Nonspecific Skin Conductance Responses Research Articles

VARIATIONS IN FREQUENCY AND AMPLITUDE OF NONSPECIFIC ELECTRODERMAL RESPONSES

VARIATIONS IN FREQUENCY AND AMPLITUDE OF NONSPECIFIC ELECTRODERMAL RESPONSES

Electrodermal activity: A continuous monitor of well-being

A smart society should not only support the efficiency and effectiveness of processes, they should also have the ability to comprehend and support its inhabitants well-being. To enable this, we need continuous information on individual’s well-being. As a first step, we suggest to evaluate people’s long term stress level, as it sheds light on their well-being. We propose using the biosignal Electrodermal Activity (EDA), a proven measure of people’s arousal or stress. Moreover, EDA can be measured continuously, in real-time, and unobtrusively via wearables. To assess this idea’s feasibility, the CASE, CEAP-360VR, and K-EmoCon datasets, including both continuous EDA recordings and continuous subjective self-reported arousal, were analyzed. With CASE and CEAP-360VR, a multilevel analysis unveiled that the frequency and amplitude of EDA’s non-specific skin conductance responses significantly correlated with the self-reported arousal. With K-EmoCon, this correlation was absent, which can be explained by the low arousal condition of this dataset. The latter also signals a main limitation: the lack of sensitivity of the proposed signal. Nevertheless, the results are promising as they show potential for EDA as a continuous stress monitor. Therefore, we are optimistic that a future smart society can be enabled to monitor and improve their inhabitant’s well-being.

Psychophysiological assessment of trauma-focused Group Music and Imagery therapy for women with PTSD or CPTSD using script-driven imagery. A randomised controlled study.

BackgroundIn posttraumatic stress disorder (PTSD), physiological reactions during trauma scripts have been anchored to the diagnosis. According to the construct of research domain criteria, physiological reactions and self-rating scales could be used to evaluate treatment effects. ObjectiveIn the present study, self-rated PTSD symptoms combined with physiological reactions during trauma script were used as outcome measurements in the domain of arousal/regulatory systems in a controlled randomised study of Group Music and Imagery (GrpMI) treatment for females with PTSD or complex posttraumatic stress disorder (CPTSD) related to violence and/or sexual abuse. Methods45 traumatised women were randomised to 12 weeks of active treatment or waiting. Before and after the intervention, an assessment was done using physiological measurements during script-driven imagery (SDI) procedures. Subjective Units of Distress (SUD) were collected immediately after the trauma script (TS). Reactions during the SDI procedure were reported using the Responses to Script Driven Imagery (RSDI) scale, measuring re-experiencing, avoidance, and dissociation. Self-reported PTSD symptoms were accessed using the PTSD checklist for DSM-5 (PCL-5). Heart rate (HR), heart rate variability (HRV), and electrodermal activity were sampled during the baseline (BL) and TS conditions of the SDI procedure. As a measure of trauma-related reactivity, the difference between TS and BL was used for statistical calculations. HRV measures included high (HF; 0.15-0.4 Hz) and low (LF; 0.03-0.15 Hz) frequency band power, the LF/HF ratio, and the root mean square of successive inter-beat differences (RMSSD). Measures of electrodermal activity included skin conductance levels (SCL) and frequencies of non-specific skin conductance responses (NS-SCR). Further, correlations between self-rated PTSD symptoms and physiological reactivity measures were analysed. ResultsDuring the TS, the absolute levels of HR, LF/HF-ratio, and NS-SCR, as well as the trauma-related reactivity of HR, RMSSD, HF, LF/HF-ratio, SCL, and NS-SCR, showed significant changes indicating decreased arousal during trauma script after treatment. Compared to the waitlist control, an interaction analysis showed significant treatment effects in the BL level of HR, the absolute TS level of HR and HF, and the trauma-related reactivity of RMSSD and HF, suggesting an improvement of vagal function in the treatment group. Significant treatment-related reductions were found in symptoms of PTSD, re-experiencing and avoidance, as well as SUD. The changes pre- to post-treatment in HR reactivity and self-rated PTSD symptoms correlated significantly. Furthermore, the initial HR reactivity predicted treatment outcome as measured with PCL-5. ConclusionIn the evaluation of treatment methods for PTSD, a combination of self-report and physiological measures seems to be feasible. The physiological measures, in combination with a robust decrease in self-rated PTSD symptoms, indicate that trauma-focused GrpMI is a promising treatment for PTSD or CPTSD. More studies are needed to confirm the results, and further research comparing with other active treatments is necessary to establish the precise role of the treatment.

