Viewing neurovascular coupling through the lens of combined EEG–fNIRS: A systematic review of current methods

Abstract

Neurovascular coupling is a key physiological mechanism that occurs in the healthy human brain, and understanding this process has implications for understanding the aging and neuropsychiatric populations. Combined electroencephalography (EEG) and functional near‐infrared spectroscopy (fNIRS) has emerged as a promising, noninvasive tool for probing neurovascular interactions in humans. However, the utility of this approach critically depends on the methodological quality used for multimodal integration. Despite a growing number of combined EEG–fNIRS applications reported in recent years, the methodological rigor of past studies remains unclear, limiting the accurate interpretation of reported findings and hindering the translational application of this multimodal approach. To fill this knowledge gap, we critically evaluated various methodological aspects of previous combined EEG–fNIRS studies performed in healthy individuals. A literature search was conducted using PubMed and PsycINFO on June 28, 2021. Studies involving concurrent EEG and fNIRS measurements in awake and healthy individuals were selected. After screening and eligibility assessment, 96 studies were included in the methodological evaluation. Specifically, we critically reviewed various aspects of participant sampling, experimental design, signal acquisition, data preprocessing, outcome selection, data analysis, and results presentation reported in these studies. Altogether, we identified several notable strengths and limitations of the existing EEG–fNIRS literature. In light of these limitations and the features of combined EEG–fNIRS, recommendations are made to improve and standardize research practices to facilitate the use of combined EEG–fNIRS when studying healthy neurovascular coupling processes and alterations in neurovascular coupling among various populations.

Neurovascular coupling in the attention during visual working memory processes

“…Rather, failures to filter distractors are frequent and the scope of attention fluctuates, paced by the natural speed of the attention systems that govern access to vWM. The relationship between task-related NVC strength and behavior performance has been assessed across individuals, 65 with subject-level analyses not reported. To fill this knowledge gap, we first continuously tracked the fluctuations in vWM processing at various levels of psychophysiological reactions (see Figure 5 ), and then for each miniblock, quantized the dynamic NVC between moment-to-moment changes in brain activity and continuous readouts of behavior.…”

Screening diagnosis of executive dysfunction after ischemic stroke and the effects of transcranial magnetic stimulation: A prospective functional near‐infrared spectroscopy study

“…(3) real‐time visualization: fNIRS can observe the changes in hemoglobin content and hemodynamics of PISEI patients in real time and dynamically. The detection process is clearly visible, and intelligent presentation and adaptive adjustment of evaluation parameters can be achieved according to the feedback data of dynamic monitoring of brain function 25 . And (4) guidance for follow‐up therapy: fNIRS can observe the hemodynamic changes in brain target areas in real time, dynamically and visually to infer the neural activity, and provide real‐time efficacy feedback and exact intervention guidance for the rehabilitation treatment of PISEI patients with the help of neurovascular coupling mechanism and blood oxygen metabolism in local brain areas 26 …”

The neurovascular coupling in the attention during visual working memory

“…Rather, failures to filter distractors are frequent, and the scope of attention fluctuates, paced by the natural speed of attention systems that govern access to vWM. The relationship between the task-related NVC strength and behavior performance was almost conducted across individuals [76], with subject-level analyses not reported. To fill this knowledge gap, we first continuously tracked the fluctuations in vWM processing at various levels of psychophysiological reactions (see Fig.…”