Functional cerebral activation detected by frequency-domain near-infrared spectroscopy

dThe aim of our study was to explore the possibility of detecting hemodynamic changes in the brain using frequency-domain near-infrared spectroscopy by exploiting the phase of the intensity modulated optical signal. To obtain optical signals with the highest possible signal-to-noise ratio, we performed simultaneous NIRS-fMRI measurements with subsequent correlation of the time courses of both measurements. The cognitive paradigm used arithmetic calculations, with optical signals acquired with sensors placed on the forehead. In three subjects we demonstrated correlation between the hemodynamic signals obtained using NIRS and BOLD fNRI.