Psychophysiological comorbidity and computerized biofeedback

Our previous research on basic and applied psychophysiology comprised the quantum model for subcellular brain processes, the psychosomatic health risk assessment and management, as well as the electrodermal biofeedback psychometrics and therapy. Based on this experience, in the present paper the stress-related psychophysiological disorders in patients dependent on hemodialysis and insulin are considered. The most frequent comorbid psychological disorders appeared to be anxiety and depression, and they are generally under-diagnosed and under-treated. It is concluded that the quality of life of these patients needs to be considerably enhanced. The application of biofeedback, as a complementary cost-effective and non-invasive psychophysiological tool is recommended. In terms of ESAO vocabulary, this technique could be viewed as some kind of artificial ANS/CNS support. Simultaneously, the concept of biocompatibility may be viewed in a larger perspective as "psychobiocompatibility".     

Psychophysiological differentiation of deception: the effects of electrodermal lability and mode of responding on skin conductance and heart rate.

The differentiation-of-deception paradigm enables the examination of deception as a psychophysiological process by varying, within subjects, two conditions which differ only with respect to honesty and deception. The present experiment assessed the effects of two group factors - electrodermal lability and mode of responding - on the deception phenomenon in a situation with low emotional involvement and mental load. Skin conductance responses, phasic heart rate, self-rated relaxation, calmness, and concentration were the dependent variables. Twenty questions referring to general knowledge were presented on a monitor. The 88 male participants answered half of the questions deceptively and the other half honestly, depending on which of two signals appeared on the screen. Half of the subjects answered verbally and the others by pressing keys. For electrodermal lability and mode of responding, significant main effects on skin conductance and heart rate were obtained. The expected main effect of truthfulness emerged in all variables, without being affected by the group factors. These findings, therefore, extend the generality and robustness of the differentiation-of-deception phenomenon.     

Psychophysiological effects of slow-paced breathing at six cycles per minute with or without heart rate variability biofeedback

Heart rate variability (HRV) biofeedback, referring to slow-paced breathing (SPB) realized while visualizing a heart rate, HRV, and/or respiratory signal, has become an adjunct treatment for a large range of psychologic and medical conditions. However, the underlying mechanisms explaining the effectiveness of HRV biofeedback still need to be uncovered. This study aimed to disentangle the specific effects of HRV biofeedback from the effects of SPB realized alone. In total, 112 participants took part in the study. The parameters assessed were emotional (valence, arousal, and control) and perceived stress intensity as self-report variables and the root mean square of the successive differences (RMSSD) as a physiologic variable. A main effect of condition was found for emotional valence only, valence being more positive overall in the SPB-HRVB condition. A main effect of time was observed for all dependent variables. However, no main effects for the condition or time x condition interaction effects were observed. Results showed that for PRE and POST comparisons (referring, respectively, to before and after SPB), both SPB-HRVB and SPB-NoHRVB conditions resulted in a more negative emotional valence, lower emotional arousal, higher emotional control, and higher RMSSD. Future research might investigate psychophysiological differences between SPB-HRVB and SPB-NoHRVB across different time periods (e.g., long-term interventions), and in response to diverse psychophysiological stressors.     

Illness perceptions in depersonalization disorder: Testing an illness attribution model

Depersonalization disorder (DPD) remains poorly understood and controversial in terms of diagnosis and treatment. Little is known about the cognitive representation of this disorder. In this study, 80 participants with DPD were assessed using the Revised Illness Perception Questionnaire to determine the nature of their perceptions, causal attributions and whether these correlate with levels of depersonalization and affect. Illness perceptions were generally negative; the nature of symptoms was described as mainly psychological but causal attributions were equally divided between psychological and physical. Over half of the sample believed that symptoms were due to ‘physical changes in the brain’. A strong illness identity, psychological illness attributions and high levels of depression were associated with greater depersonalization disorder severity. High levels of anxiety were also prevalent but the relationship between anxiety and depersonalization was unclear. The findings offer some support for a cognitive model of understanding depersonalization disorder, namely that attribution processes are linked to perceived symptom severity and a wide range of experiences come to be seen as part of the disorder. Copyright © 2007 John Wiley & Sons, Ltd.     

