Skin Conductance Response Frequency Research Articles

Associations Between Physiological Signals Captured Using Wearable Sensors and Self-reported Outcomes Among Adults in Alcohol Use Disorder Recovery: Development and Usability Study.

BackgroundPrevious research has highlighted the role of stress in substance misuse and addiction, particularly for relapse risk. Mobile health interventions that incorporate real-time monitoring of physiological markers of stress offer promise for delivering tailored interventions to individuals during high-risk states of heightened stress to prevent alcohol relapse. Before such interventions can be developed, measurements of these processes in ambulatory, real-world settings are needed.ObjectiveThis research is a proof-of-concept study to establish the feasibility of using a wearable sensor device to continuously monitor stress in an ambulatory setting. Toward that end, we first aimed to examine the quality of 2 continuously monitored physiological signals—electrodermal activity (EDA) and heart rate variability (HRV)—and show that the data follow standard quality measures according to the literature. Next, we examined the associations between the statistical features extracted from the EDA and HRV signals and self-reported outcomes.MethodsParticipants (N=11; female: n=10) were asked to wear an Empatica E4 wearable sensor for continuous unobtrusive physiological signal collection for up to 14 days. During the same time frame, participants responded to a daily diary study using ecological momentary assessment of self-reported stress, emotions, alcohol-related cravings, pain, and discomfort via a web-based survey, which was conducted 4 times daily. Participants also participated in structured interviews throughout the study to assess daily alcohol use and to validate self-reported and physiological stress markers. In the analysis, we first used existing artifact detection methods and physiological signal processing approaches to assess the quality of the physiological data. Next, we examined the descriptive statistics for self-reported outcomes. Finally, we investigated the associations between the features of physiological signals and self-reported outcomes.ResultsWe determined that 87.86% (1,032,265/1,174,898) of the EDA signals were clean. A comparison of the frequency of skin conductance responses per minute with previous research confirmed that the physiological signals collected in the ambulatory setting were successful. The results also indicated that the statistical features of the EDA and HRV measures were significantly correlated with the self-reported outcomes, including the number of stressful events marked on the sensor device, positive and negative emotions, and experienced pain and discomfort.ConclusionsThe results demonstrated that the physiological data collected via an Empatica E4 wearable sensor device were consistent with previous literature in terms of the quality of the data and that features of these physiological signals were significantly associated with several self-reported outcomes among a sample of adults diagnosed with alcohol use disorder. These results suggest that ambulatory assessment of stress is feasible and can be used to develop tailored mobile health interventions to enhance sustained recovery from alcohol use disorder.

What effort is required in retrieving self-defining memories? Specific autonomic responses for integrative and non-integrative memories.

Self-defining memories (SDM) are autobiographical memories associated with the construction and maintenance of identity, and which play a core role in establishing and achieving goals in life. The aim of this study was to evaluate the effort required in retrieving SDM as reflected by physiological activity. We examined the neurovegetative responses associated with three dimensions of SDM: specificity, integrative meaning and emotional valence. Electrodermal activity (skin conductance response frequency, phasic driver) and the high frequency component of heart rate variability (HF-HRV) were recorded during the retrieval of SDM in 36 healthy participants to assess the activation of the sympathetic and parasympathetic systems, respectively. SDM were characterized by three independent investigators with satisfactory inter-rater reliability. Linear mixed effects analyses showed that only the integrative meaning dimension led to a main effect on electrodermal activity. In addition, an interaction effect showed that the retrieval of non-integrative and specific memories was associated with a higher level of electrodermal activity than the retrieval of integrative specific memories. No effects were obtained regarding the HRV indicators. The higher activation of the sympathetic nervous system associated with the retrieval of non-integrative SDM suggests that the ability to derive meaning from personal experiences plays a regulatory role and is a fundamental component in personal adjustment.

