Cynthia A. Stifter

The regulation of negative reactivity in infancy: function and development

This research was supported by a Small Grant from the National Institutes of Mental Health (#MH44324), the Pennsylvania State University Biomedical Research Support Grant Program and the Research Initiation Grant Program awarded to the first author. Special thanks go to the parents and infants who participated in the study. We would also like to thank Mike Rovine for his statistical advice and Margaret Fish for her assistance. Correspondence to Cynthia A. Stifter, Human Development and Family Studies, The Pennsylvania State University, University Park, PA 16802.

Facial expressivity and vagal tone in 5- and 10-month-old infants☆

Abstract The relationship between heart rate variability and infant emotional expressivity was investigated in 34 5- and 10-month-old infants. Infants were videotaped during a mother and stranger approach paradigm. Heart period and a measure of heart rate variability (cardiac vagal tone) were derived from 3 min of EKG recorded prior to the experiment. Infant facial expressions were coded using Izards AFFEX system. The frequencies of the emotions of interest and joy and the behavior, look-away, were reliably coded. The durations of interest expressions and look-away behaviors were also coded. Heart rate variability was related to expressivity only for the 5-month-olds. Five-month-old infants with greater vagal tone displayed more interest, more joy, and more look-away behaviors toward the stranger. Five-month-olds also exhibited longer durations of interest expressions than 10-month-old infants. The 10-month-old infants, however, looked away longer than the 5-month-old infants.

Exuberant and inhibited toddlers: Stability of temperament and risk for problem behavior

Temperament, effortful control, and problem behaviors at 4.5 years were assessed in 72 children classified as exuberant, inhibited, and low reactive as 2-year-olds. Exuberant toddlers were more positive, socially responsive to novel persons, less shy, and rated as having more problem behaviors, including externalizing and internalizing behaviors, than other children as preschoolers. Two forms of effortful control, the ability to delay a response and the ability to produce a subdominant response, were associated with fewer externalizing behaviors, whereas expressing more negative affect (relative to positive/neutral affect) when disappointed was related to more internalizing behaviors. Interaction effects implicated high levels of unregulated emotion during disappointment as a risk factor for problem behaviors in exuberant children.

Psychophysiological correlates of infant temperament: stability of behavior and autonomic patterning from 5 to 18 months.

The stability of infant temperament and autonomic patterning (heart period and cardiac vagal tone) was examined longitudinally when infants were 5, 10, and 18 months of age. Behavioral measures of reactivity and regulation to frustration tasks, and maternal perceptions of infant temperament were obtained at each age along with baseline measures of cardiac activity. No stability was found from 5 to 10 months while some stability of behavior and autonomic patterning was identified from 10 to 18 months, with the exception of negative reactivity. High levels of cardiac vagal tone (V) were associated with negative reactivity at 18 months. When examining groups based on degrees of reactivity and regulation, we found infants who responded negatively to frustration but who also displayed more regulatory behavior to have higher V.

The regulation of positive affect: Gaze aversion activity during mother-infant interaction

Abstract The purpose of this study was to examine two aspects of gaze aversion activity in young infants: (a) at what level of positive affect infants employ gaze aversion, and (b) the relationship between maternal activity and gaze aversion activity. Sixty 5-month-old infants were videotaped while participating in a peek-a-boo was coded from the videotapes. Results revealed infant smiles of high intensity were associated with more frequent and longer gaze aversions. Moreover, the intensities of smiles to which infants averted their gaze were greater than those smiles to which infants did not change their gaze behavior. These same relationships were found for smile durations. Finally, moderate maternal activity level during peek-a-boo elicited the most gaze aversion activity following a smile. The functional significance of gaze aversion to increases in positive affect is discussed.

Parent use of food to soothe infant/toddler distress and child weight status. An exploratory study

The aim of the present study was to explore the parent feeding practice of using food to soothe infant/toddler distress and its relationship to child weight status. Seventy eight families with infants and toddlers (43 males) ranging in age from 3 to 34 months (M=14 mos, SD=9 mos) completed a survey which included questions on their use of food to soothe, questionnaires on parent feeding practices, parenting self-efficacy, child temperament and childs weight and length at the time of their last well-baby visit. Results revealed the use of food to soothe to be a valid construct. In addition, mothers who used food to soothe rated themselves lower in parenting self-efficacy and their children higher in temperamental negativity. Analyses examining weight status as the outcome variable revealed that mothers who reported the use of food to soothe had heavier children, however, this relationship was stronger for children rated as high in temperamental negativity.

