Lie detection
Encyclopedia
Lie detection is the practice of attempting to determine whether someone is lying
. Activities of the body not easily controlled by the conscious mind are compared under different circumstances. Usually this involves asking the subject control questions where the answers are known to the examiner and comparing them to questions where the answers are not known. Critics claim that "lie detection" by use of polygraphy has no scientific validity because it is not a scientific procedure.
. Voice stress analysis
may also be commonly used because it can be applied covertly to monitor voice recordings. The polygraph detects changes in body functions not easily controlled by the conscious mind. These include bodily reactions like skin conductivity and heart rate
.
Cognitive polygraph
Recent developments that permit non-invasive monitoring using functional transcranial Doppler (fTCD) technique showed that successful problem-solving employs a discrete knowledge strategy (DKS) that selects neural pathways represented in one hemisphere, while unsuccessful outcome implicates a non-discrete knowledge strategy (nDKS). A polygraphic test could be viewed as a working memory task. This suggests that the DKS model may have a correlate in mnemonic operations. In other words, the DKS model may have a discrete knowledge base (DKB) of essential components needed for task resolution, while for nDKS, DKB is absent and, hence, a "global" or bi-hemispheric search occurs. Based on the latter premise, a 'lie detector' system was designed as described in . A pattern of blood-flow-velocity changes is obtained in response to questions that include correct and incorrect answers. The wrong answer will elicit bi-hemispheric activation, from correct answer that activates unilateral response. Cognitive polygraphy based on this system is devoid of any subjective control of mental processes and, hence, high reliability and specificity; however, this is yet to be tested in forensic practice. See also cognitive biometrics
.
(fMRI) have shown that it has potential to be used as a method of lie detection. While a polygraph detects changes in activity in the peripheral nervous system
, fMRI has the potential to catch the lie at the ‘source’. However, the neurobiological systems that relate to lying are currently poorly understood. The current consensus is that faced with a forced choice paradigm, in which a subject has the choice of telling the truth or spontaneously generating a lie, lying can be distinguished due to increased prefrontal
and parietal lobe
activity. More specifically, the superiormedial and inferolateral prefrontal cortices
show net activation in the process of spontaneous lie generation (which involves suppression of the truthful response as well as generating a conceivable lie). Subjects are often offered monetary incentive if they can successfully deceive the process in hopes of generating a ‘real world’ scenario. Using this method, studies have shown that lies can be distinguished 78% of the time. That statistic can rise as high as 85–90% when predicting a lie in an individual whose baseline lie/truth levels have been closely studied, although this does rely upon the individual being co-operative.
There are currently two companies: No Lie MRI
Inc. and Cephos Corporation) who plan to advance this technology for commercial use.
In episode 93 of the TV program Mythbusters
, the three members of the build team attempted to fool an fMRI test. Although two of them were unsuccessful, the third was able to successfully fool the machine by keeping his mind in constant activity, suggesting that fMRI-based lie detection still requires further development.
is used to detect changes in brain waves.
Brain fingerprinting
uses electroencephalography
to determine if an image is familiar to the subject. This could detect deception indirectly but is not a technique for lie detecting.
Cognitive chronometry
, or the measurement of the time taken to perform mental operations, can be used to distinguish lying from truth-telling. One recent instrument using cognitive chronometry for this purpose is the Timed Antagonistic Response Alethiometer
, or TARA.
Brain-reading
uses fMRI and the multiple voxels activated in the brain evoked by a stimulus to determine what the brain has detected, and so whether it is familiar or not.
. Silent Talker monitors large numbers of Microexpression
s over time slots and encodes them into large vectors which are classified as showing truthful or deceptive behaviour by artificial intelligence or statistical classifiers. Silent Talker research has been peer-reviewed in the Journal of Applied Cognitive Psychology and in the Journal of Neural Computing and Applications . The architecture was invented between 2000 and 2002 by a team at Manchester Metropolitan University
.
s such as sodium thiopental
and marijuana (historically speaking) are used for the purposes of obtaining accurate information from an unwilling subject. Information obtained by publicly disclosed truth drugs has been shown to be highly unreliable, with subjects apparently freely mixing fact and fantasy. Much of the claimed effect relies on the belief of the subjects that they cannot tell a lie while under the influence of the drug.
sued the academic publisher for libel and forced a removal of the article from the online databases. In a letter to the publisher, Nemesysco's lawyers wrote that the authors of the article could be sued for defamation if they wrote on the subject again.
The cumulative research evidence suggests that machines do detect deception better than chance, but with significant error rates and that strategies used to "beat" polygraph examinations, so-called countermeasures, may be effective. Despite unreliability, results are admissible
in court in some countries such as the United States.
