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1.
Dampening of Adrenocortical Responses during Infancy: Normative Changes and Individual Differences 总被引：6，自引：0，他引：6
Changes in cortisol and behavioral responses were examined longitudinally in 83 infants (39 girls, 44 boys) tested at their well-baby exams with inoculations at 2, 4, 6, and 15 months (72 infants completed all testing). Another sample of 2-, 4-, and 6-month-olds ( n = 18 per age) received mock exams without inoculations to determine early developmental changes to the exam procedures. Behavioral distress was coded every 30 sec during the exam, a 5-min inoculation period, and a 20-min recovery period. Salivary cortisol was obtained upon arrival at the clinic and 25 min after the beginning of the inoculation period. To the exam-inoculation procedures, cortisol responses were high at 2 months, decreased significantly between 2 and 4 months, remained comparable between 4 and 6 months, and then declined again between 6 and 15 months. Between 6 and 15 months there was also a decrease in pretest cortisol. By 15 months, significant increases in cortisol from pre- to posttest were no longer observed for most infants. To the exam-only procedures, cortisol responses decreased between 2 and 4 months, and by 4 months most infants failed to show pre- to posttest increases in cortisol. Behavioral distress decreased between 2 and 6 months, but increased again at 15 months. While crying and cortisol were modestly correlated during the 2- to 6-month exam-inoculation procedures, at 15 months no significant correlations were obtained. Behavioral and hormonal reactions thus followed different ontogenetic paths and may provide different information about infant functioning. There was some evidence that the emergence of the circadian rhythm in cortisol might be related to the early decrease in cortisol response. 相似文献
2.
Developmental Change in Infants' Responses to Stress 总被引：2，自引：0，他引：2
Infant stress responses to a well-baby physical examination and inoculation were observed longitudinally at 2, 4, and 6 months of age. In general, there were cortisol increases over base to the procedures. Cortisol level and cortisol response decreased with age. These data indicate a developmental shift in adrenocortical functioning between 2 and 6 months of age. Further evidence for this shift was seen in the stability of individual responses between 4 and 6 months of age. Individual differences in both cortisol and behavioral responses showed the most stability between these 2 ages. Moreover, diurnal variation in baseline cortisol level was present only at 6 months of age. While a sizable minority of infants showed stress-related cortisol decreases to the procedures at a given age, there was no evidence for cross-age consistency in individual infants showing these cortisol decreases. 相似文献
3.
Differences between Japanese Infants and Caucasian American Infants in Behavioral and Cortisol Response to Inoculation 总被引：2，自引：0，他引：2
The behavioral and cortisol responses of Japanese infants and Caucasian American infants, 4 months of age, were observed during and following routine inoculation. The Caucasian American group showed a more intense initial affective response and a longer latency to quiet than the Japanese group; the Japanese group showed a greater cortisol response. A 4-group taxonomy was created based on high or low behavioral and cortisol response: high behavior–high cortisol, low behavior–low cortisol, high behavior–low cortisol, and low behavior–high cortisol. There were significant differences between the 2 groups of infants using this taxonomy: Infants in the Caucasian American group were more likely to fall in the high behavior–low cortisol group, while infants in the Japanese group were more likely to fall in the low behavior–high cortisol group. 相似文献
4.
This study examined salivary cortisol, a stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) axis hormone in 20 infants (12 females; M age = 10.8 months) and 35 toddlers (20 females; M age = 29.7 months) in full-day, center-based child care. Samples were taken at approximately 10:00 a.m. and 4:00 p.m. at child care and at home. At child care, 35% of infants and 71% of toddlers showed a rise in cortisol across the day; at home, 71% of infants and 64% of toddlers showed decreases. Toddlers who played more with peers exhibited lower cortisol. Controlling age, teacher-reported social fearfulness predicted higher afternoon cortisol and larger cortisol increases across the day at child care. This phenomenon may indicate context-specific activation of the HPA axis early in life. 相似文献
5.
This investigation considers the association between patterns of emotional reactivity and reliance on mother in infancy and cognitive and language developments at age 2. Low-income women (N = 518) and their firstborn infants participated in (1) a lab-based assessment where emotion challenges were presented when the infants were 6 to 9 months old, and (2) an assessment of language and cognitive skills at age 2. After controlling for birthweight, early sensorimotor delay, and age at testing, infants who displayed a pattern of combined high reactivity and high reliance on mother in response to positive, anger, and fear emotion challenges had higher cognitive and language skills at age 2 compared with infants who displayed patterns of low reactivity and low reliance on mother. Children who showed high fearful distress and low reliance on mother and whose mothers had low psychological resources had especially poor developmental outcomes. The role of maternal availability in the socialization of emotion and early communication is discussed. 相似文献
6.
