Differences Between Skin Resistance and Skin Conductance Responses with Respect to Change Over Trials: A Mathematical Explanation

Combining physiological measures in the detection of concealed information.

Meta-analytic research has confirmed that skin conductance response (SCR) measures have high validity for the detection of concealed information. Furthermore, cumulating research has provided evidence for the validity of two other autonomic measures: Heart rate (HR) and Respiration Line Length (RLL). In the present report, we compared SCR detection efficiency with HR and RLL, and investigated whether HR and RLL provide incremental validity to electrodermal responses. Analyses were based on data from 7 different samples covering 275 guilty and 53 innocent examinees. Results revealed that the area under the ROC curve was significantly higher for SCR than for HR and RLL. A weighted combination…

Statement validity assessment: Inter-rater reliability of criteria-based content analysis in the mock-crime paradigm

Methods. Three raters were trained in CBCA. Subsequently, they analysed transcripts of 102 statements referring to a simulated theft of money. Some of the statements were based on experience and some were confabulated. The raters used 4-point scales, respectively, to judge the degree to which 18 of the 19 CBCA criteria were fulfilled in each statement. Results. The analysis of rater judgment distributions revealed that, with judgments of individual raters varying only slightly across transcripts, the weighted kappa coefficient, the product-moment correlation, and the intra-class correlation were inadequate indices of reliability. The Finn-coefficient and percentage agreement, which were cal…

Cerebral activation in patients with somatoform pain disorder exposed to pain and stress: an fMRI study.

Patients with somatoform pain disorders are supposed to suffer from an early acquired defect in stress regulation. In order to look for common alterations of the pain- and stress-responsive cortical areas, we prospectively recorded cerebral activations induced by pin-prick pain, by cognitive stress and emotional stress using functional magnetic resonance imaging (fMRI) in a group of 17 patients and an age-matched control group. In addition, the hippocampal volumes of both groups were measured. Patients showed increased activations of the known pain-processing areas (thalamus, basal ganglia, operculo-insular cortex), but also of some prefrontal, temporal and parietal regions during first pai…

Effects of Emotional Context on Memory for Details: The Role of Attention

It was repeatedly demonstrated that a negative emotional context enhances memory for central details while impairing memory for peripheral information. This trade-off effect is assumed to result from attentional processes: a negative context seems to narrow attention to central information at the expense of more peripheral details, thus causing the differential effects in memory. However, this explanation has rarely been tested and previous findings were partly inconclusive. For the present experiment 13 negative and 13 neutral naturalistic, thematically driven picture stories were constructed to test the trade-off effect in an ecologically more valid setting as compared to previous studies…

Psychophysiologische Aussagebeurteilung: Aktueller Stand und neuere Entwicklungen

Ziel der psychophysiologischen Aussagebeurteilung ist die Differenzierung von Tätern und Unschuldigen auf der Basis physiologischer Reaktionen auf spezifische Fragen. Die beiden wichtigsten Befragungstechniken, der Kontroll- oder Vergleichsfragentest sowie der Tatwissentest, werden im vorliegenden Artikel dargestellt und hinsichtlich ihrer Testgüte miteinander verglichen. Dabei wird insbesondere die individualdiagnostische Eignung „klassischer“ polygraphischer Kenngrößen, die auf der Aktivität des autonomen Nervensystems beruhen, diskutiert. Anschließend werden neuere Ansätze, die auf der Messung der Gehirnaktivität mittels Elektroenzephalogramm oder bildgebender Verfahren beruhen, vorgest…

The effects of electrodermal lability and stimulus intensity on skin conductance habituation: A preliminary report

A between-subjects design (N=60) was used to investigate the effects of electrodermal lability and auditory stimulus intensity on habituation of the skin conductance response (SCR). Subjects were subdivided into “labile” and “stabile” groups on the basis of frequency of nonspecific electrodermal responses during the prestimulation period. They received 20 presentations of a 1,000-Hz tone of 15, 35, 55, 75, 95, or 110 dB. There were significant effects of stimulus intensity on all three habituation measures (number of trials to habituation, reciprocal of SCR frequency to the first 10 stimuli, slope of the regression of SCR amplitude on log stimulus number). Additionally, significant effects …

How can skin conductance responses increase over trials while skin resistance responses decrease?