Emotion Recognition in Virtual Reality: Investigating the Effect of Gameplay Variations on Affective Responses

Virtual reality (VR) technology offers a unique platform for affective computing research, which aims to create intelligent systems capable of recognizing, interpreting, and responding to human emotions in immersive and interactive virtual environments. This study examined how different variations of VR games can elicit different emotional responses in players. Thirty participants played three VR Pong games, and their emotional responses were measured using the Self-Assessment Manikin and physiological measures. Results showed that different gameplay variations evoked varying emotional responses in players, and two features, average heart rate and the non-specific skin conductance responses (in peaks per min), were found to differ significantly between the games. The study suggests that VR gameplay can provide an engaging and interactive platform to study human emotions and behavior, with implications for designing and developing affective computing systems in fields such as healthcare, marketing, and humancomputer interaction.

Sympathetic nervous system activity and pain-related response indexed by electrodermal activity during the earliest postnatal life in healthy term neonates.

Sympathetic nervous system (SNS) undergoes a prolonged period of fetal and neonatal development and maturation during which is vulnerable to a variety of influences (e.g. painful experiences). Thus, we aimed to evaluate SNS activity at rest and in response to stressful stimulus (pain) within the earliest postnatal life in healthy term neonates using electrodermal activity (EDA) measures. In twenty eutrophic healthy term neonates EDA was recorded within the first two hours after birth (measurement 1 - M1) and 72 h after birth (measurement 2 - M2) at rest and in response to pain (M1 - intramuscular K vitamin administration; M2 - heel stick). Evaluated parameters were skin conductance level (SCL), non-specific skin conductance responses (NS.SCRs), skin SCL 10 s before pain stimulus (SCL_10 before pain), skin conductance response (SCR) peak after pain stimulus, SCL 10 s after pain stimulus (SCL_10 after pain), SCR magnitude, latency, SCR rise/decline time, SCR half recovery time. SCL was significantly decreased at rest during M2 compared to M1 (p=0.010). SCL_10 before pain, SCR peak after pain, and SCL_10 after pain stimulus were significantly decreased in M2 compared to M1 (p=0.014, p=0.020, p=0.011, respectively). SCL was significantly decreased and NS.SCRs were significantly higher in the recovery period after the pain stimulus during M2 compared to M1 (p=0.015, p=0.032, respectively). Our results indicate EDA parameters sensitive to detect sympathetic changes during the earliest postnatal life reflecting its potential in early diagnosis of the autonomic maturation - linked pathological states in neonates.

Feasibility of wearable sensors in the NICU: Psychophysiological measures of parental stress

BackgroundParents report elevated stress during their infant's NICU hospitalization. Real-time measures may improve our understanding of parental stress in the NICU. AimExamine the feasibility of wearable sensors to describe parental stress in the NICU. Study designIn this prospective feasibility study of 12 parent-infant dyads, parents wore an Empatica E4 wristband to measure psychophysiological stress via electrodermal activity (EDA) during sensory interventions (holding, massage, reading, touch, etc) with their babies. Baseline and intervention periods were delineated during which concurrent monitoring and clinical observations of infant behavior and environmental factors were recorded. Feasibility was assessed by investigating recruitment/enrollment, retention/adherence, acceptability, sensor usability, and changes in EDA waveforms based on potential stressors. For the latter, independent samples t-tests and ANOVA were used to examine differences in EDA from baseline to intervention, and the impact of environmental and infant factors on parent stress were visually analyzed against EDA waveforms. ResultsWearable sensor use in the NICU appeared feasible as assessed by all methods. Preliminary data analysis indicated that overall parent EDA levels during parent-infant interactions were low, and engagement in sensory intervention(s) led to a non-significant increase in parental EDA, measured by both skin conductance levels and non-specific skin conductance responses. Three main patterns of EDA emerged: a temporary increase in EDA at the beginning of the intervention followed by a decrease and plateau, a plateau in EDA from baseline to intervention, and a gradual rise in EDA throughout intervention. Specific environmental and infant factors, such as infant stress and health care providers entering the room, appeared to impact parent stress levels. ConclusionAlthough these preliminary findings provide support for use of EDA in the NICU, future studies are needed.

