Electrodermal and central measures of the tonic orienting reflex (OR)

Sokolov described both phasic and tonic aspects of the Orienting Reflex (OR), but subsequent research and theory development has focussed primarily on the phasic OR at the expense of the tonic OR. The present study used prestimulus skin conductance level (SCL) during a dishabituation paradigm to model the tonic OR, examining its amplitude patterning over repeated standard stimulus presentations and a change stimulus. We expected sensitisation (increased amplitude) following the initial and change trials, and habituation (decrement) over the intervening trials. Prestimulus EEG alpha level was explored as a potential central measure of the tonic OR (as an inverse correlate), examining its pattern over stimulus repetition and change in relation to the SCL model. We presented a habituation series of innocuous auditory stimuli to two groups (each N = 20) at different ISIs (Long 13-15 s and Short 5-7 s) and recorded electrodermal and EEG data during two counterbalanced conditions; Indifferent: no task requirements; Significant: silent counting. Across groups and conditions, prestimulus SCLs and alpha amplitudes generally showed the expected trials patterns, confirming our main hypotheses. Findings have important implications for including the assessment of Sokolov's tonic OR in modelling central and autonomic nervous system interactions of fundamental attention and learning processes.

Wearable Ring-Shaped Biomedical Device for Physiological Monitoring through Finger-Based Acquisition of Electrocardiographic, Photoplethysmographic, and Galvanic Skin Response Signals: Design and Preliminary Measurements

Wearable health devices (WHDs) are rapidly gaining ground in the biomedical field due to their ability to monitor the individual physiological state in everyday life scenarios, while providing a comfortable wear experience. This study introduces a novel wearable biomedical device capable of synchronously acquiring electrocardiographic (ECG), photoplethysmographic (PPG), galvanic skin response (GSR) and motion signals. The device has been specifically designed to be worn on a finger, enabling the acquisition of all biosignals directly on the fingertips, offering the significant advantage of being very comfortable and easy to be employed by the users. The simultaneous acquisition of different biosignals allows the extraction of important physiological indices, such as heart rate (HR) and its variability (HRV), pulse arrival time (PAT), GSR level, blood oxygenation level (SpO2), and respiratory rate, as well as motion detection, enabling the assessment of physiological states, together with the detection of potential physical and mental stress conditions. Preliminary measurements have been conducted on healthy subjects using a measurement protocol consisting of resting states (i.e., SUPINE and SIT) alternated with physiological stress conditions (i.e., STAND and WALK). Statistical analyses have been carried out among the distributions of the physiological indices extracted in time, frequency, and information domains, evaluated under different physiological conditions. The results of our analyses demonstrate the capability of the device to detect changes between rest and stress conditions, thereby encouraging its use for assessing individuals' physiological state. Furthermore, the possibility of performing synchronous acquisitions of PPG and ECG signals has allowed us to compare HRV and pulse rate variability (PRV) indices, so as to corroborate the reliability of PRV analysis under stationary physical conditions. Finally, the study confirms the already known limitations of wearable devices during physical activities, suggesting the use of algorithms for motion artifact correction.

The impact of extinction timing on pre-extinction arousal and subsequent return of fear

Exposure-based therapy is effective in treating anxiety, but a return of fear in the form of relapse is common. Exposure is based on the extinction of Pavlovian fear conditioning. Both animal and human studies point to increased arousal during immediate compared to delayed extinction (>+24 h), which presumably impairs extinction learning and increases the subsequent return of fear. Impaired extinction learning under arousal might interfere with psychotherapeutic interventions. The aim of the present study was to investigate whether arousal before extinction differs between extinction groups and whether arousal before extinction predicts the return of fear in a later (retention) test. As a highlight, both the time between fear acquisition and extinction (immediate vs. delayed) and the time between extinction and test (early vs. late test) were systematically varied. We performed follow-up analyses on data from 103 young, healthy participants to test the above hypotheses. Subjective arousal ratings and physiological arousal measures of sympathetic and hypothalamic pituitary adrenal axis activation (tonic skin conductance and salivary cortisol) were collected. Increased pre-extinction arousal in the immediate extinction group was only confirmed for subjective arousal. In linear regression analyses, none of the arousal measures predicted a significant return of fear in the different experimental groups. Only when we aggregated across the two test groups, tonic skin conductance at the onset of extinction predicted the return of fear in skin conductance responses. The overall results provide little evidence that pre-extinction arousal affects subsequent extinction learning and memory. In terms of clinical relevance, there is no clear evidence that exposure could be improved by reducing subjective or physiological arousal.

Exploring the impact of human-robot interaction on workers' mental stress in collaborative assembly tasks

Advances in robotics have contributed to the prevalence of human-robot collaboration (HRC). However, working and interacting with collaborative robots in close proximity can be psychologically stressful. Therefore, understanding the impacts of human-robot interaction (HRI) on mental stress is crucial for enhancing workplace well-being. To this end, this study investigated how the HRI factors - presence, complexity, and modality - affect the psychological stress of workers. We employed both the NASA-Task Load Index for subjective assessment and physiological metrics including galvanic skin responses, electromyography, and heart rate for objective evaluation. An experimental setup was implemented in which human operators worked together with a collaborative robot on Lego assembly tasks, using different interaction paradigms including pressing buttons, showing hand gestures, and giving verbal commands. The results revealed that the introduction of interactions during HRC helped reduce mental stress and that complex interactions resulted in higher mental stress than simple interactions. Meanwhile, using hand gestures led to significantly higher mental stress than pressing buttons and verbal commands. The findings provided practical insights for mitigating mental stress in the workplace and promoting wellness in the era of HRC.

Hydrocortisone Differentially Affects Reinstatement of Pain-related Responses in Patients With Chronic Back Pain and Healthy Volunteers

Despite the crucial role of effective and sustained extinction of conditioned pain-related fear in cognitive-behavioral treatment approaches for chronic pain, experimental research on extinction memory retrieval in chronic pain remains scarce. In healthy populations, extinction efficacy of fear memory is affected by stress. Therefore, we investigated the effects of oral hydrocortisone administration on the reinstatement of pain-related associations in 57 patients with non-specific chronic back pain (CBP) and 59 healthy control (HC) participants in a differential pain-related conditioning paradigm within a placebo-controlled, randomized, and double-blind design. Participants' skin conductance responses indicate hydrocortisone-induced reinstatement effects in HCs but no observable reinstatement in HCs receiving placebo treatment. Interestingly, these effects were reversed in patients with CBP, that is, reinstatement responses were only observed in the placebo and not in the hydrocortisone group. Our findings corroborate previous evidence of stress-induced effects on extinction efficacy and reinstatement of fear memory in HCs, extending them into the pain context, and call for more research to clarify the role of stress in fear extinction and return of fear phenomena possibly contributing to treatment failure in chronic pain treatment. PERSPECTIVE: Opposing effects in HCs and patients with non-specific CBP may be associated with changes in the patients' stress systems. These findings could be of relevance to optimizing psychological, extinction-based treatment approaches.

Psychophysiological strategies for enhancing performance through imagery-skin conductance level analysis in guided vs. self-produced imagery

Athletes need to achieve their optimal level of arousal for peak performance. Visualization or mental rehearsal (i.e., Imagery) often helps to obtain an appropriate level of activation, which can be detected by monitoring Skin Conductance Level (SCL). However, different types of imagery could elicit different amount of physiological arousal. Therefore, this study aims: (1) to investigate differences in SCL associated with two instructional modalities of imagery (guided vs. self-produced) and six different scripts; (2) to check if SCL could differentiate respondents according to their sport expertise. Thirty participants, aged between 14 and 42 years (M = 22.93; SD = 5.24), with different sport levels took part in the study. Participants listened to each previously recorded script and then were asked to imagine the scene for a minute. During the task, SCL was monitored. We analysed the mean value, variance, slope and number of fluctuations per minute of the electrodermal signal. Unsupervised machine learning models were used for measuring the resemblance of the signal. The Wilcoxon signed-rank test was used for distinguishing guided and self-produced imagery, and The Mann-Whitney U test was used for distinguishing results of different level athletes. We discovered that among others, self-produced imagery generates lower SCL, higher variance, and a higher number of fluctuations compared to guided imagery. Moreover, we found similarities of the SCL signal among the groups of athletes (i.e. expertise level). From a practical point of view, our findings suggest that different imagery instructional modalities can be implemented for specific purposes of mental preparation.

