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1.
The capacity of infant squirrel monkeys to mount an antibody response to viral challenge was evaluated after removal from their mothers in several social and physical environments. Control and separated infants were injected with a benign virus, the bacteriophage X174, and levels of neutralizing antibody were assessed for 3 weeks. Infants separated alone in an unfamiliar environment showed a significant reduction in antibody levels as compared to control infants. Allowing infants to remain in the home environment, either alone or with peers, prevented this inhibition of antibody responses from occurring. Similarly, providing familiar peers in the novel environment facilitated the normal expression of antibody responses. These results indicate that the trauma of maternal separation is significantly reduced when infants are familiar with the separation environment or familiar social companions are available. The reduced antibody response was associated with the highest level of adrenal activation induced by the unfamiliar separation condition, but antibody titers and plasma cortisol levels could not be specifically correlated in individual infants.  相似文献   

2.
To describe the behavioral and physiological responses associated with colic, the responses of 20 two-month-old infants with and 20 without colic were studied during a physical examination. Parents kept a diary of infant behaviors (including crying and fussing) for 3 days following the visit. Using Wessel, Cobb, Jackson, Harris, & Detwiler criteria, colic was defined as fussing/crying for 3 hr or more on each of the 3 days. Behavioral data coded by "blind" observers showed that during the physical exam, colic infants cried twice as much, cried more intensely, and were more inconsolable than were control infants. Despite these behavioral differences, heart rate, vagal tone, and cortisol measures indicated no appreciable difference in physiological responsivity for the two groups. At home, parents collected saliva cortisol samples at wakeup, midmorning, midafternoon, and evening for 2 days. In a finding similar to that shown by the laboratory data, the colic and control infants did not have different levels of daily average cortisol. These laboratory and home data provide no evidence of greater responsivity in the physiological substrate of difficult temperament for colic infants and are consistent with evidence of similarity in temperament once colic is resolved. At home, compared with control infants, colic infants did display a blunted rhythm in cortisol production. By diary, they also slept about 2 hr less per day than did control infants. Nighttime sleep was still significantly different when fussing/crying was statistically controlled. These data suggest that colic might be associated with a disruption or delay in the establishment of the circadian rhythm in activity of the hypothalamic-pituitary-adrenocortical axis and associated sleep-wake activity.  相似文献   

3.
Neonatal Stress Reactivity: Predictions to Later Emotional Temperament   总被引:1,自引:0,他引:1  
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. Mothers completed Rothbart's Infant Behavior Questionnaire when their infants reached 6 months of age. Baseline vagal tone predicted cortisol in response to the heelstick, suggesting that baseline vagal tone reflects the infants' ability to react to stressors. Greater reactivity to the heelstick (more crying, shorter heart periods, lower vagal tone, and higher cortisol) was associated with lower scores on "Distress-to-Limitations" temperament at 6 months. This finding was consistent with the expectation that the capacity to react strongly to an aversive stimulus would reflect better neurobehavioral organization in the newborn. Recovery measures of cardiac activity approximated and were correlated with baseline measures indicating the strong self-righting properties of the healthy newborn. Finally, vagal tone and salivary cortisol measures were not significantly related, suggesting the importance of assessing both systems in studies of the ontogeny of stress-temperament relations.  相似文献   

4.
Event-related po-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. Infants scoring higher on the normative ERP factor were more distressed during separation, were reported by their parents to smile and laugh more, and had lower cortisol concentrations during ERP testing. These data were interpreted as reflecting the coordination of adaptive responding among different physiological and behavioral systems.  相似文献   

5.
Child Development, 1994, 65 , 1491–1502. Infant cortisol and behavioral responses to receiving 1 versus 2 inoculations on 1 pediatric office visit were observed at 2 and 6 months of age. Cortisol level (pre- plus postinoculation level) decreased with age, whereas cortisol response (post- minus preinoculation level) did not vary with age when the data were aggregated over infants showing a pre- to postinoculation cortisol increase and those showing a decrease. Nonetheless, for those infants who showed a cortisol increase, cortisol level and response decreased with age. Infants quieted faster at the older age. There was a moderate relation between quieting behavior and cortisol response, at least for infants who showed a pre- to postinoculation cortisol increase. These findings indicate a developmental trend for a decline over age in adrenocortical reactivity to inoculation for infants showing a cortisol release following the perturbation. Results were comparable whether infants received 1 or 2 inoculations.  相似文献   

