Correspondence of electroencephalography and near-infrared spectroscopy sensitivities to the cerebral cortex using a high-density layout

Abstract

This study investigates the correspondence of the cortical sensitivity of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). EEG forward model sensitivity to the cerebral cortex was calculated for 329 EEG electrodes following the 10-5 EEG positioning system using a segmented structural magnetic resonance imaging scan of a human subject. NIRS forward model sensitivity was calculated for the same subject using 156 NIRS source-detector pairs selected from 32 source and 32 detector optodes positioned on the scalp using a subset of the 10-5 EEG positioning system. Sensitivity correlations between colocalized NIRS source-detector pair groups and EEG channels yielded R = 0.46 ± 0.08. Groups of NIRS source-detector pairs with maximum correlations to EEG electrode sensitivities are tabulated. The mean correlation between the point spread functions for EEG and NIRS regions of interest (ROI) was R = 0.43 ± 0.07. Spherical ROIs with radii of 26 mm yielded the maximum correlation between EEG and NIRS averaged across all cortical mesh nodes. These sensitivity correlations between EEG and NIRS should be taken into account when designing multimodal studies of neurovascular coupling and when using NIRS as a statistical prior for EEG source localization.

Computational Pipeline for NIRS-EEG Joint Imaging of tDCS-Evoked Cerebral Responses—An Application in Ischemic Stroke

“…Therefore, the Laplacian spatial filter—FCz, C1, FC3, F1, and FC1, shown in Figure 2 , can be reciprocally energized using 4 × 1 HD-tDCS (Villamar et al, 2013 ) for more focal (unihemispheric) stimulation of the gray matter surface covering primarily middle frontal and superior frontal gyrus (see Figure 2B ). Also, NIRS imaging in conjunction with EEG to analyze neurovascular coupling requires development of NIRS-EEG joint-imaging sensor montage that is sensitive to the same targeted region of the brain (Giacometti and Diamond, 2014 ), which was identified using the NIRS forward model (Aasted et al, 2015 ). The preferred NIRS probe placement and its measurement sensitivity distribution at the gray matter surface is shown in Figure 3 .…”

Fusion of fNIRS and EEG Signals: Mental Stress Study

“…Combination of fNIRS and EEG has recently introduced. Few studies have used EEG and fNIRS to study the correlation between cortical activation and the hemodynamic response in human subjects [12,13]. These studies found a positive correlation in occipital cortex between alpha activity and concentration changes of HHb hemoglobin.…”

Simultaneous functional near-infrared spectroscopy and electroencephalography for monitoring of human brain activity and oxygenation: a review

“…Among the limitations with respect to other techniques, such as fMRI, a poor sensitivity of fNIRS–EEG measurements to brain activity in deep brain cortex layers should be mentioned 161 . Moreover, the main limitation when combining the two modalities derives from shared scalp surface and the presence of wires/fibers.…”