Skin Conductance Measures Research Articles

Pain perception and physiological responses are modulated by active support from a romantic partner.

As social animals, humans are strongly affected by social bonds and interpersonal interactions. Proximity and social support from significant others may buffer the negative outcomes of a painful experience. Several studies have investigated the role of romantic partners' support in pain modulation, mostly focusing on tactile support and showing its effectiveness in reducing pain perception. Nevertheless, no study so far has investigated the role of supportive speaking on pain modulation, nor has compared the effects of a tactile and vocal support within the same couples. The present study directly compared for the first time the efficacy of mere presence (Passive Support) and different forms of active (Touch, Voice, Touch + Voice) support from a romantic partner during a painful experience in a naturalistic setting. We assessed pain modulation in 37 romantic couples via both subjective (self-reported ratings) and physiological (skin conductance) measurements. We found that all three types of active support were equally more effective than passive support in reducing the painful experience at both subjective and physiological levels; interestingly, our results suggest that supportive speaking can reduce pain perception with respect to passive support to a similar extent as tactile support does. Overall, this study highlights the relevance of an active support in reducing pain perception, with active types of support being more effective than passive support, regardless of its specific modality.

Getting the better understanding of truth: Diving into the polygraph test

The field of forensic psychology has been growing in prominence in the past couple of decades. Psychology is used to detect the deception of the persons are involved in many areas that relate to crime, both solving crime and absolving people wrongly accused of committing crimes. The goal of lie detection is the discovery of a truth that is known to one person and concealed from others. Psychophysiological lie detection, or polygraphy, is based on the theory that lying produces particular emotions, which produce corresponding measurable physiological responses. Modern polygraphy measures blood pressure, breathing, and skin conductance. Alternative metrics such as voice stress analysis and functional magnetic resonance imaging are as yet unproven. The control question test uses relevant, control, and irrelevant questions. A larger response to the relevant questions is considered evidence of deception. The guilty knowledge test uses concealed information questions and irrelevant questions.Through this article authors have tried to report that how the polygraph examination of real cases is important and helpful to the investigating officer, using our three cases study, results are demonstrated.

Development of a Small Footprint Device for Measuring Electrodermal Activity in the Palm of the Hand.

This paper describes the proof of concept for a wearable device that measures skin conductance, to provide a way of quantifying an individual's physiological stress response to external stimuli. Important goals of the project were to have reliable measurements that correlate with the external stimuli, as well as a small footprint and low power consumption to facilitate battery powered operation. These goals were accomplished using a STM32L476 micro-controller to generate an AC sine voltage across two solid gel electrodes placed in the palm of the hand, converting the resulting current to a voltage with a trans-impedance amplifier, which was then sampled and processed digitally in a lock-in amplifier, to eliminate signals differing from the desired (reference) frequency and phase. The output of the lock-in amplifier represents the skin conductance and was transmitted over USB to a computer with software for serial capture.

Hybrid Decoders for Marked Point Process Observations and External Influences.

Internal physiological processes govern multiple state variables within the human body. Estimating these from point process-type bioelectric and biochemical observations is a challenge. Here we seek to estimate cortisol-related energy production and sympathetic arousal based on point process and continuous-valued data while permitting an external influence to affect the state estimates. Traditional point process state-space methods, such as those used for estimating the aforementioned quantities from cortisol and skin conductance measurements respectively, suffer from the inability to permit the state estimates to also fit to an external influence (e.g. labels) or be guided by it. Here we modify an existing recurrent neural network (RNN) approach for state-space estimation through a weighted cost-function to enable a hybrid estimator that has this capability. Results on cortisol data based on a hypothetical sleep-wake influence term show how energy production can be estimated by permitting the estimates to fit to the external influence as much as desired. We further show how overfitting may be reduced by using circadian rhythm-based influence terms. Results on skin conductance data also indicate how the method can be used to estimate sympathetic arousal in an experiment containing stressors and relaxation, and permit an external influence as well. The RNN-based hybrid method is thus able to recover internal physiological states from point process and continuous-valued observations while permitting an external influence to guide the estimates. The hybrid estimator could be embedded within wearable monitors that can be tailored based on domain expertise or individual feedback.

