Several technologies are used to map the brain activity in humans: Positron Emission Tomography (PET), Single-Photon Emission Computerized Tomography (SPECT), Functional Magnetic Resonance Imaging (fMRI) and Electroencephalography (EEG). PET and SPECT require use of positron-emitting molecules (tracer) that restrict their application in human studies. fMRI and MEG demand high cost equipment and special facilities that makes implementation of ecological studies about human decision making difficult. In addition, fMRI has a low temporal resolution although providing an excellent spatial discrimination of brain activity. EEG records electrical cortical activity at very speedy rates but it has been criticized to have low spatial resolution and to be unable to sense subcortical activity. However, recent developments have improved significantly the EEG cortical spatial resolution.
The EEG portability makes its use very easy not only in friendly human environments but also in places where professional activities are performed. Because of this, EEG was used here to record brain activity associated to financial decision making in simulated trading conditions; moral dilemma judgment; vote decision one week before Election Day; and analysis of Media Propaganda broadcasted by TV and Radio to influence voter decision.