Sensory Adaptations to Improve Physiological and Behavioral Distress During Dental Visits in Autistic Children

Autistic children have poorer oral health and greater oral care challenges, which are often associated with sensory overresponsivity, than neurotypical peers. It is important to identify innovative solutions enabling dentists to successfully perform standard clinic-based procedures for this population. To determine whether a sensory-adapted dental environment (SADE) reduces physiological and behavioral distress in autistic children undergoing dental cleanings, compared with a regular dental environment (RDE). This randomized crossover trial was conducted at a pediatric dentistry clinic in a large urban children's hospital between May 2016 and April 2022. Coders were blinded to study condition for physiological but not behavioral measurements. Autistic children aged 6 to 12 years were identified and invited to participate. Interested families were enrolled consecutively; after confirmation of autism diagnosis, children were randomized. Analysis for this per-protocol study were conducted from April to October 2022. Each child underwent 1 RDE and 1 SADE dental cleaning, administered in randomized and counterbalanced order approximately 6 months apart. SADE included modified visual, auditory, and tactile stimuli. The primary outcome was physiological stress, assessed by electrodermal activity. The secondary outcome was behavioral distress measured from video recordings. Among 452 families invited to participate, 220 children were enrolled, and 162 children (mean [SD] age, 9.16 [1.99] years; 136 [84.0%] male) with confirmed autism were randomized, with 83 children receiving RDE first and 80 children receiving SADE first. Most children (94 children [58.0%]) had moderate autism severity. Children had significantly lower physiological stress during dental care in SADE compared with RDE (mean difference in skin conductance level, -1.22 [95% CI, -2.17 to -0.27] μS), suggesting decreased sympathetic activity and increased relaxation during SADE dental care. No significant differences were found in nonspecific skin conductance responses (mean difference, -0.30 [95% CI, -0.86 to 0.25] per min). Video-coded frequency and duration of behavioral distress (but not questionnaire) measures were significantly lower in SADE vs RDE (Cohen d = -0.84 to -1.19). Physiological stress was associated with behavioral distress during the dental cleaning (eg, nonspecific skin conductance responses associated with the Frankl Scale: β = -0.29; 95% CI, -0.39 to -0.19); age, IQ, and expressive communication moderated the intervention's success. No participants withdrew due to adverse effects. In this randomized crossover trial of autistic children, using SADE was safe and efficacious in decreasing physiological and behavioral distress during dental care. This is important because enhancing oral care is critical for autistic children; this intervention may also be beneficial for populations beyond autism. ClinicalTrials.gov Identifier: NCT02430051.

Reduction of drive for thinness and body dissatisfaction in people with self-reported dysregulated eating behaviors after intermittent theta burst stimulation (iTBS) of the left dorsolateral prefrontal cortex.

This study aimed to explore the effect of intermittent theta burst stimulation (iTBS) of the right and left dorsolateral prefrontal cortex (DLPFC) in people with self-reported dysregulated eating behaviors but without a diagnosis of eating disorders (EDs). Participants were randomly divided into two equivalent groups according to the side (right or left) of the hemisphere to be stimulated and they were tested before and after a single iTBS session. Outcome measurements were scores on self-report questionnaires assessing psychological dimensions related to eating behaviors (EDI-3), anxiety (STAI-Y), and tonic electrodermal activity. The iTBS interfered with both psychological and neurophysiological measures. Significant variations of physiological arousal after iTBS of both the right and left DLPFC were witnessed by increased mean amplitude of non-specific skin conductance responses. With regard to the psychological measures, the iTBS on the left DLPFC significantly reduced the scores of the EDI-3 subscales drive for thinness and body dissatisfaction. Interestingly, these two scales are two of the three EDI-3 clinic scales (drive for thinness, body dissatisfaction, and bulimia) used as specific markers to assess the onset and/or maintenance of eating disorders. Our results show that the left DLPFC iTBS has an impact on the psychological dimensions that are risk factors for the onset of eating disorders, suggesting that an altered hemispheric asymmetry similar to that encountered in clinical populations is present in normal subjects even in the absence of clinical symptoms.

