Coherent Brain Power Imaging Method

The localization of brain sources plays an important role on clinical diagnosis, cognitive research and rehabilitation. Brain sources can be classified into coherent sources and incoherent ones. Coherence between signals of sensors covering different scalp areas is commonly taken as a measure of functional coupling. Motivated by literature [9], we develop a method of mapping coherent brain sources. The principle of this method is decomposition of correlation coefficient between different channels of EEG. This techniques decomposes, in the terms of the least squares , the mutual correlation coefficient(CC ) matrix into individual CC between any channel and the weighted sum of all the channels, and then utilizes the spatial distribution of the individual CC as the imaging map. Computer simulation test show that compared with power mapping, this algorithm is sensitive to the combination of coherent sources with different energy levels. Real VEP data tests show that it has high sensitivity in localizing 2D coherent sources, it can accurately localize multiple coherent sources, and it is also robust to noise and to referrence. Thus, it is of theoretical significance and of practical value.