Sparse Multichannel Decomposition of Electrodermal Activity With Physiological Priors.

Goal: Inferring autonomous nervous system (ANS) activity is a challenging issue and has critical applications in stress regulation. Sweat secretions caused by ANS activity influence the electrical conductance of the skin. Therefore, the variations in skin conductance (SC) measurements reflect the sudomotor nerve activity (SMNA) and can be used to infer the underlying ANS activity. These variations are strongly correlated with emotional arousal as well as thermoregulation. However, accurately recovering ANS activity and the corresponding state-space system from a single channel signal is difficult due to artifacts introduced by measurement noise. To minimize the impact of noise on inferring ANS activity, we utilize multiple channels of SC data. Methods: We model skin conductance using a second-order differential equation incorporating a time-shifted sparse impulse train input in combination with independent cubic basis spline functions. Finally, we develop a block coordinate descent method for SC signal decomposition by employing a generalized cross-validation sparse recovery approach while including physiological priors. Results: We analyze the experimental data to validate the performance of the proposed algorithm. We demonstrate its capacity to recover the ANS activations, the underlying physiological system parameters, and both tonic and phasic components. Finally, we present an overview of the algorithm's comparative performance under varying conditions and configurations to substantiate its ability to accurately model ANS activity. Our results show that our algorithm performs better in terms of multiple metrics like noise performance, AUC score, the goodness of fit of reconstructed signal, and lower missing impulses compared with the single channel decomposition approach. Conclusion: In this study, we highlight the challenges and benefits of concurrent decomposition and deconvolution of multichannel SC signals.

Correlates of Skin Conductance Reactivity to Stroke-Related Trauma Reminders During Hospitalization for Stroke

Objective Although several risk factors for stroke-induced posttraumatic stress disorder (PTSD) have been identified, objective risk measures that can be detected in the acute aftermath of these events are needed. This study is the first to collect an objective measure of psychophysiological arousal—skin conductance (SC) reactivity to a trauma interview—in patients after stroke or transient ischemic attack (TIA) and investigate correlates of SC reactivity. Methods Mobile SC measurement during a resting baseline and standardized trauma interview was performed in-hospital in 98 individuals following stroke/TIA. We examined associations between several stroke-induced PTSD risk factors (sociodemographic, psychosocial, and medical characteristics) and SC reactivity to a trauma interview involving a free-response recalling of the stroke/TIA event. Results Of the sociodemographic, psychosocial, medical characteristics examined as correlates to SC reactivity to recalling the stroke/TIA event, 2 factors reflecting aspects of prior and in-hospital experience were significantly associated with this indicator of sympathetic nervous system activation. A greater cumulative trauma burden was significantly associated with greater SC reactivity (r = .23, P = .04). Additionally, individuals administered benzodiazepines in-hospital had significantly greater SC reactivity to recalling the stroke/TIA event (M = 1.51, SD = 1.52) than those who were not (M = 0.76, SD = 1.16; P = .01). Greater cumulative trauma burden remained significantly associated with greater SC reactivity when adjusting for age and in-hospital benzodiazepine administration (β=0.22, P = .04). Conclusion This study demonstrated that SC reactivity was related to both behavioral and psychological risk factors for PTSD after a stroke/TIA event. Additionally, we demonstrated the feasibility of a low-cost, mobile measurement of SC that can be conducted in-hospital in a novel patient population: individuals with a medical trauma. With this measure, we were able to identify those individuals with the greatest trauma-related sympathetic nervous system reactivity in the days following a medical trauma. Future research is needed to determine whether SC reactivity may be leveraged in the development of brief, noninvasive screening measures for enhancing PTSD risk prediction.

A comprehensive comparison of facial skin hydration based on capacitance and conductance measurements in Chinese women.

