Feeling Touched: Emotional Modulation of Somatosensory Potentials to Interpersonal Touch

Although the previous studies have shown that an emotional context may alter touch processing, it is not clear how visual contextual information modulates the sensory signals, and at what levels does this modulation take place. Therefore, we investigated how a toucher’s emotional expressions (anger, happiness, fear, and sadness) modulate touchee’s somatosensory-evoked potentials (SEPs) in different temporal ranges. Participants were presented with tactile stimulation appearing to originate from expressive characters in virtual reality. Touch processing was indexed using SEPs, and self-reports of touch experience were collected. Early potentials were found to be amplified after angry, happy and sad facial expressions, while late potentials were amplified after anger but attenuated after happiness. These effects were related to two stages of emotional modulation of tactile perception: anticipation and interpretation. The findings show that not only does touch affect emotion, but also emotional expressions affect touch perception. The affective modulation of touch was initially obtained as early as 25 ms after the touch onset suggesting that emotional context is integrated to the tactile sensation at a very early stage.

Twenty-three generations of mice bidirectionally selected for open-field thigmotaxis: Selection response and repeated exposure to the open field

We examined: (a) the response to bidirectional selection for open-field (OF) thigmotaxis in mice for 23 generations and (b) the effects of repeated exposure (during 5 days) on different OF behaviors in the selectively bred high OF thigmotaxis (HOFT) and low OF thigmotaxis (LOFT) mice. A total of 2049 mice were used in the study. Prior to the testing in the selection experiment, the mice were exposed to the OF apparatus for approximately 2 min on each of 4 consecutive days. Thus, the selection was based on the scores registered on the 5th day after the four habituation periods. The HOFT mice were more thigmotactic than the LOFT mice in almost each generation. The HOFT mice also tended to rear less than the LOFT mice, which was explained by the inverse relationship between emotionality and exploratory tendencies. The lines did not generally differ in ambulation. Sex differences were found in thigmotaxis, ambulation, and rearing. In the repeated exposure experiment, the development of nine different OF behaviors across the 5 days of testing was addressed. Both lines ambulated, explored, and reared most on the 1st, 4th, and 5th days. Grooming and radial latency decreased and thigmotaxis increased linearly across the testing days. Line differences were found in ambulation, exploration, grooming, and rearing, while sex differences were manifested in ambulation and exploration. The line difference in thigmotaxis was evident only on the 5th day. Temporal changes were partially at variance with the general assumptions. OF thigmotaxis was found to be a powerful characteristic for producing two diverging lines of mice.

Perceived difficult temperament, hostile maternal child-rearing attitudes and insulin resistance syndrome precursors among children: a 3-year follow-up study

BACKGROUND

We prospectively examined the relationship between latent constructs of perceived difficult temperament and hostile maternal child-rearing attitudes on the one hand, and the cluster of multiple cardiovascular risk factors comprising the insulin resistance syndrome (IRS) on the other.

METHODS

A 3-year follow-up study of 451 randomly selected healthy children was used. The temperament of the children and maternal child-rearing attitudes were self-rated by the mothers. The physiological parameters measured were serum insulin, high-density lipoprotein cholesterol (HDL-C), triglycerides, systolic blood pressure, body-mass index and subscapular skinfold thickness. We analyzed the data using structural equation models that involved specific paths allowing separation, and tests of both unique and common (latent) aspects of measured variables.

RESULTS

Among boys we found a cross-lagged effect between the latent constructs of perceived difficult temperament and IRS, as well as 1 specific effect from hostile maternal child-rearing attitudes to HDL-C. Among girls there were 6 specific effects from specific measures of perceived temperamental difficultness or hostile maternal child-rearing attitudes that influenced the IRS or its components.

CONCLUSIONS

The findings suggest that temperament and maternal child-rearing attitudes may contribute to the early development of the IRS in a gender-specific way among children, thereby potentially increasing the risk of coronary heart disease later in life.

Cloninger's temperament and character dimensions in young adulthood and their relation to characteristics of parental alcohol use and smoking

OBJECTIVE

We examined the relationship of parental alcohol use (i.e., the frequency of alcohol intake and getting drunk) and smoking to Cloninger's temperament dimensions (Novelty Seeking, Harm Avoidance, Reward Dependence and Persistence) and character dimensions (Self-Directedness, Cooperativeness and Self-Transcendence) in young adulthood.

METHOD

We used a 14-year longitudinal study of 1,849 (1,101 female) randomly selected healthy adolescents and young adults, and their parents. Alcohol consumption and smoking were self-reported by the parents. Offspring temperament and character were measured by the Temperament and Character Inventory (TCI) 14 years later.

RESULTS

Maternal and paternal frequency of alcohol intake, getting drunk and smoking were associated with offspring temperament and character dimensions, particularly Novelty Seeking, in young adulthood for both men and women.

