Neonatal stress reactivity: predictions to later emotional temperament.

To investigate the relations among popular measures of neonatal stress and their link to subsequent temperament, 50 full-term newborns from a normal care nursery were examined responding to a heelstick blood draw. Baseline and heelstick measures of behavioral state, heart period, vagal tone, and salivary cortisol were obtained. Recovery measures of behavioral and cardiac activity were also analyzed.

Event-related potentials in year-old infants: relations with emotionality and cortisol.

Event-related potentials (ERPs) were recorded from year-old infants presented with sets of familiar faces presented frequently and infrequently, and a set of novel faces presented infrequently. The normative response of infants in this sample was a late positive slow wave to the Infrequent Familiar faces, and a return to baseline to the Frequent Familiar and Infrequent Novel faces (although there was a tendency for some infants to show a positive slow wave to the latter events). A factor score based on data from frontal and central leads that reflected this normative pattern was significantly associated with infant emotional behavior and cortisol.

Adrenocortical activity and emotion regulation.

Activity of the HPA system does appear to be related to emotion regulation processes in children. The conditions known to modulate HPA activity in animals, adults, and children correspond well to the behavioral strategies often discussed in the domain of emotion regulation. Individual differences in emotion processes related to negative emotion temperaments appear to be associated with individual differences in HPA reactivity among normally developing children, with both fearful, inhibited temperaments and distressed, angry temperaments being associated with greater HPA reactivity.

First time experiences in infancy: when they appear to be pleasant, do they activate the adrenocortical stress response?

The effect of a positive first-time experience on adrenocortical activity was examined in 48 6- to 13-month-old infants who took part in two sessions of a YMCA-like mother-infant swim class. Experience was manipulated by comparing Novice swimmers with infants who previously had taken a swim class, and by examining responses to first versus second class session. In addition, the effects of temperamental fear of novelty were examined by maternal report prior to the first session.

The stressfulness of separation among nine-month-old infants: effects of social context variables and infant temperament.

This manuscript reports on the results of 2 experiments dealing with behavioral and adrenocortical responses to separation among 9-month-old human infants. In both experiments the social context of separation was manipulated. The results of Experiment 1 yielded evidence of a statistically significant adrenocortical response to 30 min of separation under conditions in which the substitute caregiver responded sensitivity to infant distress, but was busy and relatively noninteractive when babies were not distressed during the separation period.

Cortisol and behavioral responses to repeated stressors in the human newborn.

This manuscript reports on the effects of stressors repeated at a 24-hr interval on three samples of human newborns. In Study 1, newborns meeting criteria for obstetric and perinatal optimality experienced either 2 mock Discharge Exams, viewed as a type of handling stressor, or 2 Heelstick Blood Draws, viewed as a type of nocioceptive stressor. As in a previous study, newborns meeting optimality criteria showed habituation of the adrenocortical response to the repeated Discharge Exam.

The effects of morning naps, car trips, and maternal separation on adrenocortical activity in human infants.

3 studies of adrenocortical activity in healthy 9-month-old infants were conducted to examine unanticipated results obtained in previous research. In the first study, morning naps were examined and found to be associated with significant decreases in salivary cortisol. These decreases were followed by a significant return to prenap cortisol concentrations.

Infant proneness-to-distress temperament, maternal personality, and mother-infant attachment: associations and goodness of fit.

66 mother-infant pairs were examined when the infants were 9 and 13 months. The purpose of this report was to examine relations between infant proneness-to-distress temperament, maternal personality characteristics, and mother-infant attachment. There were no main-effect relations between infant proneness-to-distress temperament as assessed at 9 months and infant attachment classification at 13 months.

Lack of stability in neonatal adrenocortical reactivity because of rapid habituation of the adrenocortical response.

The purpose of the study was to examine the stability of the adrenocortical response to stimulation in the human neonate. Forty-nine healthy newborns were examined twice responding to discharge examinations performed on two consecutive days. The dependent measures were salivary and plasma cortisol and behavioral state.

Studies of the human infant's adrenocortical response to potentially stressful events.

Research on the regulation of the adrenocortical response in normal, healthy human infants is still quite new. The refinement of radioimmune assays to allow the measurement of cortisol in small samples of saliva, however, promises to stimulate a marked increase in work in this area over the next few years. To summarize the work to date, we can be fairly certain of the following points: (1) The adrenocortical system is responsive to stimulation at birth, and elevations can be produced by a variety of normal events, including such seemingly minor stimuli as undressing, weighing, and measuring the newborn.