Four-month-old infants were screened (N = 433) for temperamental patterns thought to predict behavioral inhibition, including motor reactivity and the expression of negative affect. Those selected (N = 153) were assessed at multiple age points across the first 4 years of life for behavioral signs of inhibition as well as psychophysiological markers of frontal electroencephalogram (EEG) asymmetry. Four-month temperament was modestly predictive of behavioral inhibition over the first 2 years of life and of behavioral reticence at age 4. Those infants who remained continuously inhibited displayed right frontal EEG asymmetry as early as 9 months of age while those who changed from inhibited to noninhibited did not. Change in behavioral inhibition was related to experience of nonparental care. A second group of infants, selected at 4 months of age for patterns of behavior thought to predict temperamental exuberance, displayed a high degree of continuity over time in these behaviors. 相似文献
7.
The expressive behaviors of full-term and preterm infants and their mothers were examined during face-to-face interaction when the infants were approximately 2 1/2, 5, and 7 1/2 months old. Videotapes of the sessions were coded on a second-to-second basis using Izard's discrete emotion coding system. Overall, infants showed a linear increase in positive effect, especially interest and joy, and a corresponding decrease in negative affect, especially pain and knit brow, with age; decrease in negative affect was accounted for largely by the preterm infants. In terms of maternal responses, there was an increase in contingent responding to infant interest expressions and a decrease in contingent responding to infant pain expressions over time, especially in the case of the preterm infant. The data set as a whole was examined further to establish the directionality of influence between mothers and infants in change patterns over time. There was evidence of learning effects in infants as a function of maternal modeling and contingency patterns. Anomalies in maternal responses to preterm infant affect expressions were observed. Mothers of these infants displayed significantly less matching or imitation of their infant's facial expressions, showed random rather than contingent responsiveness to sadness, and a significant ignoring response to infant anger. These differences were attributed to differences in gazing patterns and negative emotion expression in preterm infants. The results are discussed within a framework of emotion socialization that recognizes bidirectionality of influence in the emotional patterns of mothers and infants. 相似文献
8.
The consequences of prenatal maternal stress for development were examined in 125 full-term infants at 3, 6, and 12 months of age. Maternal cortisol and psychological state were evaluated 5 times during pregnancy. Exposure to elevated concentrations of cortisol early in gestation was associated with a slower rate of development over the 1st year and lower mental development scores at 12 months. Elevated levels of maternal cortisol late in gestation, however, were associated with accelerated cognitive development and higher scores at 12 months. Elevated levels of maternal pregnancy-specific anxiety early in pregnancy were independently associated with lower 12-month mental development scores. These data suggest that maternal cortisol and pregnancy-specific anxiety have programming influences on the developing fetus. 相似文献
9.
Susan S. Jones 《Child development》1996,67(5):1952-1969
The claim that very young infants can imitate rests largely on reports that infants match adult displays of mouth opening (MO) and tongue protrusion (TP). Recent reviews suggest that only tongue protruding is reliably matched by young infants. This study tests the proposal that infants' "imitation" of tongue protruding reflects a coincidental match between a sight that infants find interesting and a behavior by which infants express interest. In Study 1, 4-week-old infants who looked longer at a nonsocial light display also produced TPs at higher rates than infants showing less interest. In Study 2, 4-week-old infants showed more interest in (looked longer at) a tongue-protruding adult face than a mouth-opening face. Study 3 tracked 2 infants' responses to interesting objects for several weeks before and after the onset of manual reaching. Both infants produced tongue protrusions in response to objects within reach before but not after reaching developed. Together, the results of the 3 studies suggest that infants' tongue protrusions in response to a tongue-protruding adult reflect very early attempts at oral exploration of interesting objects. 相似文献
10.
Cortisol Release in Infants in Response to Inoculation 总被引：1，自引：0，他引：1
Using a cross-sectional design, salivary cortisol was obtained from infants aged 2, 4, and 6 months, prior to and 15 min following an inoculation. Cortisol rose significantly following inoculation. Behavioral responses to inoculation were consistent with the observed patterns of cortisol release. Cortisol base level was significantly and negatively related to the cortisol change score. At 6 months the basal levels also were influenced by an adult-like circadian rhythm; infants tested shortly after awakening had higher basal levels than those tested later in the day. These data provide strong evidence that studies of stress and cortisol release in infants must be sensitive to basal level, circadian rhythm, and behavioral effects, and that appropriate statistical procedures should be employed. 相似文献
11.
