How to Calculate and Validate Inter-brain Synchronization in a fNIRS Hyperscanning Study.

Hu, Wang, Song, Pan, Cheng, Zhu, Hu (2021) How to Calculate and Validate Inter-brain Synchronization in a fNIRS Hyperscanning Study. J Vis Exp (175)


The dynamics between coupled brains of individuals have been increasingly represented by inter-brain synchronization (IBS) when they coordinate with each other, mostly using simultaneous-recording signals of brains (namely hyperscanning) with fNIRS. In fNIRS hyperscanning studies, IBS has been commonly assessed through the wavelet transform coherence (WTC) method because of its advantage on expanding time series into time-frequency space where oscillations can be seen in a highly intuitive way. The observed IBS can be further validated via the permutation-based random pairing of the trial, partner, and condition. Here, a protocol is presented to describe how to obtain brain signals via fNIRS technology, calculate IBS through the WTC method, and validate IBS by permutation in a hyperscanning study. Further, we discuss the critical issues when using the above methods, including the choice of fNIRS signals, methods of data preprocessing, and optional parameters of computations. In summary, using the WTC method and permutation is a potentially standard pipeline for analyzing IBS in fNIRS hyperscanning studies, contributing to both the reproducibility and reliability of IBS.

当个体相互协调时,个体耦合大脑之间的动态越来越多地表现为脑间同步 (IBS),主要使用 fNIRS 的同时记录大脑信号(即超扫描)。在 fNIRS 超扫描研究中,IBS 通常通过小波变换相干 (WTC) 方法进行评估,因为它具有将时间序列扩展到时频空间的优势,其中可以以高度直观的方式看到振荡。观察到的 IBS 可以通过试验、合作伙伴和条件的基于排列的随机配对进一步验证。在这里,提出了一个协议来描述如何通过 fNIRS 技术获取大脑信号,通过 WTC 方法计算 IBS,并通过超扫描研究中的排列验证 IBS。此外,我们讨论了使用上述方法时的关键问题,包括 fNIRS 信号的选择、数据预处理方法和计算的可选参数。总之,使用 WTC 方法和排列是在 fNIRS 超扫描研究中分析 IBS 的潜在标准管道,有助于提高 IBS 的重现性和可靠性。



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