CONCLUSIONS

The results support the relevance of Cloninger's concepts and the TCI in identifying subjects with unique characteristics related to their family histories. Possible mediating mechanisms are discussed.

A comparison of different time series techniques to analyze phasic coupling: a case study of cardiac and electrodermal activity

This study examined the efficiency of different time series analysis techniques to extract information on the coupling of spontaneous phasic physiological responses. We compared four bivariate approaches, cross-spectral, cross-covariance, cross-covariance with prewhitening, and dynamic factor analysis, in their ability to yield unbiased estimates of (a) shared variance, (b) covariance, (c) strength of relationship, and (d) interchannel time-lag in empirical and simulated interbeat interval-electrodermal activity (IBI-EDA) time series. All methods produced similar estimates of the grand-averaged IBI-EDA dynamics, but only the measures of covariance produced reliable and unbiased estimates of the interindividual distribution of IBI-EDA coupling. We conclude that the extraction of phasic response patterns during continuous and unrestricted experimental situations may considerably facilitate psychophysiological research.

Relationships between hostility and physiological coronary heart disease risk factors in young adults: the moderating influence of depressive tendencies

BACKGROUND

We examined whether the relationships between hostility and physiological coronary heart disease (CHD) risk factors differ as a function of depressive tendencies (DT).

METHODS

The participants were 672 randomly selected healthy young adults who self-reported their hostility (anger, cynicism, and paranoia) and DT. The physiological CHD risk factors studied were systolic blood pressure, diastolic blood pressure, body-mass index, serum high-density lipoprotein cholesterol, serum low-density lipoprotein cholesterol and serum triglycerides.

RESULTS

We found that hostility was negatively associated with the physiological CHD risk factors among individuals exhibiting high DT while hostility was positively associated with, or unrelated to, the physiological risk factors among individuals showing low DT. The Hostility x DT interaction explained 2 to 5 % of the variance in the physiological parameters.

CONCLUSION

The findings suggest that DT have a moderating influence on the relationships between hostility and CHD risk. Despite the established risk factor status of hostility, lack of anger and hostility, when combined with high DT, may represent the most severe exhaustion where the individual has given up. Disregard of this fact may explain some null findings in the research on hostility and CHD risk.

The relationship of respiratory sinus arrhythmia to the co-activation of autonomic and facial responses during the Rorschach test

We studied the relationship of respiratory sinus arrhythmia (RSA) to the co-activation of autonomic and facial expressive responses in 37 adult men during Rorschach testing. Interbeat interval (IBI), electrodermal activity, and facial electromyography were recorded continuously during the experiment. Prevailing mood and variability in the experience of valence and arousal were also measured. Bivariate intraindividual time series analysis was used to quantify spontaneously coupled phasic physiological responses. The results suggested that (a) spontaneous autonomic and expressive responses tend to parallel in time; (b) baseline, task-level, and task-induced change of RSA were positively related to coupled autonomic-expressive responses, a change in mood toward a more energetic state, and a tendency to have more variability in the emotional experience during the task; and (c) especially cardiac-expressive response coupling was related to mood change. It is concluded that the vagal system is related to the control of facial muscle activity and may mediate both tonic and phasic emotion-related changes in IBI. The role of phasic intraindividual response patterns in emotional and social behavior is highlighted.

Inhibited and disinhibited temperament and autonomic stress reactivity

We examined the relationship of temperament dimensions serving as markers for Gray's behavioral activation system (BAS) and behavioral inhibition system (BIS) with autonomic stress reactivity in 35 middle-aged men. Temperament was measured using the Strelau Temperament Inventory--Revised. Skin conductance responses and inter-beat interval were measured during administration of the Rorschach test. The results showed that temperamental activation was positively related to the task-level of and task-induced change in respiratory sinus arrhythmia (RSA) amplitude, but unrelated to heart rate (HR) reactivity. Temperamental inhibition was negatively associated with the task-level of electrodermal activity and task-induced change in RSA amplitude, and positively associated with HR reactivity. The findings are in part contrary to the hypotheses presented in the literature. They also suggest that the temperamental inhibition-HR reactivity relationship is mediated by the parasympathetic nervous system.

Identifying Cloninger's temperament profiles as related to the early development of the metabolic cardiovascular syndrome in young men

Our aim in this study was to (1) identify naturally occurring temperament profiles in young adulthood by using Cloninger's temperament dimensions and (2) examine the relationship of these profiles with the coronary heart disease (CHD) risk factors of the metabolic cardiovascular syndrome (insulin resistance syndrome, IRS) measured during adolescence and young adulthood. A randomly selected sample of 190 healthy, young adult men was divided into 4 temperament groups by cluster analysis. Physiological parameters studied were serum insulin, high density lipoprotein cholesterol, triglycerides, systolic blood pressure, body-mass index, subscapular skinfold thickness, and the IRS factor. The results showed that a temperament profile characterized by a high level of persistence and reward dependence, an average level of novelty seeking, and a low level of harm avoidance was related to a high level of physiological CHD risk factors; in 3 study phases over a 6-year period, the subjects belonging to that cluster in adulthood were shown to have always belonged to the highest risk group in terms of the physiological risk factors in adolescence and young adulthood. The findings suggest that the temperament profile in question may predispose an individual to the development of the IRS and CHD.