A descriptive analysis of infant social referencing.

The study was designed to provide a descriptive analysis of the frequency and patterning of social referencing in a seminaturalistic setting. 32 infants, half of them 12 and half 18 months old, were observed exploring a caged rabbit with their mothers present. Referencing was operationalized as looks directed toward the mother following a look to the rabbit, accompanied by quizzical facial or vocal expressions.

Adrenocortical activity and behavioral distress in human newborns.

The association between behavioral distress and adrenocortical activity was examined in two experiments with human newborns. In Experiment 1, behavioral and adrenocortical responses to 4 events (circumcision, blood sampling, weighing and measuring, and discharge examination) were compared using a between-subject design. All 4 events elicited fussing and crying and elevations in plasma cortisol; however, differences in behavioral distress among conditions did not reliably predict differences in plasma cortisol.

Local anesthesia for neonatal circumcision. Effects on distress and cortisol response.

A controlled, double-blind investigation was conducted to determine whether the dorsal penile nerve block using lidocaine hydrochloride without epinephrine would effectively reduce behavioral distress and adrenocortical responses to routine neonatal circumcision. The subjects were healthy male newborns whose parents had requested circumcision. Equal numbers (n = 20) were randomly assigned to circumcision with lidocaine, saline, or no injection.

Adrenocortical activity and the Brazelton Neonatal Assessment Scale: moderating effects of the newborn's biomedical status.

The Brazelton Neonatal Behavioral Assessment Scale with Kansas Supplement (NBAS-K) was administered midway between feedings to 60 newborns who were between 32 and 122 hours old. 35 of the newborns were classified as extremely healthy and normal (Subgroup I), whereas 25 (Subgroup II) were characterized by slight perinatal problems including gestational age 36-37 weeks or 42+ weeks, and fetal distress during labor. All of the newborns were healthy enough to be cared for in a healthy newborn, Level I nursery.

Psychobiological studies of stress and coping: an introduction.

Developmental psychobiology is the study of how the interplay between behavioral and physiological processes supports and directs development. This symposium section is devoted to work in this interdisciplinary domain focused on examining stress and how young organisms cope with and are affected by stressful experiences. In this introduction to the symposium section, the problems of interpreting and integrating information on stress reactivity derived from a combination of behavioral and physiological measures are discussed.

Adrenocortical and behavioral responses to limb restraint in human neonates.

Two experiments were conducted on human neonates examining their behavior and adrenocortical activity in response to physical restraint. In both experiments, newborns (9 per condition in Experiment I; 10 per condition in Experiment II) were tested in one of three conditions: Restraint, which involved strapping newborns to a circumstraint board for 20 min; Strapping Control, which involved strapping newborns to the board and then immediately taking them off the board and returning them to their cribs; and Control, which did not involve any restraining manipulation. In Experiment I, blood samples for plasma cortisol determination were obtained via heel-stick immediately prior to the assigned manipulations and 30 min later.

Coping with aversive stimulation in the neonatal period: quiet sleep and plasma cortisol levels during recovery from circumcision.

Measures of behavioral state and plasma cortisol were obtained on 80 healthy, full-term, 2-3-day-old, male newborns who were scheduled to be circumcised. To establish baseline or precircumcision levels, the newborns were observed, and behavioral state was recorded for the half hour prior to circumcision. Blood was sampled via heelstick for plasma cortisol determination at the end of this observation period.

Peer presence and the exploratory behavior of eighteen- and thirty-month-old children.

20 18- and 20 30-month-old children were observed in a situation requiring separation from the mother in order to play with attractive toys. An agemate was present for half the children but not the others. Peer presence facilitated leaving the mother and entering the playroom at both ages.

Sex differences in biobehavioral responses to conflict in a taste aversion paradigm.

A conditioned aversion to a novel milk solution was produced, and animals were then reexposed to milk while nondeprived (low conflict) or following a 72-hr food and water deprivation regimen (high conflict). No sex differences occurred if animals were nondeprived throughout testing. However, if deprived during the interval between conditioning and reexposure, sex differences in both behavior and adrenocortical responses occurred: (1) Presession corticoid levels of females were higher than those of males.