Psychophysiological individuality: A pattern analytic approach to personality research and psychosomatic medicine

Stress conceptions in life event research: Towards a person‐centred perspective

The present article focuses on a discussion of the theoretical foundations of life event research. Since critical life events are usually regarded as stressful events, the main question is which concepts of stress are employed in different life event approaches and what is their rationale. The discussion centres on two topics that have to be treated independently: the question of specificity vs nonspecificity and the question of individualized vs normative weightings. It is shown that different life event approaches rely on different concepts of stress. Numerous objections lead to a rejection of the nonspecificity concept and a normative proceeding. However, even when a specificity view of stress is advocated and individual weights are used, life stress measures do not account for a substantial proportion of the variance in the stress‐related dependent variables. Therefore, a reorientation of life event research is required. It is proposed that future life event research should concentrate on the individual meaning of events and adequately consider the time dimension as well CIS processes of coping.

Panic and comorbid depression and their associations with stress reactivity, interoceptive awareness and interoceptive accuracy of various bioparameters

BACKGROUND

While current theories on perception of interoceptive signals suggest impaired interoceptive processing in psychiatric disorders such as panic disorder or depression, heart-rate (HR) interoceptive accuracy (IAc) of panic patients under resting conditions is superior to that of healthy controls. Thus, in this study, we chose to assess further physiological parameters and comorbid depression in order to get information on how these potentially conflicting findings are linked together.

DESIGN

We used a quasi-experimental laboratory design which included multi-parametric physiological data collection of 40 panic subjects and 53 matched no-panic controls, as well as experimental induction of stress and relaxation over a time-course.

METHODS

Stress reactivity, interoceptive awareness (IAw; from the Body Perception Questionnaire (BPQ)) and IAc (as correlation between self-estimation and physiological data) were major outcome variables. Self-estimation of bioparametrical change was measured via numeric rating scales.

RESULT

Panic subjects had stronger HR-reaction and more accurate HR-interoception. Concurrently, though, their IAc of skin conductance level, pulse amplitude and breathing amplitude was significantly lower than that of the control group. Interestingly, comorbid depression was found to be associated with increased IAw but attenuated IAc.

LIMITATIONS

Demand characteristics and a categorical approach to panic confine the results.

CONCLUSION

The potentially conflicting findings coalesce, as panic was associated with an increase of the ability to perceive the fear-related parameter and a simultaneous decrease of the ability to perceive other parameters. The superordinate integration of afferent signals might be impaired.

Autonomic specificity of basic emotions: evidence from pattern classification and cluster analysis

Autonomic nervous system (ANS) specificity of emotion remains controversial in contemporary emotion research, and has received mixed support over decades of investigation. This study was designed to replicate and extend psychophysiological research, which has used multivariate pattern classification analysis (PCA) in support of ANS specificity. Forty-nine undergraduates (27 women) listened to emotion-inducing music and viewed affective films while a montage of ANS variables, including heart rate variability indices, peripheral vascular activity, systolic time intervals, and electrodermal activity, were recorded. Evidence for ANS discrimination of emotion was found via PCA with 44.6% of overall observations correctly classified into the predicted emotion conditions, using ANS variables (z=16.05, p<.001). Cluster analysis of these data indicated a lack of distinct clusters, which suggests that ANS responses to the stimuli were nomothetic and stimulus-specific rather than idiosyncratic and individual-specific. Collectively these results further confirm and extend support for the notion that basic emotions have distinct ANS signatures.