Normal values of sudomotor function assessed by electrochemical skin conductance in African population

BACKGROUND

Dysfunction of small nerve fibers remains a major public health concern. Subjects suspected of having small nerve fiber damage need to undergo reliable tests to confirm the diagnosis. Sudomotor function test is a reliable noninvasive exploration for detecting peripheral neuropathies. Nevertheless, the normal reference values derived from the sudomotor function test are not known in the African population. The objective of this study was therefore to describe the normal values of Electrochemical Skin Conductance (ESC) measured by the sudomotor function test in healthy African subjects.

MATERIALS AND METHODS

Between December 1st, 2021 and May 31st, 2022, ESC was measured in 475 healthy subjects (median age: 42 [31-53] years, 46% men) using a sudomotor function test, in the hands and feet. Investigators proposed the examination and received participants' consent; demographic, anthropometric, biological, and clinical data were obtained before the test. Data on 475 healthy study participants who underwent sudomotor function testing was collected and analyzed. The sociodemographic (age, sex), anthropometric (weight, height, waist circumference, body mass index), diastolic blood pressure, systolic blood pressure, heart rate, and electrochemical skin conductances of the hands and feet were assessed.

RESULTS

ESC values were statistically higher in men compared to women (right hand ESC: 70 [60-78] versus 63 [53-72], left hand ESC: 72 [61-80] versus 68 [57-75], right foot ESC: 77 [82-99] versus 72 [64-79], ESC left foot: 76 [68-82] versus 72 [62-78] respectively). ESC values were significantly inversely correlated with age (right hand ESC: r=-0.12, P=0.006; left hand ESC: r=-0.11, P=0.01; right foot ESC: r=-0.37, P<0.0001; ESC left foot: r=-0.38, P<0.0001). ESC values measured in feet were significantly inversely correlated with body mass index (right foot r=-0.22, P<0.0001; left foot r=-0.21, P<0.0001).

CONCLUSION

This study reports normal reference values for ESCs according to age and gender in the healthy African population. Progressive decrease in ESC with aging is confirmed by our data. The value of ESC seems lower in the African population than in other reported ethnicities. This finding needs to be further explored in additional studies.

Conditioning to true content and artificial intelligence in psychophysiological intention recognition

OBJECTIVE

The objective is to introduce a novel method for classical conditioning to true content (CtTC), and for the first time, apply this approach in the concealed information test (CIT) to effectively discern intentions. During CtTC, participants are trained to exhibit electrodermal responses whenever they recognize true content on a screen. Additionally, the objective is to evaluate a novel CIT-dataset preprocessing algorithm, employed to enhance machine learning (ML) classification performance.

METHODS

A total of 84 participants were evenly divided into four groups. Two groups of participants devised plans for stealing money from a supermarket, while the other two groups did not engage in any planning. One planning group and one non-planning group underwent CIT examination, while the remaining groups were subjected to CtTC.

RESULTS

The CIT accuracy initially stood at 52 % and increased to 71 % after Z-score and ML classification (McNemar test, p < 0.05). Conversely, the CtTC accuracy was 76 % and significantly improved to 93 % following Z-score and 95 % following ML classification (McNemar test, p < 0.05). In the best-performing classifiers, CtTC exhibited significantly superior metrics for guilty/innocent classification compared to CIT (Fisher's exact test, p < 0.05, power 1 - β > 0.90). In the CtTC group, reactivity and sensitivity significantly increased, indicated by higher EDR amplitudes (p < 0.05, two-tailed t-test, power 1 - β = 0.89) and the number of EDRs (p < 0.05, Fisher's exact test, power 1 - β = 0.90). There was no statistically significant difference between the Z-score and ML classification.

CONCLUSIONS

In the assessment of intentions, CtTC enhances both the sensitivity and accuracy of the CIT.

Analysis of sympathetic responses to cognitive stress and pain through skin sympathetic nerve activity and electrodermal activity

We explored the non-invasive evaluation of the sympathetic nervous system (SNS) by employing two distinct physiological signals: skin sympathetic nerve activity (SKNA), extracted from electrocardiogram (ECG) signals, and electrodermal activity (EDA), a well-studied marker in the context of the SNS assessment. Our investigation focused on cognitive stress and pain; two conditions closely associated with the SNS. We sought to determine if the information and dynamics of EDA could be derived from the novel SKNA signal. To this end, ECG and EDA signals were recorded simultaneously during three experiments aimed at sympathetic stimulation, Valsalva maneuver (VM), Stroop test, and thermal-grill pain test. We calculated the integral area under the rectified SKNA signal (iSKNA) and decomposed the EDA signal to its phasic component (EDAphasic). An average delay of more than 4.6 s was observed in the onset of EDAphasic bursts compared to their corresponding iSKNA bursts. After shifting the EDAphasic segments by the extent of this delay and smoothing the corresponding iSKNA bursts, our results revealed a strong average correlation coefficient of 0.85±0.14 between the iSKNA and EDAphasic bursts, indicating a noteworthy similarity between the two signals. We also reconstructed the EDA signals with time-varying sympathetic (TVSymp) and modified TVSymp (MTVSymp) methods. Then we extracted the following features from iSKNA, EDAphasic, TVSymp, and MTVSymp signals: peak amplitude, average amplitude (aSKNA), standard deviation (vSKNA), and the cumulative duration during which the signals had higher amplitudes than a specified threshold (HaSKNA). A strong average correlation of 0.89±0.18 was found between vSKNA and subjects' self-rated pain levels during the pain test. Our statistical analysis also included applying Linear Mixed-Effects Models to check if there were significant differences in features across baseline and different levels of SNS stimulation. We then assessed the discriminating power of the features using Area Under the Receiver Operating Characteristic Curve (AUROC) and Fisher's Ratio. Finally, using all the four EDA features, a multi-layer perceptron (MLP) classifier reached the classification accuracies 95.56%, 89.29%, and 67.88% for the VM, Stroop, and thermal-grill pain control and stimulation classes. On the other hand, the highest classification accuracies based on SKNA features were achieved using K-nearest neighbors (KNN) (98.89%), KNN (89.29%), and MLP (95.11%) classifiers for the same experiments. Our comparative analysis showed the feasibility of SKNA as a novel tool for assessing the SNS with accurate classification capability, with a faster onset of amplitude increase in response to SNS activity, compared to EDA.

Sympathetic Skin Response in Ulnar Neuropathy at the Elbow

INTRODUCTION

The sympathetic skin response (SSR) reflects the function of sudomotor sympathetic unmyelinated fibers. This study evaluates SSR abnormalities in ulnar neuropathy at the elbow (UNE).

METHODS

Sympathetic skin response was obtained after electrical stimulation of the glabella recording simultaneously from the hand palm (P), third digit (M3) and fifth digit ipsilateral (U5) and contralateral (cU5) to the side of UNE. Ten consecutive SSRs were recorded from each recording side of all participants.

RESULTS

The authors enrolled 31 patients (mean age 54.3 ± 11.4 years) and 25 subjects of a control group (mean age 52.6 ± 11.3 years). The mean of the areas and the area of the largest response of U5-SSR were significantly lower in the patients (106.9 ± 68.9 and 127.8 ± 79.7 μV/s, respectively) than in control group (161.8 ± 116.6 and 197.2 ± 143.3 μV/s, respectively) and in the affected than in the unaffected sides of the patients (155.3 ± 84.8 and 197.7 ± 103.3 μV/s, respectively); there were no differences in U5-SSR latencies and P-SSR and M3-SSR parameters. U5-SSR mean areas and U5-SSR largest area were reduced in 29% and 26% of patients, respectively. The differences between patients and control group and the number of patients with U5-SSR abnormalities increased when the ratios of M3/U5-SSR and U5/cU5-SSR areas were considered. U5-SSR area was related to UNE clinical severity and to some parameters of the ulnar nerve conduction velocity and cutaneous silent period.

CONCLUSIONS

Sympathetic skin response is useful to demonstrate abnormalities of sympathetic fibers even if UNE patients do not complain for sympathetic symptoms. The SSR abnormalities were evident only if electrophysiological damage of myelinated fibers was moderate or severe.

