Second international School On Mind, Brain And Education

2007, May 22-26

Karolinska Institute. SWEDEN

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Interventions to promote learning in school by considering sleep education, nutrition and bright light treatment
Sleep problems appear to be significant and growing in children and adolescents. The increase has been four-fold in Sweden since the middle of the 90-ties. In a representative sample of children aged 16-18 years 44% of the girls and 36% of the boys reported to have a bad sleep at least once a week. This is problematic since it is connected to a number of problems at school as well as in learning. The reasons for this recent increase of problems has been associated to life style factors related to late evening activities, increased demands on performance at school, lack of exercise and lack of outdoor exposure to mention a few. The outcome of such influences is the delay of circadian rhythms that will negatively affect sleep and alertness levels.
We have been involved in several attempts to use interventions to reduce fatigue, improve sleep and promote learning at school. These interventions have focused on nutrition, sleep education and bright light exposure.
The interventions were performed on adolescents aged 14-15 years. Before a 2-week study period 25 students were given a 2-hour lecture on sleep, rhythms and nutrition. During the study period, they were served breakfast at school and during the last week they were also exposed to bright light (>700lux) during mornings in class. These conditions compared with a baseline study week and a control group of 23 students at the same school was also included.
The intervention significantly advanced time for going to bed, delayed rising time and increased sleep length. Very little effects could be detected on sleepiness or any of the performance measures being used (reaction time, tracking test or memory two times each week). In summary the study proved to be very good in developing instruments and to gain knowledge of how to address young students and how to avoid internal missing data but the outcome variables gave only mild results. Also parent and teacher ratings were used in this study.
In another laboratory study, using university students, a daytime fast was found to be detrimental for performance on reaction time tasks throughout the day. In a second attempt to study the effects of bright light, a more sophisticated bright light intervention was used to promote sleep/alertness. In this study of 53 adolescents also light sensors and movements sensors were used as well as hormone measures of melatonin. The result showed that sleep efficiency increased by bright light and morning melatonin decreased. Alertness decreased during school days in the mornings and sleepiness increased before bedtime in the evening. In summary some positive effects of bright light interventions was shown on sleep and alertness but further attempts to also include measures of learning capabilities is strongly needed.