Heart Rate and Respiratory Responses as a Function of Task Difficulty: The Use of Discriminant Analysis in the Selection of Psychologically Sensitive Physiological Responses

The relationship between physiological response patterns.and task difficulty was investigated by evaluating heart rate and respiratory responses during a choice reaction lime tusk with three levels of task difficulty. The data fit a two-component model or attention containing reactive and sustained responses. There were two reactive responses: An immediate deceleration which was independent of task manipulation; and a short latency response, monotonically paralleling task difficulty, which was characterized by acceleration and an increase in heart rate variability. The sustained component exhibited task dependent deceleration and u generalized reduction in heart rate variability and respiration amplitude variability. A stepwise discriminant analysis was performed on the task conditions using physiological responses to determine responses sensitive to task demands. Physiological response patterns were monotonically ordered as a function of task difficulty, suggesting that this technique may have advantages for determining physiological responses most sensitive to psychological manipulation.     

Conspecific screams and laughter: cardiac and behavioral reactions of infant chimpanzees

The present study examined cardiac and behavioral reactions of infant chimpanzees to white noise and to conspecific screams and laughter. Chimpanzee screams evoked typical deceleratory cardiac orienting responses. Analysis of stimulus-evoked changes in respiratory sinus arrhythmia suggested that this cardiac deceleration arose from an increase in parasympathetic activity. In contrast, chimpanzee laughter evoked notable cardiac acceleration. Laughter also evoked vocalizations from the infant subjects, which were reminiscent of adult threat-barks. Analysis of respiratory sinus arrhythmia suggested that the cardioacceleratory response likely resulted from sympathetic activation, and was not associated with an inhibition of parasympathetic activity. The autonomic and vocal responses to laughter emerged early in development, were minimally dependent on social contact with adults, and declined in magnitude with increasing age. A consideration of the phylogeny of laughter raised the possibility that the functional reaction to this vocalization may be related to its origin in more primitive agonistic facio-vocal signals.     

Common and differential brain responses in men and women to nonverbal emotional vocalizations by the same and opposite sex

Nonverbal emotional vocalizations are one of the most elementary ways of communicating in humans. We examined the impact of sex differences on neural responses to laughter and crying produced by the same and opposite sex. Thirty subjects (15 women) underwent functional magnetic resonance imaging during a sex identification task for laughter, crying, and neutral voices. The parahippocampal gyrus was involved in both men and women while hearing laughter of the same sex, suggesting greater positive emotional processing and greater attention toward emotional context in response to laughter of the same sex than of the opposite sex. The posterior cingulate was involved in both men and women while hearing crying of the opposite sex, suggesting that empathic processing may occur more in response to crying of the opposite sex than of the same sex. Furthermore, brain responses to crying of the opposite sex seem to reflect upon men's efforts to perform emotional regulation and women's empathic concerns.     

Is motor inhibition during laughter due to emotional or respiratory influences?

We compared the effects of laughter and several respiratory movements on spinal motor excitability to unravel their respective influences. We measured H-reflexes in 13 healthy volunteers during 10 different tasks (including laughter, simulated laughter, and various respiratory movements). We compared the percentage that remained of the initial H-reflex during each task with that during a neutral task. H-reflex percentage differed between the neutral task (79.4 +/- 16.1%), true laughter (43.7 +/- 17.9%), and simulated laughter (66.6 +/- 24.3%), and between the two latter tasks. Coughing also resulted in H-reflex suppression, but not as deeply as true laughter. During the other respiratory maneuvers, the H-reflex increased compared to the neutral task. Our finding that true laughter evoked more H-reflex depression than simulated laughter suggests that mirth on its own depresses the H-reflex. This mechanism may also be involved in the pathophysiology of cataplexy, the main symptom of narcolepsy.     

Respiratory pattern modulation by the pedunculopontine tegmental nucleus

This study demonstrates respiratory modulation caused by stimulation of the pedunculopontine tegmental nucleus (PPT), a structure not classically included in the pontine respiratory neuronal network. The long-lasting increase in variability of respiratory parameters following glutamate microinjection into PPT in anesthetized, spontaneously breathing Sprague Dawley rats was more pronounced under ketamine than nembutal anesthesia. The induced respiratory perturbations were characterized by intermittent apneas and increased variability of expiratory (TE) and total (TT) breath durations in all animals. Although the baseline spontaneous breathing patterns (mean values of all respiratory parameters and their variabilities) were equivalent under ketamine and nembutal anesthesia, different anesthetic agents did affect respiratory responses to PPT stimulation by glutamate in terms of latency, duration, and structure. We conclude that glutamatergic stimulation of PPT has a significant impact on the brainstem respiratory pattern generator.     