6.
Reactivity and regulation in cortisol and behavioral responses to stress   总被引:4,自引:0,他引:4  
This study examined relations between reactivity (i.e., peak response) and regulation (i.e., response dampening) in 6-month-old infants' cortisol and behavioral responses to inoculation (N = 62). Data showed that reactivity and regulation were unrelated for both cortisol and behavior. The independence of reactivity and regulation suggests that measures of both are needed to characterize infant cortisol or behavioral response to stress more completely. For both reactivity and regulation, cortisol and behavior were unrelated, suggesting that measures of both are needed to assess infant stress more adequately. There was considerable variation in the timing of the peak cortisol response, suggesting that obtaining only a single poststressor cortisol sample does not provide a sensitive measure of cortisol reactivity.  相似文献   

7.
The current study investigated whether individual and developmental differences in look duration are correlated with the latency for infants to disengage fixation from a visual stimulus. Ninety-four infants (52 3-month-olds, 42 4-month-olds) were tested in a procedure that measured ocular reaction time to shift fixation from a central target to a peripheral target under conditions in which the central-target either remained present ("competition" condition) or was removed from the display ("noncompetition" condition). Look duration was correlated with disengagement latency; longer-looking infants were slower than shorter-looking infants to shift fixation to the peripheral target on competition trials, but not noncompetition trials. Results were similar for 3- and 4-month-olds, although 3-month-olds showed slower latencies on all trials. Furthermore, long-looking infants were not consistently slower, but rather showed greater variability in their response latencies under conditions that required disengagement of fixation. The results support the position that developmental and individual differences in look duration are linked to the development of the neural attentional systems that control the ability to disengage, or inhibit, visual fixation.  相似文献   

8.
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   

9.
Sex Differences in Neonatal Stress Reactivity   总被引:3,自引:0,他引:3  
The question of whether a sexually dimorphic stress reaction exists prior to extensive socialization was addressed by examining sex differences in physiological and behavioral stress reactivity, in healthy, term neonates, after a mildly stressful behavioral assessment procedure. The Neonatal Behavior Assessment Scale (NBAS; Brazelton, 1973) was administered to 18 male and 18 female neonates. Heart rate (HR), salivary cortisol, and behavioral states were assessed before and after the exam. Sex differences included higher cortisol response in males and a greater change in HR and higher NBAS motor performance cluster score in females. Salivary cortisol, HR change, NBAS cluster scores, and behavioral states after NBAS provided 100% discrimination between male and female infants. These findings suggest that there are neonatal sex differences in behavioral and physiological stress reactivity prior to socialization.  相似文献   

10.
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. In the second study, riding for 40 min in the car was also shown to significantly lower salivary cortisol concentrations. This effect was obtained both for infants who did and who did not sleep during the car trip. In the third study, the effect of 30 min of maternal separation in the laboratory on salivary cortisol was compared to the effect of 30 min of play with mother present. Separation resulted in significantly higher salivary cortisol concentrations as compared to play with mother present. In general, correlations between cortisol and behavior were found to be nonsignificant under conditions that did not produce stress elevations in cortisol, while less positive, more distressed behaviour was significantly correlated with cortisol under separation or stress conditions.  相似文献   

11.
The association between cortisol and behavioral reactivity to a medical heel stick and a neurobehavioral exam was examined in 100 healthy African American neonates, who have been underrepresented in this area of research. Using continuous measures, behavioral distress was associated with cortisol reactivity to both stressors. High levels of behavioral distress, however, were associated with cortisol reactivity only in response to the neurobehavioral exam. In contrast, low levels of behavioral distress were associated with cortisol reactivity only in response to the heel stick. The results highlight potentially important parameters for exploring the relation between biological and behavioral reactivity to stress such as the operationalization of behavioral distress and the context in which a stress response is elicited.  相似文献   

12.
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   

13.
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   

14.
Biobehavioral Organization in Securely and Insecurely Attached Infants   总被引:3,自引:2,他引:3  
Attachment research has shown the emergence of individual differences in the security of infant-mother attachment during the first year of life as well as their importance for later social-emotional development. A biobehavioral perspective may help settle disagreements about the validity and interpretation of 12-month-old infants' different behavioral patterns of attachment assessed by Ainsworth's Strange Situation. It was shown that, despite less overt distress in insecure-avoidant infants after short separations from the mother, overall cardiac measures indicate arousal patterns similar to the secure infants during separation. However, differences in cardiac response emerged with regard to object versus person orientation during reunion. Additionally, findings of increased cortisol in both insecure-avoidant and disorganized infants support the theoretical interpretation that these infants, in contrast to secure infants, lack an appropriate coping strategy.  相似文献   