Physiological response to acute stress against confounding factors: a white-box research method

Objectives: Physiological sensors appear a promising tool to monitor psychological stress in the daily life. Yet, despite the increasing know-how developed in affective computing, physiology-driven stress detection algorithms still yield unsatisfactory results on the field. This study intends to highlight physiological patterns that are both stress-sensitive and stress-specific, at the multi-subject scale, in several contexts. Approach: A notional framework was developed and empirically validated, which distinguishes psychological stress from two context-related confounding factors: Background and Activity. A physiological database was elaborated from a multi-task experimental protocol in a standardized environment with skin conductance, electrocardiograph and respiration recordings. Stress-induced variations were isolated in standard physiological features, to select the most stress-sensitive ones independently from confounding factors. Main Results: Most standard features were unable to distinguish acute psychological stress from low cognitive activity (e.g. frequency of skin conductance responses, or spectral power in the low and high frequency bands of the interbeat intervals). After sign-rank tests between the stressful and control conditions of two standard tasks involving arithmetic or speech, their effect sizes remained below 0.3. A number of physiological features also showed task-dependency. Yet, promising correlates were highlighted among cardiac features such as mean heart rate and its standard deviation, or the root mean square of its successive differences (effect sizes above 0.3 for both tasks). Significance: The high sensitivity to context observed in standard features is likely to explain the poor validity on the field of physiology-driven models developed in controlled environments. In particular, mental activity should be considered as confounding factor while elaborating these models to increase their accuracy. The small feature set highlighted in this paper and the use of control data should enhance the generalization abilities of any machine learning algorithm; still, further research is needed to evidence new stress-specific physiological responses.

Improving Challenge/Skill Ratio in a Multimodal Interface by Simultaneously Adapting Game Difficulty and Haptic Assistance through Psychophysiological and Performance Feedback.

In order to harmonize robotic devices with human beings, the robots should be able to perceive important psychosomatic impact triggered by emotional states such as frustration or boredom. This paper presents a new type of biocooperative control architecture, which acts toward improving the challenge/skill relation perceived by the user when interacting with a robotic multimodal interface in a cooperative scenario. In the first part of the paper, open-loop experiments revealed which physiological signals were optimal for inclusion in the feedback loop. These were heart rate, skin conductance level, and skin conductance response frequency. In the second part of the paper, the proposed controller, consisting of a biocooperative architecture with two degrees of freedom, simultaneously modulating game difficulty and haptic assistance through performance and psychophysiological feedback, is presented. With this setup, the perceived challenge can be modulated by means of the game difficulty and the perceived skill by means of the haptic assistance. A new metric (FlowIndex) is proposed to numerically quantify and visualize the challenge/skill relation. The results are contrasted with comparable previously published work and show that the new method afforded a higher FlowIndex (i.e., a superior challenge/skill relation) and an improved balance between augmented performance and user satisfaction (higher level of valence, i.e., a more enjoyable and satisfactory experience).

Investigating Driver Sympathetic Arousal under Short-term Loads and Acute Stress Events

This study involved an investigation of patterns of arousal in a driver’s sympathetic nervous system toward a system that can detect high cognitive workload, high emotional load, and acute stress (surprise or panic) experiences in drivers. Humans are exposed to cognitive and physical stressors in the driving environment that can be exacerbated when drivers are operating under the cognitive effects of incidental emotions or secondary task loads. Each type of stressor can negatively affect the control of complex operational systems, such as a vehicle, in different ways. The body’s sympathetic autonomous nervous system (the “fight or flight” system) triggers several physiological changes in the body, such as perspiratory and cardiac dynamics, in order to prepare the human to defend themselves or run away. Physiological sensor systems can therefore be used to collect data on these physiological changes (such as heart rate variability (HRV; Taelman, Vandeput, Spaopon, & Van Huffel, 2009) and skin conductance response (SCR; Boucsein, 2012; Shi, Ruiz, Taib, Choi, & Chen, 2007; Villarejo, Zapirain, & Zorrilla, 2012). Data processing techniques can be applied to identify patterns in physiological response across multiple variables and time windows that are characteristics of potentially problematic driver mental states. As a first step toward developing an online system for detecting potentially-problematic driver mental states, this study sought to identify patterns in HRV and SCR data associated with each of these states, and to investigate the predictive power of such an algorithm for explaining aspects of driving behavior. Eighty-eight people (with equal representation from each sex and each of two age groups) participated in a driving simulator study. The simulation scenarios consisted of a simulated rural highway with multiple predetermined segments where secondary task loads were applied. After a physiological baselining procedure and adequate practice with the driving and secondary tasks, participants completed scenarios under each of the six driving conditions: a “Normal” drive with a simple roadway and no secondary tasks, four “Loaded” drives that included driving-related loads (e.g., construction zones) and some additional secondary tasks designed to impose analytical cognitive, emotional, and motoric (e.g., texting task) loads. A final scenario included varied combinations of these loads and a unique surprising “Failure” event (triggered acceleration in the vehicle that mimicked unintended acceleration problems). HRV and SCR were measured throughout the experiment using Zephyr Bioharness3 and Shimmer3 sensor systems, respectively, and numerous third-party software packages were used to process the data and identify noteworthy patterns. This presentation will report the analytical results of three dependent variables: HRV, SCR-amplitude (i.e., the magnitude of characteristic increases in arousal during sympathetic response), and SCR-frequency (i.e., the frequency of skin conductance responses identified within a predetermined time window). HRV (measured over time windows of a few seconds, as well as of several minutes) and SCR-Frequency were significantly sensitive to changes in loading, and some patterns in dynamics among multiple measures can be used to differentiate the designed mental states, although further testing is underway to refine and validate these findings. In particular, SCR- amplitude may be an effective way to distinguish acute stress events, as this measure shows a significant and substantial change within 2.5 seconds after realization of the unintended acceleration event. In addition to discussing these results, the current and future efforts in the development of an online driver “stressor detector” and mitigation system will be introduced in the presentation as well.

