Abstract: With the increasing number of neuroimaging studies, researchers urgently need a way to compare and combine data from diverse studies. This article would review kinds of meta-analysis methods of brain imaging in the first place, and then introduce a coordinate-based technique which is widely used in neuroimaging studies — Activation Likelihood Estimation (ALE). ALE meta-analysis involves modeling each activated foci as a possibility distribution rather than a single point, and then assesses ALE value by the empirical estimates. To differentiate true convergence of foci from random clustering, null hypothesis is applied: to obtain an ALE null distribution the same number of foci as in the real analysis. In recent years, with the development of brain imaging component analysis fields, the ALE meta-analysis also benefit from it. Activation likelihood estimation has been revisited several times, and approved by most researchers. Two of the most important corrections were multiple comparisons and the changing from "fixed effect analysis" to "random effects analysis". The ALE has several advantages. Firstly, the ability of combining data from diverse studies is essential for building consensus crossing studies. Secondly, the use of a theoretically founded significance threshold provides a means to defend the results statistically. Finally, it can be automated following extraction of relevant foci from the literature which can maximize the efficiency and objectivity. ALE meta-analysis has widely used in the field of functional neuroimaging in the last decades. Nevertheless, we still need to realize that no matter how objective the ALE is, it is not the end but a new beginning.

Key words: meta-analysis, brain imaging, Activation Likelihood Estimation

摘要： 随着脑成像研究数量的增长，研究者迫切需要一种能够将众多研究进行整合的元分析方法。本文在简单回顾了脑成像元分析方法的基础上，介绍了激活似然性评估法(ALE)的操作实施、优势特征、更新完善，以及其发展与应用。该元分析方法将每一个激活的坐标看作一种分布的可能性，通过特定的算法与拟合获得激活似然值，最后，将不同文献汇聚计算而来的ALE值与虚无分布获得的ALE值进行对比，以确定激活的可能性分布。近十年来，激活似然性评估法几经修正，已被广泛运用于各领域元分析的研究中。

关键词: 元分析, 脑成像, 激活似然性评估