The effect of excessive crying on the development of emotion regulation

The goal of this study was to examine the effect of excessive crying in early infancy on the development of emotion self-regulation. Cry diaries were used to categorize excessive criers and typical criers at 6 weeks of age. At 5 and 10 months of age, infants and mothers participated in procedures to elicit infant reactivity and regulation during a frustration task and maternal sensitivity and intrusiveness during a free-play session. Last, maternal ratings of temperament were obtained. Results revealed excessive criers to show higher levels of negative reactivity than typical criers. Excessive criers also demonstrated lower regulation, but this finding was only significant for male infants. Boys in the excessive criers group exhibited the lowest level of emotion self-regulation. Maternal behavior and ratings of temperament at 5 and 10 months failed to distinguish the 2 cry groups. The findings suggest that excessive crying may influence the developmental trajectory of the ability of boys to self-regulate emotion. The hypothesized processes involved in this outcome are discussed.

Vagal Regulation and Observed Social Behavior in Infancy

The goal of the present study was to test a recent hypothesis that the ability to suppress cardiac vagal tone during a cognitive challenge was related to social behavior. One hundred thirty-six infants participated with their parents in laboratory visits when infants were 12 (mother visit) and 13 months (father visit) of age. To measure the infants’ regulation of cardiac vagal tone, heart rate responses were recorded during the administration of a test of mental development (father visit). Responses to a stranger interaction were measured during the 12 month visit. In addition, experimenters evaluated the infants’ behavior across the laboratory sessions using an adaptation of the Infant Behavior Record. Results revealed that infants who were able to suppress vagal tone during the cognitive challenge were rated by the experimenters as more socially approaching at the two laboratory visits. Vagal regulation was unrelated to behavior during the stranger-infant interaction. These findings partially support the hypothesis that infants who are able to regulate their vagal tone have a greater capacity for social engagement.

Opportunities for the Primary Prevention of Obesity during Infancy

Many parents, grandparents, and clinicians have associated a baby’s ability to eat and gain weight as a sign of good health, and clinicians typically only call significant attention to infant growth if a baby is failing to thrive or showing severe excesses in growth. Recent evidence, however, has suggested that pediatric healthcare providers should pay closer attention to growth patterns during infancy. Both higher weight and upward crossing of major percentile lines on the weight-for-age growth chart during infancy have long term health consequences, and are associated with overweight and obesity later in life. Clinicians should utilize the numerous available opportunities to discuss healthy growth and growth charts during health maintenance visits in the first two years after birth. Further, providers should instruct parents on strategies to promote healthy behaviors that can have long lasting obesity preventive effects.

Negative emotionality and cortisol during adolescent pregnancy and its effects on infant health and autonomic nervous system reactivity

This research examined the relations among maternal emotionality, biology, and infant outcome and autonomic nervous system reactivity (cardiac vagal tone). The sample consisted of 27 pregnant adolescents and their 3-week-old infants. Measures of anxiety, depression, anger, and saliva cortisol were obtained from the adolescents both pre- and postnatally. Infant outcome measures consisted of gestational age at delivery, birth weight, number of risk factors at birth and at 24 hr, Apgar score at 1 and 5 min, abnormalities on newborn physical exam, number of resuscitation measures used on the infant, and cardiac vagal tone. Significant relations were found among the adolescents emotionality, infant physical outcomes, and cardiac vagal tone. Higher concentrations of adolescent cortisol were associated with lower infant Apgar scores and an increased need for resuscitation measures performed on the infant. The positive association between negative emotions and better infant outcomes also was found and may reflect the sensitivity of the adolescents to their feelings and needs during pregnancy. Social support during pregnancy mediated the effects of maternal negative emotionality and infant cardiac vagal tone.