of nonlinear recurrent neural networks often assume independent and identically distributed couplings, but large-scale connectomics data indicate that biological neural circuits exhibit markedly different connectivity properties. These include rapidly decaying singular-value spectra and structured singular-vector overlaps. Here, we develop a theory to analyze how these forms of structure shape high-dimensional collective activity in nonlinear recurrent neural networks. We first introduce the random-mode model, a random-matrix ensemble related to the singular-value decomposition that enables control over the spectrum and right-left mode overlaps. Then, using a novel path-integral calculation, we derive analytical expressions that reveal how connectivity structure affects features of collective dynamics: the dimension of activity, which quantifies the number of high-variance collective-activity fluctuations, and the temporal correlations that characterize the timescales of these fluctuations. We show that connectivity structure can be invisible in single-neuron activities while dramatically shaping collective activity. Furthermore, despite the nonlinear, high-dimensional nature of these networks, the dimension of activity depends on just two connectivity parameters -- the variance of the couplings and the effective rank of the coupling matrix, which quantifies the number of dominant rank-one connectivity components. We contrast the effects of single-neuron heterogeneity and low dimensional connectivity, making predictions about how z-scoring data affects the dimension of activity. Finally, we demonstrate the presence of structured overlaps between left and right modes in the Drosophila connectome, incorporate them into the theory, and show how they further shape collective dynamics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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