PO-0724 Autonomic And Behavioural Stress Responses In Low Weight Preterm Infants During Nurse Handling In The Nicu: Abstract PO-0724 Table 1

Background and aims Preterm infants should avoid stressful events, due to their immature brain and vascular structures. The purpose of this observational study was to investigate stress responses to nurse handling in the NICU. Methods Fifteen male and fifteen female infants, gestational age 32,7 (±1, 48) weeks and birth weight 1880(± 409) grams, at postnatal day 5–7 were observed during nursing care and diaper change. Standard physiological measurements; heart rate (HR), respiratory rate (RR), and skin conductance response frequency (SCR/sec), and NIDCAP® behavioural stress cues; facial, visceral, motor, attentional, and self-consoling were recorded before and during care. Non-parametric Wilcoxon was used. Results There were statistical differences for physiological and behavioural measures from before to during the care: Conclusion SCR/sec, RR, HR and NIDCAP® stress behaviours all significantly increased during the care. Further analyses of the NIDCAP® subgroups identified motor and attentional cues, and ability to self-console as significant.

State–trait arousal and daytime sleepiness after sleep restriction

The importance of an arousal system in the regulation of sleepiness has been widely recognised in contexts of insomnia theory and research. Arousal is also incorporated in some general models of sleepiness and is considered one of the principal factors regulating sleepiness in a model by De Valck and Cluydts (2003), in which arousal has both state and trait components. In the present experimental study, we explored the effects of state and trait components of arousal on subjective sleepiness and sleep latency during daytime. On a day after partial sleep deprivation, 28 good sleepers aged 18–26years took part in two successive experimental conditions, in which the state arousal was manipulated by laboratory tasks. We measured physiological (heart rate, frequency of skin conductance responses) and subjective (Energy, Tension, Anxiety) indices of state arousal, while trait arousal was operationalised as electrodermal lability. After a moderately stressful task, which induced a relatively higher state arousal, the participants reported lower sleepiness and took longer to fall asleep than after a simple psychomotor task. Trait arousal was not associated with daytime sleepiness. The results of this study support the idea that short-term changes of state arousal are important for the regulation of sleepiness in good sleepers, even in a situation which is only moderately stressful.

Empathy in electrodermal responsive and nonresponsive patients with schizophrenia

Skin conductance response (SCR) to emotion-evoking stimuli has in previous studies suggested the existence of two subgroups of schizophrenia patients. One is characterized by absent SCR and the other by heightened or non-habituating SCR. These subgroups have also been shown to differ in symptoms, prognosis and social integration. The present project compared social cognition in the two subgroups. SCR from 28 patients with schizophrenia and 24 matched healthy controls was measured while they watched emotion-evoking and neutral video tapes. Assessments of symptoms, neurocognition, social cognition, and social function were also performed. Event related potentials (ERP) were recorded in response to pictures of people experiencing pain or not. Subjects were divided into “SCR non-responder” and “SCR responder” groups based on SCR frequency. Schizophrenia SCR responders had significantly higher self-reported personal distress in response to others in distress and lower P300 ERP responses to others in pain than schizophrenia SCR non-responders and healthy controls. SCR responsiveness is a potential marker of subgroups of patients with schizophrenia that differ in pathophysiology, function and prognosis.