Gabrielle Rappolt-Schlichtmann John B. Willett Catherine C. Ayoub Robert Lindsley Annmarie C. Hulette Kurt W. Fischer 《Mind, Brain, and Education》2009,3(3):131-142
The purpose of this research is to explore the dynamics of cortisol regulation in the context of center-based child care by examining the impact of social context (large classroom vs. small group) and relationship quality with caregivers (conflict with mothers and teachers). We extend the research on children's physiologic stress system functioning in center-based child care by focusing on morning cortisol levels among young children living in poverty. While in high-quality center-based child care, children's cortisol levels decreased over the course of the morning—a result that contrasts with findings in previous research with middle-class children, for whom cortisol typically increased over the course of the day while attending center-based child care. Cortisol levels were further reduced when children were moved from a large classroom environment to a small group context. Relationship conflict with mothers and teachers moderated these effects. Children who had high conflict with their mother exhibited cortisol levels that remained higher (decreased less) over the course of the morning, and children who had high conflict with their teacher exhibited cortisol levels that remained higher (decreased less) in response to the small group context. These results indicate that high-quality child care has the potential to support reduced stress among children living in poverty, at least as indicated by adrenocortical activity. 相似文献
12.
Treadmill-elicited stepping in seven-month-old infants 总被引：4，自引：0，他引：4
E Thelen 《Child development》1986,57(6):1498-1506
When infants begin to walk independently, their step patterns, while not fully mature, are different in kinematic details from those of newborn stepping and supine kicking. 6 7-month-old infants, who performed little or no stepping movements, were supported over a small, motorized treadmill. All showed immediate alternating stepping. These movements were more similar to adult-like steps than newborn steps. The implications of eliciting a more mature pattern by the treadmill are discussed. Although infants normally perform few steps at this age, the underlying mechanism has not "disappeared." 相似文献
13.
ObjectivesNeuroendocrine alterations may help explain health differences between intimate partner violence (IPV) exposed children and non-exposed children. We sought to determine the feasibility of having families, recruited at a child asthma visit, collect at home and return via mail child salivary samples, and whether socio-demographic variables were associated with sample return. For those returning samples, we examined whether past-year IPV exposure was associated with total cortisol output (AUC) and the magnitude of the cortisol awakening response (CAR), and whether these cortisol values were associated with asthma control.MethodsFifty-five families with an asthmatic child of any age were recruited from 2 pediatric asthma clinics. At the time of the visit, parents completed a survey packet which included a modified version of the Conflict Tactics Scale to assess IPV. Parents were given supplies to collect 3 child salivary cortisol samples (awakening, 30-min after awakening, bedtime) at home on a typical day, and return them via mail. Medical records also were abstracted.ResultsFifty-three percent (n = 29) returned child salivary samples. Families who returned samples typically returned them within 2 weeks, most commonly before we made a reminder call. Parental male sex was associated (p = .06) with increased rate of return at the trend level. In multivariable models, a 1-unit increase in IPV was significantly associated with a .93 SD increase in root-transformed total cortisol output (AUC) (un-standardized beta = 2.5; SE .59; p = .001). The odds of uncontrolled asthma were marginally higher for every nmol/l increase in CAR (OR 1.04; 95% CI 1.0, 1.1; p = .06).ConclusionsThis study provides support for the feasibility of obtaining a moderate return of salivary specimens from a convenience sample. Findings that IPV was associated with elevated total cortisol output and uncontrolled asthma was marginally associated with cortisol awakening response suggest that future studies should investigate whether cortisol mediates the IPV-child asthma relationship. 相似文献
14.
15.
Developmental change and stability of visual expectation and reaction times (RT) were examined at 5, 7, and 12 months in a longitudinal sample of term and preterm infants (birthweight <1,750 g). Using the traditional 200-ms cut-point to separate anticipatory from reactive saccades, RTs (and their standard deviations) declined markedly over age, whereas anticipations increased. Those infants who had faster RTs were more likely to anticipate upcoming events and were more attentive (fewer trials off-task and less response variability). Crossage stability was modest for most measures from 5 to 7 and 7 to 12 months, but rarely significant from 5 to 12 months. When the cut-point was lowered to 150 ms (to accommodate recent concerns that the higher cut-point may misclassify some true RTs as anticipations), the age-related increase in anticipations disappeared. Thus, although the results indicate marked increases in processing speed with age, evidence for increasing anticipations is equivocal. Findings were similar for preterm and term infants. 相似文献
16.
