In order to monitor brain activity, scientists can use many different techniques, the three most important being the EEG, the fMRI, and MEG.
EEG stands for electroencephalography, a method that measures the electrical activity of the brain.
fMRI monitors the flow of blood into different parts of the brain because the parts of the brain that are active need more oxygen that blood is delivering.
MEG measures another aspect of brain activity, the magnetic field that the brain's electrical activity is inducing.
