Frank H. Wilhelm

The tie that binds? Coherence among emotion experience, behavior, and physiology.

Emotion theories commonly postulate that emotions impose coherence across multiple response systems. However, empirical support for this coherence postulate is surprisingly limited. In the present study, the authors (a) examined the within-individual associations among experiential, facial behavioral, and peripheral physiological responses during emotional responding and (b) assessed whether emotion intensity moderates these associations. Experiential, behavioral, and physiological responses were measured second-by-second during a film that induced amusement and sadness. Results indicate that experience and behavior were highly associated but that physiological responses were only modestly associated with experience and behavior. Intensity of amusement experience was associated with greater coherence between behavior and physiological responding; intensity of sadness experience was not. These findings provide new evidence about response system coherence in emotions.

Cell aging in relation to stress arousal and cardiovascular disease risk factors

We previously reported that psychological stress is linked to and possibly accelerates cellular aging, as reflected by lower PBMC telomerase and shortened telomeres. Psychological stress is a major risk factor for cardiovascular disease (CVD), with multiple behavioral and physiological mediators. Telomere shortness has been associated with CVD, but the relationship between low telomerase activity, a potential precursor to telomere shortening, and CVD risk factors has not been examined in humans. Here we examine whether telomere length and telomerase in leukocytes are associated with physiological signs of stress arousal and CVD risk factors in 62 healthy women. Low telomerase activity in leukocytes was associated with exaggerated autonomic reactivity to acute mental stress and elevated nocturnal epinephrine. Further, low telomerase activity was associated with the major risk factors for CVD -smoking, poor lipid profile, high systolic blood pressure, high fasting glucose, greater abdominal adiposity-as well as to a composite Metabolic Syndrome variable. Telomere length was related only to elevated stress hormones (catecholamines and cortisol). Thus, we propose that low leukocyte telomerase constitutes an early marker of CVD risk, possibly preceding shortened telomeres, that results in part from chronic stress arousal. Possible cellular mechanisms by which low telomerase may link stress and traditional risk factors to CVD are discussed. These findings may implicate telomerase as a novel and important mediator of the effects of psychological stress on physical health and disease.

All in the Mind's Eye? Anger Rumination and Reappraisal

Research on rumination has demonstrated that compared with distraction, rumination intensifies and prolongs negative emotion. However, rumination and distraction differ both in what one thinks about and how one thinks about it. Do the negative outcomes of rumination result from how people think about negative events or simply that they think about them at all? To address this question, participants in 2 studies recalled a recent anger-provoking event and then thought about it in 1 of 2 ways: by ruminating or by reappraising. The authors examined the impact of these strategies on subsequent ratings of anger experience (Study 1) as well as on perseverative thinking and physiological responding over time (Study 2). Relative to reappraisal, rumination led to greater anger experience, more cognitive perseveration, and greater sympathetic nervous system activation. These findings provide compelling new evidence that how one thinks about an emotional event can shape the emotional response one has.

Autonomic and Respiratory Characteristics of Posttraumatic Stress Disorder and Panic Disorder