Respiratory Sinus Arrhythmia Predicts Heart Rate and Visual Responses during Visual Attention in 14 and 20 Week Old Infants

The prediction of cardiac attentional responses by respiratory sinus arrhythmia was tested in infants at 14 and at 20 weeks of age. Heart rate, heart rate variability, and respiratory sinus arrhythmia were measured in a 5-min baseline period. Respiration and heart rate responses were recorded during the habituation of infant visual attention. The level of respiratory sinus arrhythmia in the baseline was significantly correlated with the cardiac deceleration, especially in the 20-week-old infants. The relationship between cardiac and respiratory responses during attention was stronger in the 20-week-olds, paralleling the increase in respiratory sinus arrhythmia at this age. Visual fixation durations were also significantly correlated with measures of heart rate variability from the baseline. These results imply that cardiac variability not only predicts the level of cardiac attentional responsivity, but may be useful in the indexing of individual differences in the responsivity of more general attentional systems.     

The Development of Sustained Visual Attention in Infants from 14 to 26 Weeks of Age

The development of sustained visual attention was examined in infants cross-sectionally at 14, 20, and 26 weeks of age. Heart rate, heart rate variability, and respiratory sinus arrhythmia were measured in a 5-min baseline period. Two methods for measuring visual attention were used. The “infant control” method consisted of checkerboard presentations which were terminated when the infant looked away from them. The “interrupted stimulus” method consisted of a blinking panel in addition to the checkerboard patterns in order to attempt to actively terminate the fixation. The visual and cardiac responses during the interrupted stimulus method were more highly correlated with baseline respiratory sinus arrhythmia than were the responses during the infant control trials. The long latency heart rate responses during the interrupted stimulus trials showed a developmental change toward more mature response patterns from 14 to 26 weeks of age. It may be concluded that: 1) sustained attention, measured with the interrupted stimulus method, increases from 14 to 26 weeks of age; and 2) baseline respiratory sinus arrhythmia is correlated with sustained attention responses and their development.     

Laughter as a social rejection cue: Gelotophobia and transient cardiac responses to other persons' laughter and insult

Other persons' laughter, normally perceived as a signal that persons are friendly and inviting others to approach, can also be perceived as a cue of social rejection. In this study, prerecorded laughter was placed in a realistic and personally relevant context, and participants' responses were related to gelotophobia, a trait predisposing to perceiving laughter as a cue of social rejection. Individuals with gelotophobia showed marked heart rate deceleration in response to the laughter stimulus, possibly indicating a “freezing‐like” response. Moreover, cardiac responses to anger provocation by overtly insulting statements indicated heightened aggressive anger in response to cumulated social threat. The study adds to recent research showing specific cardiac responses to social rejection and to the literature on social rejection sensitivity by demonstrating the value of using well interpretable physiological measures in this research context.     

Patterns of laryngeal electromyography and the activity of the respiratory system during spontaneous laughter

Laryngeal muscle electromyography (EMG) and measures of the behavior of the respiratory system have been made during spontaneous laughter in two groups of subjects. The smaller group also had a direct measure of tracheal pressure during this behavior. Laryngeal adductors such as the thyroarytenoid (TA) and lateral cricoarytenoid (LCA) exhibited brief high-amplitude bursts of activity, at a rate of approximately 5 Hz, which were usually associated on a 1 : 1 basis with the sound bursts (ha ha ha) of laughter. The laryngeal abductor, posterior cricoarytenoid (PCA), also showed bursts of activity that were out of phase with TA and LCA. The cricothyroid (CT) was only weakly, if at all, modulated during the bursting activity of the other laryngeal muscles. Tracheal pressure usually exhibited positive pressure pulses during laughter that were often, but not always, temporally correlated to the bursts of laryngeal adductor EMG activity. Such pressure modulations appeared to precisely determine when-and if-phonation was produced during the laugh. During laughter, laryngeal EMG is highly stereotyped both within and between subjects. In most instances, this activity appears to be supported by coordinated pulses of tracheal pressure. The periaqueductal gray (PAG) has been shown in animal studies to produce emotionally indicative vocalizations, in which the laryngeal and respiratory system are coordinated. Therefore, it is suggested that the PAG is involved with the production of laughter.     