Preventing fear return in humans: Music-based intervention during reactivation-extinction paradigm

In several research studies, the reactivation extinction paradigm did not effectively prevent the return of fear if administered without any intervention technique. Therefore, in this study, the authors hypothesized that playing music (high valence, low arousal) during the reconsolidation window may be a viable intervention technique for eliminating fear-related responses. A three-day auditory differential fear conditioning paradigm was used to establish fear conditioning. Participants were randomly assigned into three groups, i.e., one control group, standard extinction (SE), and two experimental groups, reactivation extinction Group (RE) and music reactivation extinction (MRE), of twenty participants in each group. Day 1 included the habituation and fear acquisition phases; on Day 2 (after 24 hours), the intervention was conducted, and re-extinction took place on Day 3. Skin conductance responses were used as the primary outcome measure. Results indicated that the MRE group was more effective in reducing fear response than the RE and SE groups in the re-extinction phase. Furthermore, there was no significant difference observed between SE and RE groups. This is the first study known to demonstrate the effectiveness of music intervention in preventing the return of fear in a healthy individual. Therefore, it might also be employed as an intervention strategy (non-pharmacological approach) for military veterans, in emotion regulation, those diagnosed with post-traumatic stress disorder, and those suffering from specific phobias.

Combining electrodermal activity analysis and dynamic causal modeling to investigate the visual-odor multimodal integration during face perception

Objective. This study presents a novel methodological approach for incorporating information related to the peripheral sympathetic response into the investigation of neural dynamics. Particularly, we explore how hedonic contextual olfactory stimuli influence the processing of neutral faces in terms of sympathetic response, event-related potentials and effective connectivity analysis. The objective is to investigate how the emotional valence of odors influences the cortical connectivity underlying face processing and the role of face-induced sympathetic arousal in this visual-olfactory multimodal integration.Approach. To this aim, we combine electrodermal activity (EDA) analysis and dynamic causal modeling to examine changes in cortico-cortical interactions.Results. The results reveal that stimuli arising sympathetic EDA responses are associated with a more negative N170 amplitude, which may be a marker of heightened arousal in response to faces. Hedonic odors, on the other hand, lead to a more negative N1 component and a reduced the vertex positive potential when they are unpleasant or pleasant. Concerning connectivity, unpleasant odors strengthen the forward connection from the inferior temporal gyrus (ITG) to the middle temporal gyrus, which is involved in processing changeable facial features. Conversely, the occurrence of sympathetic responses after a stimulus is correlated with an inhibition of this same connection and an enhancement of the backward connection from ITG to the fusiform face gyrus.Significance. These findings suggest that unpleasant odors may enhance the interpretation of emotional expressions and mental states, while faces capable of eliciting sympathetic arousal prioritize identity processing.

Adaptive thresholding increases sensitivity to detect changes in the rate of skin conductance responses to psychologically arousing stimuli in both laboratory and ambulatory settings

Psychophysiologists recording electrodermal activity (EDA) often derive measures of slow, tonic activity-skin conductance level (SCL)-and faster, more punctate changes-skin conductance responses (SCRs). A SCR is conventionally considered to have occurred when the local amplitude of the EDA signal exceeds a researcher-determined threshold (e.g., 0.05 μS), typically fixed across study participants and conditions. However, fixed SCR thresholds can preferentially exclude data from individuals with low SCL because their SCRs are smaller on average, thereby reducing statistical power for group-level analyses. Thus, we developed a fixed plus adaptive (FA) thresholding method that adjusts identification of SCRs based on an individual's SC at the onset of the SCR to increase statistical power and include data from more participants. We assess the utility of applying FA thresholding across two independent samples and explore age and race-related associations with EDA outcomes. Study 1 uses wired EDA measurements from 254 healthy adults responding to evocative images and sounds in a laboratory setting. Study 2 uses wireless EDA measurements from 20 children with autism in a clinical environment while they completed behavioral tasks. Compared to a 0.01, 0.03, and 0.05 μS fixed threshold, FA thresholding at 1.9% modestly increases statistical power to detect a difference in SCR rate between tasks with higher vs. lower subjective arousal and reduces exclusion of participants by up to 5% across both samples. This novel method expands the EDA analytical toolbox and may be useful in populations with highly variable basal SCL or when comparing groups with different basal SCL. Future research should test for reproducibility and generalizability in other tasks, samples, and contexts. IMPACT STATEMENTS: This article is important because it introduces a novel method to enhance sensitivity and statistical power in analyses of skin conductance responses from electrodermal data.

Neural correlates of context-dependent extinction recall in social anxiety disorder: relevance of intrusions in response to aversive social experiences

BACKGROUND

There are phenomenological similarities between social anxiety disorder (SAD) and posttraumatic stress disorder, such as a provoking aversive event, posttraumatic stress symptoms (e.g. intrusions) in response to these events and deficient (context-dependent) fear conditioning processes. This study investigated the neural correlates of context-dependent extinction recall and fear renewal in SAD, specifically in patients with intrusions in response to an etiologically relevant aversive social event.

METHODS

During functional magnetic resonance imaging a two-day context-dependent fear conditioning paradigm was conducted in 54 patients with SAD and 54 healthy controls (HC). This included fear acquisition (context A) and extinction learning (context B) on one day, and extinction recall (context B) as well as fear renewal (contexts C and A) one day later. The main outcome measures were blood oxygen level-dependent responses in regions of interest and skin conductance responses.

RESULTS

Patients with SAD showed reduced differential conditioned amygdala activation during extinction recall in the safe extinction context and during fear renewal in the acquisition context compared to HC. Patients with clinically relevant intrusions moreover exhibited hypoactivation of the ventromedial prefrontal cortex (vmPFC) during extinction learning, extinction recall, and fear renewal in a novel context, while amygdala activation more strongly decreased during extinction learning and increased during fear renewal in the acquisition context compared with patients without intrusions.

CONCLUSIONS

Our study provides first evidence that intrusions in SAD are associated with similar deficits in context-dependent regulation of conditioned fear via the vmPFC as previously demonstrated in posttraumatic stress disorder.

Comparative analysis of electrodermal activity metrics and their association with child behavior in autism spectrum disorder

Researchers are increasingly utilizing physiological data like electrodermal activity (EDA) to understand how stress "gets under the skin." Results of EDA studies in autistic children are mixed, with some suggesting autistic hyperarousal, others finding hypoarousal, and yet others detecting no difference compared to non-autistics. Some of this variability likely stems from the different techniques used to assess EDA. Therefore, the purpose of this study is to investigate and compare commonly used metrics of EDA (frequency of peaks, average amplitude of peaks, and standard deviation of skin conductance level) using two data processing programs (NeuroKit2 and Ledalab) and their link to observed child behavior. EDA data were collected using Empatica E4 wristbands from 60 autistic children and adolescents (5-18 years old) during a 7-min play interaction with their primary caregiver. The play interaction was coded for a range of child behaviors including mood, social responsiveness, dysregulation, and cooperation. Results indicate a strong correlation between NeuroKit2 and Ledalab and a weak correlation between metrics within each program. Furthermore, the frequency of peaks was associated with more positive child social behaviors, and the magnitude of peaks was associated with less adaptive child behaviors. Recommendations for replication and the need for generalizability of this research are given.

Measurements of Electrodermal Activity, Tissue Oxygen Saturation, and Visual Analog Scale for Different Cuff Pressures

The quantification of comfort in binding parts, essential human-machine interfaces (HMI) for the functioning of rehabilitation robots, is necessary to reduce physical strain on the user despite great achievements in their structure and control. This study aims to investigate the physiological impacts of binding parts by measuring electrodermal activity (EDA) and tissue oxygen saturation (StO2). In Experiment 1, EDA was measured from 13 healthy subjects under three different pressure conditions (10, 20, and 30 kPa) for 1 min using a pneumatic cuff on the right thigh. In Experiment 2, EDA and StO2 were measured from 10 healthy subjects for 5 min. To analyze the correlation between EDA parameters and the decrease in StO2, a survey using the visual analog scale (VAS) was conducted to assess the level of discomfort at each pressure. The EDA signal was decomposed into phasic and tonic components, and the EDA parameters were extracted from these two components. RM ANOVA and a post hoc paired t-test were used to determine significant differences in parameters as the pressure increased. The results showed that EDA parameters and the decrease in StO2 significantly increased with the pressure increase. Among the extracted parameters, the decrease in StO2 and the mean SCL proved to be effective indicators. Such analysis outcomes would be highly beneficial for studies focusing on the comfort assessment of the binding parts of rehabilitation robots.

