Global component remove program is made by Dr. Zhang, Xian, Brain function lab, Yale school of medicine, Psychiatry department Please site my paper: "Separation of the global and local components in functional near-infrared spectroscopy signals using principal component spatial filtering" and "Signal processing of functional NIRS data acquired during overt speaking" ,which indicats the exist of global component in dexoyHb signal, while thought to be ignorable

Fingertappingtest.m is the sample program.