Waking-state oral parafunctional behaviors: specificity and validity as assessed by electromyography

In contrast to sleep-related oral parafunctional behaviors, little is known about waking oral parafunctional behaviors. The Oral Behaviors Checklist contains terms referring to a variety of non-observable behaviors that are reliable when prompted (e.g. 'clench') but validity data are absent. Our goal was to assess whether (i) each behavioral term is distinct electromyographically, and (ii) temporomandibular disorder (TMD) subjects differ from non-TMD subjects in their performance. Surface electromyographic (EMG) activity was used to measure bilateral masseter, temporalis, and suprahyoid muscles while subjects (27 patients with TMD; 27 healthy controls) performed ten oral behaviors without explanation. Electromyographic data were averaged between bilateral muscles and two trials. A multivariate construct (jaw muscle activity) was analyzed using Wilks lambda within multivariate analysis of variance (manova). Obvious behaviors (e.g. clench, read, tongue press) exhibited expected EMG patterns, and patients and controls produced identical profile plots of the EMG data. Of 10 tested behaviors, nine were found to be associated with significantly differing proportions of amplitudes across muscles and were thus unique. Behaviors with similar terms were associated with different EMG patterns. The present data support the specificity of behavioral terms and performances. Implications include causation related to TMD based on subtle behaviors that occur at a high frequency.

Anger and fear: Separable effects of emotion and motivational direction on somatovisceral responses

We studied whether emotion (anger vs. fear) and motivational direction (approach vs. withdrawal) have specific, separable, and independent somatovisceral response patterns. Imagination scripts about soccer game episodes with crossed Emotion x Motivational Direction content resulting in four experimental groups were presented to a total of N = 118 active soccer players. Self-reports reflected the emotion but not the motivational direction induction. Univariate and multivariate analyses of 24 somatovisceral variables and 2 a priori defined summary variables showed that anger and fear had specific response profiles with effect sizes correlating r = 0.53 with the respective effect sizes from a previous study. Approach and withdrawal profiles varied only in intensity. Emotion and motivational direction did not interact and had independent somatovisceral effects. Results suggest that anger and fear have separate underlying neurobiological organizations each capable of bi-directional motivational tuning of efferent pathways. Results support the Component Model of Somatovisceral Response Organization.

Individual differences in anger and sadness: in pursuit of active situational features and psychological processes

In the cognitive-affective personality system (CAPS) theory of Mischel and Shoda (1995, 1998), personality is conceived as a system of cognitions and affects that mediates between active situational features and behavior. Two major tasks for this approach to personality are the search for active situational features and for mediating psychological processes within a behavioral domain of interest. We report two studies to address these tasks for the domain of anger and sadness. To design these studies and to analyze the obtained data, novel extensions of our previous developed Triple Typology Model (TTM; Vansteelandt & Van Mechelen, 1998) are proposed. These extensions allow the researcher to test hypotheses concerning potentially relevant active situational features in a systematic and confirmatory way and to examine psychological processes as they occur in concrete situations.

Program running versus problem solving: Mental task effect on tonic heart rate

It was hypothesized that mental tasks that involve program running (RUN tasks) would cause a greater tonic heart rate (HR) increase than tasks that require the search for problem solutions (EDIT tasks). Three experiments using verbal, numeric, and graphic material were run to compare tasks matched for difficulty but differing in qualitative demands (RUN vs. EDIT tasks). As predicted, filling in missing letters in words caused a larger HR increase than finding words that were logical continuations of a series of words (Experiment 1) and performing arithmetic operations caused a greater HR increase than logical completion of a series of digits (Experiment 2). In Experiment 3, two of three tasks that demanded counting of graphic elements caused a larger HR increase than a task that required logical completion of a series of graphic elements. Experiments 1 and 2 also showed that RUN tasks evoked greater phasic HR acceleration than EDIT tasks.

Idiodynamic profiles of cardiovascular activity: A P-technique approach

A study was conducted to expand the conventional view of cardiovascular (CV) reactivity by using the idiodynamic paradigm for investigation of individuals. Patterns of autonomic CV regulation were assessed in six subjects across diverse laboratory tasks on three separate occasions. Individual CV profiles were derived from these data with P-technique factor analysis, and then group aggregated with chain P-technique. The composite pattern suggested a three-component solution consisting of cardiac rate, cardiac contractility, and peripheral resistance factors. Individual profiles were compared to the composite pattern; these profiles differed in the number of components derived, percentage variance explained by these components, and relative dominance of specific CV components. A hypothesis that emerged is that the subjects differed in the complexity of CV control. It appears that the idiodynamic framework, combined with novel research designs and statistical methods, may help expand the view of CV reactivity beyond the traditional unitary view as response magnitude.