EDA Positive Change: A Simple Algorithm for Electrodermal Activity to Measure General Audience Arousal During Media Exposure

Skin conductance provides an inexpensive and nonreactive measure of electrodermal activity (EDA) that is widely used as an arousal indicator. When communication research employs real-world audiovisual stimuli, the measurement sensitivity of EDA-based data can become challenging. Measures that are commonly employed to correlate EDA with continuous stimuli (the tonic skin conductance level and the frequency of skin conductance responses) are replicable for stimuli of one minute or longer. This article discusses positive changes in EDA (EPC) as a measure that integrates the frequency of skin conductance responses with their amplitude while reducing processing complexity and error. The use of EDA data from 115 subjects demonstrates that EPC is a more accurate measure of stimulus-induced arousal than the response frequency, the conductance baseline, and average skin conductance. Assets and drawbacks are discussed in the context of theoretical and practical issues.

Emotional and psychophysiological responses to tempo, mode, and percussiveness

People often listen to music to influence their emotional state. However, the specific musical characteristics which cause this process are not yet fully understood. We have investigated the influence of the musical characteristics of tempo, mode, and percussiveness on our emotions. In a quest towards ecologically valid results, 32 participants listened to 16 pop and 16 rock songs while conducting an office task. They rated experienced arousal, valence, and tension, while skin conductance and cardiovascular responses were recorded. An increase in tempo was found to lead to an increase in reported arousal and tension and a decrease in heart rate variability. More arousal was reported during minor than major mode songs. Level and frequency of skin conductance responses increased with an increase in percussiveness. Physiological responses revealed patterns that might not have been revealed by self-report. Interaction effects further suggest that musical characteristics interplay in modulating emotions. So, tempo, mode, and percussiveness indeed modulate our emotions and, consequently, can be used to direct emotions. Music presentation revealed subtly different results in a laboratory setting, where music was altered with breaks, from those in a more ecologically valid setting where continuous music was presented. All in all, this enhances our understanding of the influence of music on emotions and creates opportunities seamlessly to tap into listeners’ emotional state through their physiological responses.

Emotional and Psychophysiological Responses to Tempo, Mode, and Percussiveness

People often listen to music to influence their emotional state. However, the specific musical characteristics which cause this process are not yet fully understood. We have investigated the influence of the musical characteristics of tempo, mode, and percussiveness on our emotions. In a quest towards ecologically valid results, 32 participants listened to 16 pop and 16 rock songs while conducting an office task. They rated experienced arousal, valence, and tension, while skin conductance and cardiovascular responses were recorded. An increase in tempo was found to lead to an increase in reported arousal and tension and a decrease in heart rate variability. More arousal was reported during minor than major mode songs. Level and frequency of skin conductance responses increased with an increase in percussiveness. Physiological responses revealed patterns that might not have been revealed by self-report. Interaction effects further suggest that musical characteristics interplay in modulating emotions. So, tempo, mode, and percussiveness indeed modulate our emotions and, consequently, can be used to direct emotions. Music presentation revealed subtly different results in a laboratory setting, where music was altered with breaks, from those in a more ecologically valid setting where continuous music was presented. All in all, this enhances our understanding of the influence of music on emotions and creates opportunities seamlessly to tap into listeners' emotional state through their physiological responses.

Premenstrual distress predicts panic-relevant responding to a CO 2 challenge among young adult females

The current study examined the incremental validity of self-reported premenstrual distress in predicting panic responsivity (self-reported panic symptoms and skin conductance response frequency; SCR) following inhalation of 10% CO 2-enriched air. A community sample of young adult women ( n = 46) completed questionnaires assessing substance use patterns, premenstrual symptoms and distress, and anxiety sensitivity and underwent a laboratory biological challenge procedure (4-min 10% CO 2-enriched air inhalation). As hypothesized, higher premenstrual distress scores significantly predicted greater self-reported panic symptoms following the CO 2 challenge above and beyond other theoretically relevant variables (anxiety sensitivity, cigarette use, and alcohol consumption). In predicting SCR, premenstrual distress exhibited only a trend towards statistical significance. These findings provide preliminary evidence that premenstrual symptoms may serve as a potential risk factor to experience more intense panic symptoms in response to perturbations in bodily sensations.

