Effects of the environment of a simulated shelter in a gymnasium on sleep in children.

Effects of the environment of a simulated shelter in a gymnasium on sleep were investigated in 20 healthy school-aged children. Measurements were obtained during a one-night stay in a school gymnasium during the summer (C). Activity levels were monitored using a wrist actigraph, and temperature and humidity of the bedrooms in the subjects' homes were monitored from 3 days before to 3 days after C. The subjects were asked to provide information regarding subjective sleep estimations and thermal sensations. The results for the days before C (BC), C, the first day after C (A1), and the second day after C (A2) were compared. The bedroom temperature was significantly lower on BC than on the other nights. No significant difference was observed in bedtime, whereas wake-up time was significantly earlier on C and later on A1 than on the other nights. Total sleep time was significantly decreased on C (3.6 h) and increased on A1 when compared to the other nights. Daytime nap was significantly increased on A1 when compared to the other days. Subjective estimation of sleep quality was decreased and sweat sensation before sleep was increased on C when compared to the other nights. The main reason for sleep disturbances on C was heat. These results indicate that the environment of the simulated shelter in the gymnasium severely disturbed sleep in children. The resulting loss of sleep was compensated for by increased nocturnal sleep time and daytime napping on the next day.

Activity changes in the left superior temporal sulcus reflect the effects of childcare training on young female students' perceptions of infants' negative facial expressions.

In many developed countries, the number of infants who experience non-parent childcare is increasing, and the role of preschool teachers is becoming more important. However, little attention has been paid to the effects of childcare training on students who are studying to become preschool teachers. We used functional magnetic resonance imaging (fMRI) to investigate whether and how childcare training affects brain responses to infants' facial expressions among young females studying to become preschool teachers. Twenty-seven subjects who attended a childcare training session (i.e., the experimental group) and 28 subjects who did not attend the training (i.e., the control group) participated in this study. The participants went through fMRI scanning twice: before and after the childcare training session. They were presented with happy, neutral, and sad infant faces one by one during fMRI scanning. The present neuroimaging results revealed that the activity patterns of the left superior temporal sulcus (STS) for sad faces were modulated by the interaction between the time point of the data collection and group differences. The present results are the first to highlight the effects of childcare training on the human brain.

Sleep in a Gymnasium: A Study to Examine the Psychophysiological and Environmental Conditions in Shelter-Analogue Settings.

We aimed to examine sleep in shelter-analogue settings to determine the sleep and environmental conditions in evacuation shelters. A summer social/educational event was conducted in an elementary school, wherein children and their parents (n = 109) spent one night in the school gymnasium; a total of 15 children and 7 adults completed the study. Data were recording using wrist actigraphy and questionnaires, from two days before the event to two days after the event. During the night in the gymnasium, sleep initiation in the children was found to be significantly delayed, whereas adults did not show any significant change in actigraphic sleep parameters. Although 57% of adults complained of stiffness of the floor, only 7% of children had the same complaint. The nocturnal noise recorded at four locations in the gymnasium showed that the percentage of 1-min data epochs with a noise level >40 dB ranged from 53% to 74% during lights-out. The number of subjects that woke up during the night showed a similar pattern with the changes in the noise level. The changes in sleep might represent event-specific responses, such as to a noisy environment, and the different complaints between adults and children could be useful in shelter management.

Effect of cardboard under a sleeping bag on sleep stages during daytime nap.

Fourteen healthy male subjects slept from 13:30 to 15:30 under ambient temperature and relative humidity maintained at 15 °C and 60%, respectively. They slept under two conditions: in a sleeping bag on wooden flooring (Wood) and in a sleeping bag with corrugated cardboard between the bag and the flooring (CC). Polysomnography, skin temperature (Tsk), microclimate, bed climate, and subjective sensations were obtained. The number of awakenings in the CC had significantly decreased compared to that in the Wood. The mean, back, and thigh Tsk, and bed climate temperature were significantly higher in the CC than that in the Wood. Subjective thermal sensations were warmer in the CC than in the Wood. These results suggest that using corrugated cardboard under a sleeping bag may reduce cold stress, thereby decreasing the number of awakenings and increasing subjective warmth; the mean, back, and thigh Tsk; and bed climate temperature.

Maternal accommodation in infant-directed speech during mother's and twin-infants' vocal interactions.

In this study a mother's instinctive accommodations of vocal fundamental frequency (f0) of infant-directed speech to two different infants was explored. Maternal speech directed to individual 3-mo.-old fraternal twin-infants was subjected to acoustic analysis. Natural samples of infant-directed speech were recorded at home. There were differences in the rate of infants' vocal responses. The mother changed her f0 and patterns of intonation contour when she spoke to each infant. When she spoke to the infant whose vocal response was less frequent than the other infant, she used a higher mean f0 and a rising intonation contour more than when she spoke to the other infant. The result suggested that the mother's speech characteristic is not inflexible and that the mother may use a higher f0 and rising contour as a strategy to elicit an infant's less frequent vocal response.