Is an attenuated physiological response to family conflict, seen in some youth exposed to early adversity, protective or problematic? A longitudinal study including 54 youth (average age 15.2 years) found that those with higher cumulative family aggression exposure showed lower cortisol output during a laboratory‐based conflict discussion with their parents, and were less likely to show the normative pattern of increased cortisol reactivity to a discussion they rated as more conflictual. Family aggression interacted with cortisol reactivity in predicting youth adjustment: Adolescents from more aggressive homes who were also more reactive to the discussion reported more posttraumatic stress symptoms and more antisocial behavior. These results suggest that attenuated reactivity may protect youth from the negative consequences associated with aggressive family environments. 相似文献
17.
Activities of primiparous mothers and infants were observed at 2 and 5 months of age during naturalistic interactions at home. 5 prominent features of mother and infant exchanges in this short-term longitudinal study are described and discussed in the context of 3 models of unique environment-development relations: covariation, stability, continuity, correspondence, and prediction. Generally, mothers' activities did not positively covary at either age, nor did those of infants. Some maternal activities were stable in this time period; some developmentally increased, and some developmentally decreased. Infants' activities were unstable, but most increased over time. Specific mother and infant activities corresponded, and over time mothers and infants influenced one another in specific ways. In the critical period of the first half year, infants appear to be flexible and plastic in their behavioral repertoires and are influenced by their mothers; mothers are somewhat consistent, but they also adapt to the behaviors of their infants. 相似文献
18.
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. Immediately following administration of the NBAS-K, a blood sample was obtained for plasma cortisol determination. Correlations between behavioral responding on the NBAS-K and levels of plasma cortisol revealed few significant relations for the sample as a whole. When the 2 subgroups were examined separately, a number of significant relations emerged. Newborns in Subgroup I who were more competent in their motor control and state regulation capacities as assessed by Lester's Cluster Scores for the NBAS-K exhibited higher levels of plasma cortisol. In contrast, newborns in Subgroup II who exhibited a greater adrenocortical response to the examination showed more behaviors indicative of high behavioral arousal and distress. This pattern of relations for Subgroup II appeared to be mediated by the number of hours that had elapsed since delivery. As postpartum time increased, the strength of the association between adrenocortical activity and behavioral arousal/distress decreased for Subgroup II. A systems theory approach is used to interpret the difference in patterns of correlations found for the 2 subgroups. 相似文献
19.
2 experiments examined behavioral preferences for infant-directed (ID) speech over adult-directed (AD) speech in young infants. Using a modification of the visual-fixation-based auditory-preference procedure, Experiments 1 and 2 examined whether 12 1-month-old and 16 2-day-old infants looked longer at a visual stimulus when looking produced ID as opposed to AD speech. The results showed that both 1-month-olds and newborns preferred ID over AD speech. Although the absolute magnitude of the ID speech preference was significantly greater, with the older infants showing longer looking durations than the younger infants, subsequent analyses showed no significant difference in the relative magnitude of this effect. Differences in overall looking times between the 2 groups apparently reflect task variables rather than differences in speech processing. These results suggest that infants' preference for the exaggerated prosodic features of ID speech is present from birth and may not depend on any specific postnatal experience. However, the possible role of prenatal auditory experience with speech is considered. 相似文献
20.
Fluent conversation requires temporal organization between conversational exchanges. By performing a systematic review and Bayesian multi-level meta-analysis, we map the trajectory of infants’ turn-taking abilities over the course of early development (0 to 70 months). We synthesize the evidence from 26 studies (78 estimates from 429 unique infants, of which at least 152 are female) reporting response latencies in infant–adult dyadic interactions. The data were collected between 1975 and 2019, exclusively in North America and Europe. Infants took on average circa 1 s to respond, and the evidence of changes in response over time was inconclusive. Infants’ response latencies are related to those of their adult conversational partners: an increase of 1 s in adult response latency (e.g., 400 to 1400 ms) would be related to an increase of over 1 s in infant response latency (from 600 to 1857 ms). These results highlight the dynamic reciprocity involved in the temporal organization of turn-taking. Based on these results, we provide recommendations for future avenues of enquiry: studies should analyze how turn-by-turn exchanges develop on a longitudinal timescale, with rich assessment of infants’ linguistic and social development. 相似文献