31-03-2011, 09:32 AM
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1 INTRODUCTION:
Brain Fingerprinting is a controversial proposed investigative 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 Lawrence Farwell. 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 what Farwell calls the MERMER ("Memory and Encoding Related Multifaceted Electroencephalographic Response") response to detect familiarity reaction. One of the applications is lie detection. Dr. Lawrence A. Farwell has invented, developed, proven, and patented the technique of Farwell Brain Fingerprinting, a new computer-based technology to identify the perpetrator of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. Farwell Brain Fingerprinting has proven 100% accurate in over 120 tests, including tests on FBI agents, tests for a US intelligence agency and for the US Navy, and tests on real-life situations including actual crimes.
1.1 DEFINITION:
Brain Fingerprinting is designed to determine whether an individual recognizes specific information related to an event or activity by measuring electrical brain wave responses to words, phrases, or pictures presented on a computer screen. The technique can be applied only in situations where investigators have a sufficient amount of specific information about an event or activity that would be known only to the perpetrator and Investigator. In this respect, Brain Fingerprinting is considered a type of Guilty Knowledge
Test, where the "guilty" party is expected to react strongly to the relevant detail of the event of activity.
Existing (polygraph) procedures for assessing the validity of a suspect's "guilty" knowledge rely on measurement of autonomic arousal (e.g., palm sweating and heart rate), while Brain Fingerprinting measures electrical brain activity via a fitted headband containing special sensors.
Brain Fingerprinting is said to be more accurate in detecting "guilty" knowledge distinct from the false positives of traditional polygraph methods, but this is hotly disputed by specialized researchers.
1.2 TECHNIQUE:
The person to be tested wears a special headband with electronic sensors that measure the electroencephalography from several locations on the scalp. In order to calibrate the brain fingerprinting system, the testee is presented with a series of irrelevant stimuli, words, and pictures, and a series of relevant stimuli, words, and pictures. The test subject's 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 well known fact that an electrical signal known as P300 is emitted from an individual's brain approximately 300 milliseconds after it is confronted with a stimulus of special significance, e.g. a rare vs. a common stimuls or a stimulus the proband is asked to count. The novel interpretation in brain fingerprinting is to look for P300 as response to stimuli related to the crime in question 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.
Brain fingerprinting uses cognitive brain responses, brain finger printing does not depend on the emotions of the subject, nor is it affected by emotional responses. Brain fingerprinting is fundamentally different from the polygraph (lie-detector), which measures emotion-based physiological signals such as heart rate, sweating, and blood pressure. Also, unlike polygraph testing, it does not attempt to determine whether or not the subject is lying or telling the truth.
2 ELECTROENCEPHALOGRAPHY:
Electroencephalography (EEG) is the measurement of electrical activity produced by the brain as recorded from electrodes placed on the scalp. Just as the activity in a computer can be understood on multiple levels, from the activity of individual transistors to the function of applications, so can the electrical activity of the brain be described on relatively small to relatively large scales. At one end are action potentials in a single axon or currents within a single dendrite of a single neuron, and at the other end is the activity measured by the EEG which aggregates the electric voltage fields from millions of neurons. So-called 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. The data measured by the scalp EEG are used for clinical and research purposes.
2.1 SOURCE OF EEG ACTIVITY:
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. The neuronal networks underlying some of these oscillations are understood (such as the thalamocortical resonance underlying sleep spindles) while many others are not (e.g. the system that generates the posterior basic rhythm).
2.2 EEG VS FMRI AND PET:
EEG has several strong sides as a tool of exploring brain activity; for example, its time resolution is very high (on the level of a single millisecond). Other methods of looking at brain activity, such as PET and FMRI have time resolution between seconds and minutes.
EEG measures the brain's electrical activity directly, while other methods record changes in blood flow (e.g., SPECT, FMRI) or metabolic activity (e.g., PET), which are indirect markers of brain electrical activity.
EEG can be used simultaneously with FMRI so that high-temporal-resolution data can be recorded at the same time as high-spatial-resolution data, however, since the data derived from each occurs over a different time course, the data sets do not necessarily represent the exact same brain activity. There are technical difficulties associated with combining these two modalities like currents can be induced in moving EEG electrode wires due to the magnetic field of the MRI.
EEG can be recorded at the same time as MEG so that data from these complimentary high-time-resolution techniques can be combined. Magneto-encephalography (MEG) is an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices (SQUIDs). These measurements are commonly used in both research and clinical settings. There are many uses for the MEG, including assisting surgeons in localizing pathology, assisting researchers in determining the function of various parts of the brain, neuro-feedback, and others.
