Cortisol and Antibody Study
Study Overview:
There are numerous bidirectional influences between systems that help the body manage stress and challenge,
such as the HPA-axis, and the immune system. Work with adults has indicated that acute stressors are often related to
increases in health-promoting immune system functions, while more chronic stressors are often related to dampening of
immune system functions.
In this study, we examined cortisol (a hormone that helps the body manage stress and challenge) and sIgA
(a family of antibodies present in saliva) patterning across the day in 3-6 year old children, with the purpose of
charting diurnal patterns of sIgA in this population, and to examine whether the two patterns interact across the day.
We also assessed antibodies for the Herpes simplex virus. Once an individual has been exposed to the Herpes virus,
it must be maintained in a latent state by the immune system to prevent illness. Results indicate that sIgA exhibits a
diurnal rhythm in this population, with a trend toward patterning differences on child care and weekend days. Further,
higher cortisol levels on child care days predict lower antibody levels on child care and weekend days, and cortisol predicts
parent-reported illness frequency. However, sIgA levels did not predict parent-reported illness frequency and thus did not
mediate the cortisol-illness relation.
Manuscript preparation in progress..
Measures:
Saliva samples were taken at 10:30, 3:30 and 8:00 pm for 4 days per child.
Each sample is assayed for cortisol and for sIgA. Pooled samples from each day for each child are used to assay Herpes antibodies.
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Effortful Control Study
Study Overview:
In this study we explored the development of effortful control in preschool age children, and how it
relates to their behavior and brain activity. Neurobiological research suggests that areas in the prefrontal
cortex are involved in higher level functioning, including inhibition and other aspects of effortful control,
and that these areas are rapidly developing during the early childhood period. In this study, we asked children
to perform a novel effortful control task (the Pediatric Speaker-Word Stroop) while we collected EEG data.
Reaction time, error data, changes from baseline in EEG power on congruent and incongruent trials and children's
temperament ratings were assessed.
Manuscript preparation in progress.
Measures:
EEG was recorded from 32-channels. To measure effortful control, we developed a novel Pediatric Speaker-Word Stroop.
Temperament was assessed using the Child Behavior Questionnaire.
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Cortisol Rhythm Study 30-72 months
Study Overview:
Basal cortisol rhythms are maturing over the first few years of life. In a previous study with children within
2 weeks of their 12, 18, 24, 30 and 36-month birthday, we found that cortisol levels at each time point measured
decreased between 12 and 36 months. Through 36 months, most children were still showing a relatively flat pattern
of cortisol production across the mid-portion of the day, as compared with the decreasing pattern seen in older
children and adults. Thirty and 36-month children who were giving up their afternoon nap were more likely to show
the more mature decreasing rhythm. We also found that children rated by parents as lower in effortful control had
higher mean cortisol levels. In the current study, we have expanded our previous efforts through 72 months to further
investigate the maturation of basal cortisol across the early childhood period in relation to changes in sleep behavior
and effortful control. We have added more intensive measurements of sleep-wake behavior as well as a laboratory
assessment of effortful control.
This study was just completed with 196 families. Data analysis is in progress
Measures:
Salivary cortisol was collected at wake-up, mid-morning, mid-afternoon, and bedtime by families at home.
Sleep-wake behavior was assessed using actigraphy watches (7-9 days per child). Effortful control was assessed
using the Pediatric Speaker-Word Stroop and the Dimensional Card Sort Task. Temperament and behavior were assessed
using the Children's Behavior Questionnaire and the Child Behavior Checklist.
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Sleep Study
Study Overview:
To further examine relations between night time and day time sleeping in young children and developing
cortisol rhythms and attention, we are extending our Cortisol Rhythm Study to a sample of children with sleep difficulties.
This study has just begun. If you have a preschooler between the ages of 3- 6 year olds
and are interested in being screened for potential sleep difficulties, please contact us. CHaDlab@psy.du.edu
Measures:
Children are first screened for sleep difficulties using the Sleep Habits Questionnaire.
Children with sleep difficulties in one or more domain are invited for a laboratory visit.
Attention and effortful control are assessed using the Pediatric Speaker-Word Stroop and the
Dimensional Card Sort Task. Salivary cortisol is collected at wake-up, mid-morning, mid-afternoon,
and bedtime by families at home. Sleep-wake behavior is assessed using actigraphy watches (7-9 days per child).
Temperament and behavior are assessed using the Children's Behavior Questionnaire and the Child Behavior Checklist
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Family and Child Care Buffering Study
Study Overview:
Previous work has repeatedly found differences in cortisol patterning across the day on child care as
compared to home days for many young children studied. While on home days most children show falling cortisol,
on child care days many children show rising cortisol. The proportion of children showing this pattern is related
to child care quality, with as few as 34% of children showing the rising pattern at child care in very high quality
child care settings, and as many as 96% in a study that included centers of moderate quality. To further explore
what predicts cortisol patterning at child care and at home, this study will examine cortisol patterning in
children attending full and half-day Head Start and community child care centers. Children will be observed in the
classrooms as well as in structured one-on-one play sessions with their lead teacher. To examine the role of family
stress and family buffers, several measures of family characteristics will be included and home visits will be conducted.
To understand whether there are unique stressors and buffers among newcomer Mexican-origin families, a sub-sample of
50 Mexican origin families will be recruited. This study is jointly funded by an NICHD RO3 and a Foundation for Child Development Young Scholars Grant to Sarah Watamura, and an ACYF Child Care Scholars Grant to Lisa Badanes.
This study is just beginning. If you are a center director or teacher interested in more information, please contact us. CHaDlab@psy.du.edu
Measures:
Center directors will be interviewed about their educational approach, philosophy, and population served.
Global classroom assessments will be conducted using the Early Childhood Environment Rating Scale – Revised.
Within classrooms, salivary cortisol will be collected at child care on several days, mid-morning and mid-afternoon.
Participating children will be observed during their routine activities, as well as during short semi-structured
observations with the lead teacher. Similarly, families will be asked to collect saliva samples at home mid-morning
and mid-afternoon, parents will be interviewed about the stressors and buffers that they experience, and children
will be observed in unstructured and semi-structured observations with a parent. Parents and teachers will also be
asked about the temperament and behavior of children enrolled in the study.
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