Higher Skin Conductance Responses Research Articles

Emotional suppression in chronic fatigue syndrome: Experimental study.

Emotional processing differences in chronic fatigue syndrome (CFS) have been reported but have rarely been investigated experimentally. This study used self-report, observer ratings, and electrodermal responses to test hypotheses about emotion suppression and autonomic reactivity. Eighty adults with CFS and 80 healthy controls (HC) watched a distressing film clip. Half of each group were instructed to suppress their emotions and half were told to express their feelings as they wished. Their reactions were filmed and rated by independent observers. Electrodermal activity (skin conductance response) was used as a measure of sympathetic nervous system arousal. CFS participants reported higher anxiety and sadness than the HC, both before and after the film. However, observers rated the CFS group as having lower emotional expression than HC in both emotional suppression and expression choice conditions. Beliefs about the unacceptability of negative emotions were associated with greater self-reported suppression. Electrodermal responses were greater in the CFS group than HC participants. Higher skin conductance responses were associated with larger posttask increases in fatigue in the CFS participants but not in the HC. CFS participants had lower observer-rated emotional expression than HC, despite greater distress and higher autonomic arousal. This may have implications for their ability to access social support at times of stress. As the degree of autonomic arousal was associated with short-term increases in fatigue in the CFS participants, this requires further investigation as a contributory factor for this condition. (PsycINFO Database Record

Neural representation of swallowing is retained with age. A functional neuroimaging study validated by classical and Bayesian inference

We investigated the neural representation of swallowing in two age groups for a total of 51 healthy participants (seniors: average age 64 years; young adults: average age 24 years) using high spatial resolution functional magnetic resonance imaging (fMRI). Two statistical comparisons (classical and Bayesian inference) revealed no significant differences between subject groups, apart from higher cortical activation for the seniors in the frontal pole 1 of Brodmann's Area 10 using Bayesian inference. Seniors vs. young participants showed longer reaction times and higher skin conductance response (SCR) during swallowing. We found a positive association of SCR and fMRI-activation only among seniors in areas processing sensorimotor performance, arousal and emotional perception. The results indicate that the highly automated swallowing network retains its functionality with age. However, seniors with higher SCR during swallowing appear to also engage areas involved in attention control and emotional regulation, possibly suggesting increased attention and emotional demands during task performance.

Do patients with chronic pain show autonomic arousal when confronted with feared movements? An experimental investigation of the fear-avoidance model.

The relevance of a phobia-based conceptualization of fear for individuals with chronic pain has been much debated in the literature. This study investigated whether patients with highly fearful chronic low back pain show distinct physiological reaction patterns compared with less fearful patients when anticipating aversive back pain-related movements. We used an idiosyncratic fear induction paradigm and collected 2 different measures of autonomic nervous system activation and muscle tension in the lower back. We identified 2 distinct psychophysiological response patterns. One pattern was characterized by a moderate increase in skin conductance, interbeat interval (IBI) increase, and muscle tension increase in the lower back. This response was interpreted as an attention reaction to a moderately stressful event. The other pattern, found in 58% of the participants, was characterized by a higher skin conductance response, IBI decrease, and muscle tension increase in the lower back. According to Bradley and Lang defense cascade model, this response is typical of a fear reaction. Participants showing the psychophysiological pattern typical of fear also had elevated scores on some self-report measures of components of the fear-avoidance model, relative to participants showing the reaction pattern characteristic of attention. This study is the first to provide psychophysiological evidence for the fear-avoidance model of chronic pain.

Sweet reward increases implicit discrimination of similar odors.

Stimuli associated with emotional events signal the presence of potentially relevant situations, thus learning to rapidly identify this kind of stimuli can be highly beneficial. It has been demonstrated that individuals acquire a better perceptual representation of stimuli associated with negative and threatening emotional events. Here we investigated whether the same process occurs for stimuli associated with positive and rewarding emotional events. We used an appetitive Pavlovian conditioning paradigm during which one of two perceptually non-distinguishable odors was associated with a rewarding taste (i.e., chocolate). We investigated whether appetitive conditioning could improve the recognition of the odor associated with the reward, rendering it discriminable from its similar version that was never associated with the reward. Results revealed a dissociation between explicit perception and physiological reactions. Although participants were not able to explicitly perceive a difference, they reacted faster, inhaled more and had higher skin conductance responses when confronted with the reward-associated odor compared to its similar version that was never associated with the reward. Our findings have demonstrated that positive emotional associations can improve the implicit perceptual representation of odors, by triggering different physiological responses to odors that do not seem to be otherwise distinguishable.