Eye movement and electrodermal responses to threat stimuli in post-traumatic stress disorder

A core feature of post-traumatic stress disorder (PTSD) is hypervigilence to threatening material. This study measured processing of threat material in PTSD with simultaneously acquired initial eye movements and electrodermal activity, following presentation of threatening and neutral words. Ten PTSD subjects and 10 controls were presented with 4 words in parafoveal range. On trials in which a threat word was present, PTSD subjects demonstrated initial eye fixations on the threat word more than controls. PTSD subjects also demonstrated more orienting responses on all trials than controls. These results suggest that processing of threat information in PTSD can be usefully investigated with convergent psychophysiological methodologies.     

Psychophysiological effects of habitual caffeine consumption

Caffeine is the most widely consumed pharmacologically active substance in the world, and a key issue concerning its possible implications for human health is whether it has persistent (i.e., chronic) physiological effects on habitual consumers. This study examined blood pressure, heart rate (HR), electromyogram (EMG), and skin conductance level (SCL) in 36 healthy men and women exposed to a pattern of moderate intake. A double-blind placebo-controlled crossover design with counterbalancing was used in which all subjects participated in four experimental conditions involving the ingestion of placebo or caffeine three times daily for 6 days followed by a seventh (“challenge”) day of placebo or caffeine ingestion. Results confirmed that caffeine has significant pressor effects, and these were found to be additive to the pressor action of a laboratory stressor. Following habitual consumption of the drug, pressor effects were diminished (indicative of tolerance) but not eliminated. Effects of caffeine on other parameters were either modest (HR and EMG) or negligible (SCL). Considering the near-universal use of caffeine, the persistent pressor effects observed in this study have important implications for clinical practice and public health. This article was supported in part by Australian Research Council Grant No. A79131683 and Australian National Health and Medical Research Council Grant No. 910794     

Psychophysiological responses to idiosyncratic stress in bulimia nervosa and binge eating disorder

This study examined psychophysiological stress responses to idiosyncratically relevant stress in bulimia nervosa (BN) and binge eating disorder (BED), in relation to autonomic cardiac control and nutritional status. A total of 81 women with BN, BED and healthy controls (HC) took part in an in sensu exposure to idiosyncratic stress. Psychological and peripheral physiological parameters were measured, and tonic heart rate variability, nutritional status, and types of stress were determined. In response to stress exposure, both eating disordered groups showed a stronger reactivity of sadness, and the BED group showed a stronger reactivity of insecurity than the HC group. Desire to binge was increased in the context of interpersonal stress. Stress exposure led to increased cardiovascular activity and reduced electrodermal activity that did not differ by group. The BN-specific symptomatology moderated the association between autonomic cardiac control and psychophysiological stress responses. The results suggest common and specific psychophysiological processes in symptom maintenance through life stress in BN and BED.     

Psychophysiological effects of cardiac rehabilitation in post-myocardial infarction patients

Psychophysiological reactivity and cardiovascular functioning were assessed in 40 patients with coronary heart disease before and after taking part in either a Type A modification training program or a control condition. Treated patients showed an overall attenuated heart rate (HR) response and prolonged diastolic time to mental stress performance, during recovery and rest periods, as compared lo control patients. No other measure, including impedance-cardiography-derived measures, differentiated the two groups. The treatment group showed reduction from before lo after treatment in 24-hr minimum IIR level and decreased frequencies of premature ventricular contractions, whereas the control group showed an opposite trend. Results from an exercise test suggested the same direction for resting IIR and double-product levels. The two groups did not differ in maximal systolic and diastolic blood pressure or in maximal double-product levels, despite a differential development, in favor of the treatment group, in maximal work capacity.     

Caffeine and novelty: effects on electrodermal activity and performance

Caffeine has been shown to affect both physiological functioning and certain aspects of performance. These effects are typically attributed to a simple increase in general arousal. The present study was based on the theory that the effects of caffeine are actually multidimensional. Specifically, we hypothesized that the drug raises arousal, acts to maintain elevated arousal under conditions otherwise conductive to habituation, and enhances the impact of situational and psychological sources of arousal. Subjects were given caffeine (300 mg) or placebo and white noise or no noise and exposed to a series of pure tones and two Backwards Recall Tasks, one novel, the other repetitive. Electrodermal activity (EDA) and task performance were recorded. Caffeine increased arousal as measured by EDA. It also acted to slow habituation during repetitive stimulation, thus maintaining heightened arousal. Finally, it enhanced the effects of novel stimulation, which also independently raised arousal. These results support a multidimensional theory of caffeine effects and provide some understanding of the popularity of caffeine as a psychotropic agent.     

