“With a delay in start times, students reap the benefit of a school schedule that is in synchronization with their internal biological clock.”
—Pamela Malaspina McKeever
A study published in Social Cognitive and Affective Neuroscience proposed that there is a U-shaped relationship between student performance and time of day. Students are alert and retain the most information during mid-morning classes, while performance is lower during mid-afternoon classes, followed by early-morning classes.
This research was carried out by a team of 11 researchers, led by Suzanne Dikker, a Senior Research Scientist at the Max Planck – NYU Center for Language, Music and Emotion.
In the U.S., the average start time for middle school and high school is approximately 8:00am. For younger students, this likely isn’t a problem since children tend to be early risers. However, at the onset of puberty, adolescents experience a change in their internal clock as their circadian rhythms shift towards ‘eveningness’.
When it’s dark at night, the body releases a hormone called melatonin, which helps promote sleep. Teenagers, however, experience a delay in the release of this hormone, causing them to fall asleep 2-3 hours later than usual. Despite their later bedtime, teenagers still need about 9 hours of sleep.
Unfortunately, school start times don’t account for this biological change. As a result, teenagers are forced to endure early class times while their internal clock makes it difficult to feel alert and focused. Unsurprisingly, this affects their performance and their ability to learn.
To bring awareness and learn more about this issue, Dr. Dikker and her team of researchers monitored the brain activity of high school students throughout various times of the school day.
The researchers recruited 22 students from two high schools in New York City. Each student was connected to an electroencephalogram (EEG) and their brain activity was recorded during early morning (school 1: 8:30 am, school 2: 9:00 am), mid-morning (school 1: 10:30 am, school 2: 10:40am) and mid-afternoon (school 1: 2:20 pm, school 2: 2:00pm) classes over the course of 17 days. Before each class, students were instructed to stare at the wall for two minutes, in order to establish a baseline at rest.
During class, different types of teaching styles were used such as directly lecturing students on the material or showing students educational videos. After class, students stared at the wall for another two minutes to record their EEG activity at rest.
Following this, students reported their focus level by responding to questions such as, “how focus do you feel right now?”. In addition, in school 2, students completed a 20-question multiple-choice quiz on content taught during the class.
After completing the study, the researchers examined each participant's EEG, specifically their level of alpha waves. Alpha waves are produced by the brain when you’re awake but aren’t processing much information such as when you wake up in the morning or while you’re meditating. Higher alpha power means you’re less alert and focused.
The results of this study revealed a number of important findings. First, the researchers found that student’s alpha levels were lowest when they were watching educational videos, significantly higher when the teacher was lecturing, and highest during rest. This means that students were much more alert and focused during the educational videos compared to when the teacher was lecturing.
The students also scored higher on quiz questions about the video contents and reported paying more attention during the videos, compared to the lectures. However, it’s important to note that the teachers were instructed to keep their movement to a minimum and refrain from using visual support for their lectures. This perhaps made the lectures more dull than students were used to.
As for the main focus of this study – the results showed that the student’s alpha power was lowest during the mid-morning, allowing them to retain the most course material during mid-morning classes. As expected, alpha power was the highest during early morning classes, followed by mid-afternoon classes, resulting in less information retained.
Performance tends to be lower in the early morning due to the body’s circadian rhythm which makes it difficult to be attentive before a certain time of day. As for the reduction in alertness during mid-afternoon classes, it’s suggested that poor student performance at the end of the school day is due to fatigue.
As a result, there is a U-shaped relationship between student performance and time of day. Students’ ability to pay attention and retain information is highest during the mid-morning and lower before and after this time period.
Overall, this study found that students are least likely to be alert and retain information early in the morning, suggesting that high schools should refrain from starting too early. In addition, teachers should account for student fatigue towards the end of the school day. For example, a study found that, while test scores were lower at the end of the day, giving students a 20-to-30-minute break improved their performance. Lastly, teachers should try to adopt teaching styles that are likely to hold the student’s attention (e.g., moving around, using visual aids), especially during early morning classes.