TECHNIQUES FOR MEASURING BLOOD OXYGENATION

Neural firing is metabolically demanding and results first in a local increase in deoxygenated hemoglobin (deOxy-Hb), followed immediately by a compensatory sustained increase in oxygenated hemoglobin (Oxy-Hb) and subsequent decrease in deOxy-Hb (see Figure 1). The specific relationship of the circulatory system to local changes in neural activity is referred to as neurovascular coupling.