Electrodermal activity spectral and nonlinear analysis – potential biomarkers for sympathetic dysregulation in autism

Autism spectrum disorder (ASD) is a neurodevelopmental disease characterized by emotional and social deficits, which can be associated with sympathetic dysregulation. Thus, we aimed to analyze the electrodermal activity (EDA) using time, and novel spectral and nonlinear indices in ASD. The cohort consisted of 45 ASD boys and 45 age-matched controls. EDA was continuously recorded at rest. The EDA indices were evaluated by time-, spectral-, and nonlinear-domain analysis. Our results revealed increased non-specific skin conductance responses, spectral parameters in high and very-high frequency bands, approximate and symbolic information entropy indicating sympathetic overactivity in ASD vs. controls (p < 0.05, for all). Surprisingly, the nonlinear index from detrended fluctuation analysis α1 was lower in ASD vs. controls (p = 0.024) providing thus distinct information about qualitative features of complex sympathetic regulation. Concluding, the complex time, spectral, and nonlinear EDA indices revealed discrete abnormalities in sympathetic cholinergic regulation as one of the potential pathomechanisms contributing to cardiovascular complications in ASD.

Central and peripheral nervous system responses to chronic and paced hyperventilation in anxious and healthy subjects

The aim of the present study was to examine self-report, peripheral nervous system, and central nervous system correlates of naturally-occurring, chronic hyperventilation (HV, assessed by hypocapnia or low resting state low end-tidal CO2), and to examine the additional effect of acute, experimentally-induced HV in anxious and healthy participants. By identifying the biomarkers of anxiety-related chronic HV and examining responses to acute HV, we hope to identify meaningful, mechanistic targets for further treatment development. Seventy anxious patients and 34 healthy control participants completed electroencephalogram (EEG) and peripheral nervous system recording at baseline and following a paced breathing task. Diagnosis x baseline hypnocapnia group analyses indicated that anxious/hypocapnic patients exhibited greater nonspecific skin conductance response amplitude than did anxious/normocapnic patients, and the anxious group reported greater HV-related symptoms and anxiety sensitivity than did the control group. However, no EEG abnormalities were noted as a function of anxiety group or baseline hypocapnia status. Following paced HV, anxious patients (but not controls) exhibited an increase in left-frontal alpha 1 power. Hypocapnic, but not normocapnic, participants exhibited an increase in skin conductance levels. Anxious patients reported an increase in negative cognitive appraisals of HV symptoms, and anxious/hypocapnic participants reported an increase in affective responses to HV. Thus, chronic HV is associated with greater arousal, and increased self-reported and physiological sensitivity to paced HV. Patients who chronically hyperventilate appear to be more sensitive to respiratory distress, responding with higher levels of anxiety and poorer tolerance of the physiological sensations accompanying acute HV.

Cardiorespiratory fitness, regular physical activity, and autonomic nervous system reactivity to laboratory and daily life stress.

The cross-stressor adaptation hypothesis-which posits that adjustment to physical stress as a result of regular physical activity and its effects on fitness crosses over to psychological stress reactivity-has been around for over four decades. However, the literature has been plagued by heterogeneities preventing definitive conclusions. We address these heterogeneity issues in a combined laboratory and daily life study of 116 young adults (M=22.48 SD=3.56, 57.76% female). The exposure, i.e., the potential driver of adaptation, was defined in three ways. First, a submaximal test was performed to obtain aerobic fitness measured as the VO2 max (kg/ml/min). Second, leisure time exercise behavior, and third, overall moderate-to-vigorous physical activity (MVPA), were obtained from a structured interview. Outcomes were autonomic nervous system (ANS) reactivity and affective responsiveness to stressors. ANS activity was measured continuously and expressed as inter-beat-interval (IBI), pre-ejection-period (PEP), respiratory sinus arrythmia (RSA), and non-specific Skin Conductance Responses (ns.SCR). Negative and positive affect were recorded after each experimental condition in the laboratory and hourly in daily life with a nine-item digital questionnaire. Linear regressions were performed between the three exposure measures as predictors and the various laboratory and daily life stress measurements as outcomes. Our results support the resting heart rate reducing effect of aerobic fitness and total MVPA in both the laboratory and daily life. We did not find evidence for the cross-stressor adaptation hypothesis, irrespective of ANS or affective outcome measure or whether the exposure was defined as exercise/MVPA or aerobic fitness.

