When tonic cardiac vagal tone predicts changes in phasic vagal tone: The role of fear and perceptual load

We examined the relationship between tonic—a correlate of self‐regulatory functioning—and phasic cardiac vagal activity (indexed by heart rate variability; HRV) during a selective attentional task with varying levels of load. Participants detected a target letter among letter strings superimposed on either fearful or neutral face distractors. Letter strings consisted of six target letters under low load and one target letter and five nontarget letters under high load. With fearful distractors, lower tonic HRV was associated with phasic HRV suppression, suggesting an autonomic stress response under both low and high load. In contrast, higher tonic HRV was associated with phasic HRV enhancement, suggesting greater self‐regulatory effort under low load and an absence of phasic HRV suppression under high load. The current research suggests that tonic cardiac vagal tone is associated with the ability to flexibly adapt autonomic responses.     

Increase in vagal tone and limitation of cardiac arrhythmias during adaptation to continuous stress

Laboratory of Pathophysiology of the Heart, Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR G. N. Kryzhanovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 109, No. 5, pp. 423–425, May, 1990.     

Children's sleep and adjustment: the moderating role of vagal regulation

Children's vagal tone and vagal suppression were examined as moderators of associations between children's sleep disruptions and adjustment problems. A relatively large sample (n = 167) of boys and girls who ranged in age between 8 and 9 years participated with their parents. Sleep was examined via actigraphy in the child's home for seven consecutive days. Children's vagal tone was examined during baseline conditions, and their vagal suppression was assessed in response to an inter-adult argument. In comparison with children exhibiting higher levels of vagal tone, those with lower vagal tone were at increased risk of externalizing problems, depression symptoms and higher body mass index associated with increased sleep disruptions (i.e. lower Sleep Efficiency, increased Wake Minutes and fewer Sleep Minutes). Thus, lower vagal tone functioned as a vulnerability factor for adjustment problems in the context of sleep problems. A higher level of vagal suppression to the inter-adult argument functioned as a protective factor against externalizing behaviors otherwise associated with increased Wake Minutes and reduced Sleep Efficiency. Findings demonstrating the moderating role of vagal functioning in the context of sleep disruptions are novel, and highlight the importance of individual differences in children's physiological regulation for sleep and adjustment.     

Infant regulation of the vagal “brake” predicts child behavior problems: A psychobiological model of social behavior

Cardiac vagal tone is a construct that describes the functional relationship between the brainstem and the heart. Cardiac vagal tone is measured by quantifying the amplitude of respiratory sinus arrhythmia, a component of heart rate variability reflecting the functional output of vagal pathways on the heart. Although there is an extensive literature evaluating baseline vagal tone and its relation to behavior, the relation between individual differences in the ability to regulate cardiac vagal tone and behavior has been theoretically vague. This article introduces a theoretical model to explain the relation between vagal tone during steady states and vagal reactivity (i.e., the vagal brake) in response to environmental challenges. Based upon the proposed model, it was hypothesized that infants who had difficulties in regulating the vagal brake (i.e., decreasing cardiac vagal tone) during social/attention tasks would have difficulties developing appropriate social interactions requiring reciprocal engagement and disengagement strategies. Data from 24 infants are presented. The findings support the model and demonstrate that infants with difficulties in decreasing vagal tone during a social/attention task at 9 months of age had significantly more behavioral problems at 3 years of age. © 1996 John Wiley & Sons, Inc.     

Stability of resting frontal electroencephalogram (EEG) asymmetry and cardiac vagal tone in adolescent females exposed to child maltreatment