The aim of this study was to compare the data of conductance and capacitance measurements of facial skin hydration and to evaluate and discuss the advantages and disadvantages of the different approaches. We measured skin capacitance (Corneometer® CM 825) and skin conductance (Skicon-200EX®) on 30 pre-defined facial sites of 125 Chinese women, resulting in 3750 readings per device. The data were analysed and compared, and continuous colour maps were generated on a 3D avatar for capacitance, conductance, relative difference (Δ%) and correlation (R-value) by interpolating between the individual readings and converting the values to colours. This visualization allows a better interpretation of the results. The complexity of facial skin hydration is revealed by this approach. The similarities and discrepancies in the facial hydration maps are clearly apparent. Due to the superiority of the Skicon in measuring high hydration levels, differences in skin hydration were evident on the forehead compared with the Corneometer maps, which may be related to the more superficial measurement of the Skicon within the stratum corneum. Conversely, a greater understanding of the complexity of facial skin hydration in the nasolabial fold was obvious when using the Corneometer. The best congruence between the instruments was found at two specific but separated facial areas, one around the inner eye region and the other one on a line between the nasolabial sulcus and the oblique, lateral jaw. Interestingly, the data were not normally distributed for both instruments and they had opposite skews. All facial clusters were statistically different from each other (p< 0.001), except the cheek and jaw for the Skicon. Larger than expected percentage coefficients of variance were found for the Corneometer on some facial sites that might be explainable by differences in stratum corneum physiology and biochemistry. Corneometer values of 48 AU and Skicon values of 132 μS were taken as the cutoff for normally hydrated facial skin. Both devices have their advantages and disadvantages suggesting that bio-instrumental measurement of skin hydration is actually more complicated than commonly thought and that the different facial zones and the use of multiple instrumentation have not been adequately considered.

Assessing Workers’ Mental Stress in Hand-over Activities during Human-robot Collaboration

Human-robot collaboration (HRC) is an emerging research area that has gained tremendous attention from both academia and industry. Since some robot-related factors can elicit mental stress or have negative psychological effects on human workers, it is essential to understand these factors and maintain workers’ mental stress at a low level. Galvanic Skin Response (GSR) measures skin conductance and is known to be a physiological measurement that reflects short-term mental stress. Typically, skin conductance increases in response to greater mental stress. In this study, the mental stress caused by the hand-over activities of a collaborative robot was investigated using both GSR as an objective measurement and NASA-Task Load Index (TLX) as a subjective assessment. Several robot-related factors that may lead to mental stress were experimentally examined. GSR outcomes indicated that end effector approaching within workers’ view, low end effector speed, and constrained end effector trajectory led to a significantly lower skin conductance. Some aspects of the NASA-TLX also indicated that speed and trajectory significantly affected the scores. Yet, no significant differences were found between approaching directions regarding NASA-TLX scores.

Negative mood induction effects on problem-solving task in women with eating disorders: a multi-method examination

BackgroundThe effects of negative affect on problem-solving and its psychophysiological correlates are poorly understood in eating disorder populations.MethodsThis study examined respiratory sinus arrhythmia (RSA) and skin conductance responses of women with Binge Eating Disorder (BED: n = 56), Anorexia Nervosa (AN: n = 12), Bulimia Nervosa (BN: n = 32), and 24 healthy controls (HCs) at baseline, and then during: a negative mood induction task, an adapted Means Ends Problem-Solving (MEPS) task, and recovery. The MEPS task included four interpersonal scenarios: (1) binge-eating as a solution to stress, (2) job loss, (3) rejection by friends, and (4) by a significant other.ResultsWe found that individuals with eating disorders reported less positive mood than HCs and individuals with BN and BED reported more negative mood and greater urges to binge than HCs. After a negative mood induction, women with BED provided significantly less effective problem-solving strategies compared to HCs and women with BN for the binge-eating MEPS scenario. Relative to baseline and the negative mood induction, all participants exhibited significantly higher skin conductance measures throughout the MEPS scenarios and recovery. BED showed significantly lower respiratory sinus arrhythmia (RSA) levels than individuals with BN and HCs throughout the protocol.ConclusionsThe multimethod findings suggest individuals with BED are likely to have disorder-specific problem-solving difficulties after a negative mood induction.