Skin conductance during remote collaborative communication under noisy, reverberant and delayed communication transmission conditions

This study, which is part of a larger study, was designed to monitor skin conductance during remote collaborative communication. Ninety (45 men and 45 women) participants were divided into 30 teams with three members in each team. Each team built different LEGO models under three communication transmission delay conditions in the following order: No delay, 750 ms delay and 5000 ms delay. One individual served as the LEGO builder, who did not have the instruction manual. The remaining two team members provided instructions for building the models. Participants were in separate rooms and communicated via earphones. Background white noise (50 dB SPL) was introduced in the ear canals and reverberation was applied to the transmitted communication. Participants were fitted with Empatica E4 wristbands. The ANOVA revealed that the Sum of non-specific skin conductance response (NS-SCR) amplitude/minute was significantly reduced in the 5000 ms delay condition compared to the No delay and 750 ms delay conditions with a medium effect size. These results suggest that participants tend to adapt to the task yielding reduced stress in the last delay condition. Acknowledgement: Graduate students Sydney Osbarn and Melissa Reyes assisted in data collection. Sydney Osbarn also assisted in pre-processing the data.

Electrodermal Activity Is Sensitive to Sleep Deprivation but Does Not Moderate the Effect of Total Sleep Deprivation on Affect.

Emotion is characterized by dimensions of affective valence and arousal, either or both of which may be altered by sleep loss, thereby contributing to impaired regulatory functioning. Controlled laboratory studies of total sleep deprivation (TSD) generally show alterations in physiological arousal and affective state, but the relationship of affect and emotion with physiological arousal during TSD has not been well characterized. Established methods for examining physiological arousal include electrodermal activity (EDA) measures such as non-specific skin conductance responses (NSSCR) and skin conductance level (SCL). These measures are robust physiological markers of sympathetic arousal and have been linked to changes in experienced emotion. To explore the link between physiological arousal and affect during sleep deprivation, we investigated individuals’ EDA under TSD and its relationship to self-reported affect. We also investigated the relationship of EDA to two other measures known to be particularly sensitive to the arousal-decreasing effects of TSD, i.e., self-reported sleepiness and performance on a vigilant attention task. Data were drawn from three previously published laboratory experiments where participants were randomly assigned to either well-rested control (WRC) or 38 h of TSD. In this data set, comprising one of the largest samples ever used in an investigation of TSD and EDA (N = 193 with 74 WRC and 119 TSD), we found the expected impairing effects of TSD on self-reported affect and sleepiness and on vigilant attention. Furthermore, we found that NSSCR, but not SCL, were sensitive to TSD, with significant systematic inter-individual differences. Across individuals, the change in frequency of NSSCR during TSD was not predictive of the effect of TSD on affect, sleepiness, or vigilant attention, nor was it related to these outcomes during the rested baseline. Our findings indicate that while physiological arousal, as measured by EDA, may be useful for assessing TSD-related changes in non-specific arousal at the group level, it is not associated with individuals’ self-reported affect at rest nor their change in affect during TSD. This suggests that an essential aspect of the relationship between physiological arousal and self-reported affect is not well captured by EDA as measured by NSSCR.

Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder.

BackgroundSocial anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD.MethodsForty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary.ResultsWe observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group.ConclusionTMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.

Facilitating relaxation and stress reduction in healthy participants through a virtual reality intervention: study protocol for a non-inferiority randomized controlled trial