15.
Seventy 15-month-old infants were studied at home before starting child care, during adaptation (mothers present) and separation (first 9 days without mothers) phases, and 5 months later. Security of infant-mother attachment was assessed before and 3 months after child care began. In the separation phase, salivary cortisol rose over the first 60 min following the mothers' departures to levels that were 75% to 100% higher than at home. Compared with insecure infants, secure infants had markedly lower cortisol levels during the adaptation phase and higher fuss and cry levels during the separation phase, and their fuss and cry levels were significantly correlated with their cortisol levels. Attachments remained secure or became secure if mothers spent more days adapting their children to child care.  相似文献   

16.
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   

17.
During fMRI imaging, 12 good and 8 poor writers aged 11 wrote a newly taught pseudoletter and a highly practiced letter. Both letters were formed from the same components, but the pseudoletter had a novel configuration not corresponding to a written English letter form. On the first fMRI contrast between the newly taught pseudoletter and highly practiced letter, based on a group map, good and poor writers significantly activated many common regions; but the poor writers showed spatially more extensive brain activation than did the good writers. The additional regions of significant activation may reflect inefficiency in learning a new letter form. For the second contrast between the highly practiced and newly taught letters, individual brain activation analyses, based on exact clusters, showed that good and poor writers differed significantly in activation only in left fusiform. This individual fusiform activation correlated significantly with behavioral measures of automatic letter writing and expressive orthographic coding. Multiple regression in which both individual fusiform activation and individual orthographic coding were entered explained significant variance in written composition. Results are discussed in reference to the role of the orthographic loop, from internal letter form to external letter writing by hand, in writing letters and composing. The overall results are consistent with prior brain and behavioral studies of writing.  相似文献   

18.
100 economically disadvantaged mothers and their infants were observed in the Ainsworth and Wittig "strange situation" at 12 and 18 months. Infants were classified as secure, anxiously attached/avoidant, or anxiously attached/resistant. In addition, mothers reported occurrence of stressful events related to the stability of the caretaking environment during the 12--18 month period by completing a 44-item checklist concerning work, finances, family, neighbors, health, etc. 62 infants were assigned to the same attachment classification at both 12 and 18 months (p less than .01). Despite this stability, significantly more infants changes classification than in a recent study of stable middle-class families. With the present sample, anxious attachment was associated with less stable caretaking environments than secure attachment; change from secure to anxious attachment was associated with higher stressful-event scores than stable secure attachment.  相似文献   

19.
The role of the mother-toddler attachment relationship in moderating the relations between behavioral inhibition and changes in salivary cortisol levels in response to novel events was examined in 77 18-month-olds. Behavioral inhibition was determined by observing toddler inhibition of approach to several novel events. Attachment security to mother was assessed using the Ainsworth Strange Situation. Changes in salivary cortisol were used to index activity of the stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) system. In addition, toddler coping behaviors and the behaviors used by mothers to help toddlers manage novel events were examined. Elevations in cortisol were found only for inhibited toddlers in insecure attachment relationships. Mothers in these relationships appeared to interfere with their toddlers' coping efforts. These results are discussed in the context of a coping model of the relations between temperament and stress reactivity.  相似文献   

20.
Background: To date whether the effects of parental corporal punishment (CP) on executive function (EF) distinct components are different is less clear. Moreover, theory and empirical work suggest that physiological regulation system may help to explain the individual differences in the developmental outcomes associated with parental CP.Objective: This study examined the effects of parental CP on Chinese preschoolers’ EF and whether the cortisol stress reactivity would moderate such effects.Participants and Setting: One hundred and fifty-two preschool-aged children and their parents from Beijing China participated in the present study.Methods: Parental CP was reported by fathers and mothers respectively in the first year of the study (2015, spring), and children’s EF was assessed and salivary cortisol was collected in the second year (2016, spring).Results: Both paternal and maternal CP were negatively correlated with children’s EF one year later, and the relation between maternal, but not paternal CP and children’s EF was moderated by cortisol stress reactivity. Specifically, compared to children with high cortisol stress reactivity levels, children with low cortisol stress reactivity levels who experienced maternal CP in the past year showed poorer global EF and working memory.Conclusions: Findings highlight the critical importance of examining the interactive effects of individual physiological level and environmental-level risks on young children’s self-regulation outcomes.  相似文献   

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