Skin Conductance Reactivity Research Articles

Delayed extinction fails to reduce skin conductance reactivity to fear-conditioned stimuli.

A brief 10-min time delay between an initial and subsequent exposure to extinction trials has been found to impair memory reconsolidation in fear-conditioned rodents and humans, providing a potential means to reduce fearfulness in anxiety disorders and posttraumatic stress disorder (PTSD). The present study used videos of biologically prepared, conditioned stimuli (tarantulas) to test the efficacy of delayed extinction in blocking reconsolidation of conditioned fear in healthy young adults. Strong differential conditioning, measured by skin conductance, was observed among a screened subset of participants during acquisition. However, the delayed-extinction intervention failed to reduce reactivity to the conditioned stimulus paired with the extinction delay. These results are partially consistent with other recent, mixed findings and point to a need for testing other candidate interventions designed to interfere with the reconsolidation process.

The Role of Cross-Cue Reactivity in Coexisting Smoking and Gambling Habits

Cigarette smoking is the most common addictive behaviour co-occurring with problem gambling. Based on classical conditioning, smoking and gambling cues may acquire conditioned stimulus properties that elicit cravings for both behaviours. This study examined cross-cue reactivity in 75 men who were regular smokers, poker players or cigarette-smoking poker players. Participants were exposed to discrete cigarette, poker and neutral cues while skin conductance and psychological urges to smoke and gamble were measured. Results showed evidence of cross-cue reactivity based on skin conductance, and subjective response to smoking cues; subjective response to gambling cues was less clear. Smoking gamblers showed greater skin conductance reactivity to cues, and stronger subjective urges to smoke to smoking and gambling cues, compared to individuals who only smoked or only gambled. This study demonstrates evidence for cross-cue reactivity between a substance and a behavioural addiction, and the results encourage further research.

Can Transcranial Direct Current Stimulation Augment Extinction of Conditioned Fear?

Exposure-based therapy parallels extinction learning of conditioned fear. Prior research points to the ventromedial prefrontal cortex as a potential site for the consolidation of extinction learning and subsequent retention of extinction memory. The present study aimed to evaluate whether the application of non-invasive transcranial direct current stimulation (tDCS) during extinction learning enhances late extinction and early recall in human participants. Forty-four healthy volunteers completed a 2-day Pavlovian fear conditioning, extinction, and recall paradigm while skin conductance activity was continuously measured. Twenty-six participants received 2 mA anodal tDCS over EEG coordinate AF3 during extinction of a first conditioned stimulus. The remaining 18 participants received similar tDCS during extinction of a second conditioned stimulus. Sham stimulation was applied for the balance of extinction trials in both groups. Normalized skin conductance changes were analyzed using linear mixed models to evaluate effects of tDCS over late extinction and early recall trials. We observed a significant interaction between timing of tDCS during extinction blocks and changes in skin conductance reactivity over late extinction trials. These data indicate that tDCS was associated with accelerated late extinction learning of a second conditioned stimulus after tDCS was combined with extinction learning of a previous conditioned stimulus. No significant effects of tDCS timing were observed on early extinction recall. Results could be explained by an anxiolytic aftereffect of tDCS and extend previous studies on tDCS-induced modulation of fear and threat related learning processes. These findings support further exploration of the clinical use of tDCS.

Convergence in feeling, divergence in physiology: How culture influences the consequences of disgust suppression and amplification among European Americans and Asian Americans.

Much empirical work documents the downsides of suppressing emotions. Emerging research points to the need for a more sophisticated and culturally informed approach to understanding the consequences of emotion regulation. To that end, we employed behavioral, self-report, and psychophysiological measures to examine the consequences of two types of emotion regulation (suppression and amplification) in a sample of 28 Asian Americans and 31 European Americans. Participants were shown a neutral film and then a series of disgust-eliciting films during which they were asked to regulate their response by suppressing or amplifying their emotional behavior (counterbalanced). Despite self-reporting equal levels of disgust, European Americans showed greater skin conductance reactivity than Asian Americans in both regulation conditions, but not in response to a neutral film. These findings extend work on divergence in the consequences of emotion regulation across different cultural groups, which could help identify optimal emotion regulation strategies for health and well-being.

Effects of prefrontal rTMS on autonomic reactions to affective pictures.

