DYNAMIC MULTICHANNEL NEAR-INFRARED OPTICAL IMAGING OF HUMAN BRAIN ACTIVITY

The present paper demonstrates functional brain mapping with an optica l imaging technique by using tissue-transparent near-infrared light. W ith a maximal five-channel optical monitoring system, we succeeded in detecting region-specific changes in both the hemoglobin oxygenation s tate and blood volume during various mental tasks, in addition to visu al and auditory stimulation. The time course of increases in blood sup ply varied with each brain region and depended on the type of internal operations occurring during the mental tasks. Changes in the hemoglob in oxygenation state were also different from region to region. This s howed that there were regional variations of the oxygen delivery-oxyge n utilization relationship during activation of brain activity. The us efulness of multichannel near-infrared functional imaging was well doc umented.