Robot touch with speech boosts positive emotions

A gentle touch is an essential part of human interaction that produces a positive care effect. Previously, robotics studies have shown that robots can reproduce a gentle touch that elicits similar, positive emotional responses in humans. However, whether the positive emotional effects of a robot’s touch combined with speech can be enhanced using a multimodal approach remains unclear. This study supports the hypothesis that a multimodal interaction combining gentle touch and speech by a robot enhances positive emotional responses. Here, we conducted an experiment using a robotic arm to perform a gentle touch combined with speech and compared three conditions: touch alone, speech alone, and touch with speech. We assessed participants’ subjective ratings of valence, arousal, and human likeliness using subjective emotional responses. Furthermore, we recorded facial electromyography (EMG) from the corrugator supercilii and zygomaticus major muscles and measured skin conductance levels (SCLs) as physiological emotional responses. Our results show that touch combined with speech elicited higher subjective valence and arousal ratings, stronger zygomaticus major EMG and SCL activities than touch alone. The results suggest that the positive emotional effects of robotic touch can be boosted by combining elements of speech.

Neurophysiological Measures in Hospitality and Tourism: Review, Critique, and Research Agenda

This paper provides a critical review of studies using neurophysiological measures in tourism and hospitality. Among 145 articles covering 20 years of research, 16 studies applied either electroencephalography (EEG), functional magnetic resonance imaging (fMRI), or skin conductance (SC) measures in tourism and hospitality settings. Results show that, in general, (1) EEG studies investigated the relationships between EEG components and attention/emotion induced by destination advertisements; (2) fMRI studies examined the correlation between brain area activation and behavior (e.g., visit intention); and (3) SC studies focused on emotional responses to tourism stimuli. Neurophysiological techniques are theoretically and practically useful in tourism and hospitality: these tools uncover subjects’ objective, unbiased, and real-time responses to provide academic insight and guide industry practitioners’ decisions. Directions for future research are proposed along with solutions to address the current limitations of neuroscience measures in tourism and hospitality applications.

Quantifying the Effect of Mental Stress on Physical Stress for Construction Tasks

Because of labor-intensive and physically demanding tasks, construction workers are known to be at a higher risk of developing physical fatigue. Recent studies have shown that construction workers are also often exposed to considerable mental stresses. While a number of studies have proposed methods and tools to measure and monitor physical and mental stress disjointedly, there is a need to explore their interaction. The literature indicates that no previous study has endeavored to evaluate the effect of mental stress on physical stress for construction tasks. This investigation is necessary to better comprehend work demands of construction tasks. Accordingly, entailing a randomized crossover design and simulated manual material handling experiment, this study evaluated the effect of cognitive task-led mental stress on physical stress using both subjective (ratings of perceived exertion) and objective measures (heart rate, skin temperature, and skin conductance). The results revealed that cognitive task-led mental stress led to a significant increase in subjective ratings of perceived exertion accompanied by an increase in skin temperature and skin conductance, while heart rate remained unaffected. The findings of this study add to the body of knowledge by highlighting that traditional benchmarking of task demands using only physiological measures may not be comprehensive. Rather, it might be suggested that additional psychological measurements are also essential because they might affect physical stress development. Furthermore, the current study has increased our understanding related to the interaction of physical and mental stress by revealing interindividual differences among the participants. Accordingly, by examining each worker separately, practitioners and safety managers can develop better mitigation strategies and individualized training programs, especially for more vulnerable workers, which can enhance overall health and safety on construction job sites.

Detecting concealed information using functional near-infrared spectroscopy (fNIRS) combined with skin conductance, heart rate, and behavioral measures.