Cognition-Emotion Interaction during L2 Sentence Comprehension: The Correlation of ERP and GSR Responses to Sense Combinations

This study mainly examined the role of the combination of three senses (i.e., auditory, visual, and tactile) and five senses (i.e., auditory, visual, tactile, olfactory, and gustatory) in the correlation between electrophysiological and electrodermal responses underlying second language (L2) sentence comprehension. Forty subjects did two acceptability judgment tasks, encompassing congruent and semantically/pragmatically incongruent sentences. The event-related potential (ERP) and galvanic skin response (GSR) data for both the target and final words of the sentences were collected and analyzed. The results revealed that there is an interaction between cognitive and emotional responses in both semantically and pragmatically incongruent sentences, yet the timing of the interaction is longer in sentences with pragmatic incongruity due to their complexity. Based on the ERP and GSR correlation results, it was further found that the five-sense combination approach improves L2 sentence comprehension and interest in learning materials yet reduces the level of excitement or arousal. While this approach might be beneficial for some learners, it might be detrimental for those in favor of stimulating learning environments.

Utilising electrodermal activity sensor signals to quantify nociceptive response during movement activities

OBJECTIVE

With an increasingly ageing population and osteoarthritis prevalence, the quantification of nociceptive signals responsible for painful movements and individual responses could lead to better treatment and monitoring solutions. Changes in electrodermal activity (EDA) can be detected via changes in skin conductance (SC) and measured using finger electrodes on a wearable sensor, providing objective information for increased physiological stress response.

RESULTS

To provide EDA response preliminary data, this was recorded with healthy volunteers on an array of activities while receiving a noxious stimulus. This provides a defined scenario that can be utilised as protocol feasibility testing. Raw signal extraction, processing and statistical analysis was performed using mean SC values on all participant data. The application of the stimuli resulted in a significant average increase (p < 0.05) in mean SC in four out of five activities with significant gender differences (p < 0.05) in SC and self-reported pain scores and large effect sizes. Though EDA parameters are a promising tool for nociceptive response indicators, limitations including motion artifact sensitivities and lack of previous movement-based EDA published data result in restricted analysis understanding. Refined processing pipelines with signal decomposition tools could be utilised in a protocol that quantifies nociceptive response clinically meaningfully.

Electrodermal activity in bipolar disorder: Differences between mood episodes and clinical remission using a wearable device in a real-world clinical setting

BACKGROUND

Bipolar disorder (BD) lacks objective measures for illness activity and treatment response. Electrodermal activity (EDA) is a quantitative measure of autonomic function, which is altered in manic and depressive episodes. We aimed to explore differences in EDA (1) inter-individually: between patients with BD on acute mood episodes, euthymic states and healthy controls (HC), and (2) intra-individually: longitudinally within patients during acute mood episodes of BD and after clinical remission.

METHODS

A longitudinal observational study. EDA was recorded using a research-grade wearable in patients with BD during acute manic and depressive episodes and at clinical remission. Euthymic BD patients and HC were recorded during a single session. We compared EDA parameters derived from the tonic (mean EDA, mEDA) and phasic components (EDA peaks per minute, pmEDA, and EDA peaks mean amplitude, pmaEDA). Inter- and intra-individual comparisons were computed respectively with ANOVA and paired t-tests.

RESULTS

49 patients with BD (15 manic, 9 depressed, and 25 euthymic), and 19 HC were included. Patients with bipolar depression showed significantly reduced mEDA (p = 0.003) and pmEDA (p = 0.001), which increased to levels similar to euthymia or HC after clinical remission (mEDA, p = 0.011; pmEDA, p < 0.001; pmaEDA, p < 0.001). Manic patients showed no differences compared to euthymic patients and HCs, but a significant reduction of tonic and phasic EDA parameters after clinical remission (mEDA, p = 0.035; pmEDA, p = 0.004).

LIMITATIONS

Limited sample size, high inter-individual variability of EDA parameters, limited comparability to previous studies and non-adjustment for medication.

CONCLUSION

EDA ecological monitoring might provide several opportunities for early detection of depressive symptoms, and might aid at assessing early response to treatments in mania and bipolar depression.

The influence of instructions on reversing the generalization of valence, US expectancy, and electrodermal responding in fear conditioning

Pairing a conditional stimulus (CS) with an aversive unconditional stimulus (US) causes negative valence and US expectancy to generalize to stimuli that are perceptually and/or conceptually similar to the CS. Past research has shown that instructing participants that the US is more likely to follow stimuli that are dissimilar to the CS reversed the generalization of US expectancy but left generalized valence unchanged. Here, we examined whether instructions about the relationship between stimuli that are perceptually similar would affect the generalization of valence. A picture of an alien (CS+) was paired with an electric stimulus, while a perceptually different alien stimulus (CS-) was presented alone. After conditioning, valence, US expectancy, and electrodermal responses generalized to different aliens that were perceptually similar (by color and shape) to the CS+ and CS-. Participants were then instructed that aliens perceptually similar to the CS+ belonged to the same group as the CS- and that aliens perceptually similar to the CS- belonged to the same group as the CS+. The instructions caused an elimination (but not a reversal) of generalized expectancy and valence but did not affect generalized electrodermal responses. This suggests that evaluations of generalization stimuli are sensitive to instructions about their relationship to the CS and that dissociations reported in the literature between valence and expectancy after instructions may occur due to the type of instruction used.

Autonomic responses to pressure sensitivity of head, face and neck: Heart rate and skin conductance

Subjective scales are frequently used in the design process of head-related products to assess pressure discomfort. Nevertheless, some users lack fundamental cognitive and motor abilities (e.g., paralyzed patients). Therefore, it is vital to find non-verbal measurements of pressure discomfort and pressure pain. This study gathered the autonomic response data (heart rate and skin conductance) of 30 landmarks in head, neck and face from 31 participants experiencing pressure discomfort and pressure pain. The results indicate that pressure stimulation can change heart rate (HR) and skin conductance (SC). SC can be more useful in assessing pressure discomfort than HR for specific landmarks, and SC also possesses a faster arousal rate than HR. Moreover, HR decreased in response to pressure stimulation, while SC decreased followed by an increase. In comparisons between genders, the subjective pressure discomfort threshold (PDT) and pressure pain threshold (PPT) of women were lower than those of men, but men's autonomic responses (HR and SC) were more intense. Furthermore, there was no linear correlation between subjective pressure thresholds (PDT and PPT) and autonomic response intensity. This study has significant implications for resolving ergonomic issues (pressure discomfort and pain) associated with head-related products.

An Individualized Approach to Skin Conductance Assessment during Execution of Tasks of Different Complexities

Researchers use different approaches to analyze changes in skin conductance. At the same time, individual differences observed in both the initial values of skin conductance and response to stimuli do not allow comparing the responses of different subjects to the same impact. An individualized approach to the assessment of psycho-emotional stress has been developed using the real-time skin conductance index during continuous performance of a task with different levels of complexity. The participants, 18 second-year students at the actors' high school, performed a simple task (expressive reading aloud of a simple text) and a difficult task (expressive reading aloud of the text inverted 180°). During the task, the skin conductance in the participants was continuously recorded. We revealed a change in the parameters of skin conductivity depending on the complexity of the task, both in comparison with resting state (baseline) and with simple and complex stages of the study. However, the individual skin conduction curves in the subjects differed greatly. A method for assessing the individual differences in parameters of skin conductance was proposed based on ranking by categories of values during continuous performance of tasks with different levels of complexity. This method allows comparing the levels of cognitive load in participants with different initial levels of skin conductance due to transition from the absolute to relative values at time intervals that are important for the researcher.

Decontextualized fear memories? Stronger conditioned fear responses during extinction learning and extinction recall in a safe context predict the development of long-term analog intrusions

BACKGROUND

Difficulties in the context-dependent modulation of conditioned fear are known for posttraumatic stress disorder and may explain the occurrence of intrusive memories in safe contexts. The current study therefore investigated if reduced context-dependent modulation of conditioned fear and its underlying neural circuitry constitute risk factors for the development of analog intrusions in response to an experimental trauma.

METHODS

Eighty-five healthy women participated in the trauma film paradigm to investigate the development of analog intrusions as well as explicit memory for an experimental trauma after one week and three months, respectively. Before, participants underwent a context-dependent fear conditioning paradigm during functional magnetic resonance imaging with fear acquisition in context A and extinction training in context B on a first day, as well as extinction recall in context B and fear renewal in a novel context C one day later. Skin conductance responses (SCRs) and blood oxygen level dependent responses were main outcome measures.

RESULTS

In addition to stronger fear acquisition in context A, stronger conditioned fear responses in the safe context B, as indicated by stronger conditioned SCRs or stronger activation of fear expressing regions during extinction learning and recall, predicted the development of long-term analog intrusions.