Objective: Posttraumatic stress disorder (PTSD) and panic disorder (PD) are two anxiety disorders with prominent psychophysiological symptoms. The PTSD criterion of persistent hyperarousal suggests autonomic dysregulation, and the disorder has been associated with elevated heart rate. In contrast, PD has been associated with respiratory abnormalities such as low end-tidal Pco2. An integrated analysis of automatic and respiratory function in a direct comparison of these anxiety disorders is currently lacking. Methods: Electrodermal, cardiovascular, and respiratory psychophysiology was examined in 23 PTSD patients, 26 PD patients, and 32 healthy individuals at baseline and during threat of shock. Results: At baseline, the PTSD patients, in contrast to the other two groups, were characterized by attenuated parasympathetic and elevated sympathetic control, as evidenced by low respiratory sinus arrhythmia (a measure of cardiac vagal control) and high electrodermal activity. They also displayed elevated heart rate and cardiovascular sympathetic activation in comparison with healthy controls. PD patients exhibited lower Pco2 (hypocapnia) and higher cardiovascular sympathetic activation compared with healthy controls. PTSD patients, but not PD patients, sighed more frequently than controls. During the threat of shock phase, the PTSD group demonstrated blunted electrodermal responses. Conclusions: Persistent hyperarousal symptoms in PTSD seem to be due to high sympathetic activity coupled with low parasympathetic cardiac control. Respiratory abnormalities were also present in PTSD. Several psychophysiological measures exhibited group-comparison effect sizes in the order of 1.0, supporting their potential for enhancing differential diagnosis and possibly suggesting utility as endophenotypes in genetic studies of anxiety disorders. CSI = cardiovascular sympathetic index; CVT = cardiac vagal tone; ESI = electrodermal sympathetic index; HR = heart rate; HP = heart period; RSA = respiratory sinus arrhythmia; NS-SCR = number of nonspecific skin conductance fluctuations; HRV = heart rate variability; SCL = skin conductance level; Pco2 = end-tidal partial pressure of expired CO2; PDS = Posttraumatic Diagnostic Scale; PTSD = posttraumatic stress disorder; PD = panic disorder; STAI = State-Trait Anxiety Inventory; BDI = Beck Depression Inventory; SCRamp = amplitude of nonspecific skin conductance responses; ECG = electrocardiogram; lnHF = high-frequency power of HP variability; lnLF = low-frequency power of HP variability; lnVLF = very low-frequency power of HP variability; MANOVA = multivariate analysis of variance; HC = healthy controls.

Fear conditioning in panic disorder: Enhanced resistance to extinction.

Enhanced conditionability has been proposed as a crucial factor in the etiology and maintenance of panic disorder (PD). To test this assumption, the authors of the current study examined the acquisition and extinction of conditioned responses to aversive stimuli in PD. Thirty-nine PD patients and 33 healthy control participants took part in a differential aversive conditioning experiment. A highly annoying but not painful electrical stimulus served as the unconditioned stimulus (US), and two neutral pictures were used as either the paired conditioned stimulus (CS+) or the unpaired conditioned stimulus (CS-). Results indicate that PD patients do not show larger conditioned responses during acquisition than control participants. However, in contrast to control participants, PD patients exhibited larger skin conductance responses to CS+ stimuli during extinction and maintained a more negative evaluation of them, as indicated by valence ratings obtained several times throughout the experiment. This suggests that PD patients show enhanced conditionability with respect to extinction.

Glucocorticoids enhance extinction-based psychotherapy

Behavioral exposure therapy of anxiety disorders is believed to rely on fear extinction. Because preclinical studies have shown that glucocorticoids can promote extinction processes, we aimed at investigating whether the administration of these hormones might be useful in enhancing exposure therapy. In a randomized, double-blind, placebo-controlled study, 40 patients with specific phobia for heights were treated with three sessions of exposure therapy using virtual reality exposure to heights. Cortisol (20 mg) or placebo was administered orally 1 h before each of the treatment sessions. Subjects returned for a posttreatment assessment 3–5 d after the last treatment session and for a follow-up assessment after 1 mo. Adding cortisol to exposure therapy resulted in a significantly greater reduction in fear of heights as measured with the acrophobia questionnaire (AQ) both at posttreatment and at follow-up, compared with placebo. Furthermore, subjects receiving cortisol showed a significantly greater reduction in acute anxiety during virtual exposure to a phobic situation at posttreatment and a significantly smaller exposure-induced increase in skin conductance level at follow-up. The present findings indicate that the administration of cortisol can enhance extinction-based psychotherapy.

Visual complexity of websites: Effects on users' experience, physiology, performance, and memory

