Electroencephalography (EEG) is a neuroimaging technique which measures minute electrical current arising from the brain measured through the scalp. It works on similar principals as electrocardiogram (or ECG) used in assessment of cardiac problems. EEG has been used in the assessment of epilepsy, but with improvements in computer technology a variation in this technique called Quantitative EEG (qEEG) is allowing  its use in study of psychiatric conditions. qEEG enables sophisticated analysis of individual brainwaves and  their comparisons with normative databases allowing more precise diagnosis and treatment. This neuroimaging technique is completely non-invasive and does not involve strong radiation or magnetic field. qEEG is commonly known as Brain Mapping.

qEEGs are commonly used in assessment of cognitive and psychiatric problems, head traumas, Neurofeedback, and peak performance training. qEEG is also used in making pharmacological decisions- for example,  medication will benefit most (Pharmaco-EEG); in assessing effect of medication on brain; and monitoring brain functioning over time.

qEEGs are utilized all over the world in research into psychiatric conditions such as ADHD, autism spectrum disorders, depression, bipolar disorder, anxiety and PTSD, to name a few.

Another indication of qEEG is in recording Event-related potentials (ERPs) which provide quite specific measure of flow of information within the brain under different conditions. Together, qEEG and ERP provide us with deeper understanding of brain which is not available with other neuroimaging techniques and is helpful in making better-informed treatment decisions.