Clark Freshman, Professor of Law at University of California, Hastings College of Law, studies lies in negotiations and lies involving lawyers. Together with Michael Wheeler at Harvard Business School, he developed a series of clips of how lies – and concealed emotions – show up in real estate negotiations. His scholarship on lies and negotiations goes well beyond Paul Ekman
's original theories. Freshman and Wheeler found microexpressions of emotion and other clues in their research on negotiation.
Lie
For other uses, see Lie A lie is a type of deception in the form of an untruthful statement, especially with the intention to deceive others....
. Activities of the body not easily controlled by the conscious mind are compared under different circumstances. Usually this involves asking the subject control questions where the answers are known to the examiner and comparing them to questions where the answers are not known. Critics claim that "lie detection" by use of polygraphy has no scientific validity because it is not a scientific procedure.
Polygraph
Lie detection commonly involves the polygraphPolygraph
A polygraph measures and records several physiological indices such as blood pressure, pulse, respiration, and skin conductivity while the subject is asked and answers a series of questions...
. Voice stress analysis
Voice stress analysis
Voice Stress Analysis technology is said to record psychophysiological stress responses that are present in human voice, when a person suffers psychological stress in response to a stimulus and where the consequences may be dire for the subject being 'tested'.In the Detection Of Deception ...
may also be commonly used because it can be applied covertly to monitor voice recordings. The polygraph detects changes in body functions not easily controlled by the conscious mind. These include bodily reactions like skin conductivity and heart rate
Heart rate
Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
.
Cognitive polygraph
Recent developments that permit non-invasive monitoring using functional transcranial Doppler (fTCD) technique showed that successful problem-solving employs a discrete knowledge strategy (DKS) that selects neural pathways represented in one hemisphere, while unsuccessful outcome implicates a non-discrete knowledge strategy (nDKS). A polygraphic test could be viewed as a working memory task. This suggests that the DKS model may have a correlate in mnemonic operations. In other words, the DKS model may have a discrete knowledge base (DKB) of essential components needed for task resolution, while for nDKS, DKB is absent and, hence, a "global" or bi-hemispheric search occurs. Based on the latter premise, a 'lie detector' system was designed as described in . A pattern of blood-flow-velocity changes is obtained in response to questions that include correct and incorrect answers. The wrong answer will elicit bi-hemispheric activation, from correct answer that activates unilateral response. Cognitive polygraphy based on this system is devoid of any subjective control of mental processes and, hence, high reliability and specificity; however, this is yet to be tested in forensic practice. See also cognitive biometrics
Biometrics
Biometrics As Jain & Ross point out, "the term biometric authentication is perhaps more appropriate than biometrics since the latter has been historically used in the field of statistics to refer to the analysis of biological data [36]" . consists of methods...
.
fMRI
Studies using functional magnetic resonance imagingFunctional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
(fMRI) have shown that it has potential to be used as a method of lie detection. While a polygraph detects changes in activity in the peripheral nervous system
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
, fMRI has the potential to catch the lie at the ‘source’. However, the neurobiological systems that relate to lying are currently poorly understood. The current consensus is that faced with a forced choice paradigm, in which a subject has the choice of telling the truth or spontaneously generating a lie, lying can be distinguished due to increased prefrontal
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
and parietal lobe
Parietal lobe
The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
activity. More specifically, the superiormedial and inferolateral prefrontal cortices
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
show net activation in the process of spontaneous lie generation (which involves suppression of the truthful response as well as generating a conceivable lie). Subjects are often offered monetary incentive if they can successfully deceive the process in hopes of generating a ‘real world’ scenario. Using this method, studies have shown that lies can be distinguished 78% of the time. That statistic can rise as high as 85–90% when predicting a lie in an individual whose baseline lie/truth levels have been closely studied, although this does rely upon the individual being co-operative.
There are currently two companies: No Lie MRI
No Lie MRI
No Lie MRI is a San Diego-based company which has been offering brain-scan lie detection services using functional magnetic resonance imaging since 2006. Its president is Joel Huizenga...
Inc. and Cephos Corporation) who plan to advance this technology for commercial use.
In episode 93 of the TV program Mythbusters
MythBusters
MythBusters is a science entertainment TV program created and produced by Beyond Television Productions for the Discovery Channel. The series is screened by numerous international broadcasters, including Discovery Channel Australia, Discovery Channel Latin America, Discovery Channel Canada, Quest...
, the three members of the build team attempted to fool an fMRI test. Although two of them were unsuccessful, the third was able to successfully fool the machine by keeping his mind in constant activity, suggesting that fMRI-based lie detection still requires further development.
Brain observations
ElectroencephalographyElectroencephalography
Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...
is used to detect changes in brain waves.
Brain fingerprinting
Brain fingerprinting
P300 - Brain Fingerprinting is a discarded and highly controversial forensic science technique that uses electroencephalography to determine whether specific information is stored in a subject’s brain...
uses electroencephalography
Electroencephalography
Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...
to determine if an image is familiar to the subject. This could detect deception indirectly but is not a technique for lie detecting.