In this study, brain imaging data from functional near-infrared spectroscopy (fNIRS) associated with skin conductance response (SCR), heart rate (HR), and reaction time (RT) were combined to determine if the combination of these indicators could improve the efficiency of deception detection in concealed information test (CIT). During the CIT, participants were presented with a series of names and cities that served as target, probe, or irrelevant stimuli. In the guilty group, the probe stimuli were the participants' own names and hometown cities, and they were asked to deny this information. Our results revealed that probe items were associated with longer RT, larger SCR, slower HR, and higher oxyhemoglobin (HbO) concentration changes in the inferior prefrontal gyrus (IFG), middle frontal gyrus (MFG), and the superior frontal gyrus (SFG) compared with irrelevant items for participants in the guilty group but not in the innocent group. Furthermore, our results suggested that the combination of RT, SCR, HR, and fNIRS indicators could improve the deception detection efficiency to a very high area under the ROC curve (0.94) compared with any of the single indicators (0.74-0.89). The improved deception detection efficiency might be attributed to the reduction of random error and the diversiform underlying the psychophysiological mechanisms reflected by each indicator. These findings demonstrate a feasible way to improve the deception detection efficiency by using combined multiple indicators.

Skin conductance while facing emotional pictures at day 7 helps predicting antidepressant response at three months in patients with a major depressive episode

There are currently no reliable biological markers to identify antidepressant responders in patients suffering from major depressive disorder. In this longitudinal pilot study, we measured skin conductance response (SCR) to assess patients’ emotional reactivity after antidepressant treatment initiation. Fifty-four adult patients with a major depressive episode were recruited and followed up for 3 months. After one day of antidepressant treatment (D1) and then at day 7 (D7), emotional stimuli were presented on a computer screen while SCR and subjective emotional response were recorded. Three months later, we used Montgomery and Åsberg Depression Rating Scale (MADRS) to screen patients for treatment response, and distinguished responders (N = 28) from non-responders (N = 15). While SCR at D1 did not differ between responders and non-responders, SCR at D7 was higher in responders for both positive, negative and neutral stimuli. Skin conductance rates at D7 had a relatively poor negative predictive value (38%) but a strong positive predictive value (95%). Further studies are needed to replicate in a larger sample, and validate, these preliminary results which suggest that electrodermal activity after treatment initiation could help predict antidepressant efficacy.

Associations between children's trauma-related sequelae and skin conductance captured through mobile technology

Although many children experience trauma, few receive diagnoses and subsequent care despite experiencing trauma-related sequelae. At age nine (M = 9.11), children (N = 62; female = 46.4%) who predominantly identified as Black (78.7%) were enrolled in this first study examining how skin conductance as captured by mobile technology, eSense, related to children's traumatic experiences and trauma-related symptoms. Skin conductance measures were associated with degree of trauma exposure and PTSD hyperarousal symptoms. These findings suggest that physiological responses in addition to self-report measures may be easily used to assess children's trauma exposure and symptoms. Given eSense's ease-of-use, this technology could assist clinics and research institutions assess children's trauma-related needs.

Correlation between skin conductance measurements and subjective pain scales in children after otolaryngological procedures

Abstract Introduction Pain assessment in children is crucial in managing postoperative analgesia; it is therefore necessary to determine the most accurate tool for assessing pain in children. The aim of this study was to evaluate the correlation between skin conductance measurements and self-reporting pain scales in children after otolaryngology procedures. Materials and methods Thirty-three children (N=33) were assessed for eligibility for the research. Postoperative pain was assessed using the Visual Analogue Scale; the Wong-Baker Faces Pain Rating Scale; the Face, Legs, Activity, Cry, and Consolability scale; and a skin conductance algesimeter. The postoperative pain was measured 1 and 2 hours after the surgery. Results There was no statistically significant correlation between self-reported pain scores and the skin conductance fluctuations in the children studied, regardless of gender or age. A statistically significant correlation was found between the existing subjective pain scales in children. Conclusions The skin conductance measurements do not provide an additional reliable tool for assessing pain in patients after otolaryngological procedures. The existing self-reported pain scales are sufficient to assess postoperative pain in children.