2.3 METHOD:
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. These amplifiers amplify the voltage between the active electrode and the reference (typically 1,000–100,000 times, or 60–100 dB of voltage gain). A typical adult human EEG signal is about 10µV to 100 µV in amplitude when measured from the scalp [2] and is about 10–20 mV when measured from subdural electrodes. In digital EEG systems, the amplified signal is digitized via an analog-to-digital converter, after being passed through an anti-aliasing filter. Since an EEG voltage signal represents a difference between the voltages at two electrodes, the display of the EEG for the reading encephalographer may be set up in one of several ways.
3 ROLE IN CRIMINAL PROCEEDINGS:
The application of Brain Fingerprinting testing in a criminal case involves four phases: investigation, interview, scientific testing, and adjudication. Of these four phases, only the third one is in the domain of science. The first phase is undertaken by a skilled investigator, the second by an interviewer who may be an investigator or a scientist, the third by a scientist, and the fourth by a judge and jury.
This is similar to the forensic application of other sciences. For example, if a person is found dead of unknown causes, first there is an investigation to determine if there may have been foul play. If there is a suspect involved, the suspect is interviewed to determine what role, if any, he says he has had in the situation. If the investigation determines that the victim may have been poisoned using ricin or cadmium, two rare and powerful poisons, then scientific tests can be conducted to detect these specific substances in the body. Then the evidence accumulated through the test, the investigation, and the interview are presented to a judge and jury, who make the adjudication as to whether a particular suspect is guilty of a particular crime. In such a case, the science of forensic toxicology reveals only whether or not specific toxins are in the body. It does not tell us when or where to look for toxins, or which toxins to look for. We must rely on investigation to provide the necessary guidance on these issues. The science of forensic toxicology also does not tell us whether a particular suspect is innocent or guilty of a crime. The question of guilt or innocence is a legal one, not a scientific one, and the adjudication is made by a judge and jury, and not by a scientist or a computer.
3.1 PHASE 1: Investigation
The first phase in applying Brain Fingerprinting testing in a criminal case is an investigation of the crime. Before a Brain Fingerprinting test can be applied, an investigation must be undertaken to discover information that can be used in the test. The science of Brain Fingerprinting accurately determines whether or not specific information is stored in a specific person’s brain. It detects the presence or absence of specific information in the brain. Before we can conduct this scientific test, we need to determine what information to test for. This investigation precedes and informs the scientific phase which constitutes the Brain Fingerprinting test itself. The role of investigation is to find specific information that will be useful in a Brain Finger printing test. As with any scientific test, if the outcome of the Brain Fingerprinting test is to be useful evidence for a judge and jury to consider in reaching their verdict, then the information tested must have a bearing on the perpetration of the crime.
3.2 PHASE 2: Interview of Subject
Once evidence has been accumulated through investigation, and before the Brain Fingerprinting test is conducted to determine if the evidence can be linked to the suspect, it can in some cases be very valuable to obtain the suspect’s account of the situation. For example, if an investigation shows that specific fingerprints are found at the scene of a murder, a suspect can be interviewed to determine if there may be some legitimate reason that his prints are there. If the suspect’s story is that he was never at the scene of the crime, then a match between his fingerprints and the fingerprints at that scene would be highly incriminating. If, on the other hand, the suspect’s story is that he was at the scene for some legitimate reason just before the crime, then fingerprints must be interpreted differently, particularly if there is corroborating evidence of the suspect’s presence at the scene before the crime.
The interview with the suspect may help to determine which scientific tests to conduct, or how to conduct the tests. For example, a suspect may say that he entered and then left the room where a murder was committed a short time before the murder, and that he never saw or handled the murder weapon. In this context, a finding that the suspect’s fingerprints matched the fingerprints on the doorknob would have little value, but a finding that his fingerprints matched those on the murder weapon would provide incriminating evidence.
Prior to a Brain Fingerprinting test, an interview of the suspect is conducted. The suspect is asked if he would have any legitimate reason for knowing any of the information that is contained in the potential probe stimuli. This information is described without revealing which stimuli are probes and which are irrelevant. For example, the suspect may be asked, “The newspaper reports, which you no doubt have read, say that the victim was struck with a blunt object. Do you have any way of knowing whether that murder weapon was a baseball bat, a broom handle, or a blackjack?” If the suspect answers “No,” then a test result indicating that his brain does indeed contain a record of which of these is the murder weapon can provide evidence relevant to the case.