It is shown that the opposite trends over trials for conductance and resistance response magnitudes that have been found in recent experiments can be explained entirely by the mathematical relationship between conductance and resistance. Two conditions have to be satisfied for such opposite trends to occur: (1) a substantial increase in conductance level over the course of an experiment, and (2) a certain increase in conductance response magnitudes. The opposition in trends, being due solely to the mathematical relationship between conductance and resistance, should not be eliminated by some “correction” procedure. Instead, conductance should be taken as the appropriate variable. Also, no c…

Psychophysiological differentiation of deception: the effects of electrodermal lability and mode of responding on skin conductance and heart rate

The differentiation-of-deception paradigm enables the examination of deception as a psychophysiological process by varying, within subjects, two conditions which differ only with respect to honesty and deception. The present experiment assessed the effects of two group factors - electrodermal lability and mode of responding - on the deception phenomenon in a situation with low emotional involvement and mental load. Skin conductance responses, phasic heart rate, self-rated relaxation, calmness, and concentration were the dependent variables. Twenty questions referring to general knowledge were presented on a monitor. The 88 male participants answered half of the questions deceptively and the…

Psychophysiological and vocal measures in the detection of guilty knowledge.

The Guilty Knowledge Test (GKT) and its variant, the Guilty Actions Test (GAT), are both psychophysiological questioning techniques aiming to detect guilty knowledge of suspects or witnesses in criminal and forensic cases. Using a GAT, this study examined the validity of various physiological and vocal measures for the identification of guilty and innocent participants in a mock crime paradigm. Electrodermal, respiratory, and cardiovascular measures successfully differentiated between the two groups. A logistic regression model based on these variables achieved hit rates of above 90%. In contrast to these results, the vocal measures provided by the computerized voice stress analysis system …

Psychometric properties of non-specific electrodermal response frequency for a sample of male students.

In the present study data on the frequency of non-specific electrodermal responses (NSRs) are presented for a large and, with regard to sex, age and educational level, homogeneous sample of male students (n = 590). These data were obtained in 9 independent experiments in which NSRs were recorded under equivalent conditions. NSRs were scored as skin conductance changes greater than 0.02 muSiemens. A recording period of 5 min prior to experimental manipulations was chosen. A systematic comparison between the 9 studies, the distribution of NSRs for the total sample, as well as descriptive data for stabile and labile subgroups are presented. For 213 subjects NSR-frequency was recorded twice, wi…

Emotional arousal modulates the encoding of crime-related details and corresponding physiological responses in the Concealed Information Test

Previous studies demonstrated that concealed crime-related memories can be validly identified using the Concealed Information Test (CIT). However, its field applicability is still debated, and it is specifically unknown how emotional arousal during a crime would influence CIT results. In the current study, emotional arousal during a mock crime and the time delay between mock crime and CIT examination were manipulated. At the immediate and the delayed CIT occasion, central crime details were better remembered than peripheral ones and enhanced emotional arousal further reduced memory for peripheral information. Electrodermal, respiratory, and cardiovascular responses to central crime details …

Electrodermal habituation speed and visual monitoring performance.

Previous research has suggested that speed of habituation of the electrodermal orienting response is related to auditory vigilance performance. The present study investigated the relationship between habituation speed, nonspecific response frequency, and detection performance in a complex visual monitoring task. Two levels of task difficulty were employed. In the visual monitoring task, correct detections declined across blocks, and fewer signals were detected in the difficult task condition. Slow habituators detected more signals than fast habituators, but NSR-frequency was not significantly related to the number of correct detections. The implications of these findings for different model…

Scoring Criteria for Electrodermal Habituation: Further Research

In the context of Levinson and Edelberg's critique of scoring criteria for electrodermal habituation, the present study examined the question of whether trials-to-habituation scores based on two no-response trials are superior to scores based on three no-response trials. Male students (N=120) performed two identical habituation experiments on two consecutive days and their skin conductance responses based on a short latency window of 1–3 s were analyzed. In each experiment subjects received 20 presentations of a 1000 Hz tone at 65dB. Results showed that three-trials scores were higher overall and that the distributions of three- and two-trials scores differed. On the other hand, the twoscor…

Strength of memory encoding affects physiological responses in the Guilty Actions Test

The Guilty Actions Test (GAT) is a valid and scientifically sound technique of forensic psychophysiology that allows for the detection of concealed memories. However, its application has been challenged because the results might be affected by the culprit's forgetting of crime details as well as the leakage of information to innocents. In the current study, these aspects were examined by varying the amount of time between a mock crime and the subsequent GAT, as well as by contrasting culprits with informed innocents. It turned out that culprits specifically forgot peripheral crime details during a period of 2 weeks whereas informed innocents showed similar forgetting for all details. As a c…

Stabilität und Stimmungsabhängigkeit retrospektiver Berichte elterlichen Erziehungsverhaltens

