Brain Fingerprinting

Brain Fingerprinting is a forensic science technique that uses electroencephalography to determine whether specific information is stored in a subject’s brain. It does this by measuring electrical brainwave responses to words, phrases, or pictures that are presented on a screen.
The technique uses the well known fact that an electrical signal known as P300 is emitted from an individual's brain beginning approximately 300 milliseconds after it is confronted with a stimulus of special significance. The application of this in brain fingerprinting is to detect the P300 as a response to stimuli related to the crime or other investigated situation, e.g., a murder weapon, victim's face, or knowledge of the internal workings of a terrorist cell. The person to be tested wears a special headband with electronic sensors that measure the EEG from several locations on the scalp.
Since brain fingerprinting uses cognitive brain responses and is fundamentally different from the polygraph (lie-detector), which measures emotion-based physiological signals such as heart rate, sweating, and blood pressure.