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Cardiac vagal control (CVC), as indexed by abnormalities in resting, reactivity, and recovery levels of respiratory sinus arrythmia (RSA), has been proposed as an index of impaired self-regulatory capacity in depression. Aerobic exercise has been shown to improve positive and negative affective responses and influence autonomic function; however, it is unknown whether exercise impacts RSA reactivity and subsequent recovery to emotional challenges among individuals at risk for depression. The present study aimed to determine the effects of moderate-intensity aerobic exercise on RSA reactivity and recovery to a sad film. Using a within-subjects design, 47 individuals with variable symptoms of depression completed a 30-min session of exercise and a sedentary control condition on separate days prior to viewing a sad film. On the control day, individuals with elevated depressive symptom severity displayed less vagal withdrawal to the sad film and exhibited impaired post-film RSA recovery. Following exercise, individuals with elevated depressive symptom severity demonstrated a higher degree of vagal withdrawal to the sad film and subsequent post-film recovery that matched individuals with lower depressive symptom severity. These findings suggest that a single session aerobic exercise may be an effective approach to increase emotional and self-regulatory capacity among individual at risk for, or currently experiencing, depression.

This randomized controlled trial (NCT04786496) examined the effects of a preventive intervention based on Incremental Theory of the Personality (ITP) on psychophysiological responses to social stress and evaluated whether levels of depression moderate the intervention effects. The participants, 107 first-year university students, were randomly assigned to one of three conditions: ITP intervention, ITP + a self-affirmation intervention (SA), and a control condition (CC). Indicators of the Hypothalamic–Pituitary–Adrenal axis, autonomic nervous system, and subjective mood were assessed with the Trier Social Stress Task. Participants in the ITP condition displayed a lower decline in respiratory sinus arrythmia (RSA) compared to those in the CC during the first phases of the task [Slopes: -0.08 (0.09) vs -0.21 (0.09), z = 2.86, p = .004] and a higher decrease in cortisol at recovery [β = -0.18 (0.08), z = -2.37, p = .018]. Depressive symptoms moderated the effect of ITP [β = -0.10 (0.05), z = -2.15, p =.032] and ITP+SA [β = -0.09 (0.04), z = -2.06, p =.039] in the decline during stress and recovery in RSA. In participants with low/medium levels of depressive symptoms, both interventions predicted a lower decline during stress [Slopes: -0.06 (0.09) for ITP, -0.17 (.09) for ITP+SA, and -0.26 (0.09) for CC] and higher recovery in RSA [Slopes: 0.18 (0.01) for ITP, 0.24 (0.01) for ITP+SA, and 0.30 (0.01) for CC]. The findings suggest that the ITP intervention has the potential to be an effective preventive intervention to reduce the stress response.

Research on listening effort has used various physiological measures to examine the biological correlates of listening effort but a systematic examination of the impact of listening demand on cardiac autonomic nervous system activity is still lacking. The presented study aimed to close this gap by assessing cardiac sympathetic and parasympathetic responses to variations in listening demand. For this purpose, 45 participants performed four speech-in-noise tasks differing in listening demand—manipulated as signal-to-noise ratio varying between +23 dB and -16 dB—while their pre-ejection period and respiratory sinus arrythmia responses were assessed. Cardiac responses showed the expected effect of listening demand on sympathetic activity, but failed to provide evidence for the expected listening demand impact on parasympathetic activity: Pre-ejection period reactivity increased with increasing listening demand across the three possible listening conditions and was low in the very high (impossible) demand condition, whereas respiratory sinus arrythmia did not show this pattern. These findings have two main implications. First, cardiac sympathetic responses seem to be the more sensitive correlate of the impact of task demand on listening effort compared to cardiac parasympathetic responses. Second, very high listening demand may lead to disengagement and correspondingly low effort and reduced cardiac sympathetic response.