Effects of Music on Physiological Arousal: Explorations into Tempo and Genre

Two experiments explore the validity of conceptualizing musical beats as auditory structural features and the potential for increases in tempo to lead to greater sympathetic arousal, measured using skin conductance. In the first experiment, fast- and slow-paced rock and classical music excerpts were compared to silence. As expected, skin conductance response (SCR) frequency was greater during music processing than during silence. Skin conductance level (SCL) data showed that fast-paced music elicits greater activation than slow-paced music. Genre significantly interacted with tempo in SCR frequency, with faster tempo increasing activation for classical music and decreasing it for rock music. A second experiment was conducted to explore the possibility that the presumed familiarity of the genre led to this interaction. Although further evidence was found for conceptualizing musical beat onsets as auditory structure, the familiarity explanation was not supported.

Effects of Music on the Recovery of Autonomic and Electrocortical Activity After Stress Induced by Aversive Visual Stimuli

The purpose of this study was to compare the effects of music and white noise on the recovery of physiological measures after stressful visual stimulation. Twenty-nine participants took part in the experiment. Visual stimulation with slides eliciting disgust was followed by subjectively pleasant music, sad music, and white noise in three consecutive sessions. The spectral power of the frontal and temporal EEG, skin conductance, heart rate, heart period variability, facial capillary blood flow, and respiration rate were recorded and analyzed. Aversive visual stimulation evoked heart rate deceleration, increased high frequency component of heart period variability, increased skin conductance level and skin conductance response frequency, decreased facial blood flow and velocity, decreased temporal slow alpha and increased frontal fast beta power in all three sessions. Both subjectively pleasant and sad music led to the restoration of baseline levels on most parameters; while white noise did not enhance the recovery process. The effects of pleasant music on post-stress recovery, when compared to white noise, were significantly different on heart rate, respiration rate, and peripheral blood flow. Both positive and negative music exerted positive modulatory effects on cardiovascular and respiratory activity, namely increased heart rate, balanced heart period variability, increased vascular blood flow and respiration rate during the post-stress recovery. Data only partially supported the "undoing" hypothesis, which states that positive emotions may facilitate the process of physiological recovery following negative emotions.

Autonomic activity during task performance in adults with closed head injury

Skin conductance (SC) and heart rate (HR) were recorded in two experiments in persons who had suffered a closed head injury (CHI) at least 2 years previously and in control subjects. Experiment 1 consisted of a rest period, a series of innocuous tones, and a short simple reaction time (RT) task. Experiment 2 consisted of initial and final rest periods and a longer RT task with constant and variable preparatory intervals. The results from both protocols showed no group differences in HR, SC levels, or SC fluctuations during rest periods, but the SC variables increased less to the task instructions in the CHI group. There were no differences in SC response frequency or magnitude to innocuous tones, but the CHI subjects had fewer SC responses to the RT stimuli in both experiments. SC responses to both innocuous tones and RT stimuli had longer latencies in the CHI group. The results show that selective deficits in tonic and phasic autonomic responding to meaningful, significant, or demanding situations and stimuli are long-term sequelae to CHI. These attenuated activation increases may be related to inadequate mobilization of processing resources and to behavioral deficits shown by these patients.

Electrodermal activity and obstetric complications in schizophrenia.

The pregnancy and birth records of 79 schizophrenic patients, from whom adult electrodermal data were available, were systematically evaluated for obstetric complications using 34 criteria of nonoptimality in pregnancy, delivery, and postpartum periods. Patients with many obstetric complications had lower levels of electrodermal activity. For frequency of skin conductance responses and spontaneous fluctuations in skin conductance, the association was more evident for women than for men. However, the ratio of stimulus-elicited to spontaneous skin conductance responses showed a reliable association with obstetric complications without any gender differences. The relationship between obstetric complications and electrodermal activity was interpreted in terms of neurodevelopmental insults resulting in structural brain abnormalities interfering with orienting and electrodermal activity.