CONCLUSIONS

Stronger fear responses in safe and danger contexts were risk factors for the development of long-term analog intrusions and point to decontextualized fear memories and difficulties in the context-dependent modulation of conditioned fear. Altered fear conditioning processes and reduced storage of contextual information may cause the occurrence of fear independent of context.

Effects of background noise on autonomic arousal (skin conductance level)

This study was designed to investigate the relationship between sound level and autonomic arousal using acoustic signals similar in level and acoustic properties to common sounds in the built environment. Thirty-three young adults were exposed to background sound modeled on ventilation equipment noise presented at levels ranging from 35 to 75 dBA sound pressure level (SPL) in 2 min blocks while they sat and read quietly. Autonomic arousal was measured in terms of skin conductance level. Results suggest that there is a direct relationship between sound level and arousal, even at these realistic levels. However, the effect of habituation appears to be more important overall.

Deviations in continuously monitored electrodermal activity before severe clinical complications: a clinical prospective observational explorative cohort study

Monitoring of high-risk patients in hospital wards is crucial in identifying and preventing clinical deterioration. Sympathetic nervous system activity measured continuously and non-invasively by Electrodermal activity (EDA) may relate to complications, but the clinical use remains untested. The aim of this study was to explore associations between deviations of EDA and subsequent serious adverse events (SAE). Patients admitted to general wards after major abdominal cancer surgery or with acute exacerbation of chronic obstructive pulmonary disease were continuously EDA-monitored for up to 5 days. We used time-perspectives consisting of 1, 3, 6, and 12 h of data prior to first SAE or from start of monitoring. We constructed 648 different EDA-derived features to assess EDA. The primary outcome was any SAE and secondary outcomes were respiratory, infectious, and cardiovascular SAEs. Associations were evaluated using logistic regressions with adjustment for relevant confounders. We included 714 patients and found a total of 192 statistically significant associations between EDA-derived features and clinical outcomes. 79% of these associations were EDA-derived features of absolute and relative increases in EDA and 14% were EDA-derived features with normalized EDA above a threshold. The highest F1-scores for primary outcome with the four time-perspectives were 20.7-32.8%, with precision ranging 34.9-38.6%, recall 14.7-29.4%, and specificity 83.1-91.4%. We identified statistically significant associations between specific deviations of EDA and subsequent SAE, and patterns of EDA may be developed to be considered indicators of upcoming clinical deterioration in high-risk patients.

Simulation of ambulatory electrodermal activity and the handling of low-quality segments

BACKGROUND AND OBJECTIVES

Monitoring electrodermal activity (EDA) in daily life requires effective handling of low-quality segments, which are common in ambulatory EDA data. Although several low-quality handling methods have been implemented, systematic comparison of these methods, which requires a large annotated dataset, is lacking.

METHODS

Therefore, we proposed the simulation of realistic ambulatory EDA data starting from high-quality EDA signals, which were subsequently contaminated with varying concentrations of artifacts. Subsequently, three approaches for handling low-quality data were evaluated regarding the preservation of several EDA-derived features: removing all artifacts, interpolating over removed artifacts, and retaining all artifacts. Specifically, multiple EDA features were assessed, derived from response detection (evaluated using F1, precision, recall) as well as EDA, phasic, and tonic features (assessed using absolute error), by comparing the simulated EDA data with and without the inserted artifacts, using the latter as ground truth.

RESULTS

For response detection, retaining artifacts resulted in the highest F1-scores, while interpolating over removed artifacts achieved the highest F1-scores for the phasic signal. The approaches did significantly differ in the mean error for the phasic but not for the tonic component and raw EDA.

CONCLUSION

This work generated ambulatory EDA datasets of 200 h, containing 0.125 to 3 artifacts per minute, and showed that interpolation over removed artifacts was an effective approach to reconstruct phasic-derived features up to 2 artifacts per minute. The proposed simulation and evaluation methodology, which are easily customizable, offer opportunities for future research to develop and systematically compare signal quality indicators, decomposition methods, and response detectors for processing ambulatory EDA.

Subjective risk and associated electrodermal activity of a self-driving car passenger in an urban shared space

Shared spaces are urban areas without physical separation between motorised and non-motorised users. Previous research has suggested that it is difficult for users to appropriate these spaces and that the advent of self-driving cars could further complicate interactions. It is therefore important to study the perception of these spaces from the users' perspectives to determine which conditions may promote their acceptance of the vehicles. This study investigates the perceived collision risk of a self-driving car's passenger when pedestrians cross the vehicle's path. The experiment was conducted with a driving simulator. Seven factors were manipulated to vary the dynamics of the crossing situations in order to analyse their influence on the passenger's perception of collision risk. Two measures of perceived risk were obtained. A continuous subjective assessment, reflecting an explicit risk evaluation, was reported in real time by participants. On the other hand, their skin conductance responses, which reflects implicit information processing, were recorded. The relationship between the factors and the risk perception indicators was studied using Bayesian networks. The best Bayesian networks demonstrate that subjective collision risk assessments are primarily influenced by the factors that determine the relative positions of the vehicle and the pedestrian as well as the distance between them when they are in close proximity. The analysis further reveals that variations in skin conductance response indicators are more likely to be explained by variations in subjective assessments than by variations in the manipulated factors. These findings could benefit the development of self-driving navigation among pedestrians by improving understanding of the factors that influence passengers' feelings.

Better safe than sorry?-On the influence of learned safety on pain perception

The experience of threat was found to result-mostly-in increased pain, however it is still unclear whether the exact opposite, namely the feeling of safety may lead to a reduction of pain. To test this hypothesis, we conducted two between-subject experiments (N = 94; N = 87), investigating whether learned safety relative to a neutral control condition can reduce pain, while threat should lead to increased pain compared to a neutral condition. Therefore, participants first underwent either threat or safety conditioning, before entering an identical test phase, where the previously conditioned threat or safety cue and a newly introduced visual cue were presented simultaneously with heat pain stimuli. Methodological changes were performed in experiment 2 to prevent safety extinction and to facilitate conditioning in the first place: We included additional verbal instructions, increased the maximum length of the ISI and raised CS-US contingency in the threat group from 50% to 75%. In addition to pain ratings and ratings of the visual cues (threat, safety, arousal, valence, and contingency), in both experiments, we collected heart rate and skin conductance. Analysis of the cue ratings during acquisition indicate successful threat and safety induction, however results of the test phase, when also heat pain was administered, demonstrate rapid safety extinction in both experiments. Results suggest rather small modulation of subjective and physiological pain responses following threat or safety cues relative to the neutral condition. However, exploratory analysis revealed reduced pain ratings in later trials of the experiment in the safety group compared to the threat group in both studies, suggesting different temporal dynamics for threat and safety learning and extinction, respectively. Perspective: The present results demonstrate the challenge to maintain safety in the presence of acute pain and suggest more research on the interaction of affective learning mechanism and pain processing.

A review of clinical studies of electrodermal activity and transcranial magnetic stimulation

There is a growing body of evidence indicative of changes in autonomic nervous system (ANS) activity in patients with disorders of the central nervous system (CNS). Non-invasive measures of the ANS, including heart rate variability (HRV), electrodermal activity (EDA), and pupillary light reflex (PLR) may have value as markers of symptom severity, subtype, risk profile, and/or treatment response. In this paper we provide an introduction into the anatomy and physiology of EDA and review the literature published after 2007 in which EDA was an outcome measure of cortical stimulation with transcranial magnetic stimulation (TMS). Eleven studies were included and considered regarding the potential of EDA as an outcome measure reflecting ANS activity in TMS research and treatment. These studies are summarized according to study population, experimental methodology, cortical region targeted, and correlation with other measures of ANS activity. Results indicate that EDA changes vary with the frequency and target of TMS. Inhibitory TMS to the dorsolateral prefrontal cortex (dlPFC) was the most common paradigm in these studies, consistently resulting in decreased EDA.

