Impact of Circadian Rhythms on Schools and Classrooms
Having an understanding of how the brain works helps educators create a learning environment that acknowledges to the body’s natural rhythms . This understanding can help teachers create lessons that will more likely result in student learning. Circadian Rhythms are cycles that many of our body functions go through daily. Examples would be our body’s temperature, breathing, digestion, and hormone concentrations. One of the body’s circadian rhythms regulates our ability to focus on incoming information with intent to learn. It is referred to as the psychological-cognitive cycle. Research has shown that this circadian rhythm is the about the same for preadolescence and adults, but shifts later during adolescence.
The graph below from How the Brain Learns, 4th edition, illustrates this cognitive cycle for pre-postadolescents and adults. Notice the dip in the middle of the day. This is a low point of focus. Learning can still occur, but it requires more effort. I refer to this trough as the “dark hole of learning.” Some cultures refer to it as the “siesta,” having recognized long ago how difficult it is to accomplish much learning during this time.
Teachers can consider adjusting their schedules and lessons to accommodate the students’ cognitive cycles. I have included my Practitioner’s Corner from chapter 3 of How the Brain Learns, 4th edition, that offers teachers some ideas on how to use this information when planning lessons.
Planning Elementary School Lessons. Remember that both the teacher and elementary school students are in the trough together. The tendency here would be for all to just take a nap! That’s probably not an option, so we have to decide how to deal with the trough. Here are two things to consider:
(1) Many elementary teachers can decide what time of day to teach certain subjects. Avoid teaching the same subject every day during the trough time. Because of low focus levels, it is boring for the students and tedious for the teacher. Varying the subject taught in the trough provides novelty and interest.
(2) Keep assignments short, and frequently hold the students accountable for what they are learning. For example, instead of assigning 30 minutes of silent reading (a common practice during the trough time), assign just five minutes for the class to read two pages and give a specific assignment related to the reading. You might say: “After five minutes to read pages 12 and 13, decide what other choices the main character could have made, and why. I will call on some of you for your answers.” Repeating this process results in four or five mini- lessons that will be more productive than trying to attempt a single 30-minute lesson.
School Start Times. Note that the rhythm shifts during adolescence. Because of this shift in rhythm, teenagers are sleepier in the morning and tend to stay up later at night. They come to school sleep deprived (i.e., many suffer from Delayed Sleep Phase Disorder), and often with an inadequate breakfast (i.e., lacking glucose, the brain’s fuel). Meanwhile, students often face a long bus ride to get to high schools that are starting earlier. District leaders should consider realigning opening times and course schedules more closely with the students’ biological rhythms to increase the chances of successful learning. School districts that have adopted later starting times for their high schools are reporting positive results. These same positive results apply to elementary schools that start earlier than the traditional time of 9:00 a.m.
Classroom Lighting. Adolescents with Delayed Sleep Phase Disorder come to school with a high amount of melatonin (the hormone that induces sleep) in their bodies. One of the best ways to reduce melatonin levels is with bright light. Keep classroom lights on, open blinds, lift shades, and look for ways to get the students into outdoor light, especially in the morning (Kripke, Youngstedt, & Elliot, 1997).
Testing. School districts usually give standardized tests to all students in the morning. However, high school students tend to perform better in problem-solving and memory tasks later in the day rather than earlier. It is likely that a number of high school students do not do as well on these tests as they could because of the testing times. Some school districts have reported that testing high school students later in the morning and early afternoon improved their performance and scores.