Sensation-seeking: electrodermal and behavioral effects of stimulus content and intensity

Although a number of studies support an arousal theory interpretation of differential sensation-seeking behavior, the conditions under which arousal correlates of this personality dimension are manifest is as yet unclear. Both theory and research suggest that among the external factors affecting the differential arousal response are stimulus relevance and stimulus intensity. The present study assessed the impact of these factors on both psychophysiological and behavioral responses. Subjects were preselected to represent the extremes of the sensation-seeking dimension, then exposed to auditory and visual presentations of a series of sexual and aggressive stimuli of systematically varied intensity. High sensation seekers gave larger amplitude SCRs to violent stimuli and larger initial responses to sexual stimuli presented visually, while verbal response intensities showed an opposite pattern. Overall, results provided support for an arousal theory interpretation of sensation-seeking, but suggested that the probability and magnitude of group differences is a somewhat complex function of stimulus intensity, stimulus modality, and perhaps other factors not yet assessed.     

Psychophysiological effects of emotional responding to goal attainment

Effects of positive performance feedback on self-reported emotion and associated physiological responding and their relation to motivational engagement were investigated in an achievement context. To create a situation of self-relevant goal striving and goal attainment, appraisals of goal relevance and goal conduciveness were manipulated by presenting 65 female undergraduate students with a psychological test, followed by positive performance feedback. Emotional responding during the 1-min feedback showed elicitation of various positive achievement-related emotions associated with broad sympathetic activation (decreased pre-ejection period, increased cardiac output, and increased skin conductance and response rate). Individual-level emotion reports indicated distinct subgroups of participants experiencing primarily either interest, joy, pride, or surprise. Between-participants physiological reactivity was found to differ based on primary self-reported feelings. We discuss motivational antecedents and consequences in achievement-related emotions.     

广泛性焦虑症病人生物反馈辅助治疗的应用

目的：探讨生物反馈辅助治疗广泛性焦虑症病人的疗效。方法：将60例广泛性焦虑症病人随机分为两组：反馈治疗组（A组）和单纯药物治疗组（B组）,两组各30例。A组和B组均给予抗焦虑药物帕罗西汀10～20mg／d,A组同时行生物反馈治疗,每日1次,每次30min,每周5次,连续2周后评定疗效。疗效用90项症状因子自评量表（SCL-90）评定。结果：治疗两周后,两组SCL-90评分均较人组时显著降低。A组比B组疗效更显著,其间差异有统计学意义（P〈0．05）。结论：对于广泛性焦虑症,在抗抑郁药物治疗的基础上辅以生物反馈治疗的疗效优于单纯抗抑郁药物治疗。     

Age effects to negative arousal differ for self-report and electrodermal activity

Affective processing and emotional experience may change with age. Because findings of age differences in affective experiences are mixed even in studies using standardized stimuli, this study assessed age differences along gradual increases in negative arousal. Younger (20-30 years) and older (70-80 years) healthy adults (n=78) viewed 110 neutral to negative pictures (IAPS) while intensity ratings and electrodermal activity were recorded. Results showed that age had opposite effects on intensity ratings and electrodermal activity over gradual increases in normative arousal. Whereas older adults showed greater increases in intensity ratings than younger adults, they showed attenuated electrodermal activity, especially at high negative arousal. Because self-reports of arousal capture various aspects of affective processes (e.g., physiological changes as well as experience), effects of age may vary for these different aspects.     

Ego involvement and effort: cardiovascular, electrodermal, and performance effects

An experiment with N=52 university students manipulated ego involvement (low vs. high) and task difficulty (unfixed vs. easy) of a letter detection task. In accordance with the theoretical predictions about the role of ego involvement in active coping, high ego involvement increased the performance-related reactivity of systolic blood pressure, diastolic blood pressure, heart rate, and also the number of unspecific skin conductance responses when task difficulty was unfixed ("do your best"). Ego involvement had no impact on autonomic reactivity when task difficulty was easy due to a fixed low performance standard. Furthermore, participants in the ego involvement/unfixed condition, where autonomic reactivity was relatively strong, committed significantly fewer errors in the letter detection task than those in the other conditions, reflecting an association between mental effort and performance.     