Wrist-Worn Sensor Validation for Heart Rate Variability and Electrodermal Activity Detection in a Stressful Driving Environment

Wearable sensors are widely used to gather psychophysiological data in the laboratory and real-world applications. However, the accuracy of these devices should be carefully assessed. The study focused on testing the accuracy of the Empatica 4 (E4) wristband for the detection of heart rate variability (HRV) and electrodermal activity (EDA) metrics in stress-inducing conditions and growing-risk driving scenarios. Fourteen healthy subjects were recruited for the experimental campaign, where HRV and EDA were recorded over six experimental conditions (Baseline, Video Clip, Scream, No-Risk Driving, Low-Risk Driving, and High-Risk Driving) and by means of two measurement systems: the E4 device and a gold standard system. The overall quality of the E4 data was investigated; agreement and reliability were assessed by performing a Bland-Altman analysis and by computing the Spearman's correlation coefficient. HRV time-domain parameters reported high reliability levels in Baseline (r > 0.72), Video Clip (r > 0.71), and No-Risk Driving (r > 0.67), while HRV frequency domain parameters were sufficient in Baseline (r > 0.58), Video Clip (r > 0.59), No-Risk (r > 0.51), and Low-Risk Driving (r > 0.52). As for the EDA parameters, no correlation was found. Further studies could enhance the HRV and EDA quality through further optimizations of the acquisition protocol and improvement of the processing algorithms.

Beta spectral power during sleep is associated with impaired recall of extinguished fear

The failure to retain memory for extinguished fear plays a major role in the maintenance of posttraumatic stress disorder (PTSD), with successful extinction recall necessary for symptom reduction. Disturbed sleep, a hallmark symptom of PTSD, impairs fear extinction recall. However, our understanding of the electrophysiological mechanisms underpinning sleep's role in extinction retention remains underdetermined. We examined the relationship between the microarchitecture of sleep and extinction recall in healthy humans (n = 71, both male and females included) and a pilot study in individuals with PTSD (n = 12). Participants underwent a fear conditioning and extinction protocol over 2 days, with sleep recording occurring between conditioning and extinction. Twenty-four hours after extinction learning, participants underwent extinction recall. Power spectral density (PSD) was computed for pre- and post-extinction learning sleep. Increased beta-band PSD (~17-26 Hz) during pre-extinction learning sleep was associated with worse extinction recall in healthy participants (r = 0.41, p = .004). Beta PSD was highly stable across three nights of sleep (intraclass correlation coefficients > 0.92). Results suggest beta-band PSD is specifically implicated in difficulties recalling extinguished fear.

Child emotion lability is associated with within-task changes of autonomic activity during a mirror-tracing task

Adaptive biological and emotional stress responding are both critical for healthy human development. However, the complex associations between the two are not fully understood. The current study addresses this gap in research by studying associations of child emotion regulation and lability with within-task changes in the biological stress response during a mirror-tracing task. Participants were 59 families including two parents and a child between 5 and 12 years old (52.2% female). Parents reported on family demographics and completed the Emotion Regulation Checklist. Child skin conductance level (SCL) and respiratory sinus arrhythmia (RSA) were recorded during a baseline task and during a 3-minute mirror-tracing task. Within-task patterns of SCL and RSA during the task were estimated with multilevel modeling (measures within persons). The emotion regulation subscale was unrelated to any facet of SCL/RSA time courses. However, lower emotion lability was related to SCL patterns that changed less during the task and were overall lower. For RSA, lower emotion lability was related to higher initial RSA that significantly decreased during the task. These findings suggest that higher child emotion lability may promote increased physiological arousal of target organs during challenging activities.

Reaction time as an outcome measure during online fear conditioning: Effects of number of trials, age, and levels of processing

Recent studies have shown that fear conditioning experiments can be successfully conducted online. However, there is limited evidence that measures other than subjective ratings of threat expectancy can be collected, which means that online research may not be able to adequately replace laboratory experiments. In the current study, we conducted an online fear conditioning experiment consisting of habituation, acquisition, extinction and 48 h delayed extinction recall using ratings of threat expectancy and conditional stimulus pleasantness, and probe reaction time as outcome measures. The conditional stimuli were categories of words and a levels of processing manipulation explored whether words that were processed at a deeper level during extinction evoked smaller differential threat responses during extinction recall. Although the levels of processing manipulation did not produce a significant outcome, we found that extinction recall was successfully operationalised in our study. Reaction time indicated differential responding during both acquisition and extinction recall, and age of participants was correlated in one of two experiments with differential threat expectancy and reaction time, such that older participants showed better safety learning. The outcomes of this experiment provide multiple novel tools for researchers to explore fear conditioning, especially in an online environment.

Altered frontolimbic activity during virtual reality-based contextual fear learning in patients with posttraumatic stress disorder

BACKGROUND

Deficiency in contextual and enhanced responding in cued fear learning may contribute to the development of posttraumatic stress disorder (PTSD). We examined the responses to aversive Pavlovian conditioning with an unpredictable spatial context as conditioned stimulus compared to a predictable context. We hypothesized that the PTSD group would demonstrate less hippocampal and ventromedial prefrontal cortex (vmPFC) activation during acquisition and extinction of unpredictable contexts and an over-reactive amygdala response in the predictable contexts compared to controls.

METHODS

A novel combined differential cue-context conditioning paradigm was applied using virtual reality with spatial contexts that required configural and cue processing. We assessed 20 patients with PTSD, 21 healthy trauma-exposed (TC) and 22 non-trauma-exposed (HC) participants using functional magnetic resonance imaging, skin conductance responses, and self-report measures.

RESULTS

During fear acquisition, patients with PTSD compared to TC showed lower activity in the hippocampi in the unpredictable and higher activity in the amygdalae in the predictable context. During fear extinction, TC compared to patients and HC showed higher brain activity in the vmPFC in the predictable context. There were no significant differences in self-report or skin conductance responses.

CONCLUSIONS

Our results suggest that patients with PTSD differ in brain activation from controls in regions such as the hippocampus, the amygdala, and the vmPFC in the processing of unpredictable and predictable contexts. Deficient encoding of more complex configurations might lead to a preponderance of cue-based predictions in PTSD. Exposure-based treatments need to focus on improving predictability of contextual processing and reducing enhanced cue reactivity.

Relationship satisfaction, feelings of closeness and annoyance, and linkage in electrodermal activity

Physiological linkage refers to moment-to-moment, time-linked coordination in physiological responses among people in close relationships. Although people in romantic relationships have been shown to evidence linkage in their physiological responses over time, it is still unclear how patterns of covariation relate to in-the-moment, as well as general levels of, relationship functioning. In the present study with data collected between 2014 and 2017, we capture linkage in electrodermal activity (EDA) in a diverse sample of young-adult couples, generally representative and generalizable to the Los Angeles community from which we sampled. We test how naturally occurring, shifting feelings of closeness with and annoyance toward one's partner relate to concurrent changes in levels of physiological linkage over the course of 1 day. Additionally, we examine how linkage relates to overall relationship satisfaction. Results showed that couples evidenced significant covariation in their levels of physiological arousal in daily life. Further, physiological linkage increased during hours that participants felt close to their romantic partners but not during hours that participants felt annoyed with their partners. Finally, those participants with overall higher levels of relationship satisfaction showed lower levels of linkage over the day of data collection. These findings highlight how individuals respond in sync with their romantic partners and how this process ebbs and flows in conjunction with the shifting emotional tone of their relationships. The discussion focuses on how linkage might enhance closeness or, alternatively, contribute to conflict escalation and the potential of linkage processes to promote positive interpersonal relationships. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Five Basic Human Senses Evoke Electrodermal Activity

Electrodermal activity (EDA) usually relates to variations in the electrical properties of palmar or plantar skin sites. EDA responses, namely skin conductance responses (SCRs), skin potential responses (SPRs) and skin susceptance responses (SSRs) are shown to be sensitive indexes of sympathetic nervous system activation and are studied in many research projects. However, the association between EDA responses and the five basic human senses has not been investigated yet. Our study aimed to explore the relationship between the three EDA responses (SCRs, SSRs and SPRs) and the five basic human senses. These three EDA responses were measured simultaneously at the same skin site on each of the 38 volunteers. The tested five senses were sight, hearing, touch, taste and smell. The results showed that the different tested senses led to different degrees of EDA responses due to activation of the sympathetic nervous system and corresponding secretion of sweat. Although a controlled study on the degree of EDA as a function of the strength of each stimulus was not performed, we noted that the largest EDA responses were typically associated with the smell sense test. We conclude that EDA responses could be utilized as measures for examining the sensitivity of the human senses. Hence, EDA devices may have important roles in sensory systems for future clinical applications.

Evaluation of sympathetic skin response for early diagnosis and follow-up of diabetic peripheral neuropathy in children

BACKGROUND

The morbidity of type 1 diabetes mellitus (T1DM) in children is increasing and diabetic peripheral neuropathy (DPN) is one of the main microvascular complications of T1DM. The aim of this study was to explore sympathetic skin response (SSR) characteristics in children with T1DM and analyze the value of early diagnosis and follow-up in T1DM complicated with DPN.