1 INTRODUCTION:
Brain Fingerprinting is a controversial proposed investigative 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 Lawrence Farwell. 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 what Farwell calls the MERMER ("Memory and Encoding Related Multifaceted Electroencephalographic Response") response to detect familiarity reaction. One of the applications is lie detection. Dr. Lawrence A. Farwell has invented, developed, proven, and patented the technique of Farwell Brain Fingerprinting, a new computer-based technology to identify the perpetrator of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. Farwell Brain Fingerprinting has proven 100% accurate in over 120 tests, including tests on FBI agents, tests for a US intelligence agency and for the US Navy, and tests on real-life situations including actual crimes.
1.1 DEFINITION:
Brain Fingerprinting is designed to determine whether an individual recognizes specific information related to an event or activity by measuring electrical brain wave responses to words, phrases, or pictures presented on a computer screen. The technique can be applied only in situations where investigators have a sufficient amount of specific information about an event or activity that would be known only to the perpetrator and Investigator. In this respect, Brain Fingerprinting is considered a type of Guilty Knowledge
Test, where the "guilty" party is expected to react strongly to the relevant detail of the event of activity.
Existing (polygraph) procedures for assessing the validity of a suspect's "guilty" knowledge rely on measurement of autonomic arousal (e.g., palm sweating and heart rate), while Brain Fingerprinting measures electrical brain activity via a fitted headband containing special sensors.
Brain Fingerprinting is said to be more accurate in detecting "guilty" knowledge distinct from the false positives of traditional polygraph methods, but this is hotly disputed by specialized researchers.
1.2 TECHNIQUE:
The person to be tested wears a special headband with electronic sensors that measure the electroencephalography from several locations on the scalp. In order to calibrate the brain fingerprinting system, the testee is presented with a series of irrelevant stimuli, words, and pictures, and a series of relevant stimuli, words, and pictures. The test subject's 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 well known fact that an electrical signal known as P300 is emitted from an individual's brain approximately 300 milliseconds after it is confronted with a stimulus of special significance, e.g. a rare vs. a common stimuls or a stimulus the proband is asked to count. The novel interpretation in brain fingerprinting is to look for P300 as response to stimuli related to the crime in question 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.
Brain fingerprinting uses cognitive brain responses, brain finger printing does not depend on the emotions of the subject, nor is it affected by emotional responses. Brain fingerprinting is fundamentally different from the polygraph (lie-detector), which measures emotion-based physiological signals such as heart rate, sweating, and blood pressure. Also, unlike polygraph testing, it does not attempt to determine whether or not the subject is lying or telling the truth.
2 ELECTROENCEPHALOGRAPHY:
Electroencephalography (EEG) is the measurement of electrical activity produced by the brain as recorded from electrodes placed on the scalp. Just as the activity in a computer can be understood on multiple levels, from the activity of individual transistors to the function of applications, so can the electrical activity of the brain be described on relatively small to relatively large scales. At one end are action potentials in a single axon or currents within a single dendrite of a single neuron, and at the other end is the activity measured by the EEG which aggregates the electric voltage fields from millions of neurons. So-called 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. The data measured by the scalp EEG are used for clinical and research purposes.
2.1 SOURCE OF EEG ACTIVITY:
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. The neuronal networks underlying some of these oscillations are understood (such as the thalamocortical resonance underlying sleep spindles) while many others are not (e.g. the system that generates the posterior basic rhythm).
2.2 EEG VS FMRI AND PET:
EEG has several strong sides as a tool of exploring brain activity; for example, its time resolution is very high (on the level of a single millisecond). Other methods of looking at brain activity, such as PET and FMRI have time resolution between seconds and minutes.
EEG measures the brain's electrical activity directly, while other methods record changes in blood flow (e.g., SPECT, FMRI) or metabolic activity (e.g., PET), which are indirect markers of brain electrical activity.
EEG can be used simultaneously with FMRI so that high-temporal-resolution data can be recorded at the same time as high-spatial-resolution data, however, since the data derived from each occurs over a different time course, the data sets do not necessarily represent the exact same brain activity. There are technical difficulties associated with combining these two modalities like currents can be induced in moving EEG electrode wires due to the magnetic field of the MRI.
EEG can be recorded at the same time as MEG so that data from these complimentary high-time-resolution techniques can be combined. Magneto-encephalography (MEG) is an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices (SQUIDs). These measurements are commonly used in both research and clinical settings. There are many uses for the MEG, including assisting surgeons in localizing pathology, assisting researchers in determining the function of various parts of the brain, neuro-feedback, and others.