Zusammenfassung. Theoretischer Hintergrund: Retrospektiver Daten zum elterlichen Erziehungsverhalten sind in klinischer Psychologie und Psychotherapieforschung von Bedeutung, da Zusammenhänge zur Manifestation psychischer Störungen im Erwachsenenalter bestehen. Fragestellung: Bleibt das retrospektiv berichtete Erziehungsverhalten zeitlich stabil und welchen Einfluss nimmt die aktuelle Stimmung auf die Einschätzung? Methode: 105 Patienten wurden zu zwei Zeitpunkten im mittleren Abstand von 2,2 Jahren anhand des Kindheitsfragebogens und der Symptom-Checkliste-27 befragt. Ergebnis: Die Einschätzung des Erziehungsverhaltens weist in fast allen der erfassten Erziehungsstildimensionen hohe Stabi…

fMRI-activation patterns in the detection of concealed information rely on memory-related effects

Recent research on potential applications of fMRI in the detection of concealed knowledge primarily ascribed the reported differences in hemodynamic response patterns to deception. This interpretation is challenged by the results of the present study. Participants were required to memorize probe and target items (a banknote and a playing card, each). Subsequently, these items were repeatedly presented along with eight irrelevant items in a modified Guilty Knowledge Test design and participants were instructed to simply acknowledge item presentation by pressing one button after each stimulus. Despite the absence of response monitoring demands and thus overt response conflicts, the experiment…

Stress conceptions in life event research: Towards a person‐centred perspective

The present article focuses on a discussion of the theoretical foundations of life event research. Since critical life events are usually regarded as stressful events, the main question is which concepts of stress are employed in different life event approaches and what is their rationale. The discussion centres on two topics that have to be treated independently: the question of specificity vs nonspecificity and the question of individualized vs normative weightings. It is shown that different life event approaches rely on different concepts of stress. Numerous objections lead to a rejection of the nonspecificity concept and a normative proceeding. However, even when a specificity view of…

Covariations among fMRI, skin conductance, and behavioral data during processing of concealed information.

Imaging techniques have been used to elucidate the neural correlates that underlie deception. The scientifically best understood paradigm for the detection of deception, however, the guilty knowledge test (GKT), was rarely used in imaging studies. By transferring a GKT‐paradigm to a functional magnetic resonance imaging (fMRI) study, while additionally quantifying reaction times and skin conductance responses (SCRs), this study aimed at identifying the neural correlates of the behavioral and electrodermal response pattern typically found in GKT examinations. Prior to MR scanning, subjects viewed two specific items (probes) and were instructed to hide their knowledge of these. Two other spec…

The Orienting Response in Healthy Aging: Novelty P3 Indicates No General Decline but Reduced Efficacy for Fast Stimulation Rates

Automatic orienting to unexpected changes in the environment is a pre-requisite for adaptive behavior. One prominent mechanism of automatic attentional control is the Orienting Response (OR). Despite the fundamental significance of the OR in everyday life, only little is known about how the OR is affected by healthy aging. We tested this question in two age groups (19–38 years and 55–72 years) and measured skin-conductance responses (SCRs) and event-related brain potentials (ERPs) to novels (i.e., short environmental sounds presented only once in the experiment; 10% of the trials) compared to standard sounds (600 Hz sinusoidal tones with 200 ms duration; 90% of the trials). Novel and standa…

Electrodermal and phasic heart rate responses in the Guilty Actions Test: comparing guilty examinees to informed and uninformed innocents.

The present mock-crime study concentrated on the validity of the Guilty Actions Test (GAT) and the role of the orienting response (OR) for differential autonomic responding. N=105 female subjects were assigned to one of three groups: a guilty group, members of which committed a mock-theft; an innocent-aware group, members of which witnessed the theft; and an innocent-unaware group. A GAT consisting of ten question sets was administered while measuring electrodermal and heart rate (HR) responses. For informed participants (guilty and innocent-aware), relevant items were accompanied by larger skin conductance responses and heart rate decelerations whereas irrelevant items elicited HR accelera…

Memory detection using fMRI - does the encoding context matter?

Recent research revealed that the presentation of crime related details during the Concealed Information Test (CIT) reliably activates a network of bilateral inferior frontal, right medial frontal and right temporal-parietal brain regions. However, the ecological validity of these findings as well as the influence of the encoding context are still unclear. To tackle these questions, three different groups of subjects participated in the current study. Two groups of guilty subjects encoded critical details either only by planning (guilty intention group) or by really enacting (guilty action group) a complex, realistic mock crime. In addition, a group of informed innocent subjects encoded hal…