Response Specificity in Psychophysiology

Abstract In the field of response specificity, we are faced with a great diversity of specificity measures and definitions which make it difficult to compare the results presented in the literature. The objective of this paper is to assess different specificity calculations (individual, situational, and motivational response specificity) and to elucidate the underlying meaning of those measures which are based on correlations and on specific sources of variance. It will be shown that an approach on the basis of variance components is suitable to elucidate different specificity measures. The main advantage of this approach is that it explicitly describes the frame of reference of the specificity measures and that it clarifies the relationships between specificity, consistency, and covariation. An empirical investigation is presented which demonstrates the application of the approach and which gives an idea of the magnitude of the differences between the specificity measures. Special features (averaging procedures, fixed/random factors) are discussed and recommendations for further research are derived.

Psychophysiological stress responses in amputees with and without phantom limb pain

The present experiment tested the hypothesis that phantom limb pain amputees show a different pattern of psychophysiological reactivity to stress compared with painfree amputees. Six phantom limb pain (PLP) and five painfree upper-extremity amputees were administered two groups of tasks: stressful and relaxing. The measured dependent variables were skin temperature recorded at both stump and intact site, heart rate, blood pressure, subjective pain and stress ratings. Phantom limb pain patients were characterized by higher stump temperature compared with phantom limb painfree patients. This effect was observed during the whole recording. Consistently with the between-subjects effect, when PLP patients exhibited higher skin temperature (during relaxation, compared with during stressful tasks), they perceived more pain. The experiment showed higher cardiovascular reactivity in PLP patients, specifically to the stressful free-speech task, which focused on recollection of the amputation event. As compared with the painfree patients, during the personal stressor, PLP patients' heart rate and systolic blood pressure increased, indicating a greater sympathetic response. Results indicate that peripheral factors, such as stump temperature reliably differentiate PLP from painfree patients. Moreover, the clear cardiovascular hyperreactivity observed in PLP patients during their report of amputation suggests that PLP is associated with a long-term emotional memory for the painful experience of that event. These results are consistent with most reports in the literature relating phantom pain development to the experience of preamputation pain.

Stability of cardiovascular responses across subjects and situations: a systematic approach

This study describes the reproducibility of behaviorally elicited cardiovascular response patterns, 111 subjects were studied over a 1-year interval. Physiological variables recorded were heart rate, systolic and diastolic blood pressure, and respiratory rate. Test-retest stability coefficients were calculated and compared with the results of a study with a 3-day interval between test sessions. The physiological data are depicted in a four-dimensional data box (subjects, situations, replications, variables), and the variance components of the factors and their interactions are estimated. Some of the interaction components are associated with specificity principles and with temporal stability. To comprehensively describe special aspects of stability, measures for stability were generated (concerning subjects, situations, or both), adopting basic ideas from the covariance partitioning approach. The stability measures were compared with simple test-retest reliability coefficients and with generalizability coefficients, and systematic relationships between the stability measures are discussed.

The prediction of somatic complaints using the Autonomic Nervous System Response Inventory (ANSRI) and the Daily Stress Inventory (DSI)

Understanding and prediction of veridical somatic complaints not caused by disease, dysfunction, trauma, or toxin, requires the assessment of at least two critical variables: predisposition to respond to stressors with peripheral physiological activation; and intensity/frequency/duration of stressors. The Autonomic Nervous System Response Inventory (ANSRI) and the Daily Stress Inventory (DSI) were used to assess these variables, and somatic complaints were recorded using the Wahler Physical Symptoms Inventory (WPSI). Subjects were 72 healthy undergraduates who completed the inventories and reported illness and medication usage over a 2 week period. Regression analyses showed that ANSRI, DSI, illness, and medication accounted for 35% of the variance in somatic complaints, though only ANSRI and DSI contributed significantly. Neuroticism (Eysenck Personality Questionnaire) did not add to R2, but did influence stressors' subjective impact. The correlation between regression equation-generated WPSI scores (derivation sample) and actual WPSI scores (holdout sample) was 0.59. A discriminant function analysis equation (derivation sample) applied to the holdout sample correctly classified 80% of the upper and lower third WPSI subjects. It was concluded that the ANSRI and DSI, and the variables they assess, are substantially related to the self-report of somatic complaints.