Autonomic Responses to Social and Nonsocial Pictures in Adolescents With Autism Spectrum Disorder

It remains unclear why individuals with autism spectrum disorder (ASD) tend to respond in an atypical manner in social situations. Investigating autonomic and subjective responses to social vs. nonsocial stimuli may help to reveal underlying mechanisms of these atypical responses. This study examined autonomic responses (skin conductance level and heart rate) and subjective responses to social vs. nonsocial pictures in 37 adolescents with an ASD and 36 typically developing (TD) adolescents. Thirty-six pictures from the International Affective Picture System were presented, divided into six categories based on social content (social vs. nonsocial) and pleasantness (pleasant, neutral, and unpleasant). Both in adolescents with ASD as well as TD adolescents, pictures with a social content resulted in higher skin conductance responses (SCRs) for pleasant and unpleasant pictures than for neutral pictures. No differences in SCRs were found for the three nonsocial picture categories. Unpleasant pictures, both with and without a social content, showed more heart rate deceleration than neutral pictures. Self-reported arousal ratings were influenced by the social and affective content of a picture. No differences were found between individuals with ASD and TD individuals in their autonomic and subjective responses to the picture categories. These results suggest that adolescents with ASD do not show atypical autonomic or subjective responses to pictures with and without a social content. These findings make it less likely that impairments in social information processing in individuals with ASD can be explained by atypical autonomic responses to social stimuli.

Parenting Stress and Externalizing Behavior Symptoms in Children: The Impact of Emotional Reactivity

This study investigated whether the parenting stress-child externalizing behavior link is moderated by children's emotional reactivity, as indexed by skin conductance responses (SCRs). Participants were 61 children aged 9-12 years and their mothers. Mothers completed measures of parenting stress and their children's externalizing symptoms; children also reported on their externalizing behavior. Children's SCRs were assessed during the viewing of standardized pleasant, unpleasant, and neutral pictures. Cluster analysis on SCRs identified two groups, labeled Lower SCRs and Higher SCRs. Regression analyses indicated that among children with lower SCRs, those exposed to increased parenting stress reported more externalizing symptoms, whereas those who experienced low parenting stress reported similar rates of externalizing problems as children with higher SCRs. No effect of parenting stress emerged for children with higher SCRs. Findings suggest that higher parenting stress renders children with lower, as opposed to higher, SCRs to emotional stimuli more vulnerable to externalizing problems.

Voluntary Emotion Suppression Modifies Psychophysiological Responses to Films

A fundamental aspect of successful social interaction is the fact people do not always experience or express emotions to their fullest extent but instead control them in a context-dependent manner. Emotion regulation involves the manipulation of subjective experience, behavior, and physiology. Previous researches have studied autonomic nervous system (ANS) responses during emotion regulation using only positive and negative stimuli without distinguishing between emotions, or it has focused on one specific emotion. Given the differences of ANS reactions to different categories of emotional stimuli, our study aims at comparing the physiological activity during emotion attending and emotion suppression using specific and distinct categories of emotions. Fifty subjects were presented with five films, inducing one of five emotions: happiness, sadness, fear, peacefulness, and disgust. While viewing the films, participants were instructed to perform an attending and a suppression task. We evaluated the following physiological measures as participants engaged in these tasks: skin conductance response (SCR), heart rate (HR), and activity of zygomatic and corrugator muscles. Performing a suppression task when viewing the happy and disgusting film clips resulted in diminished, respectively, zygomatic and corrugator muscle activities. Emotion regulation leads to a lower HR when viewing the happy film, and a higher SCR when viewing the fear-inducing film. The effects of emotional control on EMG and HR are observed on the emotions that drive the most important physiological changes in the noncontrol setting, while the increased SCR for the fear-inducing film indicates that the conscious and volitional regulation of emotion has selective effect on fear emotion as compared to happiness, disgust, sadness, and peacefulness.

