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Brain Fingerprinting is a technique that measures recognition of familiar stimuli by measuring electrical brain wave responses to words, phrases, or pictures that are presented on a computer screen. Brain fingerprinting was invented by Dr. Lawrence Farwell.
Theory of operation
The theory is that the suspect's reaction to the details of an event or activity will reflect if the suspect had prior knowledge of the event or activity. This test uses a multifaceted electroencephalographic response to detect familiarity reaction. It is hoped it might be more accurate than a polygraph (lie-detector) test, which measures physiological signals such as heart rate, sweating, and blood pressure.
The person to be tested wears a special headband with electronic sensors that measure the EEG from several locations on the scalp. In order to calibrate the brain fingerprinting system, the testee is first presented with a series of irrelevant stimuli, words, and pictures, and then a series of relevant stimuli, words, and pictures. The testees brain response to these two different types of stimuli allow the testor to determine if the measured brain responses to test stimuli, called probes, are more similar to the relevant or irrelevant responses.
The technique uses the fact that an electrical signal known as P300 is emitted from an individuals brain exactly 300 milliseconds after it is confronted with a stimulus that has special significance to that individual (e.g. a murder weapon or a victim's face).
Because it is based on EEG signals, the system does not require the testee to issue verbal responses to questions or stimuli. Also, unlike polygraph testing, it does not attempt to determine whether or not the testee is lying or telling the truth. Rather, it attempts to measure the testees brain response to a record of relevant words, phrases, or pictures.
Criticisms
Some believe brain fingerprinting needs far more refinement before its use becomes widespread and court cases are decided on its evidence.
Current Uses and Research
It has been tentatively used by the FBI to test for recognition of crime scenes in hope of proving guilt. It is not admissible in court.
Jimmy Ray Slaughter was convicted of the murder of his former girlfriend and their eleven month old daughter. A few months before the execution Dr. Farwell ran the brain fingerprinting on Jimmy Ray and showed he had never seen the crime scene. "Jimmy Ray Slaughter did not know where in the house the murder took place; he didn't know where the mother's body was lying or what was on her clothing at the time of death - a salient fact in the case," says Dr Farwell.
Research into brain fingerprinting is currently being funded by the CIA. Its use has been touted as a means of intelligence gathering to prevent terrorism.
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