The experience of child maltreatment is a known risk factor for the development of psychopathology. Structural and functional modifications of neural systems implicated in stress and emotion regulation may provide one mechanism linking early adversity with later outcome. The authors examined two well‐documented biological markers of stress vulnerability [resting frontal electroencephalogram (EEG) asymmetry and cardiac vagal tone] in a group of adolescent females exposed to child maltreatment (n = 38; M age = 14.47) and their age‐matched non‐maltreated (n = 25; M age = 14.00) peers. Maltreated females exhibited greater relative right frontal EEG activity and lower cardiac vagal tone than controls over a 6‐month period. In addition, frontal EEG asymmetry and cardiac vagal tone remained stable in the maltreated group across the 6 months, suggesting that the neurobiological correlates of maltreatment may not simply reflect dynamic, short‐term changes but more long lasting alterations. The present findings appear to be the first to demonstrate stability of two biologically based stress‐vulnerability measures in a maltreated population. Findings are discussed in terms of plasticity within the neural circuits of emotion regulation during the early childhood period and alternative causal models of developmental psychopathology. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 474–487, 2009     

Maternal stress and behavior modulate relationships between neonatal stress, attention, and basal cortisol at 8 months in preterm infants

There is evidence that the developmental trajectory of cortisol secretion in preterm infants is altered, with elevated basal cortisol levels observed postnatally through at least 18 months corrected age (CA). This alteration is possibly due to neonatal pain-related stress. High cortisol levels might contribute to greater risk of impaired neurodevelopment. Since maternal factors are important for the regulation of infant stress responses, we investigated relationships between infant (neonatal pain-related stress, attention, cortisol) and maternal (stress, interactive behaviors) factors at age 8 months CA. We found that interactive maternal behaviors buffered the relationship between high neonatal pain-related stress exposure and poorer focused attention in mothers who self-reported low concurrent stress. Furthermore, in preterm infants exposed to high concurrent maternal stress and overwhelming interactive maternal behaviors, higher basal cortisol levels were associated with poor focused attention. Overall, these findings suggest that maternal factors can influence the cognitive resilience at 8 months of preterm infants exposed to early life stress.     

The role of vagal function in the risk for cardiovascular disease and mortality

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. The understanding of the risk factors for CVD may yield important insights into the prevention, etiology, course, and treatment of this major public health concern. We review the evidence for the role of vagal function in the risk for cardiovascular disease and mortality. Using a broad range of indicators of vagal function including resting heart rate, heart rate recovery, heart rate variability, and baroreflex sensitivity we show that decreased vagal function is associated with an increased risk for morbidity and mortality. These effects are independent of traditional risk factors. Moreover, we show that decreased vagal function is associated with both traditional and emerging risk factors as well as modifiable and non-modifiable risk factors. Most importantly, we provide evidence to support the notion that decreased vagal function precedes the development of a number of risk factors and that modification of risk profiles in the direction of lower risk is associated with increased vagal function. We close with a brief overview of the neural concomitants of vagal function and suggest that a model of neurovisceral integration may provide a unifying framework within which to investigate the impact of risk factors, including psychosocial factors, on cardiovascular disease.     

A follow-up study of postpartum depressed women: recurrent maternal depressive symptoms and child behavior after four years

Summary Objective: To investigate the prevalence of depressive symptoms and self reported health of women who have shown previous postpartum depressive symptoms. To examine the behavior of four-year-old children born to mothers affected by postpartum depression. Methods: Longitudinal study. The index group (n = 251) constituted of all women with postpartum depressive symptoms on the Edinburgh Postnatal Depression Scale (EPDS), in a population-based study made in the late 1990s. The control group (n = 502) consisted of women without postpartum depressive symptoms on the EPDS at the same occasion. Approximately four years after delivery these women were asked to answer a short questionnaire on general health, the EPDS, and also to assess their child’s behavior with the Richman Pre-School Behaviour Checklist. Results: Women with a history of postpartum depressive symptoms were approximately 6 times more likely to have recurrent depressive symptoms (OR = 5.82, 95% CI: 3.79–8.93), compared to those without postpartum depressive symptoms, and they were also more likely to experience physical and mental illness. Although postpartum depressive symptoms in the mothers were involved in explaining the likelihood of behavioral problems in their four-year-old children, mothers with current depressive symptoms were the most likely to have a child with behavioral problems (OR = 4.71, 95% CI: 1.88–11.78). Conclusion: Postpartum depressive illness constitutes a risk for future illness as well as maternal perceived behavioral problems in offspring. In order to diminish long-term adverse consequences for the mother and the child there is a great need to recognize and treat women with postpartum depressive symptoms as early as possible.     

