Traditional polygraph techniques mostly rely on the changes of an individual's physiological indicators, such as electrodermal activity, heart rate, breath, eye movement and function of neural signals and other indicators. They are easily affected by individual physical conditions, counter-tests, external environment and other aspects, and it is difficult to conduct large-scale screening tests based on the traditional polygraph techniques. The application of keystroke dynamics to polygraph can overcome the shortcomings of the traditional polygraph techniques to a large extend, increase the reliability of polygraph results and promote the validity of legal evidence of polygraph results in forensic practice. This paper introduces keystroke dynamics and its application in deception research. Compared with the traditional polygraph techniques, keystroke dynamics can be used with a relatively wider application range, not only for deception research but also for identity identification, network screening and other large-scale tests. At the same time, the development direction of keystroke dynamics in the field of polygraph is prospected.
Lie Detection ; Reproducibility of Results ; Forensic Medicine ; Deception

Objective To explore polygraph accuracy of Control Question Test （CQT）and whether it could be influenced by examinee's education level and type of violation of law. Methods Real cases of CQT （n=104） and the data from MAO （n=296） were collected. The polygraph accuracy of CQT was calculated. Variance analysis on three groups of different education levels was used to compare their age, and then the chi-square test was employed to compare polygraph accuracy among the groups. Independent sample t test was used to compare the age of subjects in the two groups of different types of violation of law, and then chi-square test was used to compare the true positive rate and true negative rate of lie detection after integration. Results In CQT lie detection of criminal cases, the true positive rate was 87.00%, the false negative rate was 13.00%, the true negative rate was 82.20%, and the false positive rate was 17.80%. There was no statistical significance in the differences between the true positive rate and the true negative rate （P>0.05）. In CQT lie detection of the groups of different education levels, there was no statistical significance in the differences between the true positive rates （P>0.05） while the differences between the true negative rates had statistical significance （P<0.05）. There was no statistical significance in the differences of both the true positive rates and the true negative rates between the violent violation of law and non-violent violation of law （P>0.05）. Conclusion There is no significant difference between the efficiency of CQT lie detection of identifying criminals and excluding innocents. However, a comparatively high false positive rate and false negative rate still exist. The efficiency of CQT lie detection identifying criminals may not influenced by the examinee's education level and type of violation of law, but its efficiency of excluding innocents may be influenced by the examinee's education level.
Criminals ; Lie Detection ; Monitoring, Physiologic ; Psychophysiology

Objective To investigate the application value of eye tracking in lie detection. Methods The 40 subjects were randomly divided into two groups. The pupil diameter, fixation duration, points of fixation and blink frequency of the subjects in the experimental group in observing target stimulation and non-target stimulation were recorded with eye tracker after they accomplished the mock crime. The eye movement parameters of subjects in the control group were directly collected. The differences in eye movement parameters of the experimental group and the control group in observing target stimulation and non-target stimulation were analyzed by t-test. Pearson coefficient analysis of correlation between eye movement parameters that had differences was conducted. The effectiveness of eye movement parameters to distinguish between the experimental group and the control group was calculated by the receiver operator characteristic （ROC） curve. Results Participants from the experimental group had shorter average pupil diameter, longer average fixation duration and fewer fixation points （P<0.05）, but the differences in blink frequency had no statistical significance. The differences in the above indicators of the control group in observing target stimulation and non-target stimulation had no statistical significance. The average fixation duration showed a negative correlation with fixation points （r=-0.255, P<0.05）; the average fixation duration showed a negative correlation with average pupil diameter （r=-0.218, P<0.05）; the fixation points showed a positive correlation with average pupil diameter （r=0.09, P<0.05）. The area under the curve of average pupil diameter, average fixation duration and fixation points was 0.603, 0.621 and 0.580, respectively. Conclusion The average pupil diameter, average fixation duration and fixation points obtained by the eye tracker under laboratory conditions can be used to detect lies.
Algorithms ; Eye Movements ; Humans ; Lie Detection ; Pupil ; Time Factors

Since the early 2000s, there has been a continued interest in lie detection using functional magnetic resonance imaging (fMRI) in neuroscience and forensic sciences, as well as in newly emerging fields including neuroethics and neurolaw. Related fMRI studies have revealed converging evidence that brain regions including the prefrontal cortex, anterior cingulate cortex, parietal cortex, and anterior insula are associated with deceptive behavior. However, fMRI-based lie detection has thus far not been generally accepted as evidence in court, as methodological shortcomings, generalizability issues, and ethical and legal concerns are yet to be resolved. In the present review, we aim to illustrate these achievements and limitations of fMRI-based lie detection.
Brain ; Deception* ; Forensic Sciences ; Gyrus Cinguli ; Lie Detection* ; Magnetic Resonance Imaging* ; Neurosciences* ; Prefrontal Cortex ; Rabeprazole

Assessment of post-traumatic stress disorder is a frequently encountered problem in forensic practices. Detection of malingering has become a focus in these assessments. While it is a difficult task due to kinds of traumatic events, complex clinical symptoms, subjective medical information, and presence of diverse psychotic disorders. The clinical traits, detecting methods and testing instruments of PTSD malingering were reviewed so as to help practical management and assessment.
Forensic Psychiatry ; Humans ; Lie Detection ; Malingering/diagnosis* ; Stress Disorders, Post-Traumatic/diagnosis*

