Psychophysiological Reactivity to Abuse-Related Stimuli in Sexually Revictimized Women

Prior research shows discrepant findings in relation to psychophysiological reactivity to threat in women with histories of sexual victimization. Women ages 18 to 22 (N?=?123) with histories of sexual abuse were categorized into child sexual abuse (CSA), adult sexual victimization, revictimization, or nonvictimization groups. Low- and high-frequency heart rate variability were measured at baseline and during an Emotional Stroop task of abuse-related words. Revictimized women showed a significant decrease from baseline to task in both parasympathetic and sympathetic measures when compared to the CSA group. The CSA group demonstrated chronic sympathetic activation at both baseline and task, relative to the revictimization group. Groups did not differ on performance (i.e., reaction time) on the Emotional Stroop task (i.e., more threatening stimuli, slower performance). Cardiovascular responses reported might point to biological reactivity patterns needed for women with a history of sexual abuse to cope with abuse-related stimuli.     

冠状动脉病变范围与心率变异性的相关性研究

本研究通过对69例CHD患者（完成冠状动脉造影）进行Gensini评分、分组,同时设正常对照组56例。全部进行24h动态心电图监测,并做时域指标和频域指标的HRV分析。结果显示CHD组HRV各项指标均低于对照组（P〈0．05）,不同冠状动脉病变范围和程度其时域指标及频域指标降低程度不同,各组对照具有显著性差异（P〈0．...     

Fractal dynamics of heart beat interval fluctuations in corticotropin-releasing factor receptor subtype 2 deficient mice

Non-linear fractal analysis of cardiac interbeat time series was performed in corticotropin-releasing factor receptor subtype 2 (CRFR2) deficient mice. Heart rate dynamics in mice constitutes a self-similar, scale-invariant, random fractal process with persistent intrinsic long-range correlations and inverse power-law properties. We hypothesized that the sustained tachycardic response elicited by intraperitoneal (ip) injection of human/rat CRF (h/rCRF) is mediated by CRFR2. In wildtype control animals, heart rate was increased to about maximum levels (~ 750 bpm) while in CRFR2-deficient animals baseline values were retained (~ 580 bpm). The tachycardic response elicited by ip-application is mediated by CRFR2 and is interpreted to result from sympathetic stimulation. However, the functional integrity of CRFR2 would not present a prerequisite to maintaining the responsiveness and resiliency of cardiac control to external environmental perturbations experimentally induced by extrinsic ip-application of h/rCRF or under physiological conditions that may be associated with an increased peripheral release of CRF. Under stressful physiological conditions achieved by novelty exposure, CRFR2 is not involved in the cardiodynamic regulation to external short-term stress. While the hypothesis of involvement of CRFR2 in cardiac regulation upon pharmacological stimulation cannot be rejected, the present findings suggest that the mechanism of action is by sympathetic stimulation, but would not unambiguously allow to draw any conclusions as to the physiological role of CRFR2 in the control of cardiac dynamics.     

Heart rate reactivity in HAD and LAD rats during Pavlovian fear conditioning

Recently, we reported that High-Alcohol-Drinking (HAD) rats exhibited selective deficits in active avoidance learning under alcohol-naive conditions, and that administration of moderate doses of alcohol (0.5 and 1.0 g/kg) facilitated learning in these rats (Blankenship et al., 2000; Rorick et al., 2003b). We hypothesized that the deficits resulted from excessive fear in the aversive learning context and that the anxiolytic properties of alcohol may have contributed to the improved learning that was observed after alcohol administration. This hypothesis was supported by a recent study in which prolonged freezing in HAD rats was seen after a classical fear conditioning procedure (Rorick et al., 2003a). To provide additional evidence that HAD rats indeed exhibit behaviors consistent with the expression of increased fear in aversive learning contexts, we employed a Pavlovian fear conditioning task to measure heart rate in HAD and Low-Alcohol-Drinking (LAD) rats. In this study, HAD (HAD-1 and HAD-2) and LAD (LAD-1 and LAD-2) rats were assigned to one of three pre-exposure conditions: Context Only, Context/Tone, or Sequential (Context Only followed by Context/Tone) Pre-Exposure. Following pre-exposure, fear conditioning acquisition and extinction procedures were identical for all groups. Results indicated that although no baseline differences were observed between HAD and LAD rats, HAD rats receiving Context-Only pre-exposure exhibited excessive heart rate reactivity to the tone conditional stimulus during fear conditioning acquisition, compared to LAD rats receiving the same pre-exposure conditions. These findings support the hypothesis that HAD rats exhibit behaviors consistent with increased fear in aversive learning contexts, as measured by autonomic conditioning.     

Loss aversion in the eye and in the heart: The autonomic nervous system's responses to losses

The common view in psychology and neuroscience is that losses loom larger than gains, leading to a negativity bias in behavioral responses and Autonomic Nervous System (ANS) activation. However, evidence has accumulated that in decisions under risk and uncertainty individuals often impart similar weights to negative and positive outcomes. We examine the role of the ANS in decisions under uncertainty, and its consistency with the behavioral responses. In three studies, we show that losses lead to heightened autonomic responses, compared to equivalent gains (as indicated by pupil dilation and increased heart rate) even in situations where the average decision maker exhibits no loss aversion. Moreover, in the studied tasks autonomic responses were not associated with risk taking propensities. These results are interpreted by the hypothesis that losses signal the subjective importance of global outcome patterns. Copyright © 2010 John Wiley & Sons, Ltd.     