The stress of Stroop performance: physiological and emotional responses to color–word interference, task pacing, and pacing speed

Heart rate, frequency of skin conductance responses, and self-reported anxiety were measured during performance of a computer version of the Stroop Color–Word Interference Test, and during a non-conflicting control task involving the color naming of color patches. Stroop and control stimuli were presented individually in order to vary task pacing. Subjects ( N=48) were divided into three groups assigned to self-paced, externally-paced, and fast externally-paced conditions. Performance data revealed that the relative proportion of speed and accuracy reductions which resulted from the Stroop interference varied according to task pacing and pacing speed. Stroop performance was accompanied by heightened HR levels which were sustained throughout the series. State–Anxiety scores increased after both tasks, but only among subjects who completed a large number of trials, i.e. subjects in the self-paced and fast externally-paced groups. Skin conductance responses only varied according to task order and time within series, irrespective of Stroop interference or task pacing. Overall, the results remained in accordance with an effort account of the relationship between attention and cardiac activity. They also provided indications on how the Stroop test may act as an efficient laboratory stressor. © 1997 Elsevier Science B.V.

Anxiety sensitivity and menstrual cycle reactivity: Psychophysiological and self-report differences

The role of anxiety sensitivity in the etiology and maintenance of various anxiety disorders has received increased attention over the past decade. To date, no studies have empirically addressed the relationship between anxiety sensitivity, physiological reactivity, and self-reports of anxiety symptomatology across the menstrual cycle. In this study, high- and low-anxiety sensitivity women in either the premenstrual or intermenstrual phase of the menstrual cycle completed questionnaires and listened to anxiety and neutral scenes while psychophysiological data were collected. In addition, mood ratings were obtained at baseline and after scene presentations. High anxiety sensitivity sitivity participants scored higher on measures of anxiety, depression, and menstrual distress than low anxiety sensitivity females. Premenstrually, high anxiety sensitivity females exhibited greater skin conductance response frequency and magnitude to the anxiety scenes compared to the other three groups. Similar results were obtained when initial levels of state anxiety and panic history were controlled for statistically. Furthermore, high anxiety sensitivity females reported more anxiety and depressed mood following presentation of anxiety scenes. Implications of these results for the mediation of menstrual cycle timing and anxiety sensitivity hypotheses are discussed.

Physiological changes during computer tasks: responses to mental load or to motor demands?

Cardiac and electrodermal measures are regarded as indicators of user strain during computer work, not taking the possible influence of finger and hand movements on these measures into account. For the evaluation of such effects, motor demands and mental load were both varied as independent factors in two experiments. As a motor task, subjects had to produce compensatory keystrokes at different speed levels to keep a moving mark within a target area on the computer screen. Mental load was varied in experiment 1 by manipulation of keystroke synchronization accuracy, and in experiment 2 by manipulation of memory load. Physiological measures were affected by motor activity only at a very high typing speed. At lower levels of motor activity physiological effects were dependent exclusively on mental load. Frequency of skin conductance responses was the most sensitive indicator of the emotional consequences of mental load and mean heart period reflected its attentional aspects. The study supports the assumption that physiological effects of motor activity can be neglected during typical computer tasks, demanding keystrokes at intervals of 300 ms or longer.

Psychological Correlates of Nonspecific Skin Conductance Responses

Previous research has indicated that the frequency of skin conductance responses without external stimulation or motor activity is a reliable indicator of psychophysiological states and traits. Some authors have suggested that cognitions elicit nonspecific skin conductance responses. These cognitions may resemble the stimuli that evoke a specific skin conductance response. In a within subjects design (n = 31 graduate students) the onset of nonspecific skin conductance responses triggered a signal for the subject to rate cognitions on several indices. These ratings ("absent" to "fully present") were compared with samples in the absence of phasic electrodermal activity. The subjects' current concerns, negative emotion, subjective arousal, and inner speech were rated to be significantly more intense at the time of nonspecific skin conductance responses compared to electrodermal nonresponding periods. Cognitive processes seem to be concomitants of nonspecific skin conductance responses.