METHODS

Our prospective study enrolling 85 participants diagnosed with T1DM and 30 healthy controls (HCs) in the Children's Hospital of Hebei Province from 2017 to 2020. Compared the outcomes of SSR and nerve conduction study (NCS) in T1DM, and evaluated the variations in SSR and NCS of different durations, as well as changes after six months of therapy.

RESULTS

SSR latency of T1DM group showed statistical difference as compared to HCs (p < 0.05). The SSR test was more sensitive than the NCS test in the early diagnosis of T1DM with DPN (p < 0.05). The abnormal rates of SSR and NCS in long duration of disease were higher than those in short duration of disease (p < 0.05). Among 65 participants with diabetic neuropathy, the onset latencies of SSR were shortened and the NCS were improved after treatment (p < 0.05).

CONCLUSIONS

SSR could provide the accurate early diagnosis and follow-up of pediatric diabetic peripheral neuropathy.

Electrodermal activity and heart rate variability for detection of peripheral abnormalities in type 2 diabetes: A review

Modern medicine exhibits an upward trend towards non-invasive methods for early detection of disease and long-term monitoring of patients' health. Diabetes mellitus and its complications are a promising area for implementation of new medical diagnostic devices. One of the most serious complications of diabetes is diabetic foot ulcer. The main causes responsible for diabetic foot ulcer are ischemia caused by peripheral artery disease and diabetic neuropathy caused by polyol pathway-induced oxidative stress. Autonomic neuropathy impairs function of sweat glands, which can be measured by electrodermal activity. On the other hand, autonomic neuropathy leads to changes in heart rate variability, which is used to assess autonomic regulation of the sinoatrial node. Both methods are enough sensitive to detect pathological changes caused by autonomic neuropathy and are promising screening methods for early diagnosis of diabetic neuropathy, which could prevent the onset of diabetic ulcer.

Reactions and responses to anticipation of stuttering and how they contribute to stuttered speech that listeners perceive as fluent - An opinion paper

The experience of stuttering is wide ranging and includes a variety of perceived and unperceived behaviors and experiences. One of those experiences is anticipation of stuttering. While anticipation of stuttering is commonly discussed in terms of being a prediction of an upcoming event, it has also been equated to an internal realization of stuttering - which is the conceptualization applied here. The aim of this paper is to impress upon the reader that anticipated moments of stuttering (whether at a conscious or subconscious level) must be met with an adaptive reaction or response (which may also occur consciously or subconsciously). While these adaptive reactions and responses may differ based on whether they promote positive or negative communicative behaviors, they still represent adaptations by the speaker. Among the broad category of reactions and responses to anticipation of stuttering are motoric adaptations to speech, which include characteristic stuttering behaviors and other adaptations that may contribute to speech that is perceived by listeners as fluent. An outcome of this conceptualization is, even when adaptations result in listener perceived fluency, the speech of the person who stutters is still controlled by stuttering - meaning that some observable or unobservable adaptation is required. It is critical that speech-language pathologists recognize that the behaviors of people who stutter may reflect reactions and responses to an internal realization of stuttering and observable and unobservable reactions and responses must be considered in both assessments and interventions.

Prediction of moment-by-moment heart rate and skin conductance changes in the context of varying emotional arousal

Autonomic nervous system (ANS) responses such as heart rate (HR) and galvanic skin responses (GSR) have been linked with cerebral activity in the context of emotion. Although much work has focused on the summative effect of emotions on ANS responses, their interaction in a continuously changing context is less clear. Here, we used a multimodal data set of human affective states, which includes electroencephalogram (EEG) and peripheral physiological signals of participants' moment-by-moment reactions to emotional provoking video clips and modeled HR and GSR changes using machine learning techniques, specifically, long short-term memory (LSTM), decision tree (DT), and linear regression (LR). We found that LSTM achieved a significantly lower error rate compared with DT and LR due to its inherent ability to handle sequential data. Importantly, the prediction error was significantly reduced for DT and LR when used together with particle swarm optimization to select relevant/important features for these algorithms. Unlike summative analysis, and contrary to expectations, we found a significantly lower error rate when the prediction was made across different participants than within a participant. Moreover, the predictive selected features suggest that the patterns predictive of HR and GSR were substantially different across electrode sites and frequency bands. Overall, these results indicate that specific patterns of cerebral activity track autonomic body responses. Although individual cerebral differences are important, they might not be the only factors influencing the moment-by-moment changes in ANS responses.

Design and Evaluation of Deep Learning Models for Continuous Acute Pain Detection Based on Phasic Electrodermal Activity

The current method for assessing pain in clinical practice is subjective and relies on self-reported scales. An objective and accurate method of pain assessment is needed for physicians to prescribe the proper medication dosage, which could reduce addiction to opioids. Hence, many works have used electrodermal activity (EDA) as a suitable signal for detecting pain. Previous studies have used machine learning and deep learning to detect pain responses, but none have used a sequence-to-sequence deep learning approach to continuously detect acute pain from EDA signals, as well as accurate detection of pain onset. In this study, we evaluated deep learning models including 1-dimensional convolutional neural networks (1D-CNN), long short-term memory networks (LSTM), and three hybrid CNN-LSTM architectures for continuous pain detection using phasic EDA features. We used a database consisting of 36 healthy volunteers who underwent pain stimuli induced by a thermal grill. We extracted the phasic component, phasic drivers, and time-frequency spectrum of the phasic EDA (TFS-phEDA), which was found to be the most discerning physiomarker. The best model was a parallel hybrid architecture of a temporal convolutional neural network and a stacked bi-directional and uni-directional LSTM, which obtained a F1-score of 77.8% and was able to correctly detect pain in 15-second signals. The model was evaluated using 37 independent subjects from the BioVid Heat Pain Database and outperformed other approaches in recognizing higher pain levels compared to baseline with an accuracy of 91.5%. The results show the feasibility of continuous pain detection using deep learning and EDA.

Monitoring Inattention in Construction Workers Caused by Physical Fatigue Using Electrocardiograph (ECG) and Galvanic Skin Response (GSR) Sensors

Physical fatigue is frequent for heavy manual laborers like construction workers, but it causes distraction and may lead to safety incidents. The purpose of this study is to develop predictive models for monitoring construction workers' inattention caused by physical fatigue utilizing electrocardiograph (ECG) and galvanic skin response (GSR) sensors. Thirty participants were invited to complete an attention-demanding task under non-fatigued and physically fatigued conditions. Supervised learning algorithms were utilized to develop models predicting their attentional states, with heart rate variability (HRV) features derived from ECG signals and skin electric activity features derived from GSR signals as data inputs. The results demonstrate that using HRV features alone could obtain a prediction accuracy of 88.33%, and using GSR features alone could achieve an accuracy of 76.67%, both through the KNN algorithm. The accuracy increased to 96.67% through the SVM algorithm when combining HRV and GSR features. The findings indicate that ECG sensors used alone or in combination with GSR sensors can be applied to monitor construction workers' inattention on job sites. The findings would provide an approach for detecting distracted workers at job sites. Additionally, it might reveal the relationships between workers' physiological features and attention.

Effects of interstimulus interval and significance on electrodermal and central measures of the phasic orienting reflex (OR) in a dishabituation task

Although the P300 event-related potential (ERP) is the most likely central measure of Sokolov's Orienting Reflex (OR), there are few systematic comparisons with the skin conductance response (SCR), the "gold standard" electrodermal OR measure. We examine habituation, stimulus significance, and inter-stimulus interval (ISI) effects in SCRs and components of the P300 from single-trial ERPs in an auditory dishabituation paradigm. Single trial ERP components were separated by temporal principal components analysis, and five components of the P300 were examined as potential phasic OR measures: P3a, P3b, Novelty P3, and two Slow Waves (SW1, SW2). Across the factors of ISI and significance, SCRs showed decrement over trials, recovery at a deviant, and dishabituation at the subsequent standard. This general pattern was not present in any of the components of the P300. SCRs were also larger to significant stimuli and at the long ISI; effects differed between P300 components. The electrodermal SCR showed the complete profile over trials expected of the phasic OR, and was enhanced by stimulus significance, confirming it as the model measure of Sokolov's phasic OR. Components of the P300 failed to match this profile, but instead appear to reflect different aspects of the stimulus processing involved in OR elicitation.

