Optimising experimental design for MEG resting state functional connectivity measurement
Optimising experimental design for MEG resting state functional connectivity measurement
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DOI：
10.1016/j.neuroimage.2016.11.064
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发表时间：
2017-07-15
期刊：
影响因子：
5.7
通讯作者：
Brookes, Matthew J.
中科院分区：
文献类型：
--
作者：
Liuzzi, Lucrezia;Gascoyne, Lauren E.;Brookes, Matthew J.
使用脑磁图（MEG）研究功能连接是神经成像的一个扩展领域，并为使用功能磁共振成像（fMRI）进行的更常见的评估增加了额外的维度。随着最近在临床研究中的应用，这些指标的重要性越来越大，然而，之前的报告表明，虽然组水平的静息状态连接是强大的，但单次会话记录缺乏可重复性。如果要证明MEG测量在个体受试者中的临床价值，这种稳健性是至关重要的。在本文中，我们测试了实验设计的实际方面如何影响MEG结果的受试者内部重复性；具体而言，我们评估了共登记方法和数据记录时间的影响。我们发现，使用泡沫头铸可以提高共配准精度，显著提高波束形成器重建和连通性估计的会话间可重复性。我们还表明，记录时间是一个关键参数，与使用5分钟记录相比，使用10分钟记录可以明显提高可重复性。进一步的分析表明，后一种效应的起源并不是由来源重建的技术方面所支持的，而是由大脑状态的真实影响所支持的；短记录在捕捉单个受试者的典型脑电信号网络时效率很低。我们的研究结果为实验设计提供了重要的见解，并将为未来的脑磁图连接研究提供价值。
The study of functional connectivity using magnetoencephalography (MEG) is an expanding area of neuroimaging, and adds an extra dimension to the more common assessments made using fMRI. The importance of such metrics is growing, with recent demonstrations of their utility in clinical research, however previous reports suggest that whilst group level resting state connectivity is robust, single session recordings lack repeatability. Such robustness is critical if MEG measures in individual subjects are to prove clinically valuable. In the present paper, we test how practical aspects of experimental design affect the intra-subject repeatability of MEG findings; specifically we assess the effect of co-registration method and data recording duration. We show that the use of a foam head-cast, which is known to improve co-registration accuracy, increased significantly the between session repeatability of both beamformer reconstruction and connectivity estimation. We also show that recording duration is a critical parameter, with large improvements in repeatability apparent when using ten minute, compared to five minute recordings. Further analyses suggest that the origin of this latter effect is not underpinned by technical aspects of source reconstruction, but rather by a genuine effect of brain state; short recordings are simply inefficient at capturing the canonical MEG network in a single subject. Our results provide important insights on experimental design and will prove valuable for future MEG connectivity studies.