Skin conductance and heart‐rate responses as indices of covert face recognition in preschool children

Covert face recognition was examined in 12 young preschoolers (age range 26–48 months) by comparing their autonomic functions to slides depicting former playmates from a family nursery school that the preschoolers had attended earlier with slides of their present playmates and unfamiliar children. While all preschoolers reported corroborated overt recognition of present playmates after the experiment, only three of them did so in relation to former playmates. The distribution of yes–no responses on the overt recognition task to former playmates was not significantly different from the responses to unfamiliar children. Nevertheless, the preschoolers evidenced increased skin conductance responses (SCRs) and more pronounced heart rate (HR) deceleration to the slides depicting former classmates compared to unfamiliar children. Thus, although the preschoolers' verbal responses did not differentiate between former playmates and unfamiliar children, their autonomic functions did. These findings suggest that young children can retain memories of past experiences in an implicit form without corroborated overt recognition. Copyright © 2004 John Wiley & Sons, Ltd.     

Experiencing positive affect and negative affect during stress: relationships to cardiac reactivity and to facial expressions

We examined the relationship between experienced positive/negative affect and cardiac reactivity and facial muscle movements during laboratory tasks with different demands. Heart rate, respiratory sinus arrhythmia, pre-ejection period, and facial electromyography were measured during startle, mental arithmetic, reaction time task, and speech task. The results revealed that individuals experiencing high levels of positive affect exhibited more pronounced parasympathetic, heart rate, and orbicularis oculi reactivity than others. Individuals who experienced high levels of negative affects during the tasks showed higher corrugator supercilii responses. Men and women showed slightly different response patterns. To conclude, cardiac reactivity may be associated with positive involvement and enthusiasm in some situations and all reactivity should not automatically be considered as potentially pathological.     

Is the heart preadapted to hypoxia? Evidence from fractal dynamics of heartbeat interval fluctuations at high altitude (5,050 m)

The dynamics of heartbeat interval time series over large time scales were studied by a modifed random walk analysis introduced recently asDetrended Fluctuation Analysis. In this analysis, the intrinsic fractal long-range power-law correlation properties of beat-to-beat fluctuations generated by the dynamical system (i.e., cardiac rhythm generator), after decomposition from extrinsic uncorrelated sources, can be quantified by the scaling exponent (α) which, in healthy subjects, for time scales of ∼10⁴ beats is ∼1.0. The effects of chronic hypoxia were determined from serial heartbeat interval time series of digitized twenty-four-hour ambulatory ECGs recorded in nine healthy subjects (mean age thirty-four years old) at sea level and during a sojourn at 5,050 m for thirty-four days (Ev-K2-CNR Pyramid Laboratory, Sagarmatha National Park, Nepal). The group averaged α exponent (±SD) was 0.99±0.04 (range 0.93–1.04). Longitudinal assessment of α in individual subjects did not reveal any effect of exposure to chronic high altitude hypoxia. The finding of α∼1 indicating scale-invariant long-range power-law correlations (1/f noise) of heartbeat fluctuations would reflect a genuinely self-similar fractal process that typically generates fluctuations on a wide range of time scales. Lack of a characteristic time scale along with the absence of any effect from exposure to chronic hypoxia on scaling properties suggests that the neuroautonomic cardiac control system is preadapted to hypoxia which helps prevent excessive mode-locking (error tolerance) that would restrict its functional responsiveness (plasticity) to hypoxic or other physiological stimuli. Editorial Note: A philosopher is, by definition, a lover of wisdom. In the following article, Dr. Dimitrov, as a philosopher, examines the principles that underlie being and thinking as performed by the structures of the brain. He reports his thoughts in a “virtual context.” Virtual, a word enjoying great popularity today, is derived from the Latin word for man; it describes manliness and implies apparent, but not actual, power. In his analysis of how information is dealt with by the human being, the author uses theoretical physics and mathematics that may seem arcane to some readers. A major aspect of his thesis declares that the effective performance of information systems relies not on the structures involved, but on the way they interact.     

Enhancement of conditioned autonomic responses in monkey when preshock signals occasion operant suppression.

Classical pairings of a sound stilulus with shock elicited larger magnitude and more rapidly conditioned autonomic responses when subjects were responding on variable-interval schedules for food than when they were eating freely available food. The difference was not attributable to changes in control values of heart rate and blood pressure, or to alterations in motor activity, but appeared related to operant suppression.     

Evidence for discrete profiles of children’s physiological activity across three neurobiological system and their transitions over time

The conceptualization of stress‐responsive physiological systems as operating in an integrated manner is evident in several theoretical models of cross‐system functioning. However, limited empirical research has modeled the complexity of multisystem activity. Moreover few studies have explored developmentally regulated changes in multisystem activity during early childhood when plasticity is particularly pronounced. The current study used latent profile analysis (LPA) to evaluate multisystem activity during fall and spring of children's transition to kindergarten in three biological systems: the parasympathetic nervous system (PNS), sympathetic nervous system (SNS), and hypothalamic pituitary adrenal (HPA) axis. Latent transition analysis (LTA) was then used to examine the stability of profile classification across time. Across both timepoints, three distinct profiles of multisystem activity emerged. One profile was characterized by heightened HPA axis activity (HPA Axis Responders), a second profile was characterized by moderate, typically adaptive patterns across the PNS, SNS, and HPA axis (Active Copers/Mobilizers), and a third profile was characterized by heightened baseline activity, particularly in the PNS and SNS (Anticipatory Arousal/ANS Responders). LTA of fall‐to‐spring profile classifications indicated higher probabilities that children remained in the same profile over time compared to probabilities of profile changes, suggesting stability in certain patterns of cross‐system responsivity. Patterns of profile stability and change were associated with socioemotional outcomes at the end of the school year. Findings highlight the utility of LPA and LTA to detect meaningful patterns of complex multisystem physiological activity across three systems and their associations with early adjustment during an important developmental transition.