Printed electronics for the health care sector: a real-life business case

Belgian based Quad Industries, together with the Dutch company, Mentech, have developed an electrode patch to measure skin conductance on the foot of a client with a severe intellectual disability. By measuring skin conductance, which is a key parameter for stress detection, healthcare workers can be notified automatically when a client is getting stressed. The new electrode patch was developed in collaboration with Mentech and supported by the SmartEEs programme of the European Union

Food olfactory cues reactivity in individuals with obesity and the contribution of alexithymia

Obesity has been associated with increased reward sensitivity to food stimuli, but a few studies have addressed this issue by using odors. This study investigated whether obesity is associated with increased liking and wanting of food odors and whether alexithymia, a psychological construct characterized by diminished affective abilities, contributes to altered responsiveness to food. Liking and wanting for food and pleasant non-food odors were measured through explicit (self-report ratings) and implicit measures (heart rate and skin conductance) in 23 women with healthy weight (HW) and 20 women with overweight/obesity (OW/OB). Differently from the HW group, the OW/OB group explicitly liked food odors less than non-food odors; but, at the implicit level, there were no differences in heart rate response for both types of odors, indicating that they were equally liked. Moreover, at variance with the HW group, the OW/OB group did not exhibit increased skin conductance response for food compared to nonfood odors. Alexithymia was associated with increased implicit liking and explicit wanting of food odors, in particular in the HW group. These findings show that obesity is characterized by high levels of implicit food liking and low levels of implicit food wanting. Moreover, both affective and motivational responses to food reward seem to be affected by alexithymia, which should be taken into account by studies evaluating the effect of cue exposure intervention for obesity treatment.

Rating expectations can slow aversive reversal learning.

The process of learning allows organisms to develop predictions about outcomes in the environment, and learning is sensitive to both simple associations and higher order knowledge. However, it is unknown whether consciously attending to expectations shapes the learning process itself. Here, we directly tested whether rating expectations shapes arousal during classical conditioning. Participants performed an aversive learning paradigm wherein one image (CS+) was paired with shock on 50% of trials, while a second image (CS−) was never paired with shock. Halfway through the task, contingencies reversed. One group of participants rated the probability of upcoming shock on each trial, while the other group made no online ratings. We measured skin conductance response (SCR) evoked in response to the CS and used traditional analyses as well as quantitative models of reinforcement learning to test whether rating expectations influenced arousal and aversive reversal learning. Participants who provided online expectancy ratings displayed slower learning based on a hybrid model of adaptive learning and reduced reversal of SCR relative to those who did not rate expectations. Mediation analysis revealed that the effect of associative learning on SCR could be fully explained through its effects on subjective expectancy within the group who provided ratings. This suggests that the act of rating expectations reduces the speed of learning, likely through changes in attention, and that expectations directly influence arousal. Our findings indicate that higher order expectancy judgments can alter associative learning.

The association between self-reported stress and cardiovascular measures in daily life: A systematic review.

Stress plays an important role in the development of mental illness, and an increasing number of studies is trying to detect moments of perceived stress in everyday life based on physiological data gathered using ambulatory devices. However, based on laboratory studies, there is only modest evidence for a relationship between self-reported stress and physiological ambulatory measures. This descriptive systematic review evaluates the evidence for studies investigating an association between self-reported stress and physiological measures under daily life conditions. Three databases were searched for articles assessing an association between self-reported stress and cardiovascular and skin conductance measures simultaneously over the course of at least a day. We reviewed findings of 36 studies investigating an association between self-reported stress and cardiovascular measures with overall 135 analyses of associations between self-reported stress and cardiovascular measures. Overall, 35% of all analyses showed a significant or marginally significant association in the expected direction. The most consistent results were found for perceived stress, high-arousal negative affect scales, and event-related self-reported stress measures, and for frequency-domain heart rate variability physiological measures. There was much heterogeneity in measures and methods. These findings confirm that daily-life stress-dynamics are complex and require a better understanding. Choices in design and measurement seem to play a role. We provide some guidance for future studies.