2.3 METHOD:
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. These amplifiers amplify the voltage between the active electrode and the reference (typically 1,000–100,000 times, or 60–100 dB of voltage gain). A typical adult human EEG signal is about 10µV to 100 µV in amplitude when measured from the scalp [2] and is about 10–20 mV when measured from subdural electrodes. In digital EEG systems, the amplified signal is digitized via an analog-to-digital converter, after being passed through an anti-aliasing filter. Since an EEG voltage signal represents a difference between the voltages at two electrodes, the display of the EEG for the reading encephalographer may be set up in one of several ways.
3 ROLE IN CRIMINAL PROCEEDINGS:
The application of Brain Fingerprinting testing in a criminal case involves four phases: investigation, interview, scientific testing, and adjudication. Of these four phases, only the third one is in the domain of science. The first phase is undertaken by a skilled investigator, the second by an interviewer who may be an investigator or a scientist, the third by a scientist, and the fourth by a judge and jury.
This is similar to the forensic application of other sciences. For example, if a person is found dead of unknown causes, first there is an investigation to determine if there may have been foul play. If there is a suspect involved, the suspect is interviewed to determine what role, if any, he says he has had in the situation. If the investigation determines that the victim may have been poisoned using ricin or cadmium, two rare and powerful poisons, then scientific tests can be conducted to detect these specific substances in the body. Then the evidence accumulated through the test, the investigation, and the interview are presented to a judge and jury, who make the adjudication as to whether a particular suspect is guilty of a particular crime. In such a case, the science of forensic toxicology reveals only whether or not specific toxins are in the body. It does not tell us when or where to look for toxins, or which toxins to look for. We must rely on investigation to provide the necessary guidance on these issues. The science of forensic toxicology also does not tell us whether a particular suspect is innocent or guilty of a crime. The question of guilt or innocence is a legal one, not a scientific one, and the adjudication is made by a judge and jury, and not by a scientist or a computer.
3.1 PHASE 1: Investigation
The first phase in applying Brain Fingerprinting testing in a criminal case is an investigation of the crime. Before a Brain Fingerprinting test can be applied, an investigation must be undertaken to discover information that can be used in the test. The science of Brain Fingerprinting accurately determines whether or not specific information is stored in a specific person’s brain. It detects the presence or absence of specific information in the brain. Before we can conduct this scientific test, we need to determine what information to test for. This investigation precedes and informs the scientific phase which constitutes the Brain Fingerprinting test itself. The role of investigation is to find specific information that will be useful in a Brain Finger printing test. As with any scientific test, if the outcome of the Brain Fingerprinting test is to be useful evidence for a judge and jury to consider in reaching their verdict, then the information tested must have a bearing on the perpetration of the crime.
3.2 PHASE 2: Interview of Subject
Once evidence has been accumulated through investigation, and before the Brain Fingerprinting test is conducted to determine if the evidence can be linked to the suspect, it can in some cases be very valuable to obtain the suspect’s account of the situation. For example, if an investigation shows that specific fingerprints are found at the scene of a murder, a suspect can be interviewed to determine if there may be some legitimate reason that his prints are there. If the suspect’s story is that he was never at the scene of the crime, then a match between his fingerprints and the fingerprints at that scene would be highly incriminating. If, on the other hand, the suspect’s story is that he was at the scene for some legitimate reason just before the crime, then fingerprints must be interpreted differently, particularly if there is corroborating evidence of the suspect’s presence at the scene before the crime.
The interview with the suspect may help to determine which scientific tests to conduct, or how to conduct the tests. For example, a suspect may say that he entered and then left the room where a murder was committed a short time before the murder, and that he never saw or handled the murder weapon. In this context, a finding that the suspect’s fingerprints matched the fingerprints on the doorknob would have little value, but a finding that his fingerprints matched those on the murder weapon would provide incriminating evidence.
Prior to a Brain Fingerprinting test, an interview of the suspect is conducted. The suspect is asked if he would have any legitimate reason for knowing any of the information that is contained in the potential probe stimuli. This information is described without revealing which stimuli are probes and which are irrelevant. For example, the suspect may be asked, “The newspaper reports, which you no doubt have read, say that the victim was struck with a blunt object. Do you have any way of knowing whether that murder weapon was a baseball bat, a broom handle, or a blackjack?” If the suspect answers “No,” then a test result indicating that his brain does indeed contain a record of which of these is the murder weapon can provide evidence relevant to the case.