Repetitive transcranial magnetic stimulation (rTMS) can modulate the excitability of stimulated cortical areas, such as prefrontal areas involved in emotion regulation. Low frequency (LF) rTMS is expected to have inhibitory effects on prefrontal regions, and thereby should disinhibit limbic activity, resulting in enhanced emotional and autonomic reactions. For high frequency (HF) rTMS, the opposite pattern might be assumed. The objective of this study was to determine the effects of different rTMS frequencies applied to the right dlPFC on autonomic functions and on emotional perception. In a crossover design, two groups of 20 healthy young women were either stimulated with one session of LF rTMS (1Hz) or one session of HF rTMS (10Hz), compared to sham stimulation. We assessed phasic cardiac responses (PCR), skin conductance reactions (SCR), and emotional appraisal of emotional pictures as well as recognition memory after each rTMS application. After LF rTMS, PCR (heart rate deceleration) during presentation of pictures with negative and neutral valence was significantly increased compared to the presentation of positive pictures. In contrast, the modulatory effect of picture valence and arousal on the cardiac orienting response was absent after HF rTMS. Our results suggest that frontal LF rTMS indirectly activates the ANS via inhibition of the right dlPFC activity, likely by enhancing the sensory processing or attention to aversive and neutral stimuli.

TAKING THE PULSE OF PROLONGED EXPOSURE THERAPY: PHYSIOLOGICAL REACTIVITY TO TRAUMA IMAGERY AS AN OBJECTIVE MEASURE OF TREATMENT RESPONSE.

Physiological reactivity to trauma-related cues is a primary symptom of PTSD and can be assessed objectively using script-driven imagery paradigms. However, subjective self-reported symptom measures are the most common outcome indices utilized in PTSD treatment trials and clinic settings. We examined physiological reactivity during a short trauma imagery task as an objective index of response to PTSD treatment, optimized for use in routine clinical care settings. Participants were 35 male combat veterans receiving prolonged exposure (PE) therapy in a Veterans Affairs outpatient clinic. In addition to traditional subjective self-reported and clinician-rated symptom measures, patients also completed a script-driven imagery task in which heart rate (HR) and skin conductance (SC) were recorded at three assessment points across treatment. We examined changes in subjective symptom measures and objective trauma-specific physiological reactivity over the course of PE, and investigated the association between pretreatment physiological reactivity and treatment response. Patients who completed PE showed significantly diminished HR and SC reactivity to trauma imagery across therapy. Additionally, individuals showing greater trauma-specific HR reactivity at pretreatment showed greater reductions in subjectively reported PTSD symptoms at posttreatment. Findings support the utility of physiological reactivity during trauma imagery as an objective outcome measure that has the potential to be incorporated into evidence-based PTSD treatment in routine clinical settings, or prospective studies related to the individualization of care at pretreatment.

Prospective Associations between Peer Aggression and Victimization: The Moderating Roles of Physiological Stress Reactivity and Gender

AbstractThe present investigation examined whether heightened skin conductance reactivity (SCLR) to peer stress strengthened the prospective associations between physical and relational aggression and victimization, and whether associations were stronger for physical forms of aggression and victimization among boys and relational forms of aggression and victimization among girls. A total of 91 children [M age = 10.18 years, standard deviation (SD) = .68] were assessed twice over 1 year. At the first assessment, SCLR in response to recounting a relational stressor (e.g., exclusion; SCLR‐R) and an instrumental stressor (e.g., property theft; SCLR‐I), and teacher‐reported aggression were measured. Parents reported on child victimization at both time points. Among youth with heightened SCLR‐I, physical aggression was associated with increases in physical victimization for boys and decreases in physical victimization for girls. Among youth with heightened SCLR‐R, relational aggression was associated with increases in physical victimization for girls only. Results were largely consistent with the hypothesis that aggressors with a propensity to exhibit negative displays of emotion, as indexed by heightened sympathetic nervous system (SNS) reactivity to peer stress, may be especially likely to suffer peer victimization. Gender‐specific effects highlight the importance of including both physical and relational forms of aggression and victimization to capture victimization risk among aggressive boys and girls.

Sleep deprived and sweating it out: the effects of total sleep deprivation on skin conductance reactivity to psychosocial stress.

We examined how sleep deprivation alters physiological responses to psychosocial stress by evaluating changes in skin conductance. Between-subjects design with one group allocated to 24 h of total sleep deprivation and the other to rested wakefulness. The study took place in a research laboratory. Participants were 40 healthy young adults recruited from a university. Sleep deprivation and feedback. Electrodermal activity was monitored while participants completed a difficult perceptual task with false feedback. All participants showed increased skin conductance levels following stress. However, compared to well-rested participants, sleep deprived participants showed higher skin conductance reactivity with increasing stress levels. Our results suggest that sleep deprivation augments allostatic responses to increasing psychosocial stress. Consequentially, we propose sleep loss as a risk factor that can influence the pathogenic effects of stress.

