Harvard University and the University of Pennsylvania published a new hypothesis called “the mind after midnight,” which suggests that changes occur in the brain when people are awake during the circadian biological night, that is, after midnight. The study suggests that when humans are awake after midnight, neurophysiological changes in the brain lead to more negative outcomes.
According to the research, it was already a known fact that sleep loss, or the sleep deprivation that comes with nighttime wakefulness, led to cognitive and behavioral dysregulation and the functioning of our brains the other day. However, recent findings reveal that changes in cognition and behavior occur when the individual stays awake after midnight.
Circadian biological clock is tuned to processes that promote sleep, not wakefulness
“The basic idea is that, from a high-level global evolutionary point of view, the internal circadian biological clock is tuned to processes that promote sleep, not wakefulness, after midnight,” says Elizabeth B. Klerman, MD, Researcher at the Department of Neurology at Massachusetts General Hospital, Professor of Neurology at Harvard Medical School and lead author of the paper.
According to the researchers, attention to negative stimuli is unusually high at this time as a primitive instinct. This hyperfocus on the negative can fuel an impaired motivation/reward system, making a person especially prone to risky behaviors.
In short, Klerman asserts that the circadian rhythm’s influence on brain activities changes over the course of 24 hours, affecting how we process our experiences and respond to the outside world.
Humans respond more positively during the day than at night because circadian influence is highest in the morning and lowest in the evening. Klerman also points out that the body produces more dopamine at night, which can change the reward and motivation system that could cause a person to engage in risky behavior.