Relationships between the pituitary-adrenal hormones, insulin, and glucose in middle-aged men: moderating influence of psychosocial stress

We examined whether the relationships between the pituitary-adrenal hormones (corticotropin [ACTH) and cortisol), insulin, and glucose differ as a function of psychosocial stress defined in terms of vital exhaustion (VE) and depressive behavior (DB). The participants were 69 normotensive and 21 unmedicated borderline hypertensive (BH) middle-aged men whose work is stressful. Hormonal and metabolic variables were measured during an oral glucose tolerance test (OGTT), and the cortisol response to dexamethasone (DXM) suppression and intravenous ACTH stimulation was also measured. We found that the basal ACTH level during the OGTT was positively associated with the cortisol response to ACTH at 60 minutes, the fasting insulin level, and the insulin to glucose ratio among exhausted and high DB men, while the reverse was true for nonexhausted and low DB men. Also, a high cortisol response to ACTH, a low cortisol level during the OGTT, and a high ratio of these cortisol determinations (cortisol ratio) were associated with high fasting insulin and glucose levels, the summed insulin values, and the insulin to glucose ratio only among nonexhausted and low DB men; among exhausted and high DB men, these associations were less pronounced, absent, or in the opposite direction. The findings suggest that VE and DB have a moderating influence on the relationships among the hormonal and metabolic parameters studied. Psychosocial stress may affect the pituitary-adrenocortical system in complex ways, contributing thereby to insulin resistance, hyperinsulinemia, and coronary heart disease (CHD) risk.

Perceived social support and abdominal fat distribution in adolescents and young adults: a structural equation analysis of prospective data

We prospectively examined the relationship between perceived social support and abdominal fat distribution. A 3-year follow-up study of 235 randomly selected healthy adolescents and young adults was used. Abdominal fat distribution was measured by means of the waist to hip circumference ratio (WHR), and social support was measured by the Perceived Social Support Scale-Revised. Data were analysed using structural equation models. Changes in social support were inversely associated with changes in WHR, adjusted for body-mass index, among boys and men. This association was less evident among girls and women. The relationship of social support with WHR was independent of depression and hostility. The findings suggest that social support may protect against abdominal fat accumulation, thereby potentially decreasing the risk of coronary heart disease later in life.

The synchronization of electrodermal activity and heart rate and its relationship to energetic arousal: a time series approach

We examined the synchronization between indices of autonomic nervous system (ANS) function and its relation to multiple measures of arousal in 37 middle-aged men. Electrodermal activity (EDA), heart rate (HR), and subjective and behavioral arousal were measured during administration of the Rorschach test. Prevailing mood and depression were also measured. The relationship between phasic EDA and HR activity was assessed by constructing within-subjects time series models. The results showed that phasic EDA and HR accelerations were synchronized, while there was no association between tonic EDA and HR in between-subjects analysis. In addition, EDA-HR synchronization was positively associated with verbal activity, variability of arousal experience, and activation mood, and negatively associated with depression. It is suggested that within-subjects analysis of physiological time series data can further our understanding of the individual differences in ANS function and on the correlates of effector organ synchronization.

Apolipoprotein E phenotypes and cardiovascular responses to experimentally induced mental stress in adolescent boys

We investigated the relationship between apolipoprotein E (apoE) polymorphism and cardiovascular responses to experimentally induced mental stress. Mental stress was induced in 28 healthy 16-year-old boys with a series of stressors (e.g., mental arithmetic, Stroop Color-Word Interference Test). Heart rate (HR), finger blood volume, and skin conductance level were recorded continuously during the task performance. We found that boys with apoE3/2 or apoE3/3 showed marginally significantly greater HR reactivity and significantly greater task levels of HR and HR variability (HRV) during the mental stress than subjects with apoE4/2, apoE4/3, or apoE4/4. In addition, E4/2, E4/3, and E4/4 subjects manifested a distinct stress-related decrease in HRV relative to baseline values while E3/2 and E3/3 subjects showed a slight increase. The results suggests that apoE polymorphism is associated with cardiovascular responsivity to mental stress in adolescent boys.