Effects of hearing loss on heart rate variability and skin conductance measured during sentence recognition in noise.

The purpose of the study was to determine the effects of hearing loss and noise on (1) two autonomic nervous system measures associated with stress (skin conductance and heart rate variability) and on (2) subjective ratings of workload/stress. The authors hypothesized that hearing loss would increase psychophysiological and subjective reactivity to noise during speech recognition tasks. Both psychophysiological and subjective indicators of workload/stress were expected to increase with a reduction in signal-to-noise ratio. Sentence recognition in the presence of babble noise was assessed in 15 adults with clinically normal hearing and 18 adults with sensorineural hearing loss. Mean sentence recognition was equalized for the two groups using an adaptive procedure to estimate 80% recognition of words in sentences. Sentences were then presented in quiet and at four fixed signal-to-noise ratios: -6, -3, 0, and +3 dB relative to the individually determined signal-to-noise thresholds. Electrocardiography and skin conductance recordings were obtained during each listening condition. The high-frequency spectral component of heart rate variability was extracted from the electrocardiographic recordings as a measure of parasympathetic nervous system activity. Subjective ratings of effort, mental demand, stress, and perceived performance were obtained after each listening condition using the National Aeronautics and Space Administration Task Load Index. Recognition scores referenced to the adaptive threshold were similar for the two groups. Participants with hearing loss showed a decrease in high-frequency heart rate variability at lower signal-to-noise ratios, whereas those with normal hearing did not. Skin conductance levels were not sensitive to changes in signal-to-noise ratio. However, overall skin conductance reactivity to noise (relative to quiet) was higher for those with hearing loss than for those with normal hearing. In contrast to the psychophysiological findings, there were no significant differences between subjective ratings for the two groups. Listeners with hearing loss show greater autonomic nervous system reactivity to babble noise during speech recognition than do listeners with normal hearing, when recognition performance is equal. The findings are consistent with the conclusion that listeners with hearing loss experience increased effort and/or stress during speech recognition in noise.

Beyond extinction: Habituation eliminates conditioned skin conductance across contexts

A marked signature of fear extinction is its vulnerability for relapse. Here, we departed from the standard extinction principle and examined the ability of habituation to reduce conditioned fear reactions and prevent relapse. In a human fear conditioning paradigm, we first established one visual stimulus as a signal for an impending aversive electrical stimulation, while another visual stimulus was never followed by this stimulation. Next, the screen color changed and participants were exposed to either the visual stimuli without electrical stimulation (extinction treatment) or to the electrical stimulation without the visual stimuli (habituation treatment). Finally, the screen color changed back and the two visual stimuli were tested. Verbal ratings showed a return of conditioned shock-expectancy in the two groups, while skin conductance reactivity showed conditioned discrimination following exposures to the visual stimuli, but not following exposures to the electrical stimulation. We conclude that a habituation treatment outperforms an extinction treatment, and that shock-expectancy and skin conductance can dissociate under some conditions.

Prereactivation propranolol fails to reduce skin conductance reactivity to prepared fear-conditioned stimuli.

Pharmacologic blockade of memory reconsolidation has been demonstrated in fear-conditioned rodents and humans and may provide a means to reduce fearfulness in anxiety disorders and posttraumatic stress disorder. Studying the efficacy of potential interventions in clinical populations is challenging, creating a need for paradigms within which candidate reconsolidation-blocking interventions can be readily tested. We used videos of biologically prepared conditioned stimuli (tarantulas) to test the efficacy of propranolol in blocking reconsolidation of conditioned fear in healthy young adults. Strong differential conditioning, measured by skin conductance, was observed among a screened subset of participants during acquisition. However, subsequent propranolol failed to reduce reactivity to the reactivated conditioned stimulus. These results are consistent with other recent findings and point to a need for testing other candidate drugs.

Comparative physiological reactivity during script-driven recall in depression and posttraumatic stress disorder.

Increased physiological responsiveness to trauma memories is common in posttraumatic stress disorder (PTSD) and is related to higher felt memory intrusiveness. Physiological reactivity to remembering of distressing personal events in depression and its association with memory quality have not been examined. Heart rate (HR) and skin conductance (SC) reactivity during script-driven recall were assessed in participants with a depressive episode without PTSD (n = 24), participants with PTSD (n = 24), and nondisordered controls (n = 24). Participants reported on event impact and memory quality. PTSD participants showed higher HR and SC reactivity during trauma recall compared with recall of other events and compared with depressed participants for HR and SC reactivity and compared with nondisordered participants for HR reactivity. Although reactivity between depressed and nondisordered participants was not significantly different, the findings indicated a consistent trend toward an attenuation of reactivity to memories of events subjectively associated with symptom onset for those with depression. There was no evidence that the presence of depression impacted the increased physiological responsiveness observed in PTSD. Higher avoidance was associated with lower HR reactivity to the event memory for depressed participants, whereas higher avoidance was associated with higher HR reactivity to the trauma memory for PTSD participants. Trauma remembering in PTSD is distinctive from comparable remembering in depression in triggering high physiological reactivity. Avoidance of remembering the event predicts attenuated physiological reactivity to critical event recall in depression.