BackgroundRepeated or chronic stress is considered a major source of disease, in terms of both somatic and mental illnesses. The prevention of stress-related disease by interventions for relaxation has thus increased societal relevance. In this randomized controlled non-inferiority trial, we will compare a newly developed virtual reality (VR) environment for relaxation to an active control group applying a freely chosen relaxation method. To test if our VR environment supports relaxation in a situation of acute stress, a standardized stress induction protocol will precede the relaxation phase.MethodsOne hundred healthy participants will be recruited from the University of Siegen and randomly assigned to the VR or the active control group that will be free to choose their own relaxation strategy. The multi-sensory VR includes visual, acoustic, and haptic features to induce a strong feeling of presence. The laboratory testing will comprise a baseline measurement, a stress induction, a relaxation intervention, and a recovery measurement. The primary outcomes are self-reported stress and relaxation measured with a visual analog scale (VAS) at pre- and post-baseline, at the start, middle, and end of the stress induction, at pre- and post-relaxation, at pre- and post-recovery, and in the evening of testing. Secondary outcomes are the physiological parameters, namely heart rate and heart rate variability, tonic skin conductance level as well as the number of non-specific skin conductance responses, systolic and diastolic blood pressure and respiratory rate recorded during the four experimental phases as well as state mood, and state rumination assessed at four time points (pre- and post-stress, post-relaxation, and in the evening of testing). Finally, post-event processing will be assessed after relaxation and in the evening of testing. Repeated measures ANOVAs will be performed to test for statistical effects of group, time, and group × time interaction.DiscussionThe newly developed, multi-sensory VR offers an intervention for relaxation without prior training. Its immersive character might increase efficacy compared to other relaxation methods, especially in situations of acute stress. Future directions could be the development of a mobile version of the VR to enhance accessibility for users. To achieve a transfer of training effects to real life, VR components should successively be eliminated until relaxation is practiced without guidance by the VR.Trial registrationISRCTN Registry ISRCTN11162338. Retrospectively registered on January 22, 2021

Entropy Analysis of Neonatal Electrodermal Activity during the First Three Days after Birth

The entropy-based parameters determined from the electrodermal activity (EDA) biosignal evaluate the complexity within the activity of the sympathetic cholinergic system. We focused on the evaluation of the complex sympathetic cholinergic regulation by assessing EDA using conventional indices (skin conductance level (SCL), non-specific skin conductance responses, spectral EDA indices), and entropy-based parameters (approximate, sample, fuzzy, permutation, Shannon, and symbolic information entropies) in newborns during the first three days of postnatal life. The studied group consisted of 50 healthy newborns (21 boys, average gestational age: 39.0 ± 0.2 weeks). EDA was recorded continuously from the feet at rest for three periods (the first day—2 h after birth, the second day—24 h after birth, and the third day—72 h after birth). Our results revealed higher SCL, spectral EDA index in a very-low frequency band, approximate, sample, fuzzy, and permutation entropy during the first compared to second and third days, while Shannon and symbolic information entropies were lower during the first day compared to other periods. In conclusion, EDA parameters seem to be sensitive in the detection of the sympathetic regulation changes in early postnatal life and which can represent an important step towards a non-invasive early diagnosis of the pathological states linked to autonomic dysmaturation in newborns.

Validation of Spectral Indices of Electrodermal Activity with a Wearable Device.

Electrodermal activity (EDA) has been found to be a highly sensitive, accurate and non-invasive measure of the sympathetic nervous system's activity and has been used to extract biomarkers of various pathophysiological conditions including stress, fatigue, epilepsy, and chronic pain. Recently, various robust signal processing techniques have been developed to obtain more reliable and accurate indices that capture the meaningful characteristics of the EDA using data collected from laboratory-scale devices. However, EDA also has the potential to monitor such physiological conditions in active ambulatory settings, for which the developed tools must be deployed in wearable devices. In this paper, we studied the feasibility of obtaining the highly-sensitive spectral indices of EDA using a wearable device. EDA signals were collected from left hand fingers using a wearable device and a laboratory-scale reference device, while N=18 subjects underwent the Head up Tilt test and the Stroop test to stimulate orthostatic and cognitive stress, respectively. We computed two time-domain indices, the skin conductance level (SCL) and nonspecific skin conductance responses (NS.SCRs), and two spectral indices, the normalized sympathetic components of the EDA (EDASympn), and the time-varying EDA index of sympathetic control (TVSymp). The results showed similar performances for EDASympn and TVSymp indices across both devices. While spectral indices obtained from both devices performed similarly in response to orthostatic and cognitive stress, time-domain exhibited large variation when obtained by the wearable device. Further research is required to develop and refine such devices, as well as the indices used to analyze EDA results.Clinical Relevance- This study proves the feasibility of obtaining spectral indices of EDA using a wearable device, which can be used to develop wearable tools to detect pain, stress, fatigue, between others.

