ABSTRACT
The concealed information test (CIT) assesses an examinee's crime-relevant memory on the basis of physiological differences between crime-relevant and irrelevant items. The CIT based on autonomic measures has been used for criminal investigations, while the CIT based on event-related potentials (ERPs) has been suggested as a useful alternative. To combine these two methods, we developed a quantification method of ERPs measured in the autonomic-based CIT where each item was repeated only 5 times. Results showed that the peak amplitude of the ERP difference wave between crime-relevant and irrelevant items could discriminate between guilty and innocent participants effectively even when only 5 trials were used for averaging. This ERP measure could detect some participants who were missed by the autonomic measures. Combining the ERP and autonomic measures significantly improved the discrimination performance of the autonomic-based CIT.
Subject(s)
Autonomic Nervous System/physiology , Discrimination, Psychological/physiology , Evoked Potentials/physiology , Lie Detection/psychology , Acoustic Stimulation , Adult , Data Interpretation, Statistical , Electroencephalography , Event-Related Potentials, P300/physiology , Female , Galvanic Skin Response , Heart Rate/physiology , Humans , Male , Middle Aged , Neuropsychological Tests , ROC Curve , Regional Blood Flow/physiology , Respiratory Rate , Skin/blood supply , Young AdultABSTRACT
A Concealed Information Test (CIT) investigates differential physiological responses to deed-related (probe) vs. irrelevant items. The present study focused on the detection of concealed information using simultaneous recordings of autonomic and brain electrical measures. As a secondary issue, verbal and pictorial presentations were compared with respect to their influence on the recorded measures. Thirty-one participants underwent a mock-crime scenario with a combined verbal and pictorial presentation of nine items. The subsequent CIT, designed with respect to event-related potential (ERP) measurement, used a 3-3.5s interstimulus interval. The item presentation modality, i.e. pictures or written words, was varied between subjects; no response was required from the participants. In addition to electroencephalogram (EEG), electrodermal activity (EDA), electrocardiogram (ECG), respiratory activity, and finger plethysmogram were recorded. A significant probe-vs.-irrelevant effect was found for each of the measures. Compared to sole ERP measurement, the combination of ERP and EDA yielded incremental information for detecting concealed information. Although, EDA per se did not reach the predictive value known from studies primarily designed for peripheral physiological measurement. Presentation modality neither influenced the detection accuracy for autonomic measures nor EEG measures; this underpins the equivalence of verbal and pictorial item presentation in a CIT, regardless of the physiological measures recorded. Future studies should further clarify whether the incremental validity observed in the present study reflects a differential sensitivity of ERP and EDA to different sub-processes in a CIT.
Subject(s)
Deception , Evoked Potentials/physiology , Lie Detection/psychology , Acoustic Stimulation/methods , Adult , Analysis of Variance , Electrocardiography/methods , Electroencephalography/methods , Female , Fingers/blood supply , Galvanic Skin Response/physiology , Heart Rate/physiology , Humans , Logistic Models , Male , Photic Stimulation/methods , Plethysmography/methods , Reaction Time/physiology , Respiration , Time Factors , Young AdultABSTRACT
The concealed information test (CIT) has been used to detect information that examinees possess by means of their autonomic responses. However, the central activities related to these autonomic responses remain unclear. In this study, we simultaneously recorded 128-ch event-related potentials (ERPs) and various autonomic responses (heart rate, respiratory rate, respiratory amplitude, cutaneous blood flow, and skin conductance response) to a critical item (i.e., the item that participants memorized) and to non-critical items (i.e., items other than the critical item) using the standard protocol of the autonomic-based CIT. A topographic analysis of variance and a temporal-spatial principal component analysis revealed that the critical item elicited a larger negative potential (N2b, 205-298 ms) at central regions and a larger positive potential (positive slow wave, 502-744 ms) at parieto-occipital regions, compared to the non-critical items. Correlation analysis across 21 participants showed a significant correlation between N2b increase and heart rate deceleration in response to critical items compared to non-critical items, but there were no autonomic correlates of the positive slow wave. The results suggest that at least two brain processes are involved in the autonomic-based CIT: The first is an attentional-orienting process that facilitates the processing of critical items, to which heart rate deceleration was linked, and the second is an additional process after the identification of critical items.
Subject(s)
Autonomic Nervous System/physiology , Brain Mapping , Brain/physiology , Evoked Potentials/physiology , Lie Detection , Acoustic Stimulation/methods , Adult , Blood Pressure/physiology , Brain/anatomy & histology , Electrocardiography/methods , Electroencephalography/methods , Galvanic Skin Response/physiology , Heart Rate/physiology , Humans , Lie Detection/psychology , Male , Principal Component Analysis/methods , Reaction Time/physiology , Respiration , Young AdultABSTRACT
Using physiological measures, concealed information can be validly assessed. Orienting theory has been proposed to account for concealed information testing. As orienting is characterized by heart rate deceleration, one would expect this type of heart rate response to concealed information. However, with some exceptions, an initial heart rate acceleration to concealed information is typically observed. In the present paper, we examine the role of verbalization to explain the mixed pattern of heart rate changes. Using a within-subjects design, 30 participants were asked to either remain silent or to give an overt verbal response ("yes"/"no") to concealed autobiographical and control information. The results indicate that verbalization accounts for the initial heart rate acceleration. In line with the orienting theory, initial heart rate deceleration is observed when participants remained silent.
Subject(s)
Heart Rate/physiology , Lie Detection/psychology , Verbal Behavior/physiology , Acoustic Stimulation , Adolescent , Analysis of Variance , Auditory Perception/physiology , Deception , Female , Galvanic Skin Response/physiology , Humans , Male , Perceptual Masking , Reaction Time/physiology , Respiratory Mechanics/physiology , Surveys and Questionnaires , Young AdultABSTRACT
Brain activity in humans telling lies has yet to be elucidated. We developed an objective approach to its investigation, utilizing a computer-based interrogation and fMRI. Interrogatory questions probed recent episodic memory in 30 volunteers studied outside and 10 volunteers studied inside the MR scanner. In a counter-balanced design subjects answered specified questions both truthfully and with lies. Lying was associated with longer response times (p < 0.001) and greater activity in bilateral ventrolateral prefrontal cortices (p < 0.05, corrected). These findings were replicated using an alternative protocol. Ventrolateral prefrontal cortex may be engaged in generating lies or withholding the truth.