Cognitive chronometry
Cognitive chronometry
Cognitive chronometry refers to the systematic measurement of response time as a means of illuminating either mental operations or mental associations. Two measuring instruments relying on cognitive chronometry are the Implicit Association Test, or IAT, and the Timed Antagonistic Response...
, or the measurement of the time taken to perform mental operations, can be used to distinguish lying from truth-telling. One recent instrument using cognitive chronometry for this purpose is the Timed Antagonistic Response Alethiometer
Timed Antagonistic Response Alethiometer
The Timed Antagonistic Response Alethiometer, or TARA, is a type of lie detection technique that relies upon cognitive chronometry.The TARA is a computer-based technique. It requires respondents to classify a succession of mixed statements as true or false, as quickly and accurately as they can, by...
, or TARA.
Brain-reading
Brain-reading
Brain-reading uses the responses of multiple voxels in the brain evoked by stimulus and then detected by fMRI in order to decode the original stimulus...
uses fMRI and the multiple voxels activated in the brain evoked by a stimulus to determine what the brain has detected, and so whether it is familiar or not.
Non-Verbal Behaviour
Non-invasive lie detection using non-verbal behaviour is performed by the Silent Talker Lie DetectorSilent Talker Lie Detector
The Silent Talker Lie Detector is a lie detector which observes and analyses non-verbal behaviour in the form of micro-gestures while a subject is being interviewed. It is grounded in the psychological theory that non-verbal behaviour is modified by a number of influences when a person is being...
. Silent Talker monitors large numbers of Microexpression
Microexpression
A microexpression is a brief, involuntary facial expression shown on the face of humans according to emotions experienced. They usually occur in high-stakes situations, where people have something to lose or gain. Unlike regular facial expressions, it is difficult to fake microexpressions...
s over time slots and encodes them into large vectors which are classified as showing truthful or deceptive behaviour by artificial intelligence or statistical classifiers. Silent Talker research has been peer-reviewed in the Journal of Applied Cognitive Psychology and in the Journal of Neural Computing and Applications . The architecture was invented between 2000 and 2002 by a team at Manchester Metropolitan University
Manchester Metropolitan University
Manchester Metropolitan University is a university in North West England. Its headquarters and central campus is in the city of Manchester, but there are outlying facilities in the county of Cheshire. It is the third largest university in the United Kingdom in terms of student numbers, behind the...
.
Drugs
Truth drugTruth drug
A truth drug or truth serum is a psychoactive medication used to obtain information from subjects who are unable or unwilling to provide it otherwise. The unethical use of truth drugs is classified as a form of torture according to international law. However, they are properly and productively...
s such as sodium thiopental
Sodium thiopental
Sodium thiopental, better known as Sodium Pentothal , thiopental, thiopentone sodium, or Trapanal , is a rapid-onset short-acting barbiturate general anaesthetic...
and marijuana (historically speaking) are used for the purposes of obtaining accurate information from an unwilling subject. Information obtained by publicly disclosed truth drugs has been shown to be highly unreliable, with subjects apparently freely mixing fact and fantasy. Much of the claimed effect relies on the belief of the subjects that they cannot tell a lie while under the influence of the drug.
Controversy
In the peer-reviewed academic article "Charlatanry in forensic speech science", the authors reviewed 50 years of lie detector research and came to the conclusion that there is no scientific evidence supporting that lie detectors actually work. Lie detector manufacturer NemesyscoNemesysco
Nemesysco is an Israeli company that makes lie detectors and other products based on voice analysis. They have been used in airports in Israel and Russia, by insurance companies and social security helplines in the United Kingdom and sold to consumers. It has raised controversy about privacy and...
sued the academic publisher for libel and forced a removal of the article from the online databases. In a letter to the publisher, Nemesysco's lawyers wrote that the authors of the article could be sued for defamation if they wrote on the subject again.
The cumulative research evidence suggests that machines do detect deception better than chance, but with significant error rates and that strategies used to "beat" polygraph examinations, so-called countermeasures, may be effective. Despite unreliability, results are admissible
Admissible evidence
Admissible evidence, in a court of law, is any testimonial, documentary, or tangible evidence that may be introduced to a factfinder—usually a judge or jury—in order to establish or to bolster a point put forth by a party to the proceeding...
in court in some countries such as the United States.
Clark Freshman, Professor of Law at University of California, Hastings College of Law, studies lies in negotiations and lies involving lawyers. Together with Michael Wheeler at Harvard Business School, he developed a series of clips of how lies – and concealed emotions – show up in real estate negotiations. His scholarship on lies and negotiations goes well beyond Paul Ekman
Paul Ekman
Paul Ekman is a psychologist who has been a pioneer in the study of emotions and their relation to facial expressions. He has been considered one of the 100 most eminent psychologists of the twentieth century...
's original theories. Freshman and Wheeler found microexpressions of emotion and other clues in their research on negotiation.