Sleep Dysregulation and Daytime Electrodermal Patterns in Children With Autism: A Descriptive Study

Sleep deficiency influences emotion and behavior regulation but the mechanisms of influence are poorly understood. Emotion, behavioral, and sleep theories highlight differences in autonomic function as a potential pathway of influence and research in typical populations draw links between sleep deficiency and autonomic dysregulation (e.g., elevated reactivity within the sympathetic nervous system). In populations at elevated risk for sleep deficiency/problems (i.e., individuals with autism), greater variability in sleep and autonomic/arousal profiles may be particularly informative. Using electrodermal activity (EDA) as an indicator of sympathetic nervous system activation, this descriptive pilot study aimed to document daytime EDA patterns in children with autism and to explore their relations with sleep dysregulation/deficiency. EDA and sleep were measured using ankle and wrist worn sensors in 13 children (Meanage 6.11 years). EDA indices included nonspecific skin conductance responses (NSSCR) and tonic skin conductance levels (SCL). Descriptively, children in the dysregulated sleep group had fewer NSSCRs and lower SCL in the afternoon. This blunted physiological arousal profile/pattern is consistent with previous research, but this is the first study to explore how sleep may be linked. Notably, this pattern may not reflect sleep but an overall dysregulation profile which in this sample included: dysregulated sleep, a blunted afternoon arousal profile, and elevated ASD symptom severity. Replication with larger, more diverse samples is needed to disentangle the complex relations among sleep, arousal, and ASD behavioral features. However, this study represents an important first step in documenting extended daytime arousal patterns.

User Experience Evaluation: A Validation Study of a Tool-based Approach for Automatic Stress Detection Using Physiological Signals

ABSTRACT HCI researchers and practitioners are increasingly using physiological data to measure User eXperience (UX) parameters. The dynamic nature of physiological data offers a continuous window for an in-depth understanding of users’ interaction experience. However, in order to be truly informative, physiological signals need to be linked to users’ interaction experience aspects, such as their emotional states, in a systematic and efficient way. Studies have shown that skin conductance is a physiological signal highly associated with stress. The main purpose of this paper is to present the validation study of our proposed stress detection mechanism which is integrated into a software named PhysiOBS. PhysiOBS is an observation analysis tool that can be used in the post-study analysis phase. PhysiOBS uses nonspecific skin conductance responses (NS-SCRs) in order to auto-report time periods that are probably associated with a problematic interaction. PhysiOBS can also combine multiple data sources. Hence, UX evaluators are able to further investigate a recorded session in order to reveal additional interaction flaws. The integrated stress assessment mechanism, which uses four trained classifiers, can be applied in the reported periods (auto/expert-reported) in order to classify them as stress or non-stress. For the purpose of the validation study, 24 users were recruited in order to participate in a lab experiment. Results showed that our stress assessment mechanism supports UX evaluators by accurately identifying stressful regions within an interaction scenario.

Spectral and Nonlinear Analysis of Electrodermal Activity in Adolescent Anorexia Nervosa

Anorexia nervosa (AN) is an eating disorder with increasing prevalence in childhood and adolescence. Sympathetic dysregulation is supposed to be the underlying mechanism of increased cardiovascular risk in AN. Thus, we assess the electrodermal activity (EDA) as a non-invasive index of sympathetic cholinergic activity using linear and nonlinear analysis in adolescent AN with the aim of detecting potential biomarkers for AN-linked cardiovascular risk. We examined 25 adolescent girls with AN and 25 age-matched controls. EDA was continuously recorded during a 5-min resting phase. Evaluated parameters were: time-domain (skin conductance level, non-specific skin conductance responses), frequency-domain (EDA in very low, low, sympathetic, high and very high frequency bands) and nonlinear (approximate, sample, symbolic information entropies, detrended fluctuation analysis (DFA)) parameters of EDA and peripheral skin temperature. Our findings revealed lower EDA values indicating a decrease in the sympathetic nervous activity in female adolescents with the acute phase of AN. Further, we found higher nonlinear index DFA in AN vs. controls. We assumed that nonlinear index DFA could provide novel and independent information on the complex sympathetic regulatory network. We conclude that the parameters of complex EDA analysis could be used as sensitive biomarkers for the assessment of sympathetic cholinergic dysregulation as a risk factor for AN-linked cardiovascular morbidity.