Extraction and Localization of Alpha Activity of the Brain in EEG and fMRI Using Constrained ICA

In order to extract only the alpha activity related EEG signals of the brain, we have applied constrained independent component analysis (cICA), a new extension of ICA in which some a priori knowledge of alpha activity is utilized to extract desired components. Its performance has been compared to that of conventional band-pass filtering via the scalp power maps of alpha activity. The preliminary results show that cICA-extracted alpha signals produce the alpha power maps which spatially match the activated regions of the brain mapped using fMRI more closely than those from the band-pass filtered alpha EEG signals. The use of cICA might provide a more effective means of extracting EEG alpha activity of the brain.