Submitted By: Garima Singh (57/CSE/7 th Sem) Guru Tegh Bahadur Institute of Technology
Sources of EEG
Method of EEG
Role of Brain Fingerprinting in criminal proceeding
Current Uses and Applications
Brain Fingerprinting was developed and patented in 1995 by Dr. Lawrence A. Farwell.
Is based on the theory that throughout any action, the brain plans, records, and executes all of the actions.
"Brain Fingerprinting" is a controversial forensic science technique that determines whether specific information is stored in a subject’s brain by measuring electrical brainwave responses to words, phrases, or pictures that are presented on a computer screen.
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.
The system does not require the subject to issue verbal responses to questions or stimuli.
brain fingerprinting uses cognitive brain responses, brain fingerprinting does not depend on the emotions of the subject, nor is it affected by emotional responses.
The person to be tested wears a special headband with electronic sensors that measure the EEG from several locations on the scalp.
The subject views stimuli consisting of words, phrases, or pictures presented on a computer screen. Stimuli are of three types:
“ irrelevant” stimuli that are irrelevant to the investigated situation and to the test subject,
“ target” stimuli that are relevant to the investigated situation and are known to the subject,
“ probe” stimuli that are relevant to the investigated situation and that the subject denies knowing.
A suspect is provided with information as follows :
Information the suspect is expected to know
Information suspect shouldn’t know
Information of crime that only perpetrator would know
Not Guilty Guilty
Electroencephalography (EEG) is the measurement of electrical activity produced by the brain as recorded from electrodes placed on the scalp.
Scalp EEG is collected from tens to hundreds of electrodes positioned on different locations at the surface of the head.
EEG signals (in the range of milli-volts) are amplified and digitalized for later processing
Scalp EEG activity oscillates at multiple frequencies having different characteristic spatial distributions associated with different states of brain functioning such as waking and sleeping.
These oscillations represent synchronized activity over a network of neurons.
Scalp EEG, the recording is obtained by placing electrodes on the scalp.
Each electrode is connected to one input of a differential amplifier and a common system reference electrode is connected to the other input of each differential amplifier
In digital EEG systems, the amplified signal is digitized via an analog-to-digital converter
The P300 (P3) wave is an event related potential (ERP) which can be recorded via electroencephalography (EEG) as a positive deflection in voltage at a latency of roughly 300 ms in the EEG.
The P300 signal is an aggregate recording from a great many neurons.
P300 waveform must be evoked using a stimulus delivered by one of the sensory modalities
The application of Brain Fingerprinting testing in a criminal case involves four phases:
Third -> the domain of science.(scientist)
The first phase is undertaken by a skilled investigator
The second by an interviewer (investigator or scientist)
The fourth by a judge and jury.
The various applications are as follows:-
Test for several forms of employment, especially in dealing with sensitive military and foreign intelligence screening.
Individuals who were “information present” and “information absent”
A group of 17 FBI agents and 4 non-agents were exposed to stimuli.
To detect symptoms of Alzheimer's disease, Mental Depression and other forms of dementia including neurological disorders.
Advertisements (researches are being carried on).
Research has now demonstrated that analysis of the P300 brainwave can show dementia onset and progression. MERMER technology, developed and patented by Brain Fingerprinting Laboratories, includes the P300 brainwave and extends it, providing a more sensitive measure than the P300 alone.
With early diagnosis, the progression of Alzheimer's symptoms can often be delayed through medications and dietary and lifestyle changes.
What specific information do people retain from advertising?
What specific elements in an ad campaign have the most impact?
Which type of media is most effective?
What commercial is the most effective for a single product?
How effective is the product branding strategy?
How effective is an ad campaign in different parts of the world?
What is the correlation between the campaign and the point-of-sale?
How do the effects of campaigns vary with the influence of time?
It does not detect how that information got there.
Brain fingerprinting detects only information, and not intent.
Where the suspect knows everything that the investigators can ask.
Authorities have no information about what crime may have taken place.
General pre-employment or employee screening wherein any number of undesirable activities or intentions may be relevant.
Brain fingerprinting does not detect lies. It simply detects information.
Brain fingerprinting does not determine whether a suspect is guilty or innocent of a crime. This is a legal determination to be made by a judge and jury, not a scientific determination to be made by a computer or a scientist.
the limitations on human memory and the factors affecting it
Farwell LA, Donchin E. The brain detector: P300 in the detection of deception. Psychophysiology 1986; 24:434.
Farwell LA, Donchin E. The truth will out: interrogative polygraphy ("lie detection") with event-related brain potentials. Psychophysiology 1991;28:531-541.
Farwell LA, inventor. Method and apparatus for multifaceted electroencephalographic response analysis (MERA). US patent 5,363,858. 1994 Nov 15.
Farwell LA. Two new twists on the truth detector: brain-wave detection of occupational information. Psychophysiology 1992;29(4A):S3.
Farwell LA, inventor. Method and apparatus for truth detection. US patent 5,406,956. 1995 Apr 18.