Visual complexity is an apparent feature in website design yet its effects on cognitive and emotional processing are not well understood. The current study examined website complexity within the framework of aesthetic theory and psychophysiological research on cognition and emotion. We hypothesized that increasing the complexity of websites would have a detrimental cognitive and emotional impact on users. In a passive viewing task (PVT) 36 website screenshots differing in their degree of complexity (operationalized by JPEG file size; correlation with complexity ratings in a preliminary study r=.80) were presented to 48 participants in randomized order. Additionally, a standardized visual search task (VST) assessing reaction times, and a one-week-delayed recognition task on these websites were conducted and participants rated all websites for arousal and valence. Psychophysiological responses were assessed during the PVT and VST. Visual complexity was related to increased experienced arousal, more negative valence appraisal, decreased heart rate, and increased facial muscle tension (musculus corrugator). Visual complexity resulted in increased reaction times in the VST and decreased recognition rates. Reaction times in the VST were related to increases in heart rate and electrodermal activity. These findings demonstrate that visual complexity of websites has multiple effects on human cognition and emotion, including experienced pleasure and arousal, facial expression, autonomic nervous system activation, task performance, and memory. It should thus be considered an important factor in website design.

Physiologic instability in panic disorder and generalized anxiety disorder.

BACKGROUND Because panic attacks can be accompanied by surges in physiologic activation, we tested the hypothesis that panic disorder is characterized by fluctuations of physiologic variables in the absence of external triggers. METHODS Sixteen patients with panic disorder, 15 with generalized anxiety disorder, and 19 normal control subjects were asked to sit quietly for 30 min. Electrodermal, cardiovascular, and respiratory measures were analyzed using complex demodulation to quantify variability in physiologic indices. RESULTS Both patient groups reported equally more anxiety and cardiac symptoms than control subjects, but certain other somatic symptoms, including breathlessness, were elevated only in panic disorder patients. Mean end-tidal pCO(2) and respiratory rates were lower, and tidal volume and the number of sighs were higher in panic disorder patients than control subjects. Neither cardiovascular (heart rate, arterial pressure, cardiac output), nor electrodermal instability including sighs distinguished the groups; however, tidal volume instability was greater in panic disorder than generalized anxiety disorder patients or control subjects. Several other respiratory measures (pCO(2), respiratory rate, minute volume, duty cycle) showed greater instability in both patient groups than in control subjects. CONCLUSIONS Respiration is particularly unstable in panic disorder, underlining the importance of respiratory physiology in understanding this disorder. Whether our findings represent state or trait characteristics is discussed.

Is there less to social anxiety than meets the eye? Emotion experience, expression, and bodily responding

Emotions are widely held to involve changes in experiential, behavioural, and physiological systems. It is not clear, however, just how tightly coupled these changes are during emotional responding. To examine this issue, we induced social anxiety in 47 high trait social anxiety (HTSA) and 50 low trait social anxiety (LTSA) participants using an impromptu speech paradigm. We assessed anxiety experience, behaviour, perceived physiological activation, and actual physiological activation. HTSA participants felt more anxious, perceived greater physiological activation, and exhibited more anxiety behaviour than LTSA participants. Unexpectedly, the two groups did not differ in objectively measured physiological responding. Internal analyses indicated that for both HTSA and LTSA participants, anxiety experience was associated with perceived physiological activation, but not with actual physiological responding. These results suggest that anxiety experience and perceived physiological activation may be less tightly coupled with actual physiological responses than is typically thought.

Emotions beyond the laboratory: theoretical fundaments, study design, and analytic strategies for advanced ambulatory assessment.

Questionnaire and interview assessment can provide reliable data on attitudes and self-perceptions on emotion, and experimental laboratory assessment can examine functional relations between stimuli and reactions under controlled conditions. On the other hand, ambulatory assessment is less constrained and provides naturalistic data on emotion in daily life, with the potential to (1) assure external validity of laboratory findings, (2) provide normative data on prevalence, quality and intensity of real-life emotion and associated processes, (3) characterize previously unidentified emotional phenomena, and (4) model real-life stimuli for representative laboratory research design. Technological innovations now allow for detailed ambulatory study of emotion across domains of subjective experience, overt behavior and physiology. However, methodological challenges abound that may compromise attempts to characterize biobehavioral aspects of emotion in the real world. For example, emotional effects can be masked by social engagement, mental and physical workloads, as well as by food intake and circadian and quasi-random variation in metabolic activity. The complexity of data streams and multitude of factors that influence them require a high degree of context specification for meaningful data interpretation. We consider possible solutions to typical and often overlooked issues related to ambulatory emotion research, including aspects of study design decisions, recording devices and channels, electronic diary implementation, and data analysis.