Mothers' responses to children's negative emotions and child emotion regulation: the moderating role of vagal suppression

The current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children's emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against nonsupportive emotion socialization.     

Maternal behavior in the rat: aspects of concaveation and neonatal androgen treatment

Evidence is presented to show that maternal responsiveness of lactating females differs from concaveation-induced maternal responsiveness of gonadectomized male and female rats of the Long-Evans strain. When rat pups were placed in a runway extension of the home cage lactating females retrieved the pups to a significantly greater degree than did the concaveation treated animals. The present experiment failed to show significant differences in concaveation-induced maternal responsiveness in gonadectomized males, females and neonatally androgenized females.     

Maternal memory in adult, nulliparous rats: effects of testing interval on the retention of maternal behavior

The retention of maternal behavior (i.e., maternal memory) was measured in adult, nulliparous rats induced to respond maternally by continuous exposure to foster pups. Specifically, the effects of the interval duration between the initial induction and the reinduction of maternal behavior were determined. Intact virgin rats were first exposed to foster young to induce maternal behavior. During the initial induction phase, females were required to be fully maternal on 2 consecutive test days. Animals were then assigned to one of three interval groups (10, 20, or 40 days). After being isolated from rat pups for these designated periods, females in each group were tested again for their latencies to induce maternal behavior. Whereas the initial median latencies to display full maternal behavior ranged from 4.5 to 5 days for each group, upon retesting, median latencies for each group declined to 1 to 4 days. The greatest reduction in latency was present in the 10-day group (80%), and the smallest reduction was detected in the 40-day group (20%). A significant negative linear correlation was found between test interval and percentage reduction in behavioral latency. Based upon this relationship and under these test conditions, "maternal memory" in the adult, nulliparous rat would be expected to be nondetectable after about an interval of 50 days between tests. The pattern of maternal memory acquisition and loss appears similar to that reported in parous animals. The present study highlights similarities and possible differences underlying the establishment of the retention of maternal behavior (i.e., maternal memory).     

Associations between respiratory arrhythmia and fundamental frequency of spontaneous crying in preterm and term infants at term‐equivalent age

This study investigated whether lower vagal function in preterm infants is associated with increased fundamental frequency (F₀; frequency of vocal fold vibration) of their spontaneous cries. We assessed respiratory sinus arrhythmia (RSA) during quiet sleep as a measure of vagal function, and its relationship with the F₀ of spontaneous cries in healthy preterm and term infants at term‐equivalent age. The results showed that preterm infants have significantly lower RSA, and higher overall F₀ than term infants. Moreover, lower RSA was associated with higher overall F₀ in preterm infants, whereas higher RSA was positively associated with mean and maximum F₀, and a larger F₀ range in term infants. These results suggest that individual differences in vagal function may be associated with the F₀ of spontaneous cries via modulation of vocal fold tension in infants at an early developmental stage. © 2016 The Authors. Developmental Psychobiology Published by Wiley Periodicals, Inc. Dev Psychobiol 58:724–733, 2016.     

How the neonatal rat gets to the nipple: Common motor modules and their involvement in the expression of early motor behavior

One-day-old rat pups adopt a supine posture before attaching to the mother's nipple. Body rotations performed to reach the nipple occur in a typical kinematic structure. First, the pup rotates along the longitudinal axis of the trunk and lies on its side. Next, the pup arches the trunk to achieve a U-shaped posture and then rapidly relaxes the trunk. A second cephalocaudal rotation follows at the peak of trunk relaxation as the pup achieves a supine posture. After reaching a supine posture, the pup crawls to a nipple by performing “stepping” movements on the mother's ventral surface. The kinematic structure of these movements is reminiscent of the structure of righting as seen in the newborn rat. Both righting and achieving a supine posture under the mother involve the expression of common motor modules. During righting the modules are executed in the direction of gravity, and when achieving a supine posture the modules are executed against the force of gravity. Simple motor behaviors expressed by the rat pup during early postnatal development may have common origins and common control mechanisms. © 1998 John Wiley & Sons, Inc. Dev Psychobiol 32: 57–66, 1998     

