Abstract

Since the introduction of the fMRI technique few years ago functional studies of the brain capable of good localization are now relatively common. One major drawback of the fMRI method is that the BOLD effect, which is at the basis of the method, is sensitive to changes in blood flow and volume rather than to neuronal activity. Furthermore, fMRI has not yet reached the necessary temporal resolution to follow the rapid changes due to neuronal activation. Near-ir light can pass trough the skull and reach the surface of the brain. It is well established in exposed cortex experiments that brain activity changes the brain surface optical properties in the near-ir, due both to changes in blood flow and to scattering from the brain cells.

© 2002 Optical Society of America