There is mixed evidence whether reflecting on an existential threat increases negative affect and thereby elicits subjective arousal and physiological activation. Additionally, it is debated whether different existential and non-existential threats elicit different arousal responses, although systematic comparisons are lacking. The current study explored affective, subjective, and physiological arousal responses while comparing several existential threats with a non-existential threat and with a control condition. One-hundred-and-seventy-one undergraduate students were randomly allocated to one of four existential threat conditions: mortality salience (MS), freedom restriction, uncontrollability, and uncertainty; or to the non-existential threat condition: social-evaluative threat (SET); or to a control condition (TV salience). Self-reported positive/negative affect was measured before and after reflection, while subjective arousal and physiological activation (electrodermal, cardiovascular, and respiratory) were measured on a high time-scale during baseline and reflection. Results showed larger increases in self-reported negative affect, as compared to the control condition, for all existential threat conditions, while there were no differences between the control condition and threat conditions regarding positive affect, subjective arousal, skin conductance, respiratory rate, and respiratory sinus arrythmia. There were subtle differences between existential and non-existential threat conditions, most notably in affective responses. Correlations showed positive associations between negative affect and subjective arousal and between trait avoidance and subjective arousal. This study is the first to systematically compare affective, subjective, and physiological changes in arousal due to reflecting on different existential threats, as well as one non-existential threat. We showed that, as compared to a control condition, reflecting on threats has a large impact on negative affect, but no significant impact on positive affect, subjective arousal, and physiological activation.

Although excessive avoidance has been implicated in mental health problems and socioemotional difficulties, relatively little is known about dynamic changes of avoidance behaviors. We used a latent class growth analysis to examine the temporal course of avoidance behaviors in real time and determined whether the derived classes were distinguishable on temperament and physiological markers of regulation and reactivity (N = 153; Mage = 4.20 years). A three-class solution was found and identified a low, medium, and high increasing avoidance group. The high and increasing avoidance group had the highest physiological reactivity (cortisol reactivity) and shyness, and the lowest physiological regulation (i.e., respiratory sinus arrythmia suppression). High and increasing avoidance may therefore be associated with temperamental and physiological indices of risk implicated in maladjustment and highlight the value of data-driven, group-based approaches for examining dynamic patterns of behavior.

It seems that a dual location for vagal preganglionic neurones (VPNs) has important functional correlates in all vertebrates. This may be particularly the case with the central control exerted over the heart by cardiac VPNs (CVPNs). About 30 % of VPNs but up to 70 % of CVPNs are in the nucleus ambiguus (NA) of mammals. There is a similar proportional representation of VPNs between the major vagal nuclei in amphibians and turtles but in fish and crocodilians; the proportion of VPNs in the NA is closer to 10% and in some lizards and birds it is about 5%. However, the CVPNs are distributed unequally between these nuclei so that 45 % of the CVPNs are located in the NA of the dogfish, and about 30% in the NA of Xenopus and the duck. This topographical separation of CVPNs seems to be of importance in the central control of the heart. Cells in one location may show respiration-related activity (e.g those in the dorsal vagal nucleus (DVN) of dogfish and in the NA of mammals) while cells in the other locations do not. Their different activities and separate functions will be determined by their different afferent inputs from the periphery or from elsewhere in the CNS, which in turn will relate to their central topography. Thus, CVPNs in the NA of mammals receive inhibitory inputs from neighbouring inspiratory neurones, causing respiratory sinus arrythmia (RSA), and the CVPNs in the DVN of the dogfish may generate cardiorespiratory synchrony (CRS).

International audience; The analysis of heart period series is a difficult task especially under graded exercise conditions. From all the information present in these series, we are the most interested in the coupling between respiratory and cardiac systems, known as respiratory sinus arrythmia. In this paper, we show that precise patterns concerning the respiratory frequency can be extracted from the heart period series. An evolutive model is introduced in order to achieve tracking of the main respiratory-related frequencies and their time-varying amplitudes. Since respiration acts to modulate the sinus rhythm, we relate the frequencies and amplitudes to this modulation by analyzing in detail its nonlinear transformation giving the heart period signal. This analysis is performed assuming stationary conditions but also in the realistic case where the mean heart period, the amplitude, and the frequency of the respiration are time-varying. Since this paper is devoted to the theoretical and complete presentation of the method used in a physiological study published elsewhere, the capabilities of our method will be illustrated in a realistic simulated case.