Borderline personality features as a predictor of forms and functions of aggression during middle childhood: examining the roles of gender and physiological reactivity.

The present longitudinal investigation examined borderline personality features as a predictor of aggression 1 year later. Moderation by physiological reactivity and gender was also explored. One hundred ninety-six children (M = 10.11 years, SD = 0.64) participated in a laboratory stress protocol in which their systolic blood pressure, diastolic blood pressure, and skin conductance reactivity to recounting a relational stressor (e.g., threats to relationships or exclusion) were assessed. Teachers provided reports on subtypes of aggressive behavior (i.e., reactive relational, proactive relational, reactive physical, and proactive physical), and children completed a self-report measure of borderline personality features. Path analyses indicated that borderline personality features predicted increases in reactive relational aggression and proactive relational aggression among girls who evinced heightened physiological reactivity to interpersonal stress. In contrast, borderline personality features predicted decreases in proactive physical aggression in girls. Findings suggest that borderline personality features promote engagement in relationally aggressive behaviors among girls, particularly in the context of emotional dysregulation.

Physiological stress reactivity and physical and relational aggression: the moderating roles of victimization, type of stressor, and child gender.

The purpose of the present investigation was to examine the association between physiological reactivity to peer stressors and physical and relational aggression. Potential moderation by actual experiences of peer maltreatment (i.e., physical and relational victimization) and gender were also explored. One hundred ninety-six children (M = 10.11 years, SD = 0.64) participated in a laboratory stress protocol during which their systolic blood pressure, diastolic blood pressure, and skin conductance reactivity to recounting a relational stressor (e.g., threats to relationships) and an instrumental stressor (e.g., threats to physical well-being, dominance, or property) were assessed. Teachers provided reports of aggression and victimization. In both boys and girls, physical aggression was associated with blunted physiological reactivity to relational stress and heightened physiological reactivity to instrumental stress, particularly among youth higher in victimization. In girls, relational aggression was most robustly associated with blunted physiological reactivity to relational stressors, particularly among girls exhibiting higher levels of relational victimization. In boys, relational aggression was associated with heightened physiological reactivity to both types of stressors at higher levels of peer victimization and blunted physiological reactivity to both types of stressors at lower levels of victimization. Results underscore the shared and distinct emotional processes underlying physical and relational aggression in boys and girls.

Relations between trait impulsivity, behavioral impulsivity, physiological arousal, and risky sexual behavior among young men.

The current study examined how impulsivity-related traits (negative urgency, sensation seeking, and positive urgency), behavioral measures of risk taking and reward seeking, and physiological reactivity related to three different risky sexual behaviors in sexually active undergraduate men (N = 135). Regression analyses indicated that sensation seeking and behavioral risk-taking predicted unique variance in number of sexual partners. These findings suggest that, for young men, acquisition of new partners is associated with need for excitement and reward and willingness to take risks to meet those needs. Sensation seeking, behavioral risk-taking, and skin conductance reactivity to arousing stimuli was related to ever having engaged in sex with a stranger, indicating that, for men, willingness to have sex with a stranger is related not only to the need for excitement and risk-taking but also with innate responsiveness to arousing environmental triggers. In contrast, regression analyses indicated that young men who were impulsive in the context of negative emotions were less likely to use condoms, suggesting that emotion-based impulsivity may be an important factor in negligent prophylactic use. This study adds to the current understanding of the divergence between the correlates of risky sexual behaviors and may lend utility to the development of individualized HIV prevention programming.

Physiological Arousal and Political Beliefs

It is by now well known that political attitudes can be affected by emotions. Most earlier studies have focused on emotions generated by some political event (e.g., terrorism or increased immigration). However, the methods used in previous efforts have made it difficult to untangle the various causal pathways that might link emotions to political beliefs. In contrast, we focus on emotions incidental (i.e., irrelevant) to the decision process, allowing us to cleanly trace and estimate the effect of experimentally induced anxiety on political beliefs. Further, we build upon innovative new work that links physiological reactivity (Hatemi, McDermott, Eaves, Kendler, & Neale, 2013; Oxley et al., 2008a) to attitudes by using skin conductance reactivity as a measure of emotional arousal. We found that anxiety—generated by a video stimulus—significantly affected physiological arousal as measured by tonic skin‐conductance levels, and that higher physiological reactivity predicted more anti‐immigration attitudes. We show that physiological reactivity mediated the relationship between anxiety and political attitudes.