The ontogeny of heart period patterning in the rat

Heart period, heart period variability, and respiration frequency were observed and compared longitudinally in rats from birth to 24 days of age. In addition, V, a quantification of respiratory sinus arrhythmia derived via spectral analysis of the heart period pattern, was observed. It was hypothesized that these heart period parameters would be differentially sensitive to the neural control of the heart and would, therefore, reflect different developmental patterns. Heart period and heart period variability indicated developmental patterns consistent with the literature. The ontogeny of V suggests that it may represent the developmental pattern of tonic vagal influences on the heart.     

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.     

The effect of public self-consciousness on forced laughter

The purpose of this study was to investigate the effect of public self-consciousness on forced laughter. Participants (N = 409) were asked to imagine a group of either friends or acquaintances, and then to indicate how often he or she exhibited forced laughter toward the group members. They also completed Self-Consciousness Scale (Fenigstein, Scheier, & Buss, 1975). Results indicated that persons with high public self-consciousness reported more frequent expressions of all types of forced laughter--expression control, intimacy maintenance, action control, and affect manipulation--than those who were low, regardless of interpersonal intimacy level. Besides public self-consciousness, both gender and intimate feeling toward group members influenced frequency of forced laughter. Implications for the nature of public self-consciousness and forced laughter were discussed.     

Fetal responses to induced maternal relaxation during pregnancy

Fetal responses to induced maternal relaxation during the 32nd week of pregnancy were recorded in 100 maternal-fetal pairs using a digitized data collection system. The 18-min guided imagery relaxation manipulation generated significant changes in maternal heart rate, skin conductance, respiration period, and respiratory sinus arrhythmia. Significant alterations in fetal neurobehavior were observed, including decreased fetal heart rate (FHR), increased FHR variability, suppression of fetal motor activity (FM), and increased FM-FHR coupling. Attribution of the two fetal cardiac responses to the guided imagery procedure itself, as opposed to simple rest or recumbency, is tempered by the observed pattern of response. Evaluation of correspondence between changes within individual maternal-fetal pairs revealed significant associations between maternal autonomic measures and fetal cardiac patterns, lower umbilical and uterine artery resistance and increased FHR variability, and declining salivary cortisol and FM activity. Potential mechanisms that may mediate the observed results are discussed.     

The physiological and psychological effects of the expression and inhibition of emotion

Previous work has indicated that humor enhances immunity, but the immunological effects of overt crying have not been studied. Thirty-nine women viewed sad and humorous videotapes and either inhibited or expressed overt expressions of laughter and weeping; these were observed and timed. Moods and immunity (S-IgA) were repeatedly measured. The humorous stimulus resulted in improved immunity, regardless of the overt laughter expressed; overt crying was immunosuppressive, whereas the inhibition of weeping in the context of the same sad stimulus was not. Moods were more negative following the sad stimulus and in the expression condition. The results with respect to humor are consistent with previous research; the immunosuppressive effect of overt crying is discussed in the context of various types of crying that may have different effects.     

Respiratory-phase-related coding of olfactory information in the olfactory bulb of awake freely-breathing rabbits

The "across-neuron pattern" theory of olfactory information coding states that odorants are represented by spatial patterns of activity produced across-neurons in the olfactory bulbs. The present study analyzes the different response patterns encoding olfactory information in both the inspiratory and expiratory phases of the respiratory cycles of awake freely-breathing rabbits. We recorded the single-unit responses of 31 neurons to 5 different odorants, 3 of which were repeatedly delivered 5 times each. These responses were characterized by the change in their mean firing activity during the inspiratory and expiratory phases of the respiratory cycles respectively. Their processing using principal component analyses revealed that both the inspiration- and the expiration-related across-neuron profiles of responses contained information appropriate to the specification of each odorant. It was therefore concluded that there was a dynamic representation of odorants in the olfactory bulb of awake freely-breathing animals. This alternate representation of odorants by two profiles and its physiological significance are discussed.     

Development and Stability in Visual Sustained Attention in 14, 20, and 26 Week Old Infants

Infants were studied at 14, 20, and 26 weeks of age in a longitudinal design. They were presented with varying and complex patterns on a TV screen. Two-thirds of the presentations were accompanied by a stimulus in the periphery delayed in time from the onset of fixation on the central stimulus. As in previous research, the infants were not as easily distracted by the interrupting stimulus when the presentation occurred at the point of maximal heart rate deceleration as when the presentation occurred at the end of the heart rate response. Infants with large amounts of respiratory sinus arrhythmia (i.e., heart rate variability) in a baseline recording were less distractible during the deceleration-defined trials than were infants with low amounts of respiratory sinus arrhythmia. Intra-individual patterns of development in respiratory sinus arrhythmia over the testing ages were closely paralleled by patterns of heart rate responding during sustained attention. Individual differences in baseline levels of heart rate and respiratory sinus arrhythmia were more stable than individual differences in sustained attention. The stability of attention responses over age may be mediated by the stability of the physiological system (e.g., heart rate, respiratory sinus arrhythmia, etc.), and by the within-age relation of attention to heart rate variability.     