In 35 anaesthetised human subjects, we examined the effect of cardioventilatory coupling on R-R interval and ventilatory period time series. We observed that, in the presence of coupling: (a) ventilatory period fluctuated in a quantal manner, each quantal step corresponding to a multiple (or a little less) of the heart period; (b) heart period fluctuations, associated with respiratory sinus arrythmia, were identical for consecutive ventilatory periods. The regularity of heart period variation lead to geometric patterning of raw R-R time series, R-R consecutive difference time series, the phase portrait (R-R(n) vs R-R(n+1)) and the map of R-R interval variation (DeltaR-R(n) vs DeltaR-R(n+1)). These geometric features may be useful for the determination of cardioventilatory coupling from heart rate time series.

Background In obsessive-compulsive disorder (OCD), individuals feel compelled to repeatedly perform security-related behaviors, even though these behaviours seem excessive and unwarranted to them. The present research investigated two alternative ways of explaining such behavior: (1) a dysfunction of activation—a starting problem—in which the level of excitation in response to stimuli suggesting potential danger is abnormally strong; versus (2) a dysfunction of termination—a stopping problem—in which the satiety-like process for shutting down security-related thoughts and actions is abnormally weak. Method In two experiments, 70 patients with OCD (57 with washing compulsions, 13 with checking compulsions) and 72 controls were exposed to contamination cues—immersing a hand in wet diapers —and later allowed to wash their hands, first limited to 30 s and then for as long as desired. The intensity of activation of security motivation was measured objectively by change in respiratory sinus arrythmia. Subjective ratings (e.g., contamination) and behavioral measures (e.g., duration of hand washing) were also collected. Results Compared to controls, OCD patients with washing compulsions did not differ significantly in their levels of initial activation to the threat of contamination; however, they were significantly less able to reduce this activation by engaging in the corrective behavior of hand-washing. Further, the deactivating effect of hand-washing in OCD patients with checking compulsions was similar to that for controls, indicating that the dysfunction of termination in OCD is specific to the patient's symptom profile. Conclusions These results are the first to show that OCD is characterized by a reduced ability of security-related behavior to terminate motivation evoked by potential danger, rather than a heightened initial sensitivity to potential threat. They lend support to the security-motivation theory of OCD (Szechtman & Woody, 2004) and have important implications both for research into the biological mechanisms underlying OCD and for the development of new treatment approaches.

Sinus arrhythmia is a normal respiration-related variation in heart rate that is diminished or absent in autonomic nerve dysfunction. The conventionally used measurements, R-R intervals and their standard deviations (RRSD), were made and compared with a computed statistic (![Graphic][1] ) in spontaneously diabetic BB rats and in age-matched nondiabetes-prone control rats. In addition, the effects of pentobarbital sodium anesthesia on RRSD and ![Graphic][2] values in normal control rats were compared with those of nonanesthetized animals. BB rats demonstrated a decrease in ![Graphic][3] values after 8 wk of diabetes. This decrease became more marked with increased duration of diabetes. No differences in mean R-R intervals or RRSD were obtained between diabetic and nondiabetic rats until 24 wk of diabetes. Normal control rats showed a decrease in sinus arrythmia with age. Both RRSD and ![Graphic][4] values were greatly decreased in anesthetized animals. [1]: /embed/inline-graphic-1.gif [2]: /embed/inline-graphic-2.gif [3]: /embed/inline-graphic-3.gif [4]: /embed/inline-graphic-4.gif

This research is an investigation of the relationships between several physiological measures and vigilance performance. Heart rate and sinus arrhythmia were measured throughout a 40-minute vigilance task for each of 15 subjects. Information processing rate, depth perception and critical flicker fusion frequency were measured before and after the task. Significant results were found by linear correlation techniques which showed pre-test depth perception and detection performance negatively correlated (r = .585, p < .05), pre-test critical flicker fusion frequency and detection performance positively correrlated r = .492, p < .05), and heart rate positively correlated with detection performance (r = .7703, p < .1). http://archive.org/details/physiologicalcor1094518237 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The autopsy findings of two intramyocardial infiltrating hibernomas situated in the right atrium of a 84-year-old woman are presented. The tumours might have contributed to the clinically observed sinus arrythmia, prolonged PQ-interval and bundle branch block.

