系统神经科学的一个重要目标是了解神经元相互作用的结构,经常通过研究记录的神经元信号之间的功能关系来接近。常用的成对措施(例如,相关系数)提供有限的洞察力,既不能解决估计的神经元相互作用的特异性,也不能解决神经元信号之间潜在的协同耦合。三方措施,例如部分相关,方差划分,和部分信息分解,通过将功能关系解开到可解释的信息原子(唯一的,冗余,和协同作用)。这里,我们将这些三方措施应用于模拟神经元记录,以调查它们对噪声的敏感性。我们发现,所考虑的措施对于无噪声源的信号大多是准确且特定的,但对于有噪声源却存在很大的偏差。我们表明,即使对于较小的噪声部分和较大的数据大小,对此类措施进行置换测试也会导致较高的假阳性率。我们提出了一个保守的零假设,用于三方测度的显著性检验,这显著降低了假阳性率,但以增加假阴性率为可承受的代价。我们希望我们的研究提高对显著性测试和功能关系解释的潜在陷阱的认识,提供概念和实用的建议。
三方功能关系测量能够研究神经记录中的有趣效应,比如冗余,功能连接特异性,和协同耦合。然而,这种关系的估计器通常使用无噪声信号进行验证,而神经记录通常包含噪声。在这里,我们系统地研究了使用模拟噪声神经信号的三方估计器的性能。我们证明了置换测试不是从常用的三方关系估计器推断地面实况统计关系的可靠程序。我们开发了一个调整后的保守测试程序,当应用于嘈杂数据时,降低了所研究估计量的假阳性率。除了解决显著性测试,我们的结果应该有助于准确解释三方功能关系和功能连通性。
An important goal in systems neuroscience is to understand the structure of neuronal interactions, frequently approached by studying functional relations between recorded neuronal signals. Commonly used pairwise measures (e.g., correlation coefficient) offer limited insight, neither addressing the specificity of estimated neuronal interactions nor potential synergistic coupling between neuronal signals. Tripartite measures, such as partial correlation, variance partitioning, and partial information decomposition, address these questions by disentangling functional relations into interpretable information atoms (unique, redundant, and synergistic). Here, we apply these tripartite measures to simulated neuronal recordings to investigate their sensitivity to noise. We find that the considered measures are mostly accurate and specific for signals with noiseless sources but experience significant bias for noisy sources.We show that permutation testing of such measures results in high false positive rates even for small noise fractions and large data sizes. We present a conservative null hypothesis for significance testing of tripartite measures, which significantly decreases false positive rate at a tolerable expense of increasing false negative rate. We hope our study raises awareness about the potential pitfalls of significance testing and of interpretation of functional relations, offering both conceptual and practical advice.
Tripartite functional relation measures enable the study of interesting effects in neural recordings, such as redundancy, functional connection specificity, and synergistic coupling. However, estimators of such relations are commonly validated using noiseless signals, whereas neural recordings typically contain noise. Here we systematically study the performance of tripartite estimators using simulated noisy neural signals. We demonstrate that permutation testing is not a robust procedure for inferring ground truth statistical relations from commonly used tripartite relation estimators. We develop an adjusted conservative testing procedure, reducing false positive rates of the studied estimators when applied to noisy data. Besides addressing significance testing, our results should aid in accurate interpretation of tripartite functional relations and functional connectivity.