Laughter up-regulates the genes related to NK cell activity in diabetes

To elucidate the sustainable effects of laughter on gene expression, we recruited type 2 diabetic patients who were in-patient for receiving self-management education and examined time-dependent regulation for gene expression by laughter. Two-day experiment was performed. On one day, the patients watched comic video and laughed together with hospital staffs. On the other day, they participated in an inpatient diabetes educational program. Blood samples were collected before and 1.5, 4 h after watching comic video or spending lecture time, and changes in gene expression were comprehensively analyzed by microarray technique. Of the 41,000 genes analyzed, the laughter relatively up-regulated 39 genes, among which, 27 genes were relatively increased in the expression for all the observation period after watching comic video. By functional classification of these genes, 14 genes were found to be related to natural killer cell activity. No genes were included that are directly involved in blood glucose regulation, though successive suppression of postprandial blood glucose levels was observed. These results suggest that the laughter influences the expression of many genes classified into immune responses, and may contribute to amelioration of postprandial blood glucose elevation through a modulation of NK cell activity caused by up-regulation of relating genes.     

Anger episodes in high- and low-trait-anger community adults

Anger is a basic emotion, experienced by almost all human beings in response to the unwanted and unexpected behavior of others. Yet, there is little consensus as to which characteristics may differentiate people who experience normal versus exaggerated or pathological anger reactions. We examined the self-reported characteristics of specific anger episodes in 93 community adults who were high (HTA) or low (LTA) on trait anger. Using a componential model, they were asked to identify a recent anger episode and report on the triggers and associated cognitions, characteristics of the experience, desired and actual patterns of expression, and outcomes. HTA adults, in comparison to their LTA counterparts, exhibited anger reactions that were more frequent, intense, and enduring. They also reported more negative cognitions. Of particular importance, the HTA adults reported more physical aggression, negative verbal responses, drug use, and negative anger-related consequences. Thus, clinically important anger reactions may emerge as a function of the anger trait. Results are discussed in terms of implications for diagnosis and treatment.     

Breast carcinoma in women over the age of 85: distinct histological pattern and androgen,oestrogen, and progesterone receptor status

AIMS: The pathogenesis of breast carcinoma in very elderly women is of interest, because oestrogen levels are likely to be extremely low during the development of the disease. In an effort to understand the pathogenesis of breast carcinoma in these women, this study was undertaken to compare the histological patterns and hormone receptor status of breast carcinomas arising in very elderly and younger women. METHODS AND RESULTS: Thirty-seven breast carcinomas from women over the age of 85 years at the time of their operation were examined histologically and compared with those from a large group of premenopausal women. The proportions of mucinous carcinoma and apocrine carcinoma were significantly greater in older women. The expression of steroid hormone receptors was studied immunohistochemically. Androgen receptor-positive carcinomas were significantly more frequent among older women, whereas progesterone receptor-positive carcinomas were significantly less frequent. There was no statistically significant difference in oestrogen receptor-alpha or -beta expression between the tumours from both groups. CONCLUSION: Breast carcinomas in women over the age of 85 years have a different morphological spectrum from carcinomas in younger age groups and may have different pathogenesis mechanisms that may be more dependent on androgen and androgen receptor interaction. Differences from the results of the other studies are discussed.     

Sigh rate and respiratory variability during mental load and sustained attention

Spontaneous breathing consists of substantial correlated variability: Parameters characterizing a breath are correlated with parameters characterizing previous and future breaths. On the basis of dynamic system theory, negative emotion states are predicted to reduce correlated variability whereas sustained attention is expected to reduce total respiratory variability. Both are predicted to evoke sighing. To test this, respiratory variability and sighing were assessed during a baseline, stressful mental arithmetic task, nonstressful sustained attention task, and recovery in between tasks. For respiration rate (excluding sighs), reduced total variability was found during the attention task, whereas correlated variation was reduced during mental load. Sigh rate increased during mental load and during recovery from the attention task. It is concluded that mental load and task‐related attention show specific patterns in respiratory variability and sigh rate.