Psychophysiological, somatic, and affective changes across the menstrual cycle in women with panic disorder

This study explored menstrual symptoms, somatic focus, negative affect, and psychophysiological responding across the menstrual cycle in women with panic disorder and controls. Women with and without panic disorder completed a psychophysiological task and self-report measures of menstrual symptoms, somatic focus, and negative affect on 4 occasions across 2 menstrual cycles (twice during intermenstrual and premenstrual phases). Women in the panic disorder group exhibited greater skin conductance magnitude and more frequent skin conductance responses to anxiety-provoking stimuli during the premenstrual phase than did controls. Compared to controls, women with panic disorder endorsed more severe menstrual symptoms relating to bodily sensations, anxiety sensitivity, state and trait anxiety, fear of body sensations, and illness-related concerns. The applicability of anxiety sensitivity to understanding the relation of menstrual reactivity and panic disorder is discussed.     

The effects of EMG biofeedback and relaxation training on primary dysmenorrhea

Fifteen dysmenorrhea sufferers received relaxation training with EMG biofeedback, relaxation training with no feedback, or no treatment. Participants who received biofeedback training did not differ from participants who received relaxation training in their ability to maintain a reduced level of EMG activity prior to the onset of menstruation. On the first day of menstruation, those receiving biofeedback training were able to maintain reduced EMG activity, whereas those receiving relaxation training showed an elevated level of EMG activity. Subjective reports indicated that the symptoms of dysmenorrhea improved for the biofeedback group during training but did not improve for the relaxation or control groups. Suggestions for further research are noted.The authors wish to thank Jerry Curtis for his invaluable assistance in setting up and maintaining the laboratory facilities and computer programs used to conduct this study.     

Individual differences in electrodermal and electroencephalographic asymmetries

In a continuing investigation of the relationship between differential hemispheric activation and electrodermal asymmetry, comparisons were made between the electroencephalographic asymmetries and electrodermal asymmetries exhibited by subjects carrying out particular tasks. Bilateral skin conductance responses and 28 channels of EEG data allowing the production of topographical maps were collected from 8 female and 8 male right-handed subjects during the performance of two tasks, one verbal and one visuospatial. The tasks were selected with the aim of differentially activating the hemispheres to investigate whether parallel changes in the direction of electroencephalographic and electrodermal asymmetries would occur. EEG asymmetries were compared in female and male subjects. Previous research has indicated that males tend to show stronger EEG asymmetry than females, and that this is emphasised in verbal tasks. This was confirmed by the present study. Comparison with electrodermal activity revealed a weak relationship between the two measures, with some parallels between task-related variations in the beta 2 waveband and skin conductance responses. No parallels between alpha activity or skin conductance level were demonstrated. If the subjects are regrouped according to degree of electrodermal asymmetries, then some closer parallels with electroencephalographic asymmetries are revealed with more marked electrodermal asymmetry paralleling more marked electroencephalographic asymmetry. Variations in electrodermal asymmetry appear to be related to greater activity on the hand contralateral to the hemisphere showing smaller amplitude EEG activity, generally in the beta waveband. In discussing cortical control of electrodermal activity, these findings are discussed in terms of both the contralateral excitatory and the contralateral inhibitory models.     

Psychophysiological effects of self-regulation method: EEG frequency analysis and contingent negative variations

Experiments were conducted to investigate the psychophysiological effects of self-regulation method (SRM), a newly developed method of self-control, using EEG frequency analysis and contingent negative variations (CNV). The results of the EEG frequency analysis showed that there is a significant increase in the percentage (power) of the theta-band and a significant decrease in the percentage (power) of the beta-band during SRM. Moreover, the results of an identical experiment conducted on subjects in a drowsy state showed that the changes in EEG frequencies during SRM can be differentiated from those of a drowsy state. Furthermore, experiments using CNV showed that there is a significant reduction of CNV amplitude during SRM. Despite the reduced amplitude during SRM, the number of errors in a task to evoke the CNV was reduced significantly without significant delay of reaction time. When an identical experiment was conducted in a drowsy state, CNV amplitude was reduced significantly, but reaction time and errors increased. From these experiments, the state of vigilance during SRM was discussed as a state of 'relaxed alertness'.