Invited review. The links between stress and illness

Evidence relating stress with illness has emerged from a variety of experimental, clinical and epidemiological research strategies. Psychobiological stress responses emerge through an imbalance between demands and psychosocial resources, and many factors relevant to this transaction have been identified, including the chronicity and predictability of stimulation, opportunities for control, psychological coping responses and the availability of social supports. By contrast, the mechanisms through which stress responses may increase risk of illness are poorly understood, and investigators are frequently obliged to fall back upon a poorly defined 'biological predisposition' to account for individual differences in susceptibility to disease or variations in clinical course. It is argued in this review that several distinct cognitive-behavioural and psychophysiological mediating processes may be postulated, and that these are relevant to different types of influence on health (acute and chronic effects, causal and facilitatory processes, impact on aetiology, maintenance, relapse or recurrence). It is through the recognition and identification of separate processes that questions concerning the specificity of illness outcome, personal resilience, the limits of the impact of psychosocial factors, and the appropriate forms of therapeutic intervention, may be resolved.

What do arithmetic stress tests measure? Protocol variations and cardiovascular responses

Three studies tested the effects of the following design/protocol variations in mental arithmetic: 1) Order of task, 2) vocal versus written delivery of responses, 3) effects of different types of superimposed noise distractors, and 4) varying types of mental arithmetic challenges. All studies used the same basic protocol with 20-min adaptation, 5-min task, and 3-min recovery periods; dependent cardiovascular variables were systolic and diastolic blood pressure and heart rate; in Study 2 respiration rate and respiratory amplitude were also assessed. Findings showed that vocal delivery enhanced subjective distress, lowered performance, and enhanced diastolic blood pressure responses. Noise distraction augmented distress but did not affect task performance. Variable noise distraction augmented systolic blood pressure and heart rate responses but only when math equations were presented on a video screen. Autonomic response adaptation was apparent from first to second tasks but not thereafter. The built-in replications strengthened these findings.

The autonomic differentiation of emotions revisited: convergent and discriminant validation

The convergent and discriminant validity of three models of physiological emotion specificity were compared. Forty-two female students served as subjects in a 2 (Context of emotional inductions: real-life, imagery) X 3 (Emotion: fear, anger, control) +1 (Happiness induced in real-life context) repeated measures design. The dependent measures included self-reports of emotion, Gottschalk-Gleser affect scores, back and forearm extensor EMG activity, body movements, heart period, respiration period, skin conductance, skin temperatures, pulse transit time, pulse volume amplitude, and blood volumes. Self-report data confirmed the generation of affective states in both contexts, as intended. Planned multivariate comparisons between physiological profiles established discriminant validity for fear and anger in the real-life context, whereas under imagery, emotion profiles were essentially equal. Convergent validity could not be substantiated. Implications for models of physiological specificity of emotion were discussed.

Synchrony and desynchrony in high and low arousal subjects undergoing therapeutic exposure

A comparison of synchrony and desynchrony was made among phobic patients exposed to imaginal flooding under conditions of high and low arousal, respectively. Subjective anxiety (SUDs) and skin conductance (SC) were recorded at five minute intervals during three separate sessions. Results showed some degree of synchrony (small positive relationship) between the two measures for the high arousal group and desynchrony (no relationship) between these measures for the low arousal group. However, with the exception of two cases, one from each group, the findings were by no means clear-cut, suggesting that other factors besides level of arousal may be responsible for individual differences in synchrony.