Recently, Frontiers in Human Neuroscience published a special issue on Techniques Advances and Clinical Applications in Fused EEG-fNIRS (

This special issue was organized by Associate Editor, Prof. Zhen Yuan from the CCBS of University of Macau, Editor in Brain Imaging and Stimulation, Distinguished Professor Mingzhou Ding from the Biomedical Engineering of University of Florida, and Prof. Xin Zhang from Institute of Automation of the Chinese Academy of Sciences.

Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) are two very important noninvasive neuroimaging techniques, which provide us a unique opportunity to unveil where and when neural information processing is taking place in human brain. EEG recordings capture the summation of postsynaptic potentials of thousands and millions of pyramidal neurons while fNIRS data denote the hemoglobin changes induced by firing neurons. More importantly, the hemodynamic response detected by fNIRS can only indirectly quantify the neural activity, whereas EEG can offer temporally fine and direct measure of neural activity.

Interestingly, EEG-fNIRS fusion data can offer us unique perspectives on brain activation and connectivity. Consequently, the combination of these two neuroimaging technologies is able to enhance each’s performance and compensate for each’s disadvantage. Besides, there is a potential to combine fNIRS and EEG to inspect the neurovascular coupling mechanism, which can give complementary information about the functioning of the brain. Neurovascular coupling refers to the relationship between local neural activity and subsequent changes in hemodynamic responses, where brain activation is always accompanied by a complex sequence of cellular, metabolic, and vascular processes.

Specifically, this research topic aims to utilize combined EEG and fNIRS techniques to examine the relationship between hemodynamic signals in the frontal cortex and various ERP components of the whole brain. It is expected that the combined neural features are able to reveal the complex neurovascular coupling mechanism underlying various cognitive tasks, brain intervention, and brain disorders. It is also expected that the combined ERP and fNIRS signals were best able to differentiate the patients and healthy controls with improved detection accuracy.

Altogether eight articles were published for this special issue, which involves various perspectives of cognition, behavior and brain disorders, such as individual differences, brain-computer interactions (BCI), neurorehabilitation, and clinical implications.

In summary, this special issue supports an essential role of fused EEG and fNIRS in contributing to human brain science with different latencies and activation regions. More importantly, the multimodal neuroimaging technique paves a new avenue for improving the understanding of neural mechanism underlying various cognitive tasks and brain disorders.