The role of sociodemographic risk and maternal behavior in the prediction of infant attachment disorganization

Predictors of infant attachment disorganization were examined among 203 primiparous mothers (52% European American, 48% African American) and their infants (104 female). The Strange Situation Procedure was administered at one year. Global maternal insensitivity and overtly negative maternal behavior were observed during distress-eliciting tasks when infants were six months and one year old. Mothers reported on their demographics to yield a measure of sociodemographic risk (i.e., age, education, income-to-needs). Overtly negative maternal behavior was positively associated with the infant attachment disorganization rating scale score, but did not predict being classified as disorganized. Global maternal insensitivity was associated with higher attachment disorganization, both the rating and the classification, when sociodemographic risk was high but not when sociodemographic risk was low. The pattern of results did not vary by maternal race. The results provide some support for the view that negative maternal behavior and the combination of sociodemographic risk and global maternal insensitivity play a role in the development of infant attachment disorganization.     

Maternal and littermate deprivation disrupts maternal behavior and social-learning of food preference in adulthood: tactile stimulation, nest odor, and social rearing prevent these effects

Maternal and littermate (social) separation, through artificial rearing (AR), disrupts the development of subsequent maternal behavior and social learning in rats. The addition of maternal-licking-like stimulation during AR, partially reverses some of these effects. However, little is know about the role of social stimuli from littermates and nest odors during the preweaning period, in the development of the adult maternal behavior and social learning. The purpose of this study was to examine the effects of peer- and peer-and-odor rearing on the development of maternal behavior and social learning in rats. Female pups were reared with mothers (mother reared-MR) or without mothers (AR) from postnatal day (PND) 3. AR rats received three different treatments: (1) AR-CONTROL group received minimal tactile stimulation, (2) AR-ODOR females received exposure to maternal nest material inside the AR-isolation-cup environment, (3) AR-SOCIAL group was reared in the cup with maternal nest material and a conspecific of the same-age and same-sex and received additional tactile stimulation. MR females were reared by their mothers in the nest and with conspecifics. In adulthood, rats were tested for maternal behavior towards their own pups and in a social learning task. Results confirm our previous report that AR impairs performance of maternal behavior and the development of a social food preference. Furthermore, social cues from a littermate, in combination with tactile stimulation and the nest odor, reversed the negative effects of complete isolation (AR-CONTROL) on some of the above behaviors. Exposure to the odor alone also had effects on some of these olfactory-mediated behaviors. These studies indicate that social stimulation from littermates during the preweaning period, in combination with odor from the nest and tactile stimulation, contributes to the development of affiliative behaviors.     

Maternal behavior: differences between mother and virgin mice as a function of the testing procedure

Retrieval by lactating and virgin mice was compared in a straight alley and a T-maze. In both test situations the retrieval performance of the lactating mouse was superior to that of the virgin animal. No discrimination was seen between a live pup and a dead pup; a rubber toy, however, was retrieved least by both the lactating and virgin mice. Contrary to previous results, these experiments demonstrate a significant difference in maternal behavior between lactating and virgin mice.     

The effect of postpartum depression on child cognitive development and behavior: A review and critical analysis of the literature

Summary ¶The incidence of postpartum depression (PPD) in Western societies is approximately 10–15% and its cause multi-faceted. Because mothers largely constitute infants social environment and mediate their experience of the external world, it is imperative to investigate the effects of PPD on child growth and development. PsycInfo, Medline, Embase, CINAHL, ProQuest, and Health Star databases were searched with key terms for English language abstracts from 1990 onwards, and key contents were searched. There are small effects of PPD on cognitive development such as language and IQ, seen particularly among boys. Behavioral effects are variably supported, but may persist up to 5 years postpartum and beyond. However, chronic or recurrent maternal depression, rather than postpartum depression per se is likely related to later effects on the child. These adverse effects of PPD based on sex of infant are discussed.Received February 7, 2003; accepted June 15, 2003 Published online August 12, 2003