Pain Uncertainty in Patients with Fibromyalgia, Yoga Practitioners, and Healthy Volunteers

Uncertainty about potentially painful events affects how pain is experienced. Individuals with fibromyalgia (FM) often exhibit anxiety and catastrophic thoughts regarding pain and difficulties dealing with pain uncertainty. The effects of pain uncertainty in predictably high odds (HO), predictably low odds (LO), and even odds (EO) conditions on subjective ratings of pain (PR) and skin conductance responses (SCR) following the administration of a painful stimulus were examined for individuals with fibromyalgia (IWFM), healthy volunteers (HVs), and yoga practitioners (YPs). We hypothesized IWFM would demonstrate the greatest physiological reactivity to pain uncertainty, followed by HVs and YPs, respectively. Nine IWFM, 7 YPs, and 10 HVs participated. Custom contrast estimates comparing responses for HO, LO, and EO pain conditions showed higher SCR for IWFM (CE = 1.27, p = 0.01) but not for HVs or for YPs. PR for the EO condition were significantly greater than for HO and LO conditions for IWFM (CE = 0.60, p = 0.012) but not for HVs or YPs. YPs had lower SCR and PR than did HVs. Results show that uncertainty regarding pain increases the experience of pain, whereas certainty regarding pain may reduce pain ratings for individuals with fibromyalgia.

The role of context in the processing of alcohol‐relevant cues

In line with learning theories of drug addiction, drug-related cues may be viewed as important motivators of continued drug use. They may be differentially effective depending on the context and motivational significance. The present study aimed to test the significance of different contexts in modulating alcohol-related cue reactivity. Pictures depicting alcohol intake or its paraphernalia and pictures without any relation to alcohol intake were varied to depict physical and social contexts or different consumptive contexts associated with full/half-full/empty alcohol beverage containers. We obtained ratings of craving, valence and arousal of the cues as well as skin conductance responses (SCRs) and startle reflex modulation measures from 21 abstinent alcohol-dependent patients, recruited from an addiction treatment center, and 21 matched healthy controls. Social scenes and full glasses or bottles were rated as more pleasant and arousing compared with neutral drinking situations and empty glasses or bottles in patients. Furthermore, we found a decreased startle reflex magnitude to social compared with neutral drinking situations, and both higher SCRs and decreased startle reflex magnitude to full compared with empty glasses or bottles in patients versus controls. These results show that both physical and social and consumptive contexts differentially influence cue reactivity in abstinent alcohol-dependent patients with both social and pub-related physical contexts, and the initial consumptive context eliciting the most appetitive and arousing responses. These data have not only important implications for our understanding of the role of learning in drug dependence but also for treatment, which needs to take these factors into account.

Effortless control: executive attention and conscious feeling of mental effort are dissociable

Recruitment of executive attention is normally associated to a subjective feeling of mental effort. Here we investigate the nature of this coupling in a patient with a left mesio-frontal cortex lesion including the anterior cingulate cortex (ACC), and in a group of comparison subjects using a Stroop paradigm. We show that in normal subjects, subjective increases in effort associated with executive control correlate with higher skin-conductance responses (SCRs). However, our patient experienced no conscious feeling of mental effort and showed no SCR, in spite of exhibiting normal executive control, and residual right anterior cingulate activity measured with event-related potentials (ERPs). Finally, this patient demonstrated a pattern of impaired behavior and SCRs in the Iowa gambling task—elaborated by Damasio, Bechara and colleagues—replicating the findings reported by these authors for other patients with mesio-frontal lesions. Taken together, these results call for a theoretical refinement by revealing a decoupling between conscious cognitive control and consciously reportable feelings. Moreover, they reveal a fundamental distinction, observed here within the same patient, between the cognitive operations which are depending on normal somatic marker processing, and those which are withstanding to impairments of this system.

Pain-Reduction Strategies in Hypnotic Context and Hypnosis: ERPs and SCRs During a Secondary Auditory Task

Pain-rating scores were obtained from 10 high, 10 medium, and 10 low hypnotizable subjects who were holding a painful cold bottle in their left hands and were exposed to pain reduction treatments while they were performing a secondary oddball task. All subjects received suggestions of dissociative imagery and focused analgesia as cognitive strategies for pain reduction. The following measures were obtained for tone targets of the auditory oddball task: (a) reaction time; (b) P300 peak amplitude of the event-related potentials; (c) skin conductance levels and skin conductance responses. Focused analgesia produced the most pain reduction in high, but not medium or low, hypnotizable subjects who showed shorter reaction times, higher central and parietal P300 peaks, and higher skin conductance responses. These findings were discussed vis-à-vis the dissociated-control model assuming that capacity demands of hypnotic suggestion are low.