ABSTRACT
Cortical source localization of scalp electroencephalogram (EEG) is performed under various constraints, according to which the accuracy greatly varies, whereas spatial localization of blood oxygenation level– dependent functional magnetic resonance imaging (fMRI) activities is relatively free of constraint. The central question that must be addressed when interpreting fMRI data is whether an observed change is real, in the sense of being caused by brain activation, or whether it is a random fluctuation caused by the noise in the images. Cardioballistogram or ballistocardiogram causes artifacts in EEG due to the motion of blood through the blood vessels, which are close enough to the EEG electrodes to make them very faintly wobble around due to the motion. This motion is of course strongly dependent upon the pulsation of the heart. The chapter also presents some closing thoughts on the key concepts discussed in the preceding chapters of this book.
