Estimation of functional areas probed by near-infrared spectroscopy instruments

The relationship between probe positions of near-infrared spectroscopy instruments and functional areas in the brain is very important for the brain function measurement. Light propagation in a standard brain was calculated to consider the broadening of the probing region caused by the tissue scattering in the NIRS measurements to determine the relationship between the probe positions and the functional areas. The NIRS signal tends to reflect the brain activation in different functional areas and the primary functional area is possibly different from that indicated by the simple projection of the measurement point.