Fear conditioning depends on the nature of the unconditional stimulus and may be related to hair levels of endocannabinoids

The replicability of fear conditioning research has come under recent scrutiny, with increasing acknowledgment that the use of differing materials and methods may lead to incongruent results. Direct comparisons between the main two unconditional stimuli used in fear conditioning - an electric shock or a loud scream-are scarce, and yet these stimuli are usually used interchangeably. In the present study, we tested whether a scream, a shock, or an unpredictable combination of the two affected fear acquisition, extinction, and return of fear amongst healthy participants (N = 109, 81 female). We also collected hair samples and tested the relationship between fear conditioning and hair endocannabinoid levels. Our findings suggest that, although subjective ratings of pleasantness, arousal, and anxiety were similar regardless of the unconditional stimuli used, skin conductance responses were significantly lower for stimuli paired with the scream compared to a shock alone. Further, reducing the predictability of the unconditional stimulus reduced habituation of skin conductance responses during acquisition and reacquisition, but did not produce stronger conditioning compared to shock alone. Exploratory analyses suggested that hair endocannabinoids were associated with overall physiological arousal during fear conditioning, as well as higher return of fear to the threat cue, but not to the safety cue. These findings have multiple implications for the design and replicability of fear conditioning research and provide the first evidence for an association between hair levels of endocannabinoids and human fear conditioning.

Approximating exposure therapy in the lab: Replacing the CS+ with a similar versus a different stimulus and including additional stimuli resembling the CS+ during extinction

Recent studies have shown that extinction training including the conditional stimulus (CS+) and stimuli that are similar to the CS + enhances extinction retention and generalisation to novel stimuli. However, in a clinical setting, the CS+ is rarely available for use during exposure therapy. The aim of the present study was to determine if replacing the CS+ with a similar versus different stimulus, and including other similar stimuli during extinction, could reduce fear at test on par with extinction using the original CS+ with and without other similar stimuli. In an experiment conducted in a single session, participants completed a habituation phase followed by an acquisition phase using two dog images presented with (CS+) and without (CS-) an acoustic unconditional stimulus (US). Participants were randomly allocated to four extinction conditions: similar CS + dog with novel dog images (Similar replacement extinction condition); different CS + dog with novel dog images (Different replacement extinction condition); original CS + dog with novel dog images (Multiple extinction control condition); and original CS + without novel dog images (Standard extinction control condition). All participants completed a test phase with the original CSs followed by a generalisation test with another two novel dog images. All groups acquired, and then extinguished differential skin conductance responses (SCRs) with no differences observed between groups. Whereas the Similar replacement extinction group and the Multiple and Standard extinction control groups did not exhibit significant differential SCRs when re-exposed to the original CS + relative to the CS- at test, differential responding to the CSs was significant at test in the Different replacement extinction group. There were no significant differences between groups in SCRs to the two novel dog images during the generalisation phase and in between-phase subjective ratings. Findings suggest that replacement stimuli used during extinction should be as similar as possible to the CS + to reduce physiological arousal to the original CS+.

Fear learning and extinction predicts anxiety in daily life: a study of Pavlovian conditioning and ecological momentary assessment

BACKGROUND

The association between anxious mood and aberrant fear learning mechanisms has not been fully elucidated. Studying how fear conditioning and extinction constructs relate to anxiety symptoms and reactivity to stressful and benign moments in everyday life provides a powerful addition to experimental paradigms.

METHOD

Fifty-one young adults completed laboratory-based differential conditioning and extinction tasks with (CS + ) and without (CS-) an aversive unconditional stimulus (US). Electrodermal skin conductance responses were measured during each phase, followed by ecological momentary assessment (EMA) tapping anxiety and stressors six times daily for seven days (2, 142 moments).

RESULTS

Conditioned electrodermal reactivity to the CS + and overgeneralisation to the CS- were associated with greater change in anxiety (measured via EMA), across non-stressful situations, remaining the same across stressful situations. Likewise, during extinction when the CS + is now safe, more electrodermal reactivity to the CS + was associated with more anxiety change across non-stressful situations and remained the same across stressful situations. Also, during extinction when threat is absent, more electrodermal reactivity at the late stage of the CS- was associated with less momentary anxiety change in response to stressful situations; more electrodermal activity at the late stage of the CS + was associated with more anxiety change across non-stressful situations and remained the same across stressful situations.

CONCLUSIONS

Sampling 'in vivo' emotion and stress experiences, study findings revealed links between conditioned electrodermal reactivity and overgeneralisation to safe stimuli and heightened anxious reactivity during non-stressful (i.e. safe) moments in daily life, coupled with less change in response to actual stressors.

Efficient Feature-Selection-Based Stacking Model for Stress Detection Based on Chest Electrodermal Activity

Contemporary advancements in wearable equipment have generated interest in continuously observing stress utilizing various physiological indicators. Early stress detection can improve healthcare by lessening the negative effects of chronic stress. Machine learning (ML) methodologies have been modified for healthcare equipment to monitor user health situations utilizing sufficient user information. Nevertheless, more data are needed to make applying Artificial Intelligence (AI) methodologies in the medical field easier. This research aimed to detect stress using a stacking model based on machine learning algorithms using chest-based features from the Wearable Stress and Affect Detection (WESAD) dataset. We converted this natural dataset into a convenient format for the suggested model by performing data visualization and preprocessing using the RESP feature and feature analysis using the Z-score, SelectKBest feature, the Synthetic Minority Over-Sampling Technique (SMOTE), and normalization. The efficiency of the proposed model was estimated regarding accuracy, precision, recall, and F1-score. The experimental outcome illustrated the efficacy of the proposed stacking technique, achieving 0.99% accuracy. The results revealed that the proposed stacking methodology performed better than traditional methodologies and previous studies.

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.

Fear conditioning is preserved in very preterm-born young adults despite increased anxiety levels

Very preterm birth is associated with an increased risk for anxiety disorders. Abnormal brain development may result in disordered fear learning processes, which may be exacerbated by environmental risk factors and persist in adulthood. We tested the hypotheses that very preterm-born young adults displayed higher levels of fear conditioning, less differentiation between threat (CS+) and safety (CS-) signals, and stronger resistance to extinction relative to term-born controls. A group of 37 very preterm-born young adults and 31 age- and sex-matched term-born controls performed a differential fear conditioning paradigm on two consecutive days. Acquisition and extinction training were performed on day 1. Recall and reinstatement were tested on day 2. Preterm-born participants showed significantly higher levels of anxiety in the Depression-Anxiety-Stress-Scale-21 questionnaire. The fear conditioning outcome measures, skin conductance response amplitudes and anxiety ratings, were overall higher in the preterm-born group compared to controls. Awareness of CS-US contingencies was mildly reduced in preterms. Acquisition, extinction, recall and reinstatement of differential conditioned fear responses (CS+  > CS-), however, were not significantly different between the groups. There were no significant group by stimulus type interactions. The finding of largely preserved associative fear learning in very preterm-born young adults was unexpected and needs to be confirmed in future studies.

Study of sympathetic skin response in patients with COVID-19 infection

OBJECTIVES

Many articles hypothesized the potential role of autonomic nervous system in the pathogenesis and outcome of COVID-19 infection. Several studies reported both central and peripheral nervous system involvement in COVID-19 as well. Up to our knowledge, there is no study evaluating whether this virus could invade the autonomic nervous system affecting its function adversely. Sympathetic skin response (SSR) has long been used as a method of evaluating the autonomic nervous system. Regarding the importance of the autonomic nervous system in hemostasis and wide consequences of COVID-19 infection, we designed this study to evaluate the autonomic nervous system function in patients recovered from COVID-19 compared with normal population who are not yet infected by this virus by the means of SSR.

METHODS

This case-control study included 70 patients surviving COVID-19 who met the inclusion and exclusion criteria that went under SSR. The data gathered were compared with those without the history of any symptoms attributable to COVID-19 during the pandemic.

RESULTS

There was a correlation between COVID-19 infection and abnormal SSR (p value < 0.0001) with the most effect on the latency prolongation of the action potential recorded from the median nerve at palms (effect size: right: 3.90, left: 3.69). Moreover, the greater severity of the disease correlated with more abnormality of parameters recorded by SSR technique.

CONCLUSIONS

Abnormal SSR parameters could be a good indicator of autonomic nervous system involvement in patients with COVID-19 infection. It might be a predictor of disease severity, clinical outcomes and prognosis as well.