Lie detection technology has been applied increasingly to investigate and solve criminal cases. This article explores the evolvement of lie detection technology in the ancient times and the application of the psychological and physiological parameters which have become more accurate with the introduction of modern polygraph. The cognitive exploration and the application of Event Related Potentials (ERPs), functional Magnetic Resonance Imaging (fMRI), and Event-Related functional Magnetic Resonance Imaging (E-R fMRI) have made detection technology focus on the brain activities, which produce more objective results by tracing the original state of lying. In summary, this article describes different types of lie detections, simple and complex, their working principles, the latest development, and the prospect of their application in forensic science.
Evoked Potentials ; Forensic Medicine ; Humans ; Lie Detection ; Magnetic Resonance Imaging/methods* ; Psychophysiology/instrumentation*

This paper explores the use of multi-channel event-related potentials (ERP) to identify mentality facticity or detect lie. Some identifiably meaning information, such as subjects' name and birthday, were selected as concealed information to be identified, 15 subjects were tested by concealed information test (CIT) paradigm and their electroencephalographs (EEG) were recorded from 30 electrodes. In virtue of analysis on the statistically significant difference between multi-channel ERPs evoked by probe information and that evoked by irrelevant information, the P300 amplitudes of 15 electrodes were selected as F-test samples. The significant difference of feature sample values between probe and irrelevant information was applied to identify mentality facticity. The results indicate that P300 amplitudes evoked in many electrodes are significantly different between probe and irrelevant information (P < 0.01). According to the significant difference of space sample values between probe and irrelevant information, the detection correctness to probe information reaches to 93.3% and is better than that of methods based single-channel ERP. The method proposed has the advantages of non-invasion and better accuracy, which could be used to identify mentality facticity effectively.
Adult ; Electroencephalography ; methods ; Event-Related Potentials, P300 ; physiology ; Female ; Humans ; Lie Detection ; psychology ; Male ; Neuropsychological Tests ; Young Adult

The event-related potential (ERP) P300 was recorded to analyze the temporal sequences character and the P300 compositions in premeditated and temporary deception. When 15 healthy undergraduates watched the stolen, familiar but not stolen and strange object pictures, the reaction time was recorded and EEG data were collected to analyze the amplitudes of N1, N2 and P3 sub-component of P300 in honesty and deception group respectively through analog theft paradigm. The results showed that the amplitudes of N1, N2 and P3 in premeditated deception group were markedly larger than those in temporary deception, and the reaction time of deception group was longer than that of honesty group. Compared with temporary deception, more attention resources were invested and intensely response conflict was induced by premeditated deception.
Deception ; Electroencephalography ; Event-Related Potentials, P300 ; physiology ; Female ; Humans ; Lie Detection ; Male ; Reaction Time ; physiology ; Young Adult

OBJECTIVE: To examine the self-reported scale of brief psychopathological symptoms (SBPS) to detect malingering in forensic psychiatric cases. METHODS: Two hundred and six cases with different types of psychiatric problems were tested by SBPS. All cases were separately evaluated by two experts. RESULTS: About 34.5% cases (71/206) were classified as malingering by the cut-off 13 scores of SBPS. Compared with expert's evaluation, SBPS showed a false negative rate of 19.8% and a false positive rate of 1.7%, respectively, with a total accuracy rate of 90.8%. Cases involved in compensations including working injury and traffic accidence showed the highest rate of malingering (51%). CONCLUSION SBPS is useful for detecting malingering psychopathological symptoms.
Adult ; Female ; Forensic Psychiatry ; Humans ; Lie Detection ; Male ; Malingering/psychology* ; Mental Disorders/psychology* ; Psychological Tests ; Reproducibility of Results ; Volition ; Young Adult

OBJECTIVE: To investigate the functional magnetic resonance imaging (fMRI) data of deception in antisocial personality disorders (ASPD). METHODS: A total of 32 criminals meeting the criteria for ASPD underwent fMRI at 1.5T while responding truthfully questions or lying. We compared the brain activities between truth-telling and lie-telling, and then computed the correlation coefficient between the contrast brain activities and the inclination to deception. RESULTS: The left anterior cingulate gyrus, the bilateral dorsolateral prefrontal cortex, and left inferior parietal lobule were associated with the executive aspects of deception among people with ASPD. But with the greater inclination to deception, the blood oxygen level dependent (BOLD) activities in those regions decreased. CONCLUSION Evaluations of truthful and untruthful communications pertaining to ASPD subjects may be differentiated in terms of brain BOLD activities, though those activities may decrease in habitual liars, which remains a challenge to the diagnostic accuracy in lie detection.
Adolescent ; Antisocial Personality Disorder ; physiopathology ; psychology ; Brain ; physiology ; Deception ; Humans ; Lie Detection ; Magnetic Resonance Imaging ; Male ; Prefrontal Cortex ; physiology ; Young Adult