Skin conductance rises in preparation and recovery to psychosocial stress and its relationship with impulsivity and testosterone in intimate partner violence perpetrators

Intimate partner violence (IPV) perpetrators were categorized into 2 groups using Gottman et al.'s (1995) typology depending on their skin conductance (SC) reactivity to stress. Overall, type I perpetrators tend to show autonomic underarousal, whereas type II perpetrators present a preparatory hyperreactivity to confront stress. Moreover, impulsivity traits and testosterone (T) levels may modulate SC responses to increase the risk of proneness to violence. In this study, SC response to stress was assessed by comparing IPV perpetrators with non-violent controls while performing a modified version of the Trier Social Stress Test (TSST). Subjects with a history of IPV demonstrated higher non-specific SC responses during the recovery period than the non-violent controls. Nonetheless, there were no differences between groups in the case of mean SC levels. Furthermore, impulsivity and baseline T levels were associated with higher SC level reactivity during a preparation period only in IPV perpetrators, with both relationships being mediated by anger expression. Our results confirm that the IPV perpetrators correspond physiologically to type II and support the validity of SC as a diagnostic indicator for IPV classification. Our findings contribute to the development of effective treatment and prevention programs that could benefit from the use of biological indicators for analyzing the risk of recidivism in IPV perpetrators.

Mindfulness and rumination as predictors of persistence with a distress tolerance task

Distress tolerance (DT) is a proposed transdiagnostic factor in psychopathology, yet sources of individual differences in DT are largely unknown. The present study examined mindfulness and rumination facets as predictors of persistence on a standardized DT task (mirror tracing). Acting with awareness (a facet of mindfulness) and reflection (a potentially adaptive form of rumination) predicted increased DT. Increased task-induced skin conductance reactivity predicted decreased DT. These results held after controlling for task skill and subjective and heart rate reactivity. Together, these results suggest that teaching skills to promote mindful awareness and reflection hold promise as interventions to enhance DT.

Enhancing exposure therapy for PTSD with yohimbine HCL: Protocol for a double-blind, randomized controlled study implementing subjective and objective measures of treatment outcome

Prolonged exposure (PE) therapy is considered a gold standard protocol for the treatment of PTSD, and it is associated with large treatment effect sizes in combat veteran samples. However, considering high rates of PTSD in the present veteran population, ongoing research work is important toward improving treatment efficiency by decreasing time to symptom amelioration and increasing the amount of symptom amelioration. The proposed research aims to enhance exposure therapy outcomes for veterans with PTSD via combination treatment with PE and yohimbine hydrochloride (HCL), an alpha-2 adrenergic receptor antagonist. The proposed investigation entails a randomized, placebo-controlled trial investigating the effect of a single administration of yohimbine HCL (paired with the first session of imaginal exposure) on outcome of PE in 40 veterans with PTSD. An additional goal is to establish a pragmatic method of tracking psychophysiological measures over the course of therapy for incorporation into future clinical psychotherapy trials. Thus, in addition to traditional self- and clinician-reported psychological outcomes, heart rate and skin conductance reactivity will be measured during a standard trauma-specific imagery task before, during, and after PE treatment. We will further investigate whether changes in psychophysiological measures predict changes in patient- and clinician-reported outcome measures.

Latent Inhibition Speeds up but Weakens the Extinction of Conditioned Fear in Humans

Prevention is better than cure, but little is known about effective prevention of anxiety disorders. Individuals vulnerable for trauma-exposure would benefit from effective techniques to prevent the development of post-traumatic stress. One reason for the apparent standstill in this literature may be the exclusive focus on the development of fear, while pre-clinical anxiety treatment research has turned to impaired extinction of fear as the main mechanism underlying abnormal anxiety. Conditioning theories propose latent inhibition as a technique to prevent the development of fears, but the effects on fear extinction have not been examined in detail. I conducted two experiments to evaluate the effects of latent inhibition on extinction in a standard human fear conditioning paradigm, which serves as a model for post-traumatic stress disorder. Skin conductance reactivity and online expectancy ratings revealed slower rates of fear acquisition in the latent inhibition groups, as well as a speeded extinction effect early in extinction. However, extinction of expectancy ratings was less complete in the latent inhibition groups. The beneficial effects of the latent inhibition technique may be in promoting early success of self-exposures or exposure treatment and motivating the patient to continue on the exposure path