Life changes, locus of control and metabolic syndrome precursors in adolescents and young adults: a three-year follow-up

The relations between life changes, locus of control and changes in the parameters of the metabolic syndrome were examined. A three-year follow-up study of 671 randomly selected, healthy adolescents and young adults was used. Somatic parameters measured both at the baseline and the follow-up were serum insulin, serum HDL chol, serum triglyceride, SBP and BMI. Locus of control was measured with the Nowicki-Strickland locus of control scale and subjects were asked about life changes that they had faced during the follow-up period. Results showed that, in women, there were significant main effects for life changes in predicting (high) somatic risk level, whereas, in men, an opposite association was found. In addition, locus of control had a moderating effect on the life change-metabolic parameters relation, i.e. most of the life changes predicted a lower level of somatic risk in subjects with an external rather than internal locus of control. Results question the universal applicability of beneficial health effects of internal locus of control. It was suggested that accumulation of life changes might contribute, in interaction with locus of control, to the early development of the metabolic syndrome.

Insulin resistance syndrome and autonomically mediated physiological responses to experimentally induced mental stress in adolescent boys

We investigated the relationship between hemodynamic and other autonomically mediated responses to experimentally induced mental stress and the parameters of the insulin resistance syndrome (IRS) in 48 healthy adolescent boys. Mental stress was induced with mental arithmetic and the Stroop Color-Word Test. Heart rate (HR), finger blood volume (FBV), and skin conductance level (SCL) were recorded continuously during task performance. IRS parameters measured were serum insulin, high-density lipoprotein (HDL) cholesterol, serum triglyceride (TG), systolic blood pressure (SBP), subscapular skinfold (SSF), and subscapular to triceps skinfold ratio (STR). The results indicated that a high level and an increasing linear trend of HR and FBV during task performance were related, independently of each other and of body mass index (BMI), to a high insulin concentration. An increasing linear trend of HR during mental stress was also related to high SSFs independently of MI. In addition, a high SCL during task performance was associated with high TG levels, SSFs, and STRs. It is discussed whether stress-induced sympathetic overactivity might contribute to the development of the IRS.

Type A behavior and metabolic syndrome precursors in young adults

The association between type A behavior and a cluster of parameters of the metabolic syndrome was studied in 919 randomly selected healthy young adults. Type A behavior was measured using the Type A Behavior Questionnaire for the Finnish Multicenter Study and the Hunter Wolf A-B Rating Scale. The results showed that type A men scored higher on the "Metabolic Syndrome Precursors Factor," representing a metabolic entity, than did non-type A men. In addition, type A behavior had a moderating effect on the relationship between parameters of the metabolic syndrome, that is, interdependence of these somatic factors was stronger in type A men than in non-type A men. These findings were not true of women. It is discussed whether type A behavior might affect bodily functions through increased activity along the pituitary-adrenal system resulting in insulin resistance, compensatory hyperinsulinemia, and other characteristics of the metabolic syndrome.

Type A factors as predictors of changes in the metabolic syndrome precursors in adolescents and young adults--a 3-year follow-up study

The predictive associations of Type A factors with changes in some essential parameters of the cluster of disorders known as metabolic syndrome (Syndrome X) were studied during a 3-year follow-up period in 1,147 randomly selected healthy adolescents and young adults. Type A behavior was measured with the Hunter Wolf A-B Rating Scale. Physiological parameters studied were serum insulin, high-density and low-density lipoprotein cholesterol, triglycerides (TG), systolic and diastolic blood pressure, body-mass index (BMI), subscapular skinfold thickness (SSF), and centrality index. Among the Type A factors in boys and men, high baseline Aggression predicted an increase in the individual parameters of metabolic syndrome (i.e., insulin, TG, SSF, and BMI) as well as a global aggravation of the cluster of metabolic parameters. In girls and women, increases in Eagerness-Energy and Responsibility across the 3 years of follow-up predicted an increase in serum insulin and a decrease in SSF, respectively.

Temperament and metabolic syndrome precursors in children: a three-year follow-up

BACKGROUND

Cross-sectional and predictive associations between temperament and some essential parameters of the metabolic syndrome were examined in children.

METHODS

A 3-year follow-up study of 1,589 randomly selected, healthy, 6-, 9-, 12-, and 15-year-old children was used. Somatic parameters studied were serum insulin, serum glucose, serum HDL cholesterol, serum triglycerides, systolic blood pressure, and body-mass index. Temperament of the subjects was rated by their mothers using a questionnaire and a semantic differential.

RESULTS

Temperamental factors were related cross-sectionally to, as well as predicted for, the metabolic syndrome precursors over the 3-year period. Mental vitality and positive emotionality were likely to be related and positive emotionality were likely to be related to a low somatic risk level, whereas hyperactivity, negative emotionality (e.g., aggression and anger), responsivity to others, and cooperativeness were related to a high level of somatic risk. These associations were more evident in boys than in girls.

CONCLUSIONS

It was suggested that temperament might be of importance in the early development of the metabolic syndrome.