1. 1. The heart rate of an immature male harp seal was monitored by a telemetry system modified to function through a water-air interface. 2. 2. Heart rates were correlated with basic behavioural patterns recorded by closed circuit television. 3. 3. The behavioural patterns were studied and the most consistent pattern was chosen to represent spontaneous activity. 4. 4. Surface and submerged “free swimming” heart rates, and the variability of heart activity associated with respiratory pauses were observed. 5. 5. Distinct levels of heart rate were evident during spontaneous activity: a true surface swimming rate (122 beats/min), a level of bradycardia associated with sinus arrythmia (77 beats/min). 6. 6. The surface heart rate variance was much less than that for either a submerged seal or a ventrally recumbent seal. 7. 7. During spontaneous short dives the heart rate dropped to 40 per cent of the surface rate. 8. 8. Eighty-one per cent of these dives showed anticipatory bradycardia occurring 2·5–7·5 sec before the onset of submergence. 9. 9. Trained dives, however, produced a more profound bradycardia and less anticipation.

A personal-computer-based method for the quantification of respiratory sinus arrythmia (RSA) at rest is presented. This method is based on the measurement of the variation of the heart period for each respiratory cycle. A confidence interval for the RSA mean is given. >

The analysis of heart period series is a difficult task especially under graded exercise conditions. Among all the information present in these series, we are more interested in the coupling between respiratory and cardiac systems, known as respiratory sinus arrythmia. We show in this work that from the heart period series precise patterns concerning the respiratory frequency can be extracted. Evolutive model is introduced in order to achieve the tracking of the main frequencies and their time-varying power.

For many years heart rate change has been used as an index of psychophysiological responsivity in newborn infants. We have hypothesized that a parasympathetic component of heart rate variability (HRV), respiratory sinus arrythmia (RSA), might provide a more sensitive measure of CNS reactivity to external stimulation. We investigated whether infants would show a differential response in RSA to a highly salient source of auditory stimulation - the maternal voice. Twenty-five healthy full-term neonates were presented with alternations of a period of silence followed by a period of recorded mother's voice. The heart rate data were analyzed using spectral analysis which generated an estimate of RSA, i.e., the sum of spectral densities over the respiratory band. Results show that newborns had a significantly greater RSA during mother's voice as compared to periods of silence. As anticipated, mean heart rate and sucking, traditional measures of stimulus responsivity, showed less systematic changes during stimulation. The use of RSA as a dependent measure of stimulus reactivity provides us with another method for investigating newborn perceptual and learning capabilities. Our data indicate that this measure of parasympathetic tone, in combination with other autonomic and behavioral measures, will enhance our understanding of the psychophysiological responses of newborn infants.

Reports on persistent vagal disturbances of the heart mechanism in apparently normal persons with the exception of sinus arrythmia and bradycardia are exceedingly rare. A survey of the literature revealed only 3 cases of such disturbance. 1 In a recent study of the electrocardiographic variations of the healthy heart, electrocardiograms and stethograms were made on more than 2,400 apparently normal high school students. The following case of physiologic heart block of vagal origin was the only instance of such a disturbance which was observed. It occurred in a Negro boy who except for this abnormality was clinically normal and entirely free of any sense of physical ill-being or of symptoms which could be related either directly or indirectly to a condition of heart block. Observations made in this case are reported, compared with